Review Lpr Trends & Technologies for Future Lighting Solutions Mar/Apr 2015 | Issue 48

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Review LpR Trends & Technologies for Future Lighting Solutions Mar/Apr 2015 | Issue 48

International Year of Light 2015 - Opening DC Supply Grids for LED Lighting Phase Cut Dimming Tech-Talks BREGENZ: Ewing Liu

CATEGORYEDITORIAL TOPIC 3 EnLight Outcomes

EnLight stands for “Energy efficient & intelligent lighting systems” and was an EU funded and Philips Lighting coordinated project which ran from 2011 to 2014. The consortium consisted of 27 leading European companies and academic institutions from across the entire lighting value chain.

Now, for the first time, the EnLight consortium is publishing the main technical outcomes exclusively in this issue of LED professional Review. This EnLight compendium is comprised of six articles that total 38 pages. They consist of a project overview, a description of the system architectures, definitions of new form factors and light effects, the building blocks for intelligent luminaires, highlighting of peripheral devices and the new granular lighting controls from Philips Lighting, AME, University of Erlangen, Insta Elektro, PKCE, Infineon, Fraunhofer IZM, Philips Research, Legrand, Eagle Vision Systems, Fraunhofer IIS/EAS, CEA Leti and Osram.

The project had three technical objectives namely the optimization of LED lighting modules, the design of future non-conventional luminaires and the use of new and intelligent lighting systems. As a result the energy savings in office applications could be shown at 44% compared to LED retrofit and standard controlled lighting systems. The energy savings in hospitality could nearly be doubled and ended up at a figure of 81% energy reduction by using new luminary designs with intelligent controls.

This research is fundamental because the complete value chain on all different system levels was taken into consideration. Congratulations go out to Frank von Tuijl from Philips Lighting and the whole consortium team for this highly relevant work and the fantastic collaboration.

Besides the EnLight project results, you’ll also want to read the report about the International Year of Light Opening Ceremony in Paris, Phase Cut Dimming techniques, DC Current Grids, Lighting for Horticulture, the Tech-Talk BREGENZ with Everlight, one of the Top 10 LED manufacturers and the commentary from Samsung about Human Centric Lighting.

Have a great read.

Yours Sincerely,

Siegfried Luger CEO, Luger Research e.U. Publisher, LED professional Event Director, LpS 2015

COMMENTARY REGULARS 06 LED Innovation Will Offer a Human-Centric Smart Lighting Platform 03 EDITORIAL Enabling Enterprise IoT 08 PRODUCT NEWS by Frank Harder, Samsung 26 RESEARCH NEWS 30 IYL 2015 NEWS EVENTS 106 ABOUT | IMPRINT 32 Let there be Light - A Brief Overview of the Meaning of Light by Arno Grabher-Meyer, LED professional

TECH-TALKS BREGENZ 42 Ewing Liu, Technical Marketing Manager at Everlight compiled by Dr. A. Prasad, LED professional

RESEARCH 48 Direct Current (DC) Supply Grids for LED Lighting by Prof. Eberhard Waffenschmidt, Cologne University of Applied Science IYL 2015

TECHNOLOGIES 32 Let there be Light - A Brief Overview of the Meaning of Light Solving the Phase-Cut Dimming Challenge 54 by Arno Grabher-Meyer, by Craig Sharp & Bill Trzyna, CCI Power Supplies LLC LED professional SPECIAL 60 LED Lighting for Horticulture by Ian Ashdown, Lighting Analysts

SPECIAL: ENLIGHT PROJECT OUTCOMES 68 EnLight - Next Generation Intelligent and Energy Efficient Lighting Systems by Frank van Tuijl 72 System Architecture for Distributed Intelligence by Lex James et al. SPECIAL: ENLIGHT 80 New Form Factor Luminaires and New Light Effects 66 Project Outcomes by Herbert Weiß et al. Written by various project partners

86 The Building Blocks for Intelligent Future Luminaires by Tim Böttcher et al. 92 Peripheral Devices for the Right Light by Werner Weber et al. 98 Granular Lighting Control Enables Significant Energy Savings with Optimized User Comfort by Eveliina Juntunen et al.

ADVERTISING INDEX

LUMILEDS 2 INSTRUMENT SYSTEMS 22 CREE 31 LEDFRIEND 5 GLOBAL LIGHTING TECHNOLOGIES 23 UNDERWRITERS LABORATORIES 45 INSTRUMENT SYSTEMS 7 FUHUA 24 LED EXPO THAILAND 47 LEDLINK 9 DANGOO ELECTRONICS 25 LED CHINA 53 ELLSWORTH ADHESIVES 11 INFINEON 26 GUANGZHOU INT. LIGHTING EXHIBITION 57 VOSSLOH-SCHWABE 11 EDISON 27 LED & OLED EXPO 59 BICOM 13 WEBINAR: LAMBDA RESEARCH 28 LIGHTFAIR INTERNATIONAL 65 GL OPTIC 15 WEBINAR: INFINEON 28 LED PROFESSIONAL / LPS 105 HONGLITRONIC 15 PARAGON 29 ILLUMINOTRONICA 107 EPISTAR 17 BICOM 29 WAGO 108 REFOND 19 CREE 29 LEXTAR 21 LED LIGHTING TAIWAN 29

COMMENTARYCATEGORY FRANK HARDER 6

LED INNOVATION WILL OFFER A HUMAN-CENTRIC SMART LIGHTING PLATFORM ENABLING ENTERPRISE IOT

After a century of analog electrical light, provide the environmental and situational the lighting industry has spent the last criteria that enable decision-making from decade in transition to digital light a valuable smart lighting system. sources; LEDs, sought to replace the Algorithms and analytics will be the key tungsten filament. LEDs are now differentiator to leverage data that are embedded in all market segments in both generated from sensors. residential and commercial applications. The predictions of early LED pioneers The goal is a seamless link between Frank Harder such as Dr. Roland Haitz have become LEDs and selected use cases through Frank Harder is the Vice reality today: more lumens delivered at a secure and scalable connectivity of all President of Business lower cost with increasing reliability and established wireless and wired standards, quality of light attributes. As a result, the fusion with sensors (internal and Development at the Samsung the world of electrical light has accepted external), processing power, memory and Strategy and Innovation that LEDs will be its primary light source application programmable interfaces Center in Menlo Park, and contribute to saving significant (APIs). Such innovation will be enhanced electrical energy, reducing carbon by a state machine embedded in the core California. He holds an emissions and providing increased safety of a new platform. It will offer both the M.S. degree in Electrical and comfort in our homes, at work and lighting OEM community as well as the Engineering from the even while commuting in traffic. application developer community the option to customize services tailored University of Düsseldorf and Today, we are on a fast track to the around end-user needs, ultimately to graduated from the Octagon commoditization of light sources using develop additional value and business Leadership program at the LEDs. What we have yet to realize is that opportunities far beyond energy savings this change offers an enormous to their customers. Wharton University of opportunity. The so-called digital lighting Philadelphia. revolution is about to take place and We believe that the realization of smart early efforts in the market are already lighting will require a new and holistic showing promise. Technology evangelists, platform approach and an ecosystem of the hi-tech start-up world and large sensor providers, analytics specialists technology firms equally are evaluating and app developers. No longer can we the opportunities at the intersection of think of a light source that is connected to the digital light sources and the internet other things, we must instead think about of things (IoT). Market and technical a connected platform that, among other requirements are in flux without things, also delivers light. In the near standards and the direction is still not future, appliances that deliver light will clear. How exactly will the market for also connect to the HVAC, printers, intelligent lighting evolve and how quickly the security system and other building will it become commonplace? and city functions. Companies like Samsung Electronics are addressing this At conferences around the world such as thesis by developing a smart lighting the LED professional Symposium and platform through close collaboration with LightFair International, there are many sensor, analytics and lighting partners presentations that focus on how IoT will as well as leveraging a wide range of advance intelligent applications such as divisions that operate in different markets. human-centric lighting in combination It is a holistic approach to an opportunity with connectivity, sensors and data. that will ultimately deliver a true smart A human-centric smart lighting system platform that forever changes the way will require broad awareness with a deep we think about light. level of systems understanding in order to F.H.

NEWS PRODUCTS 8

Flip Chip Opto Utilizing elements of the Cree SC5 available for all CXA2 LED arrays for lighting Introduces 300, 600 & Technology™ Platform, this improvement in manufacturers seeking Energy Star® lumen density enables better performance qualification. The CXA2 LED arrays are also 960 W CoB LEDs and radically reduces system size and cost. UL®-recognized components and feature Flip Chip Opto, a LED lighting technology The new chip-on-board (CoB) LEDs allow a level 4 rating. company, announced its innovative P-Series lighting manufacturers to rapidly deliver more of high-power LED Flip Chip / Chip-on-Board innovative solutions for applications such as Through improvements in the light (COB) products. These high-performance track, downlight and outdoor lighting. conversion process, Cree has reduced lighting modules are comprised of patented LED-to-LED color variations and, among 3-Pad LED flip chips with a Pillar Metal Core other options, offers CXA2 LED arrays in Printed Circuit Board (P-MCPCB) to 2-step and 3-step EasyWhite® bins. substantially reduce module thermal XLamp® CXA2 LED arrays are available in resistance, and results in lower junction 2700 K to 6500 K, CRI options of 70, 80 temperature, lower thermal decay and the and 90 with multiple voltage options in LES feasibility of smaller light emitting surfaces ranging from 6-30 mm with a lumen range of (LES). Our innovation enables designers to 250-19,000 lumens to address a wide variety enhance “Lumen-per-Dollar” performance of applications. Product samples are by either driving the modules at higher available now, and production quantities are currents for more light output, or shrinking available with standard lead times. Cree’s CXA2 now incorporates SC5 the heatsinks and optics dimensions, technology to boost performance and or reducing LED chip counts. reliability to a new level

“We are working together with Cree to Osram Opto Updates evaluate their latest CoB technology,” Duris E 3 for Cost- said Massimo Parravicini, R&D director of Effective Linear Tubes Reggiani Illuminazione. “I believe that the new CXA2 LED arrays, which deliver Osram Opto Semiconductors is presenting excellent performance in such small LES a new version of the well-established Duris [light emitting surface], would be a great product family: the Duris E 3 (GW JCLMS1. solution for the new generation of indoor EC). Featuring a new leadframe material, luminaires we are currently developing.” the LED offers a longer lifetime and greater performance reliability than its predecessors. Flip Chip Opto’s 300, 600 and 960 W CoB LED modules are based on their patented 3-Pad With the new CXA2 LED arrays, lighting In linear tube lighting applications, the new LED Flip Chips with Pillar Metal Core PCBs manufacturers can achieve the same or Duris E version boasts a high efficacy of better performance with a smaller LES typically 135 lm/W at 4000 K and 65 mA The High Power P-Series COBs feature compared to earlier products. For example, as well as one of the best lumen/cost ratios 45x45 mils 3-Pad LED flip chips and high flux a 3800 lumen output from a larger 19 mm in the series. density in small LES. The current models, LES LED can be replaced with a smaller P110-12S8P (96 chips), P110-15S12P (180 12 mm LES LED, resulting in up to 60% chips) and P110-15S19P (285 chips) support system cost savings from lower LED, “Boost” power at 300 W, 600 W and 960 W mechanical and optic material costs. with LES of 45 mm, 60 mm and 85 mm, respectively. Their high “lumen-per-dollar” “The new CXA2 LED arrays make it possible value and extremely low thermal resistance for lighting designers to radically reduce (0.01°C/W, 0.008°C/W and 0.007°C/W) system costs in the next generation of make these COB solutions ideal to replace industry-leading lighting products,” said Dave HID luminaires applied over stadium, sport Emerson, vice president and general complex, wharf, storage, airport, golf course, manager for Cree LEDs. “By giving our farmland and architectural display. customers innovative LED solutions instead of incremental LED improvements, we enable them to differentiate their products in the marketplace and deliver more value to their Osram Opto’s new Duris E 3 offers compact size and excellent price-performance ratio Cree Updates CXA end customers.” Platform with SC5 Technical Data: Technology CXA2 LED arrays share the same physical • Footprint: 3.0 mm x 1.4 mm design as earlier arrays, allowing lighting • Typical flux (at 65 mA, 4000 K): 27 lm Cree, Inc. introduces a new addition to its manufacturers to leverage the existing • Viewing angle: 110° industry leading CXA LED array family, optical, mechanical and electrical design • Efficacy: typ. 135 lm/W at 4000 K CXA2 LED arrays, delivering up to 33% elements to accelerate time to market • Color rendering (CRI): min. 80 higher efficacy in the same form factors. without additional cost. LM-80 data is

NEWS PRODUCTS 10

The package of the new Duris E 3 is made luminous flux is more than 60% greater than coverage of a 5-step MacAdam ellipse. from a special PCT leadframe material that that offered by the preceding TL1L3 series. 3-step MacAdam grouping is additionally permits a longer lifetime and higher This contributes to improved luminous available. As its predecessors, the products performance reliability than the PPA material efficacy and lower power consumption for are grouped at the junction temperature of used in the current Duris E 3 version LED applications. 100° C instead of at room temperature. (LxW JNSH.EC). As a result, it achieves the Another positive characteristic is the best brightness level per dollar (lm/$) within Available in nine-color variations from 2700 K improved thermal conductivity. the Duris E series. Furthermore, the new to 6500 K, the TL1L4 series utilizes cost- LED has a high efficacy of typically 135 lm/W effective gallium nitride-on-silicon (GaN-on-Si) The footprint (5.89 mm x 5.2 mm) of the new at 4000 K. The new Duris E 3 offers a range wafer technology to create LEDs optimized high-power LEDs exactly corresponds to the of lumen packages from 25 lumens (lm) to for both output and energy efficiency. existing Duris S 8 versions as well as the 30 lm, which can optimally be used in linear viewing angle of 120°. The optics are also tube light applications. Integrated in these The devices are housed in a compact compatible to the predecessors so the lighting solutions, the number of LEDs can 3.5 x 3.5 mm lens and rated to support an different versions can be replaced easily. be minimized and the so-called hot-spot absolute maximum forward current of 1.5 A The correlated color temperatures (CCTs) effect can be avoided. The Duris E 3’s max at Ta<55°C and Tj<150°C. Hot binning can be chosen between 2,700 and 4,000 K. thermal resistance is typ. 41 K/W. tests for electrical and optical characteristics With the new Duris LEDs single light source are conducted at 85°C and If = 350 mA that design can be implemented. This avoids With a beam angle of 110°, the Duris E 3 is simulate real-life operating conditions. multiple shadow effects and simplifies lens ideal for homogenous and uniform light and PCB (printed circuit board) design. distribution. Another advantage is the small footprint of 3.0 mm x 1.4 mm, a competitive The new Duris S 8 can be inserted in value by industry standards. With its New Duris S 8 LEDs retrofits and fixtures for accent and effect excellent color uniformity, stability and a with Even Better Color lighting in shops and museums. good color rendering of min. 80, the new Rendering & Consistency The certification process for the high lifetime LED is particularly suitable for interior lighting standard of LM-80 with 6,000 hour tests for applications like linear, troffer or panel lights, Osram Opto Semiconductors presents two both new LEDs is done and the results are retrofits - especially fluorescent replacement new members of its Duris LED family with a already available. lamps - downlights and fixtures. very good color rendering. The CRI of the Duris S 8 GW P9LM32.CM and GW P9LR31. CM is at 95 (typ.) respectively 90 (min.). Due to the same footprint and design the Osram Opto Offers Toshiba’s Improved different versions can be replaced easily. “Far Red” LED for White GaN-on-Si LEDs The thermal resistance and the forward Horticultural Lighting with up to 160 lpw voltage of the new products are lower than its predecessors. The LEDs are binned at Osram Opto Semiconductors is expanding Toshiba has launched a new series of high 100°C, so their brightness and color values its LED product range for horticultural lighting power LEDs ideal for use in a wide variety of can accurately be determined with regard to with a new type of the well-proven Oslon residential, commercial and industrial their later use. SSL. In addition to the existing hyper red lighting applications. The TL1L4 series offers (660 nm) and deep blue (450 nm) versions, significantly better performance than the high-tech company developed a far red the preceding TL1L3 series. Oslon SSL LED with a wavelength of 730 nm.

The new Duris S 8 not only features high color consistency for directional retrofits, downlights and spots, but also the highest CRI of up to 95 Toshiba’s latest GaN-on-Si TL1L4 series LEDs The far red Oslon SSL LED with a wavelength are capable of being driven with up to 1 A of 730 nanometers leads to better growth for The new Duris S 8 with CRI 90 is the next certain plants such as tomatoes, pepper or roses The new TL1L4 series achieves an industry step in the Duris S series regarding leading high luminous efficacy that increasingly better color rendering. The very For certain plants such as tomatoes, pepper surpasses 160 lm/W at room temperature good color consistency (color binning) is or roses, it is exactly this wavelength which operation. Under conditions of Ta = 85°C, achieved through the close grouping of the leads to better growth. Customers now have operating current can be driven to 1 A and multi-chip LEDs, which corresponds to the a better coverage of the color spectrum.

The new ultra compact Oslon Oslon SSL LED family (far red SSL will be available in two new (730 nm), hyper red (660 nm) and product versions with a narrow deep blue (450 nm)) provides an beam angle of 80° and 150°. optimal growth pattern. With this Because of these features, the range of three colors, the LEDs can be arranged close to customers can address a large one another and offer a uniform variety of plants. light impression. All Oslon SSL versions can be combined easily There are several general because of the same size of benefits of LEDs for use in footprint and solder pad and horticultural lighting: Because of because they feature the same the single LEDs, the lighting technical characteristics. can easily be steered and This offers high design flexibility controlled in the greenhouses. for ambitious horticultural LEDs have a longer lifetime than lighting applications, where other lighting technologies; they each greenhouse lighting system are very energy-efficient and needs a tailor-made solution. thus drastically reduce energy consumption over time. LED lighting can stimulate plant They also emit no heat in the growth by up to 40%. Different lighting direction, so the plants wavelengths address different will not be damaged. plant properties: blue light Furthermore LEDs are available supports flowers to open up and in different wavelengths and red light helps stems to grow lighting solutions can be exactly better. Thus, a combination of adjusted to the value the the three existing versions of the respective plant needs.

Bridgelux’s New LED of Bridgelux color and uniformity that thermal conductivity as well as lower forward Arrays with 130+ lm/W our customers have come to rely upon,” voltage (3 V at 120 mA). The optics are said Aaron Merrill, Director of Product absolutely compatible to all members of the Warm White Efficacy Marketing at Bridgelux. “With advancements Duris family and the platform design is the Bridgelux, a leading developer and in phosphor and die technology we’re same, so customers can replace the current manufacturer of LED lighting technologies, already achieving efficacies on our current LED versions easily. is now shipping its Vero® and V Series™ platform that position Bridgelux to push our LED array products with high performing efficacy leadership well into the future.” The typically good color rendering of 95 warm white efficacy of 130 lumens per makes the new Duris E5 ideal for watt (lm/W) and greater. This enhanced With a strong focus on R&D advancing applications in which the requirements for performance delivers up to 10% additional emerging technologies, Bridgelux is a good quality of light are particularly high, energy savings over previous generations. leading innovator in the ever-expanding e.g. professional lighting solutions in shops Furthermore, the company has achieved a market for LED lighting solutions. or museums, but they can also be used record warm white efficacy of greater than The company is dedicated to the efficient for non-directional indoor LED retrofits. 160 lm/W on its existing chip on board delivery of differentiated, high performance The well-known package offers great design platforms. With these efficacy gains, and cost-effective light source solutions flexibility for the customers and facilitates Bridgelux continues its tradition of that delight the public with aesthetically the replacement of previous product breakthrough LED chip and packaging pleasing, energy saving LED lighting. versions, too. technology innovation and helps further accelerate the adoption of solid-state lighting. Osram Opto Adds High Cree Expands SC5 CRI Duris E5 for High Technology Platform Quality Applications with New XLamp MHD

Osram Opto Semiconductors presents a Building on the success of the XLamp® new Duris E5 with a significantly improved MH family of LEDs, Cree introduces the efficacy of more than 130 lm/W compared to XLamp MHD-E and MHD-G LEDs, the the current version. A high color rendering high-power LEDs that combine the high index (CRI) of more than 90 and typically 95 lumen density and reliability of a ceramic enables high quality lighting solutions in chip-on-board LED with the design and shops or museums. Due to the same manufacturing advantages of a surface- footprint and other common features the mount package. Utilizing elements of new mid-power LED can replace the current the Cree SC5 Technology™ Platform, Bridgelux’s latest generation of Vero® and V product versions very easily. the ceramic XLamp MHD LEDs simplify Series™ LED array products exceed 130lm/W efficacy development, increase design flexibility and improve manufacturing efficiency LED arrays with an efficacy of 130lm/W compared to mid-power LEDs. The MH not only provide a significant return on family enables new designs and significantly investment to end customers, but also help lower system costs, all while delivering OEMs and manufacturers better compete industry-leading performance. with product offerings in state of the art LED based products. The featured 130 lm/W efficacy is now a standard across all Bridgelux Vero and V Series product form factors (3000K, 80 CRI nominal current). Bridgelux Vero arrays provide designers with a best-in-class light source design, a wide range of premium color options, easy integration and installation, With a high CRI and high efficiency, the new Duris E5 is the ideal choice for cost effective, reduced manufacturing costs and the high quality general lighting products industry’s best product warranty for LED Cree’s latest extension of the SC5 platform light source products. Bridgelux V Series The new Duris E5 (GW JDSRS1.CC) will technology, the XLamp MHD series, is ideal arrays leverage the technology and complement the well-known Duris product for semi-directional, high-lumen applications performance of the Vero products in smaller, family of Osram Opto Semiconductors by cost effective packages. mid of January 2015. With an improved Cree XLamp MH LEDs “The high lumen efficacy of 131 lm/W at 4000 K and 120 mA output and high reliability of Cree’s new “Our team is committed to programs it can be used perfectly for energy saving MHD-G LED allows us to develop a new that improve LED package efficiencies, lighting applications. Furthermore, the new downlight that outperforms other downlights while maintaining the dazzling high-level mid-power LED features an improved in the market,” said Baly Luo, general manager,

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Aeon Lighting Technology. “ALT’s compact- The 320x320 mm OLED light panel is a size, 4-inch downlight that is built with the 0.88 mm thick panel and has an efficiency of MHD-G LED generates over 1800 lumens at 60 lm/W, CRI over 90, and has output levels 3000 K while other downlights can only of 800 lm with a nominal input (8.5 V 1.6 A). produce 800 to 1000 lumens.” The panel’s output can reach 1,200 lm which is similar to a common 60-75 Watt Featuring Cree EasyWhite® technology in a incandescent lamp. This is significant 7 mm x 7 mm package, XLamp MH LEDs because it marks the first time that OLEDs enable a smaller board size, tighter beam can be considered as an energy-efficient / angle and a more traditional appearance human-friendly light source available for Soraa’s Optical Light Engines provide fixture than mid-power LEDs. Delivering more than general purpose use. manufacturers access to the company’s full 1800 lumens at 14 W and 2500 lumens at 19 visible spectrum GaN-on-GaN LED technology W respectively, the XLamp MHD-E and With LG Chem having begun mass- MHD-G LEDs are ideal for semi-directional, producing the 320x320 mm panels in Soraa’s Optical Light Engines produce high-lumen applications such as downlights, January, the panels can be ordered at US incredibly high CBCP; and the engine’s high-bay and outdoor area applications. $680 per panel, with a lower negotiated optical design provides flawless beam price for bulk orders. definition, smooth beam edges and is “At Cree, we continue to deliver innovative customizable with the company’s SNAP products that give our customers a LG Chem has also completed development System. Designed for seamless fixture competitive edge in the marketplace,” said of a truly flexible plastic-based OLED light integration, the Optical Light Engines are Paul Thieken, Cree director of marketing, panel and engineering samples are now compatible with a wide variety of industry- LED Components. “With the MHD LEDs, available. LG Chem’s current bendable OLED standard LED drivers and perfect for use we’re offering chip-on-board performance to panels (F6BA40, F6BA30) are thin-glass in enclosed, non-ventilated indoor and lighting manufacturers that prefer surface- based that provides a limited bending radius outdoor fixtures. mount technology, making it easier for them of 75 mm. The new flexible OLED panel has to achieve lower system cost than with the vastly increased the bending radius flexibility “Fixture manufacturers have been asking same commoditized mid-power LEDs that to 30 mm because of the adoption of a for a compact, powerful, high-quality light everyone is using.” plastic substrate for the panel, which also engine and our full visible spectrum GaN-on- eliminates the danger of the panel shattering GaN LED technology has delivered. With when excessive force is applied. Soraa’s signature Point Source Optics™, VP3 Vivid Color™ and VP3 Natural White™ LG Chem Announces The main challenge of converting from a technology imbedded in the engine, we have Two OLED Lighting glass substrate to plastic was to maintain the brought brilliance to light,” said Susan Product Milestones performance levels of efficiency, luminance, Larson, VP of OEM Sales at Soraa. and CRI. LG Chem has overcome this “Fixture manufacturers everywhere now LG Chem announced that it achieved two challenge by adopting its expertise in barrier have a true source of design inspiration.” important milestones in the development of and encapsulation technology. OLED lighting products with the start of Soraa’s Point Source Optics™ technology mass production of the 320 x 320 mm OLED The specifications of LG Chem’s new produces beautiful, high-intensity and light panel, the world’s largest available in the plastic-based OLED light panel are 60 lm/W uniform beams within a very slim form factor. market, and the completion of the research efficiency, 75 lm brightness, 3,000 K in color Narrow spot options at 10 degree or and development phase for a new plastic- temperature, and CRI over 85. Engineering narrower are offered with an unprecedented based flexible OLED light panel. samples are available at US $250 per panel. low profile of only 16 mm for 500 lumens, Mass production of the flexible panel is and 28 mm for 1,000 lumens. The optics scheduled to begin in July 2015. The price technology also enables the offering of a will be adjusted accordingly once mass unique 4 degree ultra-narrow spot version production starts. that is as low as 28 mm.

Soraa’s Violet-Emission 3-Phosphor (VP3) LED technology allows for perfect rendering Soraa Enters LED Light of colors and whiteness. Utilizing every color Engine Business with in the rainbow, especially deep red emission, “Optical Light Engines” Soraa’s VP3 Vivid Color™ renders warm tones beautifully and accurately. It achieves Soraa, the world leader in GaN-on-GaN™ a color-rendering index (CRI) of 95 and deep LED technology, launched a small, low profile red (R9) rendering of 95. The VP3 Natural series of light engines that provide fixture White™ is achieved by engineering the violet Area size comparison of LG Chem’s new manufacturers access to the company’s full emission to properly excite fluorescing 320x320 mm OLED to conventional standard sized OLED panels visible spectrum GaN-on-GaN LED brightening agents including natural objects technology. From narrow spot to flood, as well as manufactured white materials.

Soraa’s new Optical Light make use of the efficiency from Engines are available in three each chip and at the same time sizes 11, 16, 30 (or 1.5”- 37 mm, save the cost and space wasted 2”-50 mm, and 4”-100 mm on the PC board. This design diameters); lumen outputs of could provide professional 500 or 1000; 4 degree, 10°, 25°, commercial and home lighting and 36° beam angles; 2700 K, fixtures a better solution to bring 3000 K, 4000 K, and 5000 K out a higher efficiency within color temperatures; and with an limited space without causing optional heat sink. Additionally, light spots or asymmetric viewing Soraa’s narrow spot beam light angle issues like traditional engines work with its award- DoB modules. winning magnetic accessory SNAP System. With a simple magnetic accessory attachment, beam shapes can be altered and color temperature can be modified, allowing endless design and display possibilities.

Ledtech Offers New Ledtech’s DoB modules were Driver On Board demonstrated at LED EXPO India Light Engine last December

As a leading supplier of LED low Ledtech’s ceramic based DoB temperature lighting and CoB series is not only better in design (Chip-On-Board) components, of viewing angle and efficiency Ledtech Electronics has applied but we also put a lot of effort in its advanced technology in high LED protection devices to make wattage CoB modules and sure our partners get the most develops a brand new ceramic reliable products. With 200 to based Driver On Board (DoB) 240 VAC direct input, Ledtech’s light engine module which is far DoB features in protection way different from existing SMD devices from soft start, over type DoB modules. Ledtech’s voltage protection), to heat new design on DoB could better compensation.

In addition, the standard dimension of Zhaga The pre-tensioned leaf springs, which are CoolStrates™ allow customers to easily has also been adopted by Ledtech DoB fixed with two standard screws, ensure a apply the LED chip, thus reducing steps in series. From settings with a diameter of defined contact pressure of the light source the manufacturing process and enabling 40 mm (Book 11), 50 mm (Book 3) to 75 mm to the heat sink and thereby constant heat more efficient production. They are available (Book 10) of our circle shape PCB we could dissipation. for chip-on-board, chip-on-heatsink and work easily with big names in the LED standard packaging technology. lighting industry, allowing customers to The versions with 1,200 lm, 2,000 lm, and change light source in fixtures as easy as 3,000 lm luminous flux, as well as with “We are constantly seeking ways in which changing a light bulb. Ledtech has shown 3,000 K and 4,000 K color temperature, we can improve our products and processes their great ambition by dauntlessly enable easy entry with low-maintenance, for customers with cutting edge innovation competing with industry giants to provide flexible LED solutions in shops, offices and and ideas,” said Mark Challingsworth, premium light sources and fight for a higher the hospitality field. R&D Manager at Heraeus. “We feel we’ve market share in LED components. done just that with CoolStrates™, and we With a thermal resistance of 1.1°C/W in a are looking forward to introducing it to Ledtech and its subsidiary Energyled diameter of 99 millimeter, the BJB LED star the market.” attended the great LED EXPO in New Delhi cooler offers a perfect passive cooling last December and demonstrated the brand platform for luminaires up to 5000 lumen. The Celcion components used in new premium DoB module on site. Many of Through a modular mounting pattern the CoolStrates™ are recognized by Underwriter the international and local distributors and GH36d LED cooler offers a wide platform Laboratories (UL®). agents were extremely keen to get the price of mechanical exchangeability - and excited about this new module released including Zhaga book 3 and Zhaga in the market. book 11 mounting platforms. Fischer Introduces Active Ledtech’s premium DoB light engine can Specific on this design is the advanced Heat Dissipation System provide lighting output from 3 W to 45 W performance under tilted positioning. While for LEDs with 90 lm/W, PF>0.9, CRI >85 and all these most star shaped LED coolers lose over 30% features allow the most popular home of their cooling capacity once tilted over Fischer Elektronik is now specifically lighting products like bulbs, track lights, angles of more than 40 degrees this design expanding its comprehensive product down lights and bay lights compatibility with is optimized for tilting luminaires like track portfolio for weight-sensitive applications some authentic and well-designed light spots and globes. with an active LED heat dissipation concept. fixtures with limited space. It allows easy mounting for Zhaga- compatible modules and uses a special Heraeus Introduces low-noise fan. MechaTronix Launches CoolStrates™ PCBs Universal LED Cooler for BJB LED Module Heraeus Electronics, a world leader in electronic packaging materials and The BJB LED star cooler GH36d is technology, will soon unveil CoolStrates™, a specifically designed for luminaires using the new line of circuit boards made with BJB GH36d series LED modules and various Celcion™ Thick Film Paste. These innovative brands of COB LED modules mounted by boards utilize cooler aluminum substrates, BJB Zhaga Book 3 or Zhaga Book 11 LED resulting in improved thermal management, holders. The compact module GH36d performance and cost in LED systems. While Zhaga-compatible modules can be consists of a based and encapsulated LED mounted directly to the heat sink, for other lamp with suitable Twist&Lock lamp holder. modules and holders, a pre-threaded mounting plate is available

The lifetime of LEDs directly depends on the heat dissipation concept. Drastic temperature fluctuations will considerably shorten it, and overstepping the permitted chip temperature has a direct impact on the light yield. The use of extruded aluminum heat sinks for free convection already serves as an effective LED heat dissipation concept.

MechaTronix’s star cooler GH36d accommodates all versions of BJB modules With an active LED heat dissipation concept Heraeus calls its latest thermal management and holders under the article number LA LED 68, innovation CoolStrates™ Fischer Elektronik expands its product

portfolio for weight-sensitive applications. The base is made from a thermos-technically optimized aluminum hollow- chamber profile. Zhaga-conform LED modules can be directly bolted to the front of this by way of additional threads. There is also the option of fastening various LED modules from different manufacturers, as well Infineon’s ICL5101 is targeting as their holder systems, to the indoor and outdoor high-power pre-threaded mounting plate LED lighting applications like with the help of an adapter high-bay/low-bay lighting or street lighting screwed into the base section. The highly integrated ICL5101 A special low-noise fan motor allows for advanced LED driver in a round design is integrated designs with approximately 25% in and fastened to the back of less components compared to the base section. The motor similar solutions which require has a double slide bearing and separate PFC and resonant ICs. is designed for the special This leads to smaller form requirements of LED applications factors with more reliable where noise and lifetimes are designs, less complex PCB concerned. Mechanical layouts and reduced costs. processing, cover panels with The ICL5101 integrates the ventilation slits, customized half-bridge and the PFC gate designs and surface coatings drivers. All operation parameters are also all available for your of the IC are adjustable by application. simple resistors, enabling cost effective but reliable and stable parameter-settings. The chip supports outdoor use by an Infineon ICL5101- extended junction temperature HV Resonant LED ranging from -40°C to +125°C. Controller with PFC The LED controller ICL5101 is Introducing the ICL5101, Infineon designed to control resonant Technologies AG extends its converter topologies such as portfolio of lighting control ICs, LLC. The integrated digital PFC addressing lighting systems in stage operates both in critical the range of 40 W to 300 W. conduction mode (CrCM) and The new high-voltage resonant discontinuous conduction mode controller IC provides a high level (DCM), which allows an extremely of integration which translates to stable regulation in low load a reduction in system cost. conditions, occurring, e.g. when Typical applications which the device is dimmed. The LED benefit from these features lighting can be dimmed down include indoor and outdoor LED over an extremely wide range lighting, high-bay and low-bay from 100% to 0.1% of its nominal lighting, street lighting, parking load. State of the art dimming garage and canopy lighting, today typically ranges from office lighting, retail and shop 100% to 5%. In addition, lighting. Since the total cost of the ICL5101 enables a fast time ownership is an important to light - under any conditions - aspect for industrial lighting, with less than 200 ms. customers prefer to use resonant topologies supported by the The adjustable PFC stage of the new ICL5101 due to its high ICL5101 delivers high power efficiency up to 95%. quality, providing a low total

harmonic distortion (THD) of less than 10% Faster time to LED market: Access to a standardized ecosystem and a high power factor of more than 0.99 With this offering, EnOcean’s OEM A unique strength of the EnOcean LED over wide line input voltage range. This customers benefit from significantly shorter control portfolio is its compatibility with the enables lighting manufacturers to comply development timelines and reduced strong EnOcean Alliance eco-system. with energy efficiency standards. investment, enabling them to focus on the OEMs have access to hundreds of Furthermore, the output of the ICL5101 is quickly evolving LED market opportunities. automation products and solutions based extremely stable over line voltage variations. Employing EnOcean modules, OEMs can on the leading EnOcean wireless standard A comprehensive set of protection features develop products on their own, leveraging and standardized application profiles. including external over temperature established LED control applications. This huge range of interoperable wireless protection and capacitive load protection Those OEMs seeking a ready-to-use self-powered devices is already established ensure the detection of fault conditions and solution can employ finished products to on the market and offers LED control a increase system safety. speed time-to-market and reduce consequently standardized communication. development effort. With the comprehensive EnOcean LED control portfolio, OEMs can fall back on this Wireless control and daylight harvesting: broad line of interoperable products to create EnOcean Launches The new LEDR/LEDD controllers use a flexible LED control solution meeting Complete Wireless LED wireless technology to communicate at 902 specific customer requirements. Control System in the US MHz with other self-powered EnOcean- based products. It provides a simple solution Both LEDR and LEDD controller employ the LED lighting is one of the most promising for dimming control of a single fixture or a Remote Commissioning certification recently and fast-growing technologies of today. zone of multiple daisy-chained LED fixtures. defined by the EnOcean Alliance, which EnOcean, the leading provider of energy In addition, it supports daylight harvesting provides a common framework for over the harvesting wireless solutions, announces a scenarios, occupancy control and manual air linking and configuration of EnOcean- comprehensive LED control system for the dimming processing data from EnOcean- based networks. North American market based upon based self-powered wireless occupancy innovative self-powered sensors and sensors, light level sensors, and switches. switches, combined with LED fixture The compact size enables flexible installation controllers and commissioning tools to inside of or next to electrical boxes and New 480 V High simplify installation and setup. fixtures so it can be easily wired out of sight Wattage LED Drivers using standard wiring practices. from TRP

Users can connect the LEDR/LEDD Thomas Research Products has introduced controller to a central controller or a gateway new 277-480 V LED drivers with 96 W to integrate lighting control into building output. This eliminates the need for step- automation systems. Alternatively, the TCM down transformers inside luminaires. 330U transceiver module can be Thomas Research Products is a leading implemented into existing controllers. It manufacturer of SSL power solutions. already includes the firmware to get immediately started with wireless control.

The comprehensive LED control portfolio is based on the widely adopted energy Easy setup and remote configuration: harvesting wireless standard LEDR/LEDD provides a very simple manual user interface for configuration and linking of The building blocks include: devices. With only two buttons, the user can • LED controller family: the transceiver link and unlink sensors and switches, to dim module (TCM 330U) for integration into up and down manually, and to set the drivers and modules as well as LED minimum dimming value. Fixture/Zone Controllers with relay and TRP’s PLED96W LED driver perfectly 0-10 V output, and without relay For the LED lighting configuration of accommodates both high wattage indoor or • Comprehensive application firmware advanced settings, EnOcean offers the outdoor LED luminaires enabling dimming, occupancy, daylighting easy-to-use wireless Navigan remote and Title 24-compliant controls right out commissioning software to link devices New PLED96W-HV series drivers are based of the box and set parameters (e.g. ramp speeds, on TRP’s high performance PLED96W series. • Navigan, an easy-to-use commissioning dimming levels, integrated repeater etc.) Providing flicker-free output, these drivers are tool to link devices and setup parameters from a laptop computer. Using the Navigan perfect for high wattage indoor or outdoor over the air from a graphical user interface commissioning tool, installers can easily LED luminaire designs. Available in constant- • EnOcean’s established line of white label configure the LEDR/LEDD controller over current, dimmable, and constant-voltage self-powered wireless switches, the air in accordance with on-site versions, the new High Voltage drivers work occupancy and light level sensors requirements, define properties and on any mains from 277-480 Vac. This makes settings as well as edit and store projects. them perfect for 347 V applications.

NEWS PRODUCTS 20

The driver design is robust enough that The VEML6040’s built-in ambient light lighting to be monitored at any time and from it also qualifies for hazardous locations. photo-diode offers extremely high sensitivity, anywhere in the world, it also allows These models are Type HL rated by UL. with detection from 0.0056 lx to 11.7 klx, employees to adjust the lighting to suit their Even though not all applications require this allowing the device to operate in applications own individual needs quickly and easily via a rating, it provides OEMs assurance that with dark lens designs. The sensor provides PC or smartphone app. Both the intensity these drivers will perform in a variety fluorescent light flicker immunity, low power and the light color (Tunable White) can be of environments. in shutdown mode of < 1 µA, and excellent adjusted, thereby making employees feel temperature compensation stability from more comfortable at work, as those who TRP’s new drivers offer the same features -40°C to +85°C. took part in the study can testify. as their regular PLED drivers, including Black Magic Thermal Advantage™ aluminum The device features an operating voltage and Whether the DALI system is a new one or an enclosures. They are also IP66, rated for I²C bus voltage range of 2.5 V to 3.6 V and is existing one, integrating it in a high-level light dry and damp locations. offered in a lead (Pb)-free, 4-pin OPLGA management system via the connecDIM package. The VEML6040 is RoHS-compliant, Gateway is much easier, quicker and more halogen-free, and Vishay GREEN. cost-effective than has ever been possible with other approaches. This solution is based Vishay - Integrated Tiny on standard hardware and internet RGBW Color Sensor technologies so there is no need to invest in Tridonic connecDIM - with I²C Interface expensive specialist hardware or software. Decentralised Light connecDIM is easy to install, operate and The Optoelectronics group of Vishay Management 2.0 tailor to individual customer requirements, Intertechnology, Inc. introduced a new digital and offers automated emergency lighting test RGBW sensor featuring Filtron™ technology Tridonic unveils connecDIM, an easy-to- functions. Once connected to the internet, for accurate RGBW spectral sensitivity while integrate light management system solution the gateway, as the heart of the system, providing ambient light spectral sensitivity for industry and commerce. The system, collects all the data and parameters of the with responses close to that of the human comprising connecDIM Gateway and connected DALI devices and transfers them eye. Vishay Semiconductors’ VEML6040 connecDIM Cloud, combines cost efficiency via TCP/IP to the central ConnecDIM cloud. incorporates photo-pin-diodes (RGBW) and user-friendly design with decentralized and a signal processing IC in a compact light monitoring and control options from The data stored in the cloud can be 2.0 mm by 1.25 mm by 1.0 mm surface- anywhere in the world. Small applications accessed at any time from anywhere in the mount package while offering an I²C bus with only a few DALI devices can benefit just world. Access is possible via web browsers interface for simple operation. as much as complex lighting systems. from any PC or Mac, and also wirelessly via tablets or smartphones running iOS or Android. There are apps available for wireless access, namely connecDIM Lite for monitoring and controlling the installation within the property via the in-house WLAN and connecDIM Architect for commissioning and maintaining the installation.

Building operators, facility managers and operation and maintenance personnel all benefit from the central monitoring functions. Vishay’s Filtron™ sensor technology offers an Based on standard hardware and internet excellent RGBW spectral sensitivity technologies, Tridonic’s connecDIM is a cost Not only do they receive an overview of the effective smart controls solution connected DALI devices, they can also see The device released today senses red, any lamp faults, hardware faults and dimming green, blue, and white light, and it offers A long-term study conducted by Zumtobel in values at a glance so they can immediately 16-bit resolution for each color channel. The cooperation with the Fraunhofer IAO has take appropriate action. It is also possible to VEML6040 is ideal for consumer devices confirmed that the present lighting situation change the energy consumption without such as smartphones, digital cameras, and in offices often does not meet the having to be on site. televisions, where it allows the brightness requirements of the various groups of users. and color temperature of backlighting to be Lighting that is tailored to the needs of users If the luminaire installation is expanded adjusted based on ambient light, making has been shown to improve their well-being additional DALI devices can be easily LCD and LED panels more comfortable for and make workplaces more attractive. More integrated via a PC or Mac internet end users’ eyes. Containing the circuitry than 50 percent of all employees would like connection or wirelessly via a tablet or needed for color balancing, backlight control, individually adjustable lighting that they can smartphone. This involves addressing the and color temperature measurement in one tailor to their specific needs and to the devices, defining test routines (for example device, the sensor saves space, lowers requirements of changing work situations. for emergency lighting operation), setting up costs, and simplifies designs by eliminating connecDIM makes this possible. This light predefined lighting scenes and controlling the need for an external resistor. management solution not only enables the the light color in the case of tunable white.

Issue 48 | © 2015 Luger Research e.U. NEWS PRODUCTS ams Combines Daylight Sensor & Lighting Manager to an IoT-Hub ams AG, a leading provider of high performance analog ICs and sensors, introduced its revolutionary AS721x Autonomous Daylighting Manager, the industry’s first integrated chip-scale Internet of Things (IoT)-connected smart lighting manager. This new class of sensor- integrated smart lighting manager solutions delivers cost-effective, IoT-connected integrated control capabilities to luminaire, light engine and replacement lamp manufacturers. A Smart Lighting Integration Kit (SLIK) allows for easy and quick implementation.

To get started, ams offers the Smart Lighting Integration Kit (SLIK)

Attributes of the ams’ AS721x Autonomous Daylighting Manager: • 20-pin 2.1 x 2.3mm chip-scale and 4.5 x 4.7mm land grid array package options • Photopic daylighting sensor for accurate ambient light sensing and control • Integrates with industry standard 0-10V controls, driving 0-10V and multi-channel PWM outputs • Standard serial UART (AS7211) for expansion to any standard networking or integrated IR remote control decoding (AS7210) • Network-enabled architecture with a high-level, driverless smart lighting command set for IoT connectivity via Bluetooth 4.x (BLE), ZigBee, WiFi, Ethernet/PoE or other networks • I²C sensor expansion creating lighting-hosted sensor-bridge capabilities

Photopic sensors built with nano-optic filters integrated into the AS721x series are designed to help lighting manufacturers address the growing challenges of energy-saving lighting mandates, including daylighting controls. These challenges are more cost-effectively met by bringing the controls and high-granularity sensing into the luminaires themselves.

The AS721x family is ams’ first platform technology of integrated sensor solutions that provide system-level sensing and control capabilities, greatly reducing system costs and shortening time-to- market. The AS721x Autonomous Daylighting Manager senses the ambient daylight and enables the delivery of constant lux levels in the space by managing subtle adjustments as the amount of outside light varies. Integrating a sensor-based manager into each luminaire optimizes the overall responsiveness and efficiency of the lighting system, maximizing energy savings. The approach also delivers accurate lumen maintenance over time and temperature variations, and allows fully connected luminaire systems to respond to building- or space-level command and control strategies.

Competitive offerings in the space are Technical data: technology leader Everlight Electronics, essentially “build your own” devices • DALI to PWM controller Billion develops its wholly owned Street requiring discrete components, including • According to DIN EN 62386-101/-102/-207 Light Control Management System (LCMS) sensors, processors, memory, and I/O • All protocol elements implemented that provides automatic dimming schedule, chips, that require design, integration and • PWM output at 500 Hz streetlight status diagnosis, and remote time-consuming programming of control • PWM dimming from 0.1 % to 100 % control for streetlights operation. Besides the and communications algorithms. In • Logarithmic and linear dimming curves new streetlight control solution, Billion contrast, the AS721x family delivers a fully • Available as module or DIL8/SOIC8 chip develops a rich selection of LED Drivers integrated solution, providing users with a serving as outperforming power supplies high level of integration at far lower cost and For each of the four channels the forward and essential engines for the operation of complexity. “ams’ ground-breaking sensor- current and brightness of the LEDs can be solid lighting systems. integrated manager series addresses individually and independently programmed. head-on the lighting industry’s desire for Current can be programmed from 200 mA to technically feasible integrated controls that 1000 mA in steps of 5 mA. Brightness is are also cost- and space-effective. It’s a controlled by internal 12 bit PWMs for each solution that will truly revolutionize the channel, allowing 4096 steps. lighting industry, and deliver the kind of network-connected system approach that Programmability of the LED forward current exemplifies the power of the Internet of enables the use of a single type of driver for Things,” said Brian Bedrosian, Senior a wide range of LEDs. The high resolution of Director, Product Marketing of Broadcom, the brightness control allows precise color which is providing Bluetooth Low Energy mixing or calibration of multiple LED groups. Billion Electric’s smart Lighting Control (BLE) Smart connectivity for the IoT- Management System (LCMS) basically connected AS721x series. I²C, DMX512 and DALI are available for consists of the Smart Lighting Transceiver (A), control of the four channels. The I²C interface a Gateway (B), online server (C) and an also allows programming the LED-Warrior04 operator control software (D) for stand-alone operation. Code Mercenaries - To achieve lifetime sustainability and energy New 4 Channel The I²C interface may be used for service to efficiency, Billion’s LED Drivers are compact, Intelligent LED Driver recalibrate already installed units. Light versatile, and reliable, supporting a broad scenarios can be programmed for stand range of indoor and outdoor lighting Code Mercenaries introduces a 4 channel, alone operation, to run independent effects applications. The high quality LED Drivers are intelligent, and programmable LED driver. like fading or color change. LED-Warrior04 available in Constant Current and Constant LED-Warrior04 has I²C, DMX512, and DALI operates with DC input from 7 V to 32 V and Voltage varieties; non-dimming and dimming interfaces. Bluetooth LE can be added with drives up to 4 x 25 W to the connected LEDs drivers; PWM or 1-10v dimming; and various a piggyback module. at up to 94% efficiency. application specific products, including those designed for the signage market.

Billion’s Class 2 LED Drivers are exclusively Billion Electric Offers installed with power isolation mechanism and Smart Lighting Solution have a current leakage smaller than 0.25 mA. and LED Driver With the designed functionality, Billion’s Class 2 LED Driver is able to provide more Billion Electric Co. Ltd. announces the launch user safety and overheat protection than of Smart Lighting Control Management other LED driver brands in the market. System (LCMS) and High Efficiency Class 2 The Billion’s Class 2 LED Drivers serve as Code Mercenaries’ LED-Warrior04 is a 4 x 25 W Drivers to the global LED Lighting market. power dimmable lamps and are easy to intelligent, and programmable LED driver with I2C, DMX512, and DALI interfaces Continuing the cooperation with lighting deploy for various lighting scenarios.

Putting LEDs in the Right Light SSL solutions from the world leader in LED measurement. Spectroradiometers Unprecedented photometric and colorimetric accuracy Goniophotometers Three models for different sample sizes Integrating Spheres Ranging from 25 cm to 2 m in diameter www.instrumentsystems.com Imaging Photometers and Colorimeters Homogeneity of extended sources and OLEDs

IS LumiCam 1300 The LumiCam software also provides a Advanced - Six Filters comprehensive range of tools for evaluating the test results. Luminance, for Precise Color luminous intensity, contrast, color Measurement coordinates and dominant wavelength can be determined within seconds. German specialist for light measurement Different manual and automatic analytical solutions Instrument Systems presents tools operate on configurable regions of the LumiCam 1300 Advanced. This new interest and allow for clear visualization. imaging photometer and colorimeter has been designed for the highest accuracy when analyzing the characteristics of displays and electronic panel graphics. New Multi-Exposure (HDR) Feature for Imaging Photometers

SphereOptics introduced a new “multi- exposure” feature (also known as “HDR” or High Dynamic Range mode) for their I- and Y-Series ProMetric™ imaging photometers made by Radiant Vision Systems. Radiant Vision Systems, formerly known as Radiant Zemax, is well known for their ProMetric™ high performance imaging photometers and colorimeters (cameras which measure the Instrument Systems’ LumiCam 1300 amount and color of light) which are Advanced provides more accurate widely used in the development and measurement and eye sensitivity curve adjustment with its six channels testing of flat panel displays, lighting, LEDs and in vehicle lighting applications. The innovative camera concept of the LumiCam 1300 Advanced is based on six filters. Alongside the four optical filters used in the LumiCam 1300 Color, the new camera has been expanded by two filters. The patent-pending procedure allows very accurate adjustment to the eye sensitivity functions using the data recorded from the six channels.

The LumiCam 1300 Advanced provides The new HDR function of SphereOptics’ I- and Y-Series ProMetric™ imaging excellent accuracy for the color photometers offers a similar effect as in coordinates particularly when taking LED ordinary photo cameras extending the color measurements. Therefore it offers a dynamic range while reducing image noise good alternative to spectroradiometric instruments with significantly shorter The new HDR mode increases the measurement times. dynamic range of the ProMetric camera significantly (up to 1,000,000:1). The LumiCam 1300 Advanced is the third The newly developed algorithm achieves member of the LumiCam family and this range extension by combining complements the proven camera models separate images with different exposure LumiCam 1300 Mono and Color with a times. This method increases the grey further imaging measurement system. If scale range of the image while at the required, the advanced model can be same time, lowering the noise level. operated in exactly the same way as the The accuracy of the measured luminance Mono or Color versions - with analog and color remains very high, with a measuring times and accuracies. The percentage error of +/- 3 % for luminance relevant operating mode can easily be (cd/m²) and color coordinates x, y selected in the software. of +/- 0,003.

Screenshot of Labsphere´s CCS-1000 system SW interface

Traditionally flat fielding and other camera and sensor corrections were made with Nora Lighting offers six LED Tape Light Channel models with various channel depths, uniform sources including a halogen light including a corner model source, due to the constant output of halogen lamp over time and the well-known Constructed from aluminum, all channels linear spectrum. But because of the change include end caps and a white diffuser panel in time and the replacement of traditional to soften the LED lighting effect. The new light sources with LED sources there is a channels accommodate the complete line of demand to adapt calibration equipment as Nora LED tape lights, which are available in well. white or amber. They include: Hy-Brite LED Tape Light; Standard LED Tape Light; High Cold white LEDs consist of a blue LED with a Output LED Tape Light; Side-Lit LED Tape yellow phosphor layer on the top. Therefore, Light; along with RGB Color Changing LED they have a large peak in the blue range Tape Light. which does not appear in case of a halogen spectrum. As the calibration scenario shall Nora Lighting is an innovator in the be as close as possible to the later usage of introduction of LED products and now offers the devices, it is important to adapt the LED retrofit downlights; LED track and rail integrating sphere systems. fixtures; LED puck lights; LED pendants; LED step and brick lights; and LED emergency / Labsphere´s latest series of CCS-1000 exit signs. The multi-exposure HDR feature allows for a systems replaced the halogen source, inside more accurate luminance analysis of a device the high reflectance integrating sphere, made Along with LED fixtures, Nora manufactures under test that features both low and bright out of the material Spectralon™, by 16 LEDs incandescent, fluorescent and HID sources light illumination levels simultaneously. distributed over the VIS and NIR range to in track and rail systems, recessed lighting, A good example of such an application is the generate almost every spectrum. Standard multiple lighting systems, under cabinet and measurement of emergency signs when sources like illuminant A, B, C, D50, 55, 65, an expanding series of accent lights, looking simultaneously at the sign and at the 75, F2 and F12 are set as defaults; customer including pendants and sconces. light pattern on the wall. Other examples are specific spectra could be composed easily. street lights and their pattern on the street or on the pavement, where the HDR mode allows for the measurement of the Green Creative’s New illumination pattern as well as the light Nora Lighting Adds New BR30 LED Lamp with emitted directly from the lamp. Light Channels to Their “Cloud” Design Product Portfolio Green Creative, the commercial grade LED Nora Lighting introduces a new series of LED lighting manufacturer proudly announces the Labsphere Introduces Tape Light Channels that expand the launch of its new BR30 8 W LED lamp. The New Uniform Light versatility of the Nora tape light product line. BR30 8 W Cloud is the latest addition to Sources for Calibration The channels can be recessed or surface Green Creative’s Titanium LED Series 4.0 mounted in interior walls, hallways and and was selected by the Illuminating Every day improvements of cameras and stairways or within railings and ceilings. They Engineering Society (IES) for its prestigious sensors in terms of color perception and can also be mounted under cabinets for 2014 Progress Report. Green Creative had resolution lead to higher requirements in energy-saving LED lighting in homes or five lamps chosen for the 2014 Progress quality assurance and production control. offices. The channels are available in 4-foot Report which showcases unique and Labsphere´s new series of uniform light lengths, which can be joined for longer runs. innovative products significant to the lighting sources CCS-1000 is dedicated to camera Six models are offered with various channel industry. and sensor calibration in the production line. depths, including a corner model.

is Energy Star certified, dimmable, lasts Some LED manufacturers have found it very 25,000 hours and is available in 2400 K, difficult to replicate dichroic lighting largely 2700 K, 3000 K and 4000 K CCT. due to the necessity of a sizable heatsink. Verbatim’s new high quality dichroic MR16 Green Creative will be releasing a full line of and PAR16 lamps deliver a high quality beam BR lamps utilizing the Cloud design in the without any noticeable heatsink in sight and coming months. as a result it fits neatly into standard fixtures while providing all the energy saving benefits of LED lighting.

Verbatim’s Dichroic LED Verbatim’s 3.7 W dichroic MR16 LED lamp Lamps Deliver High- with GU5.3 base delivers excellent optical Quality Light Beams control with minimal spill and a crisp 35° beam angle focusing light where it’s needed. Green Creative’s BR30 LED Cloud, offers the same quality and features of their other Verbatim has unveiled dichroic-effect LED A 4 W dichroic PAR16 lamp with GU10 base products in an innovative lightweight design lamps as cost-effective replacements for is also available offering the same beam dichroic halogen lamps. Using technology angle. Besides delivering a higher power Weighing less than 100 g, the BR30 Cloud developed by parent company Mitsubishi output and light intensity, its 3000 K warm features a revolutionary design that is 60% Chemical Corporation, Verbatim has white color temperature, 480 cd luminous lighter than the previous generation BR30. provided an energy-efficient alternative to the intensity and luminous flux of 250 lm at 90° This dimmable lamp emits smooth and MR16 and PAR16 halogen lamps popularly angle are all of equal measure to the MR16 evenly distributed light and is one of the only used for track lighting, pendant fixtures and lamp. Competing LED products in the market BR30 65 W replacements available that is retail display lighting to produce a unique, tend not to deliver as much of a glitter effect suitable for use in totally enclosed fixtures. Its surround lighting and glitter effect. from the dichroic mirror they employ. traditional incandescent form factor makes it an ideal choice for recessed, accent and “Making dichroic-effect LED MR16s without general lighting applications. a noticeable heatsink and delivering high performance, reliability and quality at the “The BR30 Cloud is more than just a same time isn’t easy. Verbatim has delivered uniquely designed product,” says Green yet another outstanding product that our Creative’s Principal, Cole Zucker. “It uses customers tell us more than matches their 35% less material than our previous needs. Verbatim has introduced many high generation but at the same time raises the quality, innovative LED products in recent bar for energy efficiency in the market.” months and we are looking forward to unveiling many more high-performance At 81 LPW, this lamp’s efficacy is more than spotlights in 2015,” commented Jeanine 20% higher than the Tier 1 LED 65 W Verbatim’s dichroic MR16 LED lamp with Chrobak, Business Commercial Manager replacement industry average and exceeds GU5.3 base as well as the GU 10 LED lamp LED EUMEA, Verbatim. Energy Star® requirements. The BR30 Cloud version delivers excellent optical control

Osram Improves lowest typical values in this component class Epitaxy expert at Osram Opto Semiconductors. Efficiency of Blue LED worldwide. At 85° C a voltage of 2.78 V can This would improve the efficiency of the LED be achieved in the component. Depending chips by a further percentage point. “In view Chips by Reducing on the operating point, this translates into an of the speed with which this first step has Forward Voltage increase in efficiency of these light emitting been implemented, we are confident that the diodes (LEDs) of six to eight percent, which improved process can be transferred to Osram Opto Semiconductors has achieved can be transferred to the entire UX:3 chip production by the summer of 2015”, added one of the best values in the world in terms family. These chips can be found in all blue Hertkorn. “Any further reductions in forward of forward voltage for blue high-current and white LEDs. The LEDs are used in an voltage will then only be marginal owing to chips. This has led to an increase in extremely wide range of applications – the the laws of physics.” efficiency of up to eight percent. Optimized Osram Oslon Square, for example, in street InGaN chips (Indium-Gallium-Nitride) lighting and industrial lighting. “The reduction featuring UX:3 chip technology are the basis in forward voltage was achieved thanks to a for blue or white LEDs – and are already new process in the epitaxy”, said Dr. Marcus Novel LEDs by Band- used in production. Osram experts also see Eichfelder, Project Manager at the Structure Engineering considerable potential for reducing the value Regensburg high-tech company. Production in van der Waals by a further 20 to 30 millivolts (mV) by the of the first optimized chips started back in summer of 2015 – offering a further boost in August 2014. Heterostructures efficiency. Semi-transparent, flexible electronics are The next steps: transfer to production no longer just science-fiction thanks to The blue Osram Oslon Square (LD CQAR), There is still enormous potential. “In the graphene’s unique properties, University for example, now has a typical forward laboratory we have already succeeded in of Manchester researchers have found. voltage of only 2.87 volts (V) instead of the further reducing the forward voltage by as Published in the scientific journal, 3.05 V specified so far in the data sheet – the much as 30 mV”, said Dr. Joachim Hertkorn, Nature Materials, University of Manchester and University of Sheffield researchers show that new 2D ‘designer materials’ can be produced to create flexible, see-through and more efficient electronic devices including semi-transparent LEDs.

The team, led by Nobel Laureate Sir Kostya Novoselov, made the breakthrough by creating LEDs which were engineered on an atomic level. The new research shows that graphene and related 2D materials could be utilized to create light emitting devices for the next-generation of mobile phones, tablets and televisions and other devices to make them incredibly thin, flexible, durable and even semi-transparent.

The LED device was constructed by combining different 2D crystals and emits light from across its whole surface. Being so thin, at only 10-40 atoms thick, these new Osram experts have significantly reduced the value of the forward voltage, compared with the components can form the basis for the first data sheet for the previous Osram Oslon Square generation of semi-transparent smart devices.

New ICL5101 High-Voltage Resonant Controller IC for LED Drivers

The ICL5101 integrates a half-bridge controller with a PFC stage for efficient and compact professional lighting. The PFC stage supports stable operation at low load conditions and the LLC half-bridge resonant stage provides gate drive function for MOSFETs rated up to 650 V. The high level of integration leads to smaller form factors with more reliable designs, less complex PCB layouts and reduced costs. All operation parameters are adjustable with simple resistors allowing simple configuration. www.infineon.com/icl5101

Schematic of the SQW heterostructure for graphene based, band- structure engineered LEDs

By building heterostructures - stacked layers of various 2D materials - to create bespoke functionality and introducing quantum wells to control the movement of electrons, new possibilities for graphene based optoelectronics have now been realized.

Freddie Withers, Royal Academy of Engineering Research Fellow at The University of Manchester, who led the production of the devices, said: “As our new type of LED’s only consist of a few atomic layers of 2D materials they are flexible and transparent. We envisage a new generation of optoelectronic devices to stem from this work, from simple transparent lighting and lasers and to more complex applications.”

Explaining the creation of the LED device, Sir Kostya Novoselov said: “By preparing the heterostructures on elastic and transparent substrates, we show that they can provide the basis for flexible and semi-transparent electronics.”

“The range of functionalities for the demonstrated heterostructures is expected to grow further on increasing the number of available 2D crystals and improving their electronic quality.”

Prof Alexander Tartakovskii, from The University of Sheffield added: “The novel LED structures are robust and show no significant change in performance over many weeks of measurements.”

Despite the early days in the raw materials manufacture, the quantum efficiency (photons emitted per electron injected) is already comparable to organic LEDs.

The paper Light-emitting diodes by band-structure engineering in van der Waals heterostructures by F.Withers, O. Del Pozo-Zamudio, A. Mishchenko, A. P. Rooney, A. Gholinia, K.Watanabe, T. Taniguchi, S. J. Haigh, A. K. Geim, A. I. Tartakovskii and K. S. Novoselov appears in Nature Materials.

Researchers at the The Future of More Ohio State University Efficient LEDs and Lasers have developed a technique for making Probably Starts in 2D one-atom-thick sheets of germanium The future of electronics could lie in a for eventual use in material from its past, as researchers from advanced electronics. The Ohio State University work to turn In 2010, MIT’s Material Research germanium - the material of 1940s transistors - Group already into a potential replacement for silicon. demonstrated the first germanium laser At the American Association for the (Photo: Dominick Reuter/MIT) Advancement of Science meeting, assistant professor of chemistry Joshua Goldberger reported progress in developing a form of germanium called germanane.

In 2013, Goldberger’s lab at Ohio State became the first to succeed at creating one-atom-thick sheet of germanane - a sheet so thin, it can be thought of as two- said. “So potentially we could make a “topological insulator,” which conducts dimensional. Since then, he and his team material that traverses the entire electricity only at its edges,” Goldberger have been tinkering with the atomic bonds electromagnetic spectrum, or absorbs explained. “Such a material is predicted to across the top and bottom of the sheet, and different colors, depending on those bonds.” occur only with specific bonds across the creating hybrid versions of the material that top and bottom surface, such as a incorporate other atoms such as tin. As they create the various forms of hydroxide bond.” germanane, the researchers are trying to The goal is to make a material that not only exploit traditional silicon manufacturing Goldberger’s lab has verified that this transmits electrons 10 times faster than methods as much as possible, to make any theoretical material can be chemically stable. silicon, but is also better at absorbing and advancements easily adoptable by industry. His lab has created germanane with up to 9 emitting light - a key feature for the percent tin atoms incorporated, and shown advancement of efficient LEDs and lasers. “Aside from these traditional semiconductor that tin atoms have strong preference to applications, there have been numerous bond to hydroxide above and below the “We’ve found that by tuning the nature of predictions that a tin version of the material sheet. His group is currently developing these bonds, we can tune the electronic could conduct electricity with 100% efficiency routes towards preparing the pure tin 2D structure of the material. We can increase or at room temperature. The heavier tin atom derivatives. decrease the energy it absorbs,” Goldberger allows the material to become a 2D

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EPIC is an industry association that promotes the sustainable development of organizations working in the field of photonics in Europe. We foster a vibrant photonics ecosystem by maintaining a strong network and acting as a catalyst and facilitator for technological and commercial advancement. To achieve our mission, we publish market and technology reports, organize technical workshops, B2B roundtables and coordinate EU funding proposals, and more.

IYL 2015 AND DAY OF PHOTONICS: AVENUES TOWARDS GLOBAL AWARENESS OF PHOTONICS by Carlos Lee, Director General, EPIC – European Photonics Industry Consortium

The responsibility of an association is also to promote the sector the process of global photonics appreciation. The first edition towards the general public, which is why EPIC initiated DAY OF of this biennial event took place in 2014 with 130 companies, PHOTONICS as a preparatory action leading up to the International universities, and organizations in 30 countries reaching out Year of Light 2015 (IYL). to their communities and raising awareness about photonics and its importance. They opened their doors to the public, Someday the word ‘photonics’ will be as common as ‘electronics’. invited journalists and families to visit facilities and encouraged People recognize the important role of electronics in our society staff to make presentations at schools to promote photonics. and in today’s world. The DAY OF PHOTONICS aims to accelerate International Year of Light 2015 is a most unique and important initiative because of its global scope and because it involves people from various sectors: non-profit organizations, scientific societies, academic and research institutions, and private companies from all over the world. Every country in the UN community has been tasked to take part and reach out to the public and most have responded positively. For instance, Israel has issued a stamp commemorating IYL 2015! Technologies have no borders and photonics companies are found everywhere in the world, so it makes sense to have a global initiative which has a very strong, local, regional and national aspect – and this is what IYL offers.

In order to show the multidisciplinary character of the year, Epic plans on collaborating in specific events with international student organizations with which we are connected through the Informal Forum of International Student Organizations (IFISO).

EPIC is a “Gold Associate Sponsor” of IYL because when people understand photonics, they will press politicians to support the industry. Government aid, will, in turn, spur investments and more parents will likely support children interested in pursuing studies in photonics-related courses. With more young and bright minds involved in photonics, new ideas and innovations will constantly be produced, making the whole industry ecosystem even more dynamic and vibrant! Both IYL2015 and DAY OF PHOTONICS are important because they complement each other in many ways, and learnings can be shared from both initiatives. This year, however, all attention and support from the photonics industry should be directed towards the International Year of Light - so become engaged and start by reviewing the latest Day of Photonics celebrated at the Australian National University updates on www.light2015.org. in Canberra C.L.

CATEGORYEVENTS IYL INAUGURATION 32 Let there be Light - A Brief Overview of the Meaning of Light

The inauguration of The International Year of Light at the UNESCO headquarters in Paris brought to mind that, despite its importance, LED lighting only represents a small fraction of the photonics world. All of the many light based technologies are included in The Year of Light. Arno Grabher-Meyer from LED professional attended the opening ceremony and talks about the journey he made there through lighting history, space, culture and inventions.

Ancient cultures may only world’s major religions. The idea ceremony demonstrated have been subconsciously of bringing light to the world is this idea by touching on aware of the relevance of of great importance to nearly scientific, religious, political, light in connection to life, all natural and world religions. cultural, artistic, humanistic, especially for humans. economic and ecological As the early religions formed Rekindling the idea that light viewpoints. The contributions so did prehistoric man start is necessary for our lives and were of great interest, even for comparing their god(s) to light. cultures is one of the most those of us whose professional Later, the idea that God is important aspects of the lives only revolve around light became the belief for the Year of Light. The inauguration LED lighting.

Inauguration ceremony in the plenar hall of the UNESCO

Ahmed Zewail was After the welcome speech made the first of the Nobel by the Secretary General of the laureates to speak. United Nations, Ban Ki Moon, He made the audience Irina Bokova, Director General of fimiliar with the history of lighting science, UNESCO and Flavia Schlegel, future challenges and Assistant Director General for opportunities, and his Natural Science at UNESCO understanding of a better world made their speeches. They were followed by dignitaries from some of the initiating states and organizations who also addressed the audience. The program continued to impress the guests with “Nobel Plenary Lectures” held by Nobel Prize winners in the fields of photonics and “Thematic Sessions” where experts shared their opinions on He emphasized that the process of Alhazen, who has been credited as the given topics. photosynthesis, probably the most being the founder of modern optical important process for life, has not science and is a central figure of There were also several artistic been able to be replicated despite one of the remarkable campaigns performances, movies, the huge amount of money invested for the Year of Light. Ibn al Haytham presentations of planned activities, in research. He also conveyed how was the first to understand and and a cocktail party. To complete impressed he is by the highly describe the basics of vision the event that evening, the outside efficient biological process that correctly. He invented the Camera of the UNESCO building was allows us to see and pointed out Obscura, which is still the basis of imaginatively illuminated. that without light there wouldn’t be today’s photo and video cameras. any vitamin D synthesis. And without Mr. Zewail applauded Gallileo, vitamin D we wouldn’t be able to Newton, Fresnel, Young, Maxwell, Nobel Laureate’s survive. In addition, Ahmed Zewail as well as Einstein, Planck, and de Plenary Lectures also gave an historical account Broglie for describing the nature of Nobel Laureate Ahmed Zewail of optical science from the early light. He also acknowledged the chose the topic of “Light and Life” [1] days up until today. He talked relevance of coherent light, where he showed different biological about the life of Ibn al Haytham known as laser light, that has processes that are based on light. (965 - 1039 A.D.), also known as allowed for many new developments

Nobel laureate, Steven Chu, emphasized that climate changes are made by man. He described how photonics can contribute towards environmental protection

like trapping and cooling atoms, “Not Having”, and alleviating the such as Beijing, the average optical communications and “Not Free”, by providing education concentration is 194 µg/m³, which is quantum physics. Finally, and science, aid on a partnership significantly higher than in a room he introduced his own research of basis, and liberty and justice. full of smokers. Your chances of Femtochemistry and Femtobiology getting lung cancer in Beijing are where his team not only wanted to Steven Chu, who shares the Nobel 27 times higher! Mr. Chu also understand molecular processes in Prize for Physics and awarded for showed that generating electricity time, but also in space. One of the laser cooling and the trapping of using alternative energy tools needed to do that is the atoms, talked about “Energy and technologies is cheaper than electron microscope. This had to Climate Change: Challenges and conventional energy generation. be developed into a so-called Opportunities” [2]. He started his Real contracts for wind power ultrafast 4D electron microscope. speech with the philosophical purchase are based on This microscope allows movies statement that the words ‘vision’ approximately $0.03 (US) per kWh, to be taken of moving objects and ‘insight’ go well beyond the whereas a new natural gas based on the nm scale. These films can be sensory input. Honoring Maxwell’s contract is approximately $0.05 (US) used in many research areas to help achievements he gave a brief per kWh. Similarly, he showed that clarify the mechanisms of diseases overview of the frequencies that photovoltaic-based electricity is on like Alzheimer’s and possibly to are used and known today. a par with natural gas based defeat it. And everything is light He produced clear evidence of contracts. He demonstrated that based. Mr. Zewail also raised the the climate change from the rise there is a huge demand for off grid topic of “Light and the Future of of global average temperatures to photovoltaic solutions using Civilization”. Here he mentioned the increased worldwide weather batteries and that the cost of challenges and showed examples related losses of insurance batteries is crucial. In the last part in medicine and biology, alternative companies. He explained that of his lecture he talked about light clean energy, global warming, measuring the current and projected and some of the latest achievements water, food and population, rise of the sea level and the like improved light measurement nano-machines and molecular shrinkage of glaciers is based on and increased sensitivity and control, information technology photonics. Environmental issues resolution. Here he mentioned the and space exploration. Finally, included the example of particulate development of algorithms that he pointed out that the driving matter less than 2.5 microns, which increase the resolution of optical power for science is curiosity. are known to increase the risk of microscopes by determining the Ahmed Zewail closed his lecture lung cancer by 36% per 10 µg/m³. centers of the blurred light points. with a plea for a better AAA world. While the current annual EPA He also showed an example of rare, The three A’s stand for alleviating average limit already allows earth-based nanoparticles the “Not Knowing”, alleviating the 12 µg/m³ (WHO 50), in some areas, developed by his team, that have

The Nobel Prize winner for Physics 1997, William D. Phillips, used - as he said - “the coldest stuff you’ve ever seen”, liquid nitrogen, to demonstrate what the advances in photonics mean for laser cooling technologies and subsequently for practical applications

several advantages over known of 3 nK in 2002. In 2003 the record His closing statement was, quantum dots, being brighter and was broken and a new record of “We are coming to the end. more stable. These molecules emit 500 pK was set. This resulted in But it is not the end, it is just in a wavelength where tissues are highly improved accuracy of the the beginning.” transparent and could be used in atomic clocks from a 1·10-16, different medical diagnostics which means that the clock is “Light and the Quantum”, the title applications. Another fascinating accurate to within one second in of Serge Haroche’s lecture, optical mathematical method for 300 million years, to 2.4·10-18, sounded as if only Nobel laureates optical microscopy, called which equals an accuracy of one would be able to understand it structured imagination, does not second to 13.7 billion years, but Prof. Haroche made it easy increase resolution much, but gives which is the age of the universe. for everyone to comprehend. a 3D image of the observed object. If you’re wondering if this is of He demonstrated quantum physics practical importance, the answer based on three questions about the William D. Phillips, the 1997 Nobel is yes. Because of this, the accuracy nature of light at the beginning of the Prize winner for Physics, had an of GPS measurement and the 20th century: Why does the spectral action-packed presentation titled satellite-based measurement of sea distribution of a heated body follow “Einstein, Time and Light” - levels and other altitudes has a bell-shaped curve? Why is there a a revolution resulting from Einstein’s increased from meters to a few threshold for the photoelectric E = m·c². Schools and universities centimeters. Why was this a relevant effect? Where do the discrete lines use liquid nitrogen for experiments, part of the Year of Light opening? in absorbed or emitted light come and using it as well, Prof Phillips Quite simply, the technology was from? The answers opened the way showed what the race for lowering only made possible by using light in to the world of microscopic atoms temperatures closer and closer to the form of laser based cooling. and photons and led to today’s absolute zero means. The boiling Mr. Philips concluded with a list of quantum physics that finally gave point of liquid nitrogen is -196°C or what this technology could be used the keys to modern technologies. 77 K and this, as Mr. Phillips said, for in the future in regards to light Using Schrödinger’s Cat thought “is the coldest stuff you’ve ever and cold matters. He mentioned experiment, he illustrated how seen”, but it is far from the better clocks, cold chemistry, quantum physics are challenging temperature that researchers are tests of the fundamental our common understanding. trying to achieve. In 1995, the lowest understanding of nature, quantum He emphasized that the strange temperature record was set at 1 µK. information, quantum computer behavior of quantum physics holds Since this breakthrough, many research, and quantum simulation. the key for new technologies for groups throughout the world He also said, “Perhaps the IYL communication and computing. routinely reach nK temperatures will inspire young people to think He explained that light extends with a reported lowest temperature of even more exciting ideas.” far beyond the visible range

The wave-particle dualiism of light, here introduction he concentrated on perfectly interpreted by solid-state lighting, giving an historic the artist D. Hofstadter, overview, starting with Oleg Losev is the basis of quantum who discovered visible light in a physics and was a core concept of silicon-carbide point contact diode Prof. Haroche’s lecture for the first time in 1923 - the first LED. Prof. Alferov continued with an introduction to semiconductor heterostructures, and super lattices, necessary for solid-state lasers and LEDs, and the Nobel Prize laureates in the related research fields. While being important for opening the way to fast fiber optical telecommunications via laser diodes and LEDs that can work at room temperature, heterostructures are also relevant for other applications like solar cells. Prof. Alferov pointed out the corner stones of the (radio waves, x-rays, etc.) and Cavity Quantum Electrodynamics, development of modern LEDs, went on to talk about the findings which aims to explain interactions mentioning the first pn-junction that led to this new world of between matter and light on a very laser and LED development. exciting new applications like fundamental level. Then he asked He commended the academic ultra-deep cooling and MRI. the question “why is this basic achievements of Isamu Akasaki, Basically, it was Einstein’s finding research important?” The simple Hiroshi Amano, and Shuji Nakamura that light waves are quantized answer is: Wanting to understand for inventing the blue, light emitting photons, Bohr’s finding that there how nature behaves on a certain diodes. One slide and side-note are quantized electronic orbits and level. This understanding finally were used to give a short overview de Brogli’s theory that electrons leads to new and modern of a color tunable monolithic have wave properties. The quantitative technologies and applications; multi-color heterostructure LED as formulations of these findings by applications that often even a next step leading to phosphor Heisenberg, Schrödinger and exceed the imagination of the converted LEDs. Besides the Dirac in the mid 1920’s finally researcher who did the basic commonly known figures on energy opened the door to today’s physics. work and the inventor of the saving and market penetration, Prof. Haroche showed the resulting new technology. he showed some very interesting strangeness of quantum physics facts about the Chinese goals of when he explained that sending Prof. Zhores Alferov led the targeting 70% SSL penetration in photons one at a time through audience through the world of 2020. This would cause an energy a double-slit leads to the same “Efficient Light Conversion and savings of 340B kWh/year - interference pattern as the Generation” [5], by citing George which equals four times the classical double-slit experiment. Porter from the Royal English production of the Three Gorges He also made the basics of Society of Science who said, hydroelectric power plant on the complex superposition “Science is always applied science; the Yangtze River in China. and entanglement topics don’t divide between basics and He also compared the potential understandable in his illustrative applications. The only difference is of heterostructure based silicon speech. He demonstrated the that some applications appear solar cells, especially in multi-junction influence of the environment on immediately, while others need configurations, with GaAs/GaInP experiments and showed why the time.” Prof. Alferov started with solar cells. Finally, he referred to the classical world observations don’t explaining about research on lecture of Prof. Chu, when he show the strangeness of the nuclear energy and weapons, showed the prediction for energy “quantum world”. Prof. Haroche namely the hydrogen bomb, sources in 2013 and said: “While it pointed out that tunable lasers, “which is basically a simulation of is always hard to make a prediction, today’s fast computers and the sun on earth” based on nuclear solar energy conversion made by superconducting materials are fusion. Despite being skeptical, photovoltaic semiconductor direct results of the understanding he is convinced that if there is a materials will definitely be one of quantum theory. Leading up solution for the commercial use of of the main energy sources. to “Schrödinger’s Cat” and nuclear fusion for power generation And semiconductor lasers and uncertainties, he spoke briefly to become reality, laser technology LEDs will be the main light sources about his own research, will play the key role. After his for many applications.”

John Dudley (left) and Joseph J. Niemela (right), two of the coordinators and initiators of the IYL, led a good number of the thematic sessions

Short Overview on the would exceed the objectives of This is seen to be the Thematic Sessions this article; therefore just a handful key for reducing poverty for The thematic sessions were of exemplary statements and an several reasons: Firstly, LED lighting segmented into “The International overall summary for each session in combination with photovoltaics Community of Light and Light- shall be covered here. helps people to save money. Based Technology”, “Lighting the It provides light in the evening and Future”, “Light for Humanity and There was one unmistakable major nighttime with no additional costs. Culture”, “Light on Development”, message in “The International Secondly, it allows children and “Light at the Limits, “The Future of Community of Light and Light- students to learn in the evenings Light” also called “Science Based Technology” session and thereby improve education in Frontiers”, “Light Solutions” which dealt with context, these countries. Thirdly, it helps to and “Science Policy”. More than challenges and opportunities in improve health and saves the 35 powerful speakers from different 2015 for the lighting community: environment because no kerosene disciplines and countries presented Affordable lighting for the or candles need to be burned in their views on these topics. underprivileged is essential, the quarters that release toxic An overview of all of the lectures especially in emerging countries. fumes. In addition, the need

Speakers from very different regions and disciplines held talks demonstrationg their commitment to the IYL. Just to name a few (from top left to bottom right): Charles Falco from the University Arizona, Danielle Harper representing the Int. Association of Physics Students, Alain Aspect - UNESCO Niels Bohr Medal Laureate, Sune Svanberg - former chair of the Nobel Committee for Physics, Eric Rondolato representing Royal Philips as CEO of the lighting sector, and Yanne Kouomou Chembo from the African Physical Society

for a better cooperation with of paintings and artworks visible. The subsequent sessions emerging countries was The cultural importance is also “The Future of Light” and “Science addressed. In this sense, marked by the fact that all the Frontiers” took up the thread by Francis Allotey from Ghana said, known geniuses devoted following the application path. “Africa missed several technical themselves to light. Probably the Alain Aspect from the Institut advances and trends but must not most outstanding person in this d’Optique did a thorough review on miss the photonics revolution.” context was Ibn Al-Haytham whose how and which basic research has findings and life were impressively yielded important applications in The session “Lighting the Future” reviewed by Charles Falco. many different areas of science and also addressed the topic of lighting technology. Bernard Kress from for the poor as well as other aspects The thematic sessions of the Google C-Labs provided an like safety, lighting of cultural second day started with the topic overview about their projects and heritage sites, lighting for improved “Light on Development”. In a developments that are based on quality of life or energy waste and mixture of lectures representing photonics technologies and light pollution. The contributors the broad view of this issue, research, and how they think these approached these topics from lectures were held presenting the applications could ease and improve different sides, taking philosophic, status and impact of optics and people’s quality of life, especially in pragmatic and exemplary views. photonics research in Africa, remote areas. Ways to fight The theme running through these as well as the impact of lasers as diseases with biophotonics was speeches was that lighting the medical instruments on societies the topic of Brian Wilson from the future means developing innovative by the example of the lives of University Health Network solutions that keep in mind the vulnerable communities in Vietnam. Biophotonics, while Sune Svanberg, various aspects presented and Sudhanshu Sarronwala from the former Chair of the Nobel providing light to improve the WWF in Singapore closed the Committee for Physics introduced quality of life. session with his report on the the audience to the history and history and status of the Earth Hour principles of the Nobel Prize and “Lighting for Humanity and Culture” campaign by demonstrating the the success story of light being covered lectures of a very different power of light as a vehicle to recognized numerous times for character. The tremendous point the way. this highest scientific award. significance of light in different cultures and for civilization was “Light at the Limits” was the The journey into “Light Solutions” impressively demonstrated. very apt title for the lectures that once again led the audience through For instance, Gianfranco Cardinal followed. The speakers gave an emerging countries. While Illac Ravasi gave an overview of what impressive demonstration of how Diaz from the “Liter of Light” light means in religions and how it studying the properties of light and “My Shelter Foundation” is interpreted. Light is not just a have led to breakthroughs in our demonstrated a simple DIY solution medium that passes knowledge understanding of the physical world. for bringing light to houses in and tradition from generation to They showed how limits were tropical regions without heating generation, it is also relevant for art, pushed further and further. them up, Martin Aufmuth from art history and art science. The results have proved to not “The OneDollarGlasses Association” For example, an artwork can be just be relevant for optical science, showed a business model that perceived differently depending on but also for new advances and provides affordable glasses to the light used. In addition, using understanding in fundamental ametropic people in emerging imaging technologies with different physics and multidisciplinary countries while giving local lighting can make invisible layers applications. individuals a business perspective.

The last program point before the official closing was a panel discussion about science policies with former and active ministers for science and technology, university members, and board members of the EC and UNESCO

Impressive artistic performances and artworks were presented to demonstrate the importance of light in different human cultures and ages. The spectacular showcase of “From Darkness to the World of Light” by the Ngati Ranana London Maori Club visualized the struggles of bringing light to the world. The film, “Einstein’s Light” from Nicolas Barris with the music composed by Bruce Adolphe and divinely interpreted by Joshua Bell on a Stradevari, accompanied by Marija Stroke on the Piano, honored Einstein’s contribution to today’s modern world.

A similar idea to provide affordable in 1015, is recognized as the father by Marija Stroke on the Piano, solar lights was proposed by Linda of optics. He invented the camera delighted the audience with his Wamune, representing “Sunny obscura, which is still the basis of divine interpretations of Bruce Money” and “Solar Aid”, from Kenya. today’s cameras. Adolphe’s compositions on a Stradivari. His three compositions The last session before the closing The performance “From Darkness for the film; “Light, Speed, Grace”, remarks was held as a round table to the World of Light” by the Ngāti “Einstein’s Sarabande - discussion under the title of Rānana London Maori Club, The Loneliness of Genius and the “Science Policy”. The participants visualized the genesis from Guidance of Light”, as well as were in agreement when they stated emptiness to the existing world: “Innovation - From Mozart, War, that the fruits of science have to At the beginning, the earth and to Flash of Scientific Insight” were have a long-lasting impact on the skies came into being through inspired by the importance of light. society, but at the same time the self-generation of Ranginui, emphasized that to facilitate this, sky father, and Papatuanuku, The Reception Cocktails were many issues and topics have to be earth mother. Ranginui and served in the Salle des Pas Perdus addressed and some problems Papatuanuku prevented light from of the “Light is Here” illuminated need to be solved. With their reaching the world because of their UNESCO building. The evening different backgrounds, they close embrace, and their offspring ended in a relaxed atmosphere that recognized that the North-South lived in a world of darkness and invited the guests to experience the cooperation needs to be improved ignorance between the bodies of exhibition. The opportunity to by promoting education in science their parents. They plotted against communicate and to come to know and engineering as well as driving their parents in order to let light into each other better was taken innovation and economic growth. the world. It is said that some of the advantage of by most of the visitors. They also agreed that a good sons decided that their situation The outside illumination was portion of civic engagement will could be remedied only if they designed and implemented by be necessary. Naledi Pandor, separated their parents, so that the Finnish artist Kari Kola who Minister of Science and Technology Ranginui would be pushed up to transformed the facade of the of South Africa reminded the become the sky and Papatuanuku building into the Aurora Borealis. audience that emerging countries would remain as their Earth. and their research institutes, When they set about their task, even if they have the prerequisite it was Tane who finally got them Closing Remarks capabilities and resources, are not apart by resting his shoulders on The opening ceremony for the recognized as possible partners in Papatuanuku and thrusting his legs International Year of Light and Light projects. She also pleaded for a upwards and pushing Ranginui to Based Technologies in Paris was a kind of emancipation of emerging the sky. By this separation of brilliant start. It opened everybody’s countries, Africa, in particular. Rangi and Papa the world of light, eyes to the different meanings of of existence, the third state of light. Even though it was a festive creation, came into being. event, the speakers also addressed Supporting Program and The impressive rendering of this serious topics. The program Artistic and Cultural Acts myth demonstrated the global and covered all possible aspects of light Different session topics of the first universal relevance of light across from fundamental scientific research day were not just addressed by different cultures. to applications, art, culture and lectures, but also visualized with social and political consequences. artistic performances, exhibits and Equally impressive was “Einstein’s It gave a first overview of what else installations. With the 1001 Inventions Light”, impressions of images and can be expected from upcoming and the World of Ibn Al-Haytham music. The tripartite film, “Einstein’s events celebrating the Year of Light Campaign, the life of this Light”, from Nicolas Barris and 2015. It will be well worth keeping outstanding scientist, inventor, Imaginary Films was a fantastic our eyes open for the numerous architect and artist was honored arrangement of film sequences, events around the world and and the world of photonics images, documents, and artworks attending as many as possible. presented. Al-Haytham, who from and around Einstein’s life and published his “Book of Optics” work. Joshua Bell, accompanied

References: [1] “Light and Life”, Ahmed Zewail: http://www.youtube.com/watch?v=FxHkAoAFGHs [2] “Energy and Climate Change”, Steven Chu: http://www.youtube.com/watch?v=P59f8x6Xgg4 [3] “Einstein, Time and Light”, William D. Phillips: http://www.youtube.com/watch?v=eodXu0t78ns [4] “Light and the Quantum”, Serge Haroche: http://www.youtube.com/watch?v=_7D5SlYa28g [5] “Efficient Light Conversion and Generation”, Zhores Alferov: http://www.youtube.com/watch?v=BOuHWzUEUXw

Some of the exhibits from the “1001 Inventions and the World of Ibn Al-Haytham” campaign were on display in the Segur Hall of the UNESCO building, creating an inspiring ambience for the “Evening Cocktail Reception”. Contemporary light art was presented in the exhibition area and Finnish artist, Kari Kola, re-created one of the most fascinating natural light phenomena, the Aurora Borealis, to illuminate the façade of the UNESCO building

Ewing Liu Ewing Liu is the Technical Marketing Manager at Everlight Americas, Inc. After completing his education at the University of Texas he joined Everlight as a Strategic Account Manager. He is well versed with a variety of Everlight products, technologies, global market performance and trends.

LED manufacturers have different strategies and approaches for their product portfolios depending on from which business they are originated. Everlight has a very long experience in optoelectronics as packaging company. Accompanied by Christopher Keusch, Director of Lighting Business EMEA, Ewing Liu, Technical Marketing Manager at Everlight, talks about about the background of the company, the worldwide strategies and upcoming techologies.

LED professional: Could you give Ewing Liu: Yes, our main business lifetime to be at a certain level there us some background information is packaging and we are vertically is a cost advantage. You can use a about Everlight? integrated with Epistar. 75% of the different type of LED and different chips we use come from Epistar. type of packaging material. So there Ewing Liu: Robert Yeh founded Our largest segment is backlighting is a cost lifetime trade-off depending Everlight in 1983 to manufacture, at the moment. This includes TVs, on the market. I think for large market and sell LEDs. In 1983 we laptops, cellphones and even manufacturers with billions of pieces started with visible LEDs and a year navigation units. That is about 25% per month, the quality level is on a later with IR LEDs, photo couplers of our business. The next largest set path. Unless we drastically and other products. This enabled us would be our infrared business change a chip, material or bonds to be a complete optoelectronic - which is about 22% and then there will not be a big difference manufacturer. We have between lighting comes in at about 13% to in reliability. 5,000 and 6,000 employees 15%. We also do a little bit of worldwide and that makes us one of automotive and signage. The rest LED professional: There is a trend, the largest LED manufacturers in are standard commodity indication also due to cost optimization, to Asia. Mr. Yeh has a background in type LEDs. In 2014, Everlight was eliminate the package entirely and production and is responsible for a ranked 8th in the world by a market just put the dye on the substrate, lot of Taiwan’s LED market. For survey and showed the highest directly on the heat sink. Are you example, Epistar, the largest chip growth in the industry across all also moving in this direction? manufacturer in the world, only areas. Most of our growth comes made 4 element chips at first. When from lighting. Ewing Liu: In the overall scheme of everyone started to shift towards 3 things Everlight’s focus is still on element InGaN chips Epistar didn’t LED professional: Cost reduction, components but Everlight does have have the capital to buy MOCVD longer lifetimes and higher a lighting fixture business. In the machines. Robert Yeh stepped up efficiencies are always a topic for USA and Europe it is called Zenaro. and supported Epistar in terms of industry. What are the main In China it is called Everlight Solid creating the blue LED business. packaging trends and challenges? State Lighting. So we are headed in If that hadn’t happened, the white that direction. It has to do with LED business would be very Ewing Liu: Cost is a given since survival because at some point different, right now. Mr. Yeh was on everyone tries to make bigger profits there won’t be too much demand the Board of Directors of Epistar for so the price per component has to for packaging in lighting, with the quite some time and he’s also the go down. Longer lifetimes are not exception of very low-cost products. owner of Everlight. In 1990 Everlight necessarily true any longer for a lot It takes huge capital investment to was publicly traded on the Taiwan of lighting products. Of course there be able to do chip on heat sink or stock exchange. Since Epistar is the are different segments in lighting; chip on substrate and no one has largest chip manufacturer in the you have consumer products, the capacity to do it on a large scale world and we are one of their largest professional lighting type products as yet. It might not even make sense customers, this enables our and industrial type products. You in terms of the investment into capacity to be one of the largest in may have to maintain a high lifetime facilities and labor. the industry as well. By the end of for professional and industrial November 2014 we were selling 4 products, but for consumer Christopher Keusch: We have billion LEDs per month. products reliability is not a main developed all the packaging issue anymore. It is all about cost. technology at Everlight and this is LED professional: Everlight’s main For example, everyone wanted a still our focus, but we have business is packaging. What are the minimum of 50,000 hours for a light discontinued the so-called ‘old main fields of applications that you bulb and this came at a certain cost packages’ with high thermal supply to and what is the but people are now dropping down impedance or high thermal approximate share for each in terms to 15,000 hours, and for some resistance because they didn’t of lighting, medicine, displays and specific cases they only require provide the required efficiency. so on? 8,000 hours. When you allow Therefore, all of the LED packages

modular and flexible. We set some parameters but in the lighting market everybody wants something slightly different. Each application is very different so it usually depends on what the customer wants. We select a particular chip, lead frame, specific package material and phosphor to create a combination that works for the customer. The lighting industry moves too fast for us to have one set LED with a very clear family line.

LED professional: How big do the volumes have to be for customization?

Ewing Liu: It is quite easy if it is just a matter of switching out a smaller chip for a bigger one so that it’s a bit brighter and customers can underdrive for higher efficiency. We can open that up for a particular customer. As an example, we have started to serve low power packages with high CRI since we see a trend towards more light quality. We can easily follow this trend and simply adapt the phosphor that we developed for the low power, to COBs with high CRI - it depends on what the customer Ewing Liu brought currently provided have an internal efficiency applications that need wants. Our marketing team also brand new demo samples of Everlight’s heat slug that allows the chip heat better thermal resistance and maps out what the requests could latest products. The to be transferred directly to the heat better thermal dissipation. If the be from the market. For example, Color Choice® Series sink. A metal piece located right product is more cost conscious, most requests for CRI 90 come from makes designing CCT underneath the chip allows the chip we switch to a newer version that Europe and mid–power mainly comes tunable luminaires easier to dissipate heat directly to the heat is not thermally isolated and we’re from Europe, Korea and Japan. sink. In earlier designs, heat had to dissipating the heat through the travel all the way through the heat anode or cathode. That’s the LED professional: What is the base frame and this has been eliminated. main difference. A lot of the cost material, the substrate and package We can achieve 30% to 40% better conscious products won’t need itself and will that change? thermal resistance with this design. thermal isolation because they can have a higher case temperature Ewing Liu: We are right in the LED professional: How do you for the LED for a lower cost. process of very large changes decide whether to have a separate Those with long lifetime, high- with packaging material because or integrated heat slug with the grade product requirements of the different design trends cathode? What are the pros and might choose the heat slug. and directions on the market. cons and are they application Both directions mainly go towards specific? LED professional: Do you use more cost effective products. single dies or multiple dies in a First we have to make the package Ewing Liu: When you have a package? smaller - the less silicon or thermally isolated lead frame like a phosphors you need to fill the heat slug, the cost is slightly higher. Ewing Liu: There are many different cavity - the lower the cost. So cost is one consideration. types of combinations. Everlight has We’re going from sizes like 5630, For many of our low to mid power one of the largest capacities on the 3528, 3020 right down to 2016 type components, we originally started market so it is hard to have a single, sizes (2 mm x 1.6 mm) this is a very with thermally isolated products focused product or combination for small LED with a low to mid power and it still remains for a lot of higher any type of LED. We are very chip in it but you save a lot of the

packaging costs. When that happens LED professional: Another aspect is how you have less thermal dissipation. tightly packed the LEDs are to get a low A standard PPA type of material might light emitting surface. Currently it looks not be sufficient enough for some like ceramic is the first choice for tightly lifetime requirements so we may need packed systems. Is that also your view? to switch to a higher grade chip or we may need to switch to a different Ewing Liu: COB is one way that everyone type of packaging material to dissipate is trying to get a smaller LES. Cree has heat from this chip so PPA goes to one that is 6 mm and Everlight has one PCT with better heat dissipation. that is 5.7 mm. For a lot of the But these are still in the plastic realm. professional lighting products where you Another realm is called thermal molding; have to pair secondary optics, the smaller either epoxy molding compound (EMC) the package, the more lumens you can or silicone molding compound (SMC). get. Everlight is doing that with our next There, thermal dissipation is significantly generation of COBs. There is another better than PPA and PCT. Everlight is concept of a smaller package with higher focusing a lot more on thermal molding power called CSP or chip scale because performance is a lot better packages, where the substrate is than plastic but price is not much higher. 1.1 times the chip size used so you can So everything is going in that direction. make a very small LED. With that you But in the next stage you want even have a lot of design flexibility. You can better thermal dissipation and ceramic use one at very high lumens with optics, materials are probably the highest level and control the light whenever you want you can get for an LED lifetime or or put a cluster together to have even reliability using a ceramic substrate. more lumens from a small LES. Those are We offer all of these materials because, the two directions we are going to reach especially with ceramics, there are smaller or higher lumen density. different types of applications. Our complete portfolio includes low, LED professional: Are you thinking about mid and higher power LEDs and adding other components to the LED like COBs some with the EMC package optics, intelligence or drivers? What will already implemented. The size is come next? smaller but we can still achieve 0.06 W to 0.5 W and potentially up to Ewing Liu: I think for the European 1 W with the 2016. The higher the market there is more need for “value wattage, the better the material you added”. Labor here is more expensive and need to use. But because it is so small it would be easier to buy a board with it will still be more cost effective. LEDs and optics designed in the Larger manufacturers like OSRAM application. They can just put it into the and Philips who are very interested assembly and it becomes a fixture. in these packages, also support That is a high demand from countries this trend. where labor is expensive. Everlight is not going in this direction right now but we Another design trend is to increase the have the capabilities if the need arises. power of the package itself. This allows the customer to overdrive the package LED professional: High voltage for more lumens while maintaining good components were also mentioned. What performance. That means the lumen is your view and understanding of this? per dollar is a lot higher. So it is still the COB philosophy but instead of putting Ewing Liu: This whole idea initially started it on an aluminum or ceramic substrate because the pressure on we package it like standard LEDs in a LED components was too much. 5050 type of package made of EMC. Dropping 30% to 40% per year in terms This can drive from 3 W all the way of component cost is too much and up to 9 W or 10 W and because standard causes a lot of manufacturers to drop EMC packaging material is a lot more out; mainly the competitors from China cost effective then COB ceramic or that came up so quickly. They are trying aluminum, you have a much better cost to slightly take attention away from vs. performance, high power product. component cost. The driver is a big cost, This is on our latest roadmap. especially for consumer products.

Using high voltage LEDs you don’t LED professional: Is 48 Volts color temperature you want. need to down convert or transform the maximum? Other manufacturers make similar the different voltages as much. products. Ours is circular because At Everlight, we approach it from a Ewing Liu: It could go higher the final application in usually a high voltage DC perspective so you but the price scheme would be a spotlight using a round reflector. still need a bridge rectifier to lot higher. Epistar has 50 V, 70 V Sharp, for example, uses a silicone convert AC to DC but from there and even a 110 V chip. dam in- between each color. you can go directly to a string. We don’t have anything in-between. This saves a lot on the converter Christopher Keusch: It should be We have a patented way of putting in the driver. For about 120 V you mentioned that there is a low the phosphors right next to each might need forty 3 V LEDs but voltage directive of 50 V so a lot of other and keeping it separate so we have chips with packages for manufacturers have to consider that that everything can be shrunken 30 V or 48 V so all you need is they may exceed this directive. even further. three or four LEDs. But more customers now have the competencies to do proper isolation LED professional: Many major LED professional: Are single dies in in order to allow using higher players in this market are now series within the package or is it the voltages. The low voltage directive is looking at added value in the monolithic chip approach? a hurdle but also an opportunity to electronics provided. Right now the build up competency. products have a very high quality Ewing Liu: Actually, both concepts and standard. Lifetime, reliability, exist. We use monolithic Epistar Ewing Liu: Every direction we have color aspects, etc., are very chips for our 30 V or 48 V HV LEDs, talked about so far has been for important in the European market. but we have also LEDs with slightly cost-down, smaller packages, One of these trends is Human higher voltage compared to multiple chips and higher lumens Centric Lighting with controls, standard LEDs. These are 6 V, 9 V per dollar or high voltage LEDs to sensors, drivers, and so on. or 12 V packages consisting of reduce costs on total lamp cost What are your comments about multiple single chips which we through the driver. All have been this trend? connect in series inside the package. cost driven types of designs. In the next 2 to 3 years there will be an Ewing Liu: This is true because Christopher Keusch: For example, overhaul of lighting manufacturers. the European market has to justify for a high voltage bulb consisting Some might go out of business or a higher price compared to Asian of 30 V LEDs, basically the benefit naturally pull out because the competition and they have to find is you can save drastically on driver margin is so low. their way in this very competitive cost using linear driver technology business. However, since we are a instead of the old driver concept LED professional: Could you tell us components manufacturer we with components that wear out a more about tunable white COB would like to serve these luminaire lot faster. For instance, capacitors technology? manufacturers within Europe and tend to dry out. This doesn’t happen we would like to provide them with with linear driver technology. In fact, Ewing Liu: This is also in the concepts and solutions to stay we have high-end customers, even category of higher ASP (Average competitive so that they can provide in Germany, who developed linear Selling Price) for professional lighting this added value. Our core driving technology simply following markets. In retail applications, competency is packaging and our the concept of using a lot of LEDs in you will often see a mixing of warm job is to do it as well as possible series or using high voltage LEDs in and cool white lamps. Or they might and meet requirements in terms of order to connect them to main turn different lamps on at different efficiency and competitive prices. voltage. Some customers have times of the day. Using this type of eliminated ripples by these kinds COB technology, all you need is one LED professional: Thank you of driving technologies. lamp you can create any type of very much.

RESEARCHCATEGORY DC SUPPLY GRIDS FOR LED LIGHTING 48 Direct Current (DC) Supply Grids for LED Lighting

Since many alternative energy sources as well as electronics and controls technologies are based on DC current, DC grids have been investigated more intensely in the last decade. DC grids with a centralized AC/DC conversion have proven to be advantageous in server farms. While LED lighting is also a DC current related technology, an obvious choice would be to use DC grids for them. Prof. Eberhard Waffenschmidt from the Cologne University of Applied Science in conjunction with Philips Research presents the results of an office building DC lamp system installation with photovoltaic (PV) support.

Most electrical devices First, the component effort Introduction operate on direct current (DC) for solutions with AC and DC One trend in lighting is to distribute internally, but are supplied current supply is compared. light sources. This becomes by alternating current (AC). LED-lamps can especially possible with LED lamps, which A power supply with DC benefit from a DC supply offer a small amount but efficient makes the rectifier electronics because lamp drivers can light power. However, this also unnecessary. This makes the be reduced to a few reliable requires efficient lamp drivers. devices simpler and more components and then a Furthermore, assigning each lamp reliable and generates less loss breakdown including its individual lamp driver becomes a power losses. When many transmission losses is high effort in material. Therefore, identical devices like lamps in presented. The major concepts are needed to deal with an supermarkets or open offices advantage of a DC supply increased number of similar lamp are operated, this becomes appears if a micro-grid drivers. One solution could be to especially evident. including decentralized energy use a DC power supply. This makes generation and storage is omission of the rectifier electronics This publication aims to show considered. In addition, possible, which, in turn, makes the solutions of DC operated standardization initiatives devices simpler, more reliable and professional buildings like working on high voltage DC generates less power losses. This is offices or supermarkets and grids are listed. Finally, an attractive especially in installations homes. A special focus is put implemented office test bed where a high number of lamps are on high voltage supply at including DC LED illumination connected to a power rail, like in 380 VDC. and photovoltaic (PV) support open space offices or supermarkets is presented. (Figure 1). Each lamp contains an AC to DC conversion circuit, which can be omitted with a DC supply rail. This becomes particularly attractive if the system is combined with a local photovoltaic generator, as shown in [1].

DC supply systems are proposed by a number of publications especially for residential applications, e.g. [2] [3]. But as derived in [4], a large variety of different requirements for different devices, a DC system for residential applications faces even larger challenges. Contrarily, in

Figure 1: Lamp installations in open office space (left) and supermarkets (right)

lighting applications the loads are Space and components As discussed, these components quite similar in their requirements saving might also be necessary for DC and thus much better suited for a Figure 3 shows a photograph of a operation. An overview of this is common DC supply. Philips Xitanium lamp driver for a shown in table 1. The bridge 39 W light emitting diode (LED) lamp rectifier may be necessary to as used in the reference setup. allow an arbitrary connection of Effort for AC to DC In the figure, all parts that are the DC supply leads. However, Conversion necessary for AC to DC conversion, this problem may also be solved Figure 2 shows the block diagram are marked. As can be seen, by a suitable mechanical coding of of a typical lamp driver operated approximately 40% of the printed the plug to avoid a wrong on AC with the parts necessary circuit board (PCB) is occupied by connection. The elcap may be for AC to DC conversion. these components. Especially the needed to suppress voltage dips of Similar components are necessary PFC and the filter circuit require a the DC supply. However, it should for all AC power supplies. lot of space. The storage elcap is be acceptable for lamps to pass also significant, but the bridge the dips to the lamp and allow a The rectifier is the essential element rectifier itself is a comparable short flicker. Then an elcap is and is typically a bridge rectifier small component. not necessary. consisting of four diodes. Figure 2: The electrolytic capacitor (elcap) Typical AC lamp driver levels out the pulsating rectified sinusoidal voltage. Recently IEC SC77A WG1 agreed to a new review of the standard IEC 61000-3-2, which means that in the near future lamp drivers with more than 5 W will require a power factor correction (PFC) circuit. A PFC ensures that Figure 3: the current drawn from the grid is Power driver for a 35 W sinusoidal. The PFC may consist of LED lamp an inductor, but this is usually too bulky. Especially for higher power levels a switch mode converter, typically a step up converter (boost converter) is used. However, this requires a filter to avoid higher frequency content generated by the switched mode PFC polluting the grid.

Table 1: DC wide voltage range DC narrow voltage range, Overview of required Component AC supply and reverse polarity protection mechanical rev. polarity protection components for AC to DC conversion Required because Filter Required because of DC-DC Can be omitted with linear driver of PFC

Rectifier Required Required for reverse polarity Omitted

Power factor correction Required Required to match wide Not necessary (PFC) / DC-DC converter for P > 25 W voltage range

Required to avoid Can be omitted, if dips are Elcap storage Required because of dips flickering accepted

Figure 4: Power and loss Linear LED driver characteristic of The advantage of a lighting DC a linear current supply becomes most obvious with controlled LED driver LED lamps. A most simple “driver” for an LED is simply a resistor. If the supply voltage is very well defined, this would be the most simple, reliable and durable “lamp driver”. However, if the voltage is less stable, the brightness of the LED would vary remarkably, because a small voltage variation would already lead to big changes of the output power.

A solution, nearly as simple, is a linear current driver. A linear current source can easily be built with Figure 5: Loss comparison of AC one J-FET and one resistor. grid (a) and DC grid (b) The efficiency of such a circuit is good and is calculated assuming a

constant forward voltage Ud of the LED and neglecting a residual voltage drop at the FET. The results are presented in figure 4. As long as

the DC supply voltage Us is larger than the forward voltage U , Figure 6: d Loss comparison of the LED power (blue) is the nominal AC grid (a) and DC grid value. If the supply voltage increases (b) with photovoltaic above Ud, the voltage across the and battery storage FET rises linearly. The power loss operation in the FET (orange) increases proportionally to it. Efficiency (yellow) is calculated from the LED power and the losses.

If the voltage variation is within

±10% of the nominal voltage UN (like in the public AC grid), efficiency can still be above 84%. This simple and reliable circuit can thus achieve similar efficiency to small-switched mode converters, as long as the voltage range is narrow enough.

Loss savings If the DC supply voltage has a large If the lamp driver itself uses The components needed for AC to variation, it may be necessary to switched mode conversion, DC conversion also generate losses. convert it to a constant level of an it remains necessary. However, Typically, the smaller the device, the intermediate voltage. This requires a with a linear lamp driver, even the lower the efficiency. Our own DC-to-DC converter, similar to an filter may be omitted. measurements showed losses in the active PFC. However, if the DC order of 5% of the output power for voltage range has a narrow In conclusion, the components lamp drivers. This arrangement is specification the DC-to-DC needed for AC to DC conversion shown in figure 5a. These losses converter can be omitted. can be omitted if the DC power can be avoided if the device is plug is mechanically coded, operated on DC. But if the AC grid The filter is necessary to suppress if dips can be accepted, if the supplies the DC grid, an additional high frequency contents of switched voltage is specified in a narrow central rectifier is needed. However, mode converters. It becomes range and, optionally, if a linear this central rectifier can be more necessary if an active PFC is used. lamp driver is used. efficient due to its larger size.

Figure 7: Its losses are estimated at about 2% Comparison of cable of its output power, as illustrated in losses for different figure 5b. In addition, cable losses supply systems. can be reduced if a DC voltage of Losses are scaled to 230 VAC. Cable losses 380 V is used, as shown in figure 7. are equivalent to the In total, losses of about 5% of the amount of copper that output power could be avoided is needed to achieve identical losses for using a 380 V DC grid. the different voltages. Remark: 380 VDC Even larger loss savings can be requires similar achieved in a different use case as insulation to 230 VAC illustrated in figure 6. It shows a system that is optimized for self-consumption of photovoltaic (PV) energy. The PV energy harvested during the day is stored Table 2: in battery storage and used in Organization Topic Overview of the evening. organizations working Many standards covering low voltage DC grid systems on standardization of already If all components are connected low voltage DC grids to the AC grid, losses in the AC to International SMB SG4 working group “LVDC distribution systems Electrotechnical up to 1500V DC”: Managing new standardization DC (and vice versa) converters Commission (IEC) projects at IEC technical committees (TC) end up to be 10% to 13% of the National standardization working groups. Germany: output power (Figure 6a). In a TBINK-LVDC working group at DKE/VDE DC system, these losses can be completely avoided (Figure 7b). European European standard: EN 300 132-3-1 V2.1.1 (2012-02) Telecommunication Reference [5] shows a similar Standardisation Value: Definition of DC appliance inrush current limits result for such a system, where Institute (ETSI) and measurement setup operation including PV and Standardization working group on 380 V DC power battery is considered. grids for datacenters EMerge Alliance Standardization working group on 380 V DC for campus and microgrids Voltage Selection The supply voltage of the DC grid also has an influence on the losses. It is clearly seen that the low Standardization on Low voltages like 24 V or 48 V have voltages of 24 V and 48 V either 380 V DC the advantage of being safe to touch generate extremely high losses or The voltage level of 380 V DC is and commercially available devices require significantly more copper. not only attractive for lighting exist. However, to transmit the same It also shows that a 380 V DC applications, but also for other power, much higher current I is supply generates only about 1/3 of applications like the power supply necessary compared to 230 V AC. the losses compared to 230 V AC. in data centers. A standardized A high DC voltage like 380 V is It should be noted that insulation DC supply system will produce the compatible to many 230 V AC properties of 230 V AC cables are most advantages. Table 2 gives an devices, which operate on a similar also suitable for 380 V DC operation overview of the organizations that intermediate DC voltage internally. because they need to withstand work on standardization and the peak voltage. their current work.

The power loss Ploss in the cable is proportional to the square of the This safety issue is discussed with 2 current I: Ploss ~ I . Figure 7 shows other safety issues in more detail in DC Lighting Demonstration the cable losses that appear at reference [6]. It concludes that Setup different supply voltages, scaled to operating at a DC voltage of less To demonstrate the functionality the losses at 230 V AC. To achieve than 380 VDC can be considered and to experience the problems the same losses at higher currents, similar to operating at 230 VAC. related to it, a DC lighting the cable cross sectional area A A further safety aspect of DC grids demonstration is set-up in an office must also be scaled proportionately discussed is arcing, which mainly building at Philips Research in to the current: A ~ I2. Therefore, the appears when a load is unplugged Eindhoven, The Netherlands. same figure 7 shows the amount of during operation. Therefore, copper that is necessary to achieve one must take care that lamps are Figure 8 shows a schematic the same losses as with the 230 V not exchanged during operation overview of the system. AC supply. in a DC system.

Figure 8: DC-grid demo A 230 V AC system is also in installation with solar operation as a reference. Here, support and an AC the PV power is directly fed into reference grid. the mains grid. Furthermore, Grid voltage: 380 VDC, Solar modules: 2 kWpk, 18 comparable AC operated LED lamps: 56 x 37 W, Xitanium LED lamps are monitored. adapted LED drivers, Reference system: In the DC system the energy drawn 230 VAC from the mains grid is monitored. In the reference AC system, the energy needed by the lamps (including drivers) and the energy generated by the photovoltaic system (grid feed in) is monitored. To get a comparison, the needed lamp energy in the AC system is scaled to the number of lamps in the DC system. The generated PV energy in the AC system is scaled to the size of the DC PV system and finally both values are subtracted to achieve a net energy Figure 9: Photos of the reference demand comparable to the DC system: Photovoltaic system. Data was measured from panels (left), LED- April 29th, 2013 until Sept. 6th, 2013. Lamps (right) The average power was calculated from the monitored energy. The results are shown for the DC power demand and the scaled AC power demand in figure 10. There are two gaps in the data resulting from failures and maintenance time, which are not considered for the final comparison. Figure 10: Comparison of total The figure shows that the power consumption in the demand of the DC system is DC system and the always lower than that of the AC reference system. comparable AC system. In total, The energy in the AC system is scaled to the the DC system demand was DC system 2132.6 kWh, while 2181.4 kWh relate to the scaled AC system. In conclusion, the DC system energy demand was 2.24% lower than the comparable AC system.

Conclusion Operating lamps and other devices with a residential DC grid offers two major benefits:

The DC part operates on 380 VDC illuminate the floor and are switched Overall power losses can be and consists of a rectifier, a 2 kWpk on during working hours throughout reduced. However, for a supply of photovoltaic (PV) generator and the day. In the best case, the PV the residential DC grid from a public 54 LED lamps with 37 W each. generator is able to supply all the AC grid, this effect is partly The lamps are driven by lamp DC lamps. No feed in of PV power compensated by losses in the drivers, which are adapted to the into the AC grid is provided. central rectifier. But energy savings DC system. Figure 9 shows The lamps are Philips Xitanium become especially visible with the photographs of the PV panels and of lamps, with drivers modified for integration of additional local some of the lamps. The lamps DC operation. power sources.

As a further benefit, complexity From a system point of view, The specification of a DC system can be reduced in the powered it is advantageous to make should take these benefits into devices by shifting it into the those devices, which are account: To reduce losses in the infrastructure. This can make the needed in large numbers as distribution system and the voltage devices more durable and reliable. simply and cheaply as possible should be as high as possible. Especially for mass products and to allow a few central devices For lamps, an operating voltage like lamp drivers and consumer to be more complex. This cost like 380 V DC is proposed. devices, which are manufactured advantage should be considered To allow the reduction of complexity, and used in a huge number, as the main benefit of the the definition of a narrow voltage this will reduce the overall cost. DC system. tolerance is required.

References: [1] Ulrich Boeke, Matthias Wendt, Lennart Yseboodt, “Combined Solar and AC Mains Powered LED Lighting System”, 14th European Conference on Power Electronics and Applications (EPE’11), Birmingham, United Kingdom, 30. Aug. - 1. Sept. 2011. [2] T.-F. Wu, Y.-K. Chen, G.-R. Yu, Y.-C. Chang, “Design and Development of DC-Distributed System with Grid Connection for Residential Applications”, 8th International Conference on Power Electronics - ECCE Asia, May 30 - June 3, 2011, The Shilla Jeju, Korea, paper no. TuF1-4. [3] Rakwichian Wattanapong, “Community Smart Grid for ASEAN Decentralize Power”, Presentation at World Alternative Energy Forum, Chiang Mai, Thailand, 12.-14. Dec. 2012. (Online available (29.6.2014) at http://www.adicet.cmru.ac.th/waef2012/) [4] Bernhard Scheeren, “Optionen für eine Gleichstromversorgung in einem Wohnhaus“, Masterthesis at Cologne University of Applied Science, Institute for Electrical Power Engineering, Cologne, Germany and Zuyd Hogeschool, Heerlen, The Netherlands, 16. April 2014. [5] Suponthana Wuthipong, „MW Scale Stand-Alone PV Hybrid Mini Grid System”, Presentation at World Alternative Energy Forum, Chiang Mai, Thailand, 12.-14. Dec. 2012. (Online available (29.6.2014) at http://www.adicet.cmru.ac.th/waef2012/) [6] Jung-Hoon Ahn, Dong-Hee Kim, Byoung-Kuk Lee, Hyun-Cheol Jin, Jae-Sun Shim, “DC Appliance Safety Standards Guideline through Comparative Analysis of AC and DC Supplied Home Appliances”, Journal of Electrical Engineering & Technology Vol. 7, No. 1, 2012, pp. 51~57, (Online available (29.6.2014) at: http://dx.doi.org/10.5370/JEET.2012.7.1.51)

The evolution of dimmable LED lighting is an ongoing subject and phase-cut dimming is often dissatisfactory. While some weaknesses may be acceptable in residential applications, they are definitely not acceptable in professional applications. Stage lighting, studio lighting, TV and movie lighting set the highest standards. Craig Sharp and Bill Trzyna, Research & Design Engineers at CCI Power Supplies LLC discuss which developments helped to overcome limiting obstacles and led to a solution that also satisfies stringent requirements.

Stage lighting has always been one of the most progressive and advanced lighting applications. Using a vast number of different filters for accurate color appearance or unlimited light levels from zero to full brightness to support different scenes are examples of this. Some of these tasks have become simpler with LED lighting, but others, like dimming, have become more complex and challenging. It comes to no surprise, then, that stage, studio, architectural, and other high-performance lighting professionals are about to raise the curtain on full-range LED dimming again. This giant leap was recently made possible by the introduction of a new LED power supply dimming technology being studied and adapted by LED lamp and fixture manufacturers.

Figure 1: Stage lighting is certainly one of the most challenging tasks. Correct light distribution and light level are necessary to highlight the graceful moves of a ballerina

Early Days of Dimming Phase-cut dimmers can operate on operation. The dimmable LED fixture With the advent of the electric light, the leading edge (forward phase-cut) has to provide this load current even the need for dimming was immediate. or trailing edge (reverse phase-cut) at low line voltage, which is contrary It was easy to turn down the lights of the waveform. Forward phase-cut to the improved efficiency of the LED with a simple valve when gas developed naturally from the compared to an incandescent lamp. illumination was the rule. But those thyristor behavior. The SCR or new-fangled electric lamps posed TRIAC is triggered to turn it on and Because of these limitations a challenge. The first method it turns off when the waveform dimming LED fixtures with existing commonly in use placed jars of crosses zero voltage. Reverse phase-cut systems were generally salt water in series with the lamps. phase-cut dimming was developed unsatisfactory. Dimming below 30% The electrodes could be withdrawn to improve performance of low brightness was unreliable. Fixtures to vary their resistance and throttle voltage halogen lamps operating on would pop on as the dimmer control the current flow to the lamps. an electronic transformer, a type of was advanced. Sometimes the In 1890 Granville Woods invented switch mode power supply. fixtures would behave erratically, the safety dimmer, a form of cycling between zero and full resistance wire rheostat Let’s look at some of the challenges brightness. To overcome these (flow control), which persists in in controlling LED lamps with limitations, technology developers some installations to this day. phase-cut dimmers, because this have looked to digital methods for Both of these methods generated technology has dominated the LED dimmable control. In many a tremendous amount of heat market for decades and there’s a fields of engineering, digital and sometimes caused fires. huge installed base of these dimmers. innovation has often removed In 1933 General Radio announced barriers to improved product the invention of the Variac Simple phase-cut dimmers are performance and application cost. (a contraction of vary AC), connected in series (two wires) with Could a digital solution similarly a continuously adjustable an incandescent lamp and can only be written for LED dimming? autotransformer. This was a major draw power for its electronics during improvement in dimmer technology, the period when the AC line is cut substantially reducing the power off. This is when there is voltage The Digital Dimming wasted in comparison to resistive present across the dimmer. Dilemma dimmers. However, like the rheostat, More sophisticated dimmers require Both dimmers and drivers have it is a mechanical device that more power for their electronics and various requirements that must be adjusts slowly. have an added wire (three wires) met so as to achieve smooth LED provided to power their electronics. operation. Digital dimmers are one A dimmable LED fixture has only the of the toughest problems to solve Phase-Cut Dimming two wires from the dimmer to with LED lamps because the In 1959 Joel Spira invented the provide power, without the benefit microprocessor requires power even SCR (silicon controlled rectifier) of the full line voltage being present while the dimmer is off. This results controlled dimmer and a year later during the cut off part of the phase. in a small current, typically around Eugene Alessio announced a TRIAC Thyristor based dimmers require a 20 mA that needs to flow through the (Triode for AC) controlled dimmer. minimum load current for proper lamp when the light should be off. These thyristor-based controls are Figure 2: the mainstay of dimmer technology The relative light output today, although the IGBT (Insulated curve of a digitally Gate Bipolar Transistor) is used in controlled LED dimming some of the newest dimmer designs power supply fails to produce the low-end, because it is an easier device to full-range “S” curve drive and control. that is characteristic of traditional incandescent dimming. All of these devices work by cutting This has been off part of each half cycle of the AC characteristic of LED line waveform. The amount that’s dimming attempts to cut off is measured by the phase date angle. A complete sine wave is 360 degrees in length; a half wave is 180 degrees. If the dimmer cuts off 90 degrees of each half cycle, the effective voltage applied to the lamp is reduced by half because only one half of the waveform or 180 degrees remains.

Figure 3: A recently introduced line voltage. The relationship LED dimming between the PWM signals and technology produces effective line voltage is defined in the an “S” curve that microprocessor programming to emulates the light output of traditional produce the desired dimming curve. incandescent dimming. Importantly, low end When an AC line dimmer is set dimming for scene for low brightness, the effective exits and transitions is closely emulated voltage applied to the fixture is low. Because of this, the power supply in an AC line dimmable fixture has to operate down to extremely low input voltage. It also has to provide a minimum load for thyristor phase- cut dimmers or they will malfunction. Another challenge is suppressing electromagnetic interference from the switching supply without inducing ringing of the AC line current, which can also cause The drivers must convert a chopped phase controlled dimming, thyristor phase-cut dimmers to AC signal from the dimmer into a resistive or auto-transformer malfunction. Often this malfunction steady DC signal for the LED’s in dimming and can also be controlled is exhibited as strobing or pulsation, order to emit a constant light, via an RS 485 bus. A key or sometimes the brightness varies while interpreting the altered engineering objective behind the erratically like the flickering of a waveform to the appropriate technology has been to provide a candle. The new LED power supply dimming level. In other words, smooth, full-range dimming curve, dimming technology incorporates a drivers must be designed to no matter what type of dimming power factor corrected front end interpret a duty cycle modulated system the customer used. Powered and matching EMI filter developed signal and transfer the information by this driver type, a LED lamp can specifically for this application. to constant current output levels. mimic an incandescent lamp’s It operates down to extremely low As the conduction phase angle is dimming behavior, so that in the input voltage and presents an decreased, the output current must theatrical, stage and TV world, appropriate load for phase-cut also decrease. Providing constant a newly integrated LED lighting dimmers, even during the narrow light output requires a balancing act fixture can seamlessly blend, and conduction angles necessary between drawing current through therefore support, a venue’s for low brightness settings, the AC waveform while it is being transition from incandescent to LED while meeting FCC Class B cut out by the dimmer. Storing power over a cost-managed period of time. conducted emissions limits. in capacitors and inductors helps provide power when there is none. The inner workings of a typical LED A particularly annoying behavior of fixture include a switching power some AC line dimmable LED fixtures supply that is more complex than is called popcorn turn-on. As the How the New Technology the electronic transformer used dimmer’s brightness setting is Works for low voltage halogen lamps. increased, the fixtures turn-on at The ultimate challenge around LED The power supply rectifies the line different levels and times, creating dimming is to satisfy the aesthetic voltage and then reduces the the popcorn effect. In the new eye of the technical artist. When it voltage to a level suitable for the technology approach, a separate comes to utilizing high wattage LED driver. It may feature control power supply starts up first stage and television lights, the sophisticated controls, DMX or WiFi, then the microprocessor monitors technical producer is looking for but it is incompatible with AC line the AC line to determine when the flicker-free lighting with smooth controlled dimming. The new LED PWM outputs will commence dimming from less than 1% to 100% power supply technology also operation. This sequence is not as just as one would experience with powers the LED driver. Additionally, dependent on the dimmer setting an incandescent light fixture. This it provides two AC line dependent or the main power supply start-up has been extremely difficult to pulse width modulated (PWM) time, effectively eliminating achieve up until now. control signals to the LED driver that popcorn-turn-on. regulates the current through the A recently introduced LED power LED array. The driver can now For high-end LED fixtures, supply dimming technology called regulate the LED current in compatibility with video cameras is DimMaster™ is compatible with proportion to the effective AC also a great concern. Some

TECHNOLOGIES PHASE-CUT DIMMING 58

Figures 4a-c: (a) Analog controlled LED dimming. (b) Digital controlled LED dimming. (c) DimMaster™ controlled LED dimming

dimmable fixtures control the Along with higher power LED the dimmer setting. The approach is LED current by producing a burst lighting came the demand for better compatible with all forms of AC line of pulses from the LED driver, dimming characteristics. Analog controlled dimming. If you happen to which causes a flickering brightness controls for constant current, be using jars filled with salt water as of video displays. Other LED fixtures PWM LED drivers were developed your dimmer it will work with that too. switch continuously, but at a that improved efficiency and relatively low frequency, which is eliminated color shift with changes good for efficiency, but causes a in brightness. Digital controls that Conclusions venetian blind effect of light and generate the PWM signal after By closely emulating an dark horizontal bands across the calculating the conduction angle incandescent lamp’s dimming video display. Alternatively, the new from the measured line voltage behavior, improved LED power technology’s PWM output presents parameters were developed supply dimming technology will a continuous stream of pulses at a (Figure 4b). With this approach, enable those in the theatrical, frequency high enough to eliminate the dimming characteristics could stage and TV world to seamlessly the venetian blinds effect, but not be precisely adjusted, but distortion blend their differently generated so high that it reduces efficiency. of the voltage waveform and lighting to make the transition transients on the AC line can disturb from incandescent to LED over The first dimmable LED power the brightness setting. Measuring a cost-managed duration. supplies used an analog control the conduction duration is attractive, approach (Figure 4a). They sensed because it is easy to implement in Venue owners and stage managers the rectified DC value of the line the microprocessor program. can incrementally and cost- voltage and used this to directly However, this measurement is affordably retrofit their incandescent control the output current of a frequency sensitive and it is unable systems to LED, with no loss in switched mode power supply. to determine the brightness setting lighting performance. Full-range, The most common topology for of non-phase controlled dimmers. high performance LED dimming the DC-DC stage is the flyback, is about to take center stage. because it is a good choice for low The new LED power supply cost at low power and it can also technology uses a hybrid approach provide power factor correction to sensing the effective line voltage, as in a single stage. This is still a which does not depend on directly popular approach for consumer- measuring the conduction duration oriented LED lighting. Often the (Figure 4c). The new approach dimming range is limited and the integrates the absolute value of the color of the light shifts as the AC line voltage waveform and then current to the LEDs is reduced. measures the result to determine

CATEGORYSPECIAL HORTICULTURE 60 LED Lighting for Horticulture

Solid-state lighting is increasingly being used in horticultural applications, including greenhouses and indoor “vertical farms”. To meet the needs of the horticultural industry, SSL manufacturers and lighting designers will need to understand the spectral power distribution requirements of photosynthesis for optimal plant health and growth. Ian Ashdown, Chief Scientist of Lighting Analysts, provides an overview of plant action spectra and how to convert lumens and lux into units of PAR and PPFD.

There is a bright future for Plant Photosynthesis Whether a photon with a given solid-state lighting in Photosynthesis is the process used wavelength is absorbed by a plant horticulture, including by plants to convert electromagnetic leaf is dependent on the spectral greenhouses and indoor radiation - light - into chemical absorptance of the leaf, which in “vertical farms”. For SSL energy that is used for growth and turn, is determined largely by the product manufacturers development. All that is needed for leaf optical properties, including

and lighting designers, this process is carbon dioxide (CO2), the concentration of plant however, the problem is that nutrients, and water. The process photopigments such as chlorophyll horticulturalists speak an itself is not particularly efficient; A and B, various carotenoids unfamiliar language. Success only 4 to 6 percent of the absorbed (carotenes and xanthophylls), in this market will depend radiation is converted into chemical and anthocyanins. (The chlorophylls on a basic understanding of energy [9]. Still, it is the engine that are responsible for the characteristic plant photosynthesis and the drives most life on this planet. green color of leaves; the carotenoids spectral power distribution and anthocyanins contribute to the (SPD) requirements for optimal Photosynthetically active radiation yellow, orange, and red colors plant health and growth. SSL (PAR) is defined as electromagnetic respectively of autumn leaves after manufacturers and lighting radiation over the spectral range of the chlorophylls decompose.) designers will also need to 400 nm to 700 nm that photosynthetic understand how to convert organisms are able to use in the Typical absorptance spectra for photometric units of lumens process of photosynthesis to chlorophyll A, chlorophyll B,

and lux into Photosynthetically “fix” the carbon in CO2 into beta-carotene, and two isoforms of Active Radiation and carbohydrates. Horticulturalists phytochrome are shown in figure 1. Photosynthetic Photo Flux measure PAR for both plant It must be noted, however, Density for different light research and greenhouse lighting that these spectra are approximate. sources, including both white design using specialized They are measured in vitro by light and quasimonochromatic photometers [1]. dissolving the pigments as extracts LEDs. For horticulturalists, in a solvent, which affects their the availability of multichannel A common unit of measurement for absorptance spectra. By themselves, SSL luminaires with color- PAR is photosynthetic photon flux they suggest that blue and red LEDs tunable SPDs will provide new density (PPFD), measured in units of alone are sufficient for horticultural opportunities to explore the moles per square meter per second [i]. applications. In reality, however, the unique spectral requirements In this case, every absorbed photon, situation is much more complicated. of different crops and the regardless of its wavelength (and integration of SSL products hence energy), is assumed with greenhouse climate to contribute equally to the Photosynthetic Action control systems. photosynthetic process. This is in Spectra accordance with the Stark-Einstein McCree [4] measured the quantum

law, which states that every photon yield of CO2 assimilation for the (or quantum) that is absorbed will leaves of 22 species of crop plants [ii]. excite one electron, regardless of Taking the average measurements the photon’s energy, between at 25 nm intervals for all plant 400 nm and 700 nm. For this species, he produced an action reason, photosynthetic photon flux spectrum plot (Figure 2) that is is also referred to as quantum flux. representative of most crop plants. -

PHOTOSYNTHESIS AND VISIBLE LIGHT

For illumination engineers, it might seem suspicious that the respond under dim light conditions. However, these are likely photosynthetically active radiation is defined over the spectral range suppressed under high light conditions by the xanthophyll process. 400 nm to 700 nm - exactly the range we commonly assume for human vision. What about longer and shorter wavelengths? Above 700 nm, the photon energy is too low to activate the photosynthetic process via the chlorophylls and various cartenoids. When McCree [4] measured his 22 crop species both in the field However, the phytochrome photopigment, which is responsible for and in laboratory growth chambers (with very similar results), stem elongation, leaf expansion, shade avoidance, neighbor he obtained the following action spectra. perception, seed germination, and flower induction, has two isoforms called Pr and Pfr. In its ground state Pr, phytochrome has a spectral absorbance peak of 660 nm. When it absorbs a red photon, it converts to its Pfr state, which has a spectral absorbance peak of 730 nm. When the phytochrome molercule absorbs a far-infrared photon, it converts back to its Pr state, and in doing so triggers a physiological change in the plant.

The action spectra clearly explain the logic of the 400 - 700 nm spectral range

Below 400 nm, there is the risk of photooxidation that generates toxic radicals, which can destroy the cell’s chlorophyll and other cellular components. Under intense UV radiation , violaxanthin (which is involved in photosynthesis) is converted via the xanthophyll cycle into zeaxanthin. In doing so, it receives excess energy from Phytochrome action spectra chlolorphyll and releases it as heat. This process thereby offers the plant photoprotection. Chlorophyllous leaves are transparent to infrared radiation. So the phytochrome signaling mechanism is ideal for sensing the lighting At the same time, other plant photopigments, including environment on forest floors and in the presence of neighboring cryptochromes and phototropins, do have sensitivities plants competing for available direct sunlight. (as measured in vitro) that extend into the ultraviolet, and likely Ian Ashdown, P. Eng., FIES. Chief Scientist, Lighting Analysts Inc.

Figure 1: An action spectrum is simply a Photopigment spectral plot of biological effectiveness as absorptances a function of wavelength of incident light.

As noted by McCree [4], PPFD is not a perfect measure of photosynthetically active radiation in that it systematically overestimates the effectiveness of blue light relative to red. It is useful, however, in that it is independent of any particular plant species, and it can be measured both in the laboratory and in the field using a radiometer with a spectrally-calibrated quantum sensor such as the LI-190SA from LI-COR [5].

Figure 2: W (λ) Action spectrum rel Φ (λ) / lm = 700 for crop plant 6 8 3·∑ 400 V(λ) W (λ) Δλ photosynthesis rel

where Wrel(λ) is the relative spectral power distribution, V(λ) is the luminous efficiency function at wavelength λ, and Δλ is the wavelength interval (typically 5 nm). For the above example, the spectral radiant flux per nanometer for each lumen at 440 nm is 22.5 microwatts, while the total radiant flux per lumen is 3.18 milliwatts.

With this, we can calculate the photosynthetic photon flux (PPF) per nanometer in micromoles per second per Figure 3: 5000 K LED relative nanometer: spectral power distribution λ Φ (λ) PPF / nm = 10 -9 · -6 (Na · 10 ) hc

(where Na is Avogardo’s constant), while summing over the range of 400 nm to 700 nm yields the photosynthetic photon flux (PPF) per lumen for the given light source:

10 -3 PPF = · ∑ 700 λ Φ(λ) Δλ ≈ 400 Nahc

Figure 4: CIE 1931 luminous 8.359 10 -3 · ∑ 700 λ Φ(λ) Δλ efficiency function V(λ) 400

Given an illuminance value (lumens per square meter) and knowing the light source SPD, we can similarly calculate the photosynthetic photon flux density (PPFD) in micromoles per second per square meter (μmol/sec-m2) for the given light source. Again for the above example, one kilolux is equal to 14.62 μmol/sec-m2.

Conversion Factors It is easy enough to find graphical representations of light source spectral power distributions, but it is considerably more difficult to find this information in From Lux to PPFD tabular form suitable for the above calculations. As lighting designers, we need some method of Fortunately, this information is published in CIE 15:4, converting lumens to quantum flux (PAR) and Colorimetry [2]. It does not include white light LEDs, illuminance to quantum flux density (PPFD). But we can but this information can be obtained by digitizing do so only if we know or can estimate the spectral manufacturers’ product catalog data (e.g., [6]). power distribution (SPD) of the light source. Given such information, it is possible to calculate Suppose then that we have a light source with a known kilolux-to-PPFD conversion factors for common relative spectral power distribution (SPD), such as, for light sources: example, a typical 5000 K “cool white” LED (Figure 3). Table 1 does not include commercial products such as One watt of radiant power at 555 nm is, by definition, the Sylvania SHP-TS Grolux (with a CCT of 2050 K) equal to 683 lumens. Given the CIE 1931 luminous because Sylvania and most other lamp manufacturers efficiency function (Figure 4), we can calculate the do not publish their lamp SPDs in tabular form. It is spectral radiant flux Φ(λ) in watts per nanometer for possible to digitize the graphical representations of each lumen as: white light LEDs because the bandwidth of the blue “pump” LEDs is at least 15 nm. With high-pressure

Table 1: Herein, however, lies a problem: Light Source Conversion Factor Illuminance (kilolux) 450 nm and 660 nm are close to the to PPFD (μmol/sec m2) CIE A (incandescent, 2856 K) 17.0 limits of our color vision (Figure 4). conversion factors CIE 5000K daylight (D50) 28.5 Consequently, Philips and other manufacturers typically express the CIE 5500K daylight (D55) 28.0 optical performance of these CIE 6500K daylight (D65) 25.2 products in radiometric rather than CIE 7500K daylight (D75) 22.8 photometric terms - milliwatts CIE HP1 (standard HPS, 1959 K) 3.9 instead of lumens. CIE HP2 (color-enhanced HPS, 2506 K) 13.0 So, the lighting design process CIE HP3 (metal halide, 3144 K) 9.2 becomes a bit more complicated. CIE HP4 (metal halide, 4002 K) 9.0 We first need to digitize the published LED spectral power CIE HP5 (metal halide, 4039 K) 13.9 distributions to determine the 2700 K white light LED 16.9 conversion factors between 3000 K white light LED 18.2 milliwatts and lumens - these will 3500 K white light LED 17.4 be needed for the lighting design simulations. These are given by: 4000 K white light LED 17.7 700 Φ (λ) V(λ) 5000 K white light LED 14.6 ∑400 R

ΦL = 0.683 · ∑ 700 V(λ) 400 sodium and metal halide lamps, adding white or blue light to deep however, it is impossible to digitize red light can beneficially increase where ΦL is the luminous flux, ΦR(λ) their published SPDs because the the rate of photosynthesis. is the relative spectral radiant flux wavelength resolution is unknown. and V(λ) is the luminous efficiency A subnanometer-wide line emission, Green light is also used in function at wavelength λ. for example, could vary in height by photosynthesis, as can be seen five times, depending on whether the from the crop action spectrum Using the Philips Luxeon Royal Blue wavelength binning is 1 nm or 5 nm. (Figure 2). It has been established and Deep Red products as an that green light drives example, the conversion factors are photosynthesis more effectively approximately 0.07 and 0.03 lumens LED Lighting for than red or blue light deep within per milliwatt (lm/mW) respectively. Horticulture the leaf [8]. Further, the insects However, these figures must be At this time, high-pressure sodium used in greenhouses as pollinators approached with some caution, as (HPS) lamps are the most common and biological control agents see they apply to 450 nm and 660 LEDs light source for greenhouse lighting, best in the green and ultraviolet only. If, for example, the peak where it is commonly used to regions of the spectrum. wavelength of deep blue LED was supplement daylight during the 440 nm rather than 450 nm, winter months. However, with the It is likely, for this reason, that many the conversion factor would be growing interest in urban horticulture horticultural LED modules feature 0.05 lm/mW. Similarly, if the peak that relies exclusively on electric efficient 450 nm indium-gallium- wavelength of the deep red LED lighting, light-emitting diodes offer nitride (InGaN) deep blue LEDs and was 650 nm rather than 660 nm, many advantages. This is 660 nm aluminum-indium-gallium the conversion factor would be particularly true for multilayer phosphide (AlInGaP) deep red 0.06 lm/mW. The Philips LED cultivation, where the close spacing LEDs. Typical examples of these binning ranges are 440 to 460 nm of plants in vertical rack-mounted LEDs are the Philips Luxeon Royal and 650 to 670 nm respectively, trays make HPS lighting impractical. Blue and Deep Red products [7]. which equates to (from Figure 4) Both of these products are quite conversion factor uncertainties of McCree [4] noted that the relative efficacious, converting some 45% +75%, -50% for blue and +60%, quantum yield for crop plant of their electrical input power into -30% for red. The above conversion photosynthesis has two peaks at visible light. Green LEDs, while factors are therefore decidedly 440 nm and 620 nm. He also noted beneficial, are rarely used because approximate. however, the Emerson effect, which of their much lower radiant states that photosynthesis in the efficacies. (This may soon change (Some horticultural LED module presence of two or more however, as Osram Opto recently manufacturers bin their LEDs more wavelengths can be more efficient announced the development of tightly, as peak maxima shifts as than the sum of that due to the 530 nm InGaN green LEDs with small as 10 nm have been shown to individual wavelengths. In particular, 25% external quantum efficiency.) have dramatic effects on plant

Figure 5: Test installation for horticulture lighting (Credits: Aeon Lighting Technology Inc. - www.aeonlighting.com)

Table 2: growth. However, unless the binning Conversion orientation) and circadian rhythms Illuminance (kilolux) to Light Source Factor PPFD (μmol/sec-m2) policy is stated in the manufacturer’s (for which blue light is the most conversion factors product literature, this cannot be 450 nm deep blue LED 14.3 effective), photomorphogenesis assumed.) 525 nm green LED 1.0 (plant shape), root growth, stomatal opening, chloroplast 660 nm deep red LED 15.6 A further word of caution: even the movement, etc. The list goes on, best illuminance meters can be as horticultural researchers continue wildly inaccurate when measuring How horticulturalists choose to to explore the role between lamp deep blue and deep red light levels. balance the ratio of red to blue light SPDs and optimal plant health Commercially available photometers will likely depend on the specific and growth [iii]. are usually classified according to plant species being cultivated and their f1’ number (with f1’ < 3% being their stage of growth. Some plants preferred), which is basically a like shade, while others prefer Summary measure of how closely the spectral direct sunlight, with different SPD As a reminder, photosynthetically response of the meter matches that requirements. Regardless, active radiation (PAR) does not of the photopic visual efficiency the above conversion factors consider the spectral response of function (Figure 4). As noted in will still be useful. plants (Figure 2); it simply represents CIE 127:2007, Measurement of the number of photons (quanta) per LEDs [3], this is useful for white light In addition to using chlorophylls and unit area per second within the measurements only. To quote, carotenoids for photosynthesis, range of 400 to 700 nm. With the “In the case of single-color LEDs, plants use these and other availability of color-tunable LED the spectral mismatch errors can be photopigments for a wide variety modules for greenhouse lighting, very large even if f1’ is reasonably of functions. The phytochromes horticulturalists will likely want to small, due to the fact that some LED Pr and Pfr, for example, respond to experiment with different SPDs for spectra are peaking in the wings of 660 nm red and 735 nm infrared specific crops and flowering plants, the V(λ) function where the deviation radiation respectively, and in doing as well as both the directionality makes little effects on f1’ but can so induce seed germination and and daily timing of the luminaires. cause large errors.” flowering, regulate leaf expansion Regardless, being able to convert and stem elongation, and trigger predicted and measured illuminance With these conversion factors photoperiod and shade avoidance values to PPFD values for common in hand, we can now calculate responses. light sources will certainly ease the approximate illuminance-to- the communication problems PPFD conversion factors for Other photopigments regulate between lighting designers horticultural LEDs: phototropism (leaf and stem and horticulturalists.

Notes: [i] A mole is a unit of measurement used in chemistry to express the number of elementary entities in a substance that is equal to the number of atoms in 12 grams of the isotope carbon-12. It corresponds to the Avogadro constant, whose value Na is 6.022 1023 particles (in this case photons) per mole. A micromole is one millionth of a mole [ii] The quantum yield in photosynthesis is defined as the micromoles of carbon dioxide fixed per micromole of photons absorbed [iii] See www.photobiology.info for an informative summary of plant photobiology

References: [1] Barnes, C., T. Tibbitts, J. Sager, G. Deitzer, D. Bubenheim, G. Koerner, and B. Bugbee. 1993. “Accuracy of Quantum Sensors Measuring Yield Photon Flux and Photosynthetic Photon Flux,” Horticultural Science 28(122):1197-1200. [2] CIE. 2004. Colorimetry, Third Edition. CIE Technical Report 15:2004. Vienna, Austria: Commission Internationale de l’Eclairage. [3] CIE. 2007. Measurement of LEDs, Second Edition. CIE Technical Report 127:2007. Vienna, Austria: Commission Internationale de l’Eclairage. [4] McCree, K. J. 1972. “The Action Spectrum, Absorptance and Quantum Yield of Photosynthesis in Crop Plants,” Agricultural and Forest Meteorology 9:191-216. [5] www.licor.com [6] Philips Lumileds. 2014a. Luxeon Rebel ES Portfolio Datasheet DS61. Philips Lumileds Lighting Company. [7] Philips Lumileds. 2014b. Luxeon Rebel Color Portfolio Datasheet DS68. Philips Lumileds Lighting Company. [8] Terashima, I., T. Fujita, T. Inoue, W. S. Chow, and R. Oguchi. 2009. “Green Light Drives Leaf Photosynthesis More Efficiently than Red Light in Strong White Light: Revisiting the Enigmatic Question of Why Leaves are Green,” Plant & Cell Physiology 50(4):684-697. [9] Zhu, X.-G., S. P. Long, and D. R. Ort. 2010. “Improving Photosynthetic Efficiency for Greater Yield,” Annual Review of Plant Biology 61:235-261.

SPECIAL: ENLIGHT PROJECT OUTCOMES

Summary EnLight - Next Generation Intelligent and Energy Efficient Lighting Systems 68 The “LEDification of lighting” has led to by Frank van Tuijl, Philips Lighting breakthroughs in light source efficiency and lifetime. However, the real revolution, 72 System Architecture for Distributed Intelligence the digitization of lighting is yet to come. by Lex James, Philips Research; Martin Creusen, Philips Lighting; The EnLight consortium, made up of Micha Stalpers, AME 27 key players in the lighting market, has been working on developing a next generation lighting solution based New Form Factor Luminaires and New Light Effects 80 on intelligent, networked luminaires for by Herbert Weiß & Thomas Noll, Osram; Martin Möck, University the last three years. Shifting from a of Erlangen-Nuremberg; Martin Creusen, Philips Lighting; centralized control system to a network Friedhelm Holtz, Insta Elektro of intelligent luminaires, the EnLight system enables each individual light 86 The Building Blocks for Intelligent Future Luminaires source to adjust to the conditions by Tim Böttcher & Lucie Chandernagor, NXP; Philippe Maugars, PMC; around it based on input for its own Hannu Vihinen, Helvar; Mark Coopmans, Philips Lighting; sensors and other sensor and control Olli-Pekka Jokitalo, PKC Electronics; Raimo Ontero, Valopaa; inputs using programmed rules and a Christian Paul, Infineon; Rafael Jordan, Fraunhofer IZM modular Plug-and-Play intra-luminaire bus architecture. In pilots, the EnLight solution, with its inherent granular Peripheral Devices for the Right Light 92 lighting control, has already achieved by Werner Weber, Infineon Technologies; Lex James, Philips Research; energy savings from 40% for office to Arjan van Velzen, Plugwise; Bruno Vulcano, Legrand; Micha Stalpers, 80% for hospitality, while providing the AME; Arend van de Stadt, Eagle Vision Systems; Jens Döge, Fraunhofer same or better level of user comfort as IIS/EAS; Wilfried Rabaud, CEA Leti today’s leading LED solutions. Fuelling new growth opportunities in LED lighting 98 Granular Lighting Control Enables Significant Energy Savings applications, EnLight will lead in the with Optimized User Comfort creation of new lighting solutions that by Eveliina Juntunen, VTT; Frank van Tuijl, Philips Lighting; inspire and enable designers in ways Herbert Weiss, Osram; Ambali Talen, Philips Research conventional lighting never could.

THE ENLIGHT PROJECT

The EnLight project ran from 2011 to 2014 EnLight Consortium Partners: • NXP Semiconductors France SAS and was coordinated by Philips Lighting. • Applied Micro Electronics (AME) B.V. • NXP Semiconductors Germany GmbH In 2014, at the European Nanoelectronics • Besi Netherlands B.V. • OSRAM GmbH Forum in Cannes, the project received the • BJB GmbH & Co KG • Philips Electronics Nederland B.V. 2014 Innovation Award from the ECSEL • Commissariat à l’énergie atomique et • Philips Lighting B.V. Joint Undertaking. aux énergies alternatives • PKC Electronics Oy • Eagle Vision Systems B.V. • Plugwise B.V. The project was supported and partially • Enel Distribuzione SpA • Rheinisch-Westfälische Technische funded by the Public Private Partnership • Fraunhofer Gesellschaft zur Förderung Hochschule Aachen ENIAC JU under the Nanoelectronics der angewandten Forschung e.V. • Technische Universiteit Delft Energy Efficiency subprogram and by the • Helvar Oy Ab • Technische Universiteit Eindhoven respective national agencies. The ENIAC • Infineon Technologies AG • There Corporation Ltd. Joint Undertaking (JU) is a public-private • I-NRG B.V. • Università degli Studi di Perugia partnership on nanoelectronics bringing • Insta Elektro GmbH • Valopaa Oy together the ENIAC member States, • Legrand France SA • VTT Technical Research Centre the European Union, and AENEAS • TNO Nederlandse Organisatie voor of Finland (an association representing European Toegepast Natuurwetenschappelijk R&D actors in this field). Onderzoek

ENLIGHT PROJECT INTRODUCTION 68 EnLight - Next Generation Intelligent and Energy Efficient Lighting Systems

The “Solid State Lighting Revolution” has given lighting and controls new significance. Research projects have become necessary to explore new opportunities and set free the full potential of the new technology. Perhaps the most extensive research in this direction was performed by the EnLight consortium. Frank van Tuijl from Philips Lighting introduces the project and explains why it was initiated and what the aims were. Furthermore, he provides some background information about the five selected technical articles.

The lighting industry is To achieve this, a consortium Energy Saving undergoing a radical of 27 leading European through Intelligence transformation, driven by companies and academic The main goal of the project was to rapid progress in solid-state institutions have been working exploit the full potential of solid-state lighting and semiconductor together on the project [3], lighting through breakthrough technologies as well as a pre-competitive three-year innovations on non-conventional, changing societal needs ENIAC-JU R&D program energy efficient, intelligent lighting for sustainability, improved to develop technology systems beyond today’s common

energy efficiency and CO2 breakthroughs for energy- lighting control applications. reduction. To serve the latest efficient and intelligent The aim was to achieve 40% energy business requirements and LED lighting solutions. reduction compared to today’s drive R&D, these changes Partners include a number of LED retrofit systems. need to happen quickly leading European companies and take place in an open- in the lighting industry The project had three innovation ecosystem [1]. (including Philips and Osram), technical objectives: the semiconductors industry • Optimized LED lighting modules: Recent advancements in (NXP and Infineon) and the Improved optical design, solid state lighting (LED), lighting controls industry thermal management, driver the “LEDification of lighting”, (including Insta and Legrand), integration and realization of a have led to breakthroughs in plus universities and research communication interface light source efficiency and centers from across the • Future, non-conventional lifetime. However, the real semiconductor and luminaires: Allowing for freedom revolution, the digitization lighting value chain. of design, integration of novel of lighting is yet to come and features, architectural flexibility will involve a paradigm shift and serviceability, unrestricted by from a lighting component retrofit solution constraints approach to an application • Intelligent lighting systems: centric approach [2]. Providing means for data mining, smart sensors, sensor fusion and interfacing with Building Management Systems (BMS)

EnLight explored next generation intelligent lighting systems, with the goal of improving light source

energy efficiency (i.e. electrical And finally, a third digitalization wave over lifetime. The inter-luminaire efficiency of LED drivers and power is associated with controls and architecture is described in the supplies, optical efficiency and sensors, which may be part of the article “Lighting System Architecture thermal efficiency) and control luminaire and make the luminaire for Distributed Intelligent”. system intelligence to provide the ready for the Internet of Everything. right light, in the right amount, at the right place and at the right time. Digital modular Breakthrough Innovations luminaire architecture As a “Green Field Approach”, Breakthrough innovations in the A novel Plug-and-Play intra- the project addressed the second following areas were achieved, luminaire bus architecture and solid state lighting (SSL) transition taking a disruptive step into the communication protocol was wave, overcoming restrictions of future of lighting. created that allows the development legacy technology and infrastructure. and management of a portfolio of The project examined the integration re-usable and easily exchangeable of electronics and controls into Distributed intelligence luminaire building blocks. The intra- luminaires, with a focus on optimal Inspired by the Internet-of-Things, luminaire communication bus is built utilization and integration of LEDs, the project partners explored a on an I²C physical layer, using ILB optics, sensors and heat novel distributed rules-based as the communication protocol. management systems. intelligence system allowing each The building blocks include LED individual luminaire to make lighting light engines, embedded sensors, The goal was not just to improve decisions based on presence, high- and low-power supplies, and efficiency through reduction of the occupancy events or ambient light embedded controllers. The modular junction temperature and improved information detected by its own approach makes it easier to manage light output ratios [4] but to take a integrated sensors, or events and the diversity and complexity of next step towards the shape and information from other nodes in the luminaires throughout the supply functional integration of the luminaire, network (sensor, luminaire or user chain, decouples lifecycles of breaking completely free from the control). To enable this, a few independent modules/technologies conventional form factors associated additional Zigbee cluster libraries and enables market players to with traditional lighting. The notion were defined. contribute, differentiate and of a luminaire was taken much compete. The “Lighting System farther than could be imagined with Distributed intelligence enables Architecture for Distributed traditional light sources. In this respect, deep energy savings with optimal Intelligent” and “The Building Blocks the objectives are clearly beyond user centered comfort. Without the for Intelligent Future Luminaires” those of the Zhaga program, which need of a central controller, articles describe the intra-luminaire focuses on the standardization of it reduces installation and architecture and the modular mechanical, electrical and thermal commissioning effort and increases building blocks. interfaces on the components level. robustness, flexibility & scalability

Figure 1: System hierarchy and building blocks

Figure 2: Office and hospitality demonstrations (from left to right: Office demonstration - Philips; office demonstration - VTT; hospitality demonstration - Osram)

Technical Highlights showing that with only a limited set regulation and personal control The consortium partners developed of intra-luminaire modules, a large with smart integrated desk lights. EnLight-compatible building blocks variety of luminaires can be Comfort enhancing features using at module, fixture and system level constructed across different module tunable white and colors were also as illustrated in figure 1. These suppliers and luminaire makers. demonstrated including circadian contributions included modules, The building blocks are described rhythm in the open office and intelligent luminaire and e xternal in the “The Building Blocks for scene settings with ambient sensors and local user controls. Intelligent Future Luminaires” article. colors to support activities in the meeting room.

Modules External sensors and local Specific technologic innovations user controls Validation of energy efficiency included compact multi-channel At fixture level System-on-Chip and user comfort results LED drivers and power supplies with (SoC) implementations for advanced For evaluation, the Lighting Energy high electrical efficiencies (up to and cost effective image and radar Numeric Indicator (LENI) described 90-95%) over the whole dimming sensors for reliable occupancy, in standard EN 15193 was used: range, electronic designs for low presence and activity detection Energy performance of buildings - standby power, compact embedded were developed by several Energy requirements for lighting sensors (ambient light, occupancy, academic and SME partners as the indicator of the energy ambient temperature), LED light (University Perugia, Institutes TNO, performance. This measures the engine designs for high LOR (Light Fraunhofer-EAS, CEA-Leti and actual annual energy consumption Output Ratio, up to 90%) and high SME Eagle Vision). External sensors of the lighting system (in kWh/m2 per thermal efficiency. and user controls were developed year) taking into account the installed by Plugwise, AME and Legrand. power of the luminaires, the lighting They are described in the controls strategy and system Intelligent luminaires “Peripheral Devices for the parasitic power. Philips contributed the (mini)- Right Light” article. PowerBalance and TaskFlex The results from the three intelligent luminaires as the lead representative office and hospitality carrier platform for this development. System Demonstrations pilots realized in the project The PowerBalance luminaires were Three system demonstration pilots confirmed significant energy savings equipped with 4-channel LED strings in the office and hospitality of between 44% and 81% compared for tunable white applications and application domains were realized at to current LED retrofit applications the combined PIR/light level/ three different locations (Figure 2), with a standard room occupancy- temperature multi-sensor. each using 60-120 EnLight compliant based control strategy. ZigBee nodes (intelligent luminaires, Osram developed an extendable external sensors or user control) The office pilot demonstrated overall RGBW decorative tile concept and without any central controller. energy savings of 44% with an novel luminous door concept, average contribution from the while Insta contributed the Glow, Sophisticated energy saving sophisticated granular control a suspended intelligent luminaire strategies were demonstrated, strategy of 30% and an overall with both task and ambient light. such as task tuning, personal lumen efficacy improvement of 20%. The “New Form Factor Luminaires control, occupancy control and and New Light Effects” article gives daylight harvesting. As both The hospitality pilot demonstrated an introduction into the novel embedded sensors and external even larger overall energy savings of luminaire concepts. sensors provide information to 81%, with a 67% average contribution the luminaires, granular control from the control strategy and 42% All luminaire types were built from strategies have been tested from luminaire efficacy improvement. the same plug-and-play building centered around users using The large difference between the blocks developed in the project, light bubbles, local daylight office and hospitality results was

Figure 3: Energy saving results for office (left) and hospitality (right) demonstrations

due to the higher lighting power per year for the LED retrofit baseline. savings without compromising and density, lower occupancy and use These results amply exceed the even improving light quality and user of decorative but less efficient best in class scores of the building comfort. The substantial additional luminaires in the hospitality energy performance benchmarks energy savings for lighting will lead application. (i.e. EN 15193 [5], ASRAE [6], to a reduction of global CO2 Title 24 [7]) and score the emission. This is an important step As the resulting energy saving for maximum of LEED [8] credit points. to meet the EU directive 2010/31/EU the total installation for each of the The hospitality installation surpassed for a near zero energy building pilots was more than the targeted even green building performance performance in 2020. 40%, the primary challenge of the norms with a 45% better saving project was accomplished. performance (20.2 kWh/m2 per year). By building on Europe’s leadership in semiconductor and lighting From a lighting comfort perspective, The energy efficiency and user technology and exploring future based on key lighting parameters validation results are described in ecosystems featuring the intra- such as lighting quality, brightness the “Granular Lighting Control luminaire bus and decentralized (glare) and room appearance, Enables Significant Energy Savings rule-based intelligence, this new the new developed system delivered with Optimized User Comfort” article. concept is helping shape the a comparable performance with lighting market for the coming years. respect to reference non-retrofit It enables new lighting solutions that LED lighting installations. The Road Ahead were not possible with conventional While significant differences in EnLight developed a novel, lighting technology. lighting comfort were not statistically decentralized and modular system proven, qualitative analysis results architecture for next generation This creates opportunities both showed an 80% preference for intelligent lighting systems, for large companies and SMEs. the EnLight system over a state-of- empowering the next generation Fuelling new growth opportunities the-art LED reference system. smart lighting systems. in LED Lighting applications, this project will lead to the creation The LENI energy values measured Driven by granular control of new lighting solutions that inspire overall for office are 12.4 kWh/m2 strategies, the new system and enable designers in ways per year compared to 20.4 kWh/m2 demonstrated significant energy conventional lighting never could.

References: [1] http://www.eniac.eu/web/downloads/projectprofiles/call3_enlight.pdf [2] Dr. Kees van der Klauw: „The Paradigm Shift in Lighting” ISS Europe 2013, Milan (2013) [3] EnLight: http://www.enlight-project.eu [4] The ratio of luminous flux emitted by the LED light source and that emitted by the entire luminaire system. [5] EN 15193:2007 Energy performance of buildings - Energy requirements for lighting [6] ANSI/ASHRAE/IES Standard 90.1-2007 [7] http://www.energy.ca.gov/2012publications/CEC-400-2012-004/CEC-400-2012-004-CMF-REV2.pdf [8] Leadership in Energy and Environmental Design (LEED)

The usage of intelligence and sensors is not totally new, but solid-state lighting has brought it to a new level that has led to a new way of thinking about system architecture. The EnLight project found the distributed intelligence approach to be the preferable solution. Lex James from Philips Research, Martin Creusen from Philips Lighting, and Micha Stalpers from AME explain the reasons why, what the system architecture for distributed intelligence looks like, and how it works.

System architecture is about with rules. The rules specify System Hierarchy partitioning a system into its how each subscriber acts when Four distinct aggregation levels components and defining the it receives an event. So the make up the EnLight architecture, relationships between those rules have a dependency with as shown in figure 1. The project components. In general, it is the publisher rather than the focused on luminaire and area good practice to partition a decision engine itself. levels, together with the system so that the components corresponding intra- and inter- are loosely coupled and have The third important architecture luminaire communication few dependencies while still choice for this project is closely technologies. Building and maintaining the cohesion of the related to the economy of scale enterprise, the two higher system as a whole. The notion of luminaire manufacturing. aggregation levels, are also of “separation-of-concerns” The concept of an Intra supported by the new architecture should be leading in any Luminaire Bus (ILB) allows (for example, to release information system architecture. luminaire manufacturers to from the lighting system to the build a large variety of building management system). This is certainly true for luminaires from standardized the EnLight project which HW/SW modules. The decentralized architecture is introduces a paradigm shift based on distribution of information in lighting control by applying Since it would be impossible to rather than controlling individual the “publish-subscribe” design address the complete EnLight luminaires via a centralized control pattern, appreciated both for its system architecture in this unit. Thus “events” generated by scalability and loose coupling. article, the following three key sensors are distributed across the In such a lighting system, topics have been selected. whole network. Thereafter each sensors inform luminaires The chapter on system luminaire decides autonomously, instead of controlling them. hierarchy addresses the various according to its own embedded As a result, the publisher control levels of the system. rules, how to control its lighting (e.g. sensor) does not need any The area level communication function based on notified events. knowledge of its subscribers section describes the So, decision making is made at the (e.g. luminaires). It just delivers communication protocol that lowest aggregation level instead of its event to any subscribed implements the “publish- in the centralized control unit. device. This makes the subscribe” pattern. The third publisher subscriber-agnostic, chapter covers the intelligent Another key architecture element but what if the subscriber could luminaire which acts as both a is the decoupling of the lighting also be publisher-agnostic too? subscriber (light sources) and a domain from adjacent domains. publisher (embedded sensors). Sensors report events without To achieve this objective, a Due to the decentralized knowing the type of subscribed second architectural choice is nature of the architecture, luminaires. Therefore, events are needed: every subscriber needs the intelligent luminaire is not interpreted or prioritized by the to be equipped with a decision the cornerstone of the new distributing sensor. This yields a engine that can be programmed developed lighting system. transparent architecture with a

Figure 1: Levels of lighting control

Figure 2: Area lighting system

clear division of responsibilities in In principle, any external device On the Area level, the lighting which the behavior of the main that can generate an event is control network connects the building block, the intelligent capable of informing luminaires and intelligent luminaires and key luminaire, is determined by the therefore interacting with the components, such as local rules configuration - which can be lighting system. The event source user controls and external easily adapted to a changing does not require any upfront sensors (Figure 2). building environment. Additionally, knowledge of the luminaires, self-learning algorithms would enabling a smooth integration with The Area configurator enables the typically be accommodated by building management systems. configuration of these components the intelligent luminaire. simply by changing the rules-based

logic of the intelligent luminaires. The main objective of the project Area Level Communication Optionally, events generated by was to develop a lighting system Communication between devices multiple external area level sensors that offers excellent user comfort within an area plays a prominent role can be aggregated and processed at the lowest possible energy in the EnLight architecture. It is using the Sensor Fusion function to consumption. This requires the right designed to run on top of existing reduce the network’s overall light to be generated in the right communication standards like communication load. place at the right time. This was ZigBee and/or IP and to support achieved by adopting granular scalability and flexibility of the For monitoring or logging functions, sensing and control in a connected lighting system. The communication the area controller and communication lighting system. function is implemented as a set of unit can send information from the reusable modules to guarantee area network to the higher building Granular sensing ensures, consistency and facilitate ease level and vice versa. Furthermore, for example, uninterrupted of integration. the area controller can transfer luminaire operation during network events generated at different network interruptions. Granular control levels. Finally, the area controller can comes from embedding most of Communication protocol also propose a certain light control the decision logic in the luminaires, The communication protocol is function, such as an orchestrated instead of using a centralized designed in such a way that new color change, at the area level. controller to send commands to sensors and luminaires can be individual luminaires. The luminaire added to the area network while In the final EnLight demonstrations, is intelligent because it autonomously other devices remain operational. the lighting control network was controls its own light sources. System intelligence, in the form of based on wireless ZigBee technology, Thus the lighting system is rules, can be configured and as this ensures a scalable low power effectively a collection of connected simulated off-line. Offering and low cost implementation. and cooperating intelligent intelligence by configuration is a key Figure 3: Wired implementations are also luminaires which are able to adapt element of decentralized systems Example of including a possible, but were not implemented to changes in the environment. and accommodates the system with new sensor in the area in the demonstrations. a number of unique properties. network

• In a building environment, new sensors can be installed and put into operation without needing to take the whole system offline. Luminaires requiring sensor input for their decisions can be easily updated with new rules in just a few seconds. • Once installed, new luminaires can be quickly put into operation by connecting the power and providing them with their initial rules. • All EnLight devices are interconnected - there is no dependency on a physical topology. This allows unlimited intelligence reconfiguration simply by providing the luminaire with new rules. Reconfiguring an area with 40 luminaires only takes a few minutes. • Reconfiguration of a single sensor, luminaire or part of the system is possible without impacting the rest of the system. • As the impact on uptime is very limited, automation of the reconfiguration process is possible allowing for self-learning capabilities.

Figure 4: Example of a bridge interconnecting two area networks

The communication protocol is best Information provided by the implementation across devices from explained by the example outlined in system can be valuable in multiple partners, ease integration figure 3 where sensor A is newly determining energy saving strategies. and minimize development effort. added to the system. First the area Examples are “heat maps” of The framework provides the “glue” configurator configures the sensor occupancy information and between an EnLight C-API and the by sending one or more parameters daylight measurements. EnLight binary protocol. It enforces (e.g. absence delay). Since the a clear separation between sensor is new, the area configurator application development and will also program one or more rules Bridging areas communication technology. into the luminaires telling them how The Area-to-Area (A2A) bridge has to respond to events from the sensor. been developed to interconnect When an instruction from the networks. The bridge can connect C-API is invoked, the framework After configuration, the sensor networks based on different encodes a message containing the announces itself to the network. communication technologies (e.g. corresponding command and sends Announcing is typically initiated by ZigBee to IP bridge) but can also be this to a given target device in the a button press or internal timer. used to scale a network to any size network, identified by a unique When receiving the announcement, independent of communication- 8-byte device ID. It assumes the each intelligent luminaire checks the technology constraints. The bridge existence of basic communication occurrence of the sensor in its rules. acts as proxy for devices on other operations “send” and “receive” for If it is found, the luminaire sends networks and is therefore invisible a particular technology. It also a subscription request. As a result for the light designer. converts device IDs to technology- the sensor adds the luminaire to specific network addresses, such its subscription list. Figure 4 outlines how the bridge as ZigBee short IDs or internet IP interconnects two area networks for addresses. The response received After subscription, the newly a presence sensor and an intelligent from the target device is decoded added sensor is now operational luminaire programmed to respond by the framework and results in within the area network. As soon to the sensor’s events. the corresponding API callback as the sensor detects something of to the application. interest, it sends an event message As described previously, including to all devices in its subscription list. devices in the network and device The main benefit of this framework Each luminaire receiving an event configuration is performed locally approach is that the complex that matches one (or more) of its at area network level. The protocol communication layer is made rules will execute the associated was designed to allow inter-area available to application builders via a actions. More details are given in communication for announcement simple interface without needing to the next section. and operation by making a distinction know all the details underneath. between a message’s local source The protocol separates the sensor and its origin in the system. The ZigBee technology layer was domain from the luminaire domain. implemented for a Windows Devices other than luminaires environment using a ZigBee dongle, can send events without adding Communication framework with a number of sensors running lighting-specific details. They can The communication framework was on an EM250 (Silicon Labs) and the also subscribe to events for developed with three objectives in luminaire running on a JN5168 (NXP). monitoring and analysis. mind: ensure a consistent protocol For security, the Common Security

Figure 5: Communication framework layering

Model with a predefined link key The device configuration interface of these parameters. This allows a was used. Conforming to the ZigBee offers run-time configuration of particular device’s parameters to be cluster library format, EnLight’s sensor and luminaire parameters in extended without any impact on the ZigBee implementation can coexist an operational system. To avoid protocol structure. with other ZigBee profiles such inconsistencies during configuration, as home automation. the configuration start and end are The programming interface offers explicitly communicated. Getting run-time configuration of the and setting device parameters is luminaire intelligence. The rules are Interface details based on key-value pairs. Moreover, encoded into a compact binary The communication framework the list of parameters supported by format and transmitted to the offers a set of interfaces that can be a particular device can be luminaires in packets. regarded as clusters of commands requested, and only the Area which will be described individually. Configurator requires knowledge The event subscription interface is typically implemented by (but not Table 1: limited to) a sensor device to allow Device configuration Method Notes interface other devices to subscribe to its StartConfiguration() Starts configuration of the device events. It also allows other Returns the list of parameter identifiers the networked devices to request a GetParameterList() device supports sensor device to announce itself, Returns the value of a parameter, gives its enforcing announcement after GetParameter() identifier system reconfiguration. The intelligent luminaire uses the Sets the value of the parameter with the given SetParameter() identifier interface to subscribe to sensor events. The notification command Signals that configuration of the device EndConfiguration() is used to inform other devices is complete of an event.

Table 2: Programming rules Method Notes interface Intelligent Luminaire StartProgramming() Starts programming of rules for the device

AddRuleFragment() Adds (a fragment of) a new rule for the device Luminaire architecture There are diverse contemporary EndProgramming() Ends programming of rules for the device luminaire designs across various, regionally different lighting market Table 3: Event subscription & Method Notes segments. A main architectural notification interface question is therefore how to manage SubscribeToEvent() Subscribes to the given event of this device such a scattered mass-volume UnsubscribeFromEvent() Unsubscribes from the given event of this device market cost-effectively. To avoid specific (low volume) peak designs, RequestToAnnounce() Request a device to announce itself with relatively high development and Announces that the device is operational and Announce() bill-of-material (BOM) cost, common ready for subscription modules and standardized interfaces Notifies the occurrence of an event to NotifyEvent() need to be (re-)defined as the the subscribers lighting industry has always

Figure 6: Modular luminaire block diagram

been based on standardized The different functions in the LED light engine light sources and interfaces diagram can be either integrated The LLE actually produces the light (e.g. E27, E14, GU10, etc.). or stand-alone, as preferred. and is thus the module with the For example, it is possible to largest diversity. In a full color To date, standardized interfaces combine the driver and LED engine, luminaire like the Wedge, the LED for LED-based light sources have or the embedded controller and engine differs significantly from the been scarce. However, the global LED engine. The distributed power single channel LLE used in the lighting consortium, Zhaga, architecture uses centralized TaskFlex. The LLE’s key functions published its first interchangeability high- and low-power supply units, are depicted in figure 7. standards in 2012. Zhaga standards supplying 24 V DC (i.e. SELV) to focus on non-competitive aspects the LED modules and drivers The color generation module of the main interfaces, ensuring (optionally, the 24 V DC supply can calculates the individual primary sufficient design freedom to also be used for power-demanding colors intensity to realize the closest differentiate and compete. This will embedded sensors), and 5 V for the color possible. Because some lower the adoption hurdle for LED communication bus. It centralizes applications require slow color design-ins and further fuel the the power factor control and transitions combined with a fast LED-based lighting industry. harmonic distortion circuits, and response to brightness changes, ensures low voltage Plug-and-Play the LLE has a separate brightness The EnLight luminaire architecture operation for the luminaire’s other and color fader. uses an I²C-bus interface to key components. This reduces interconnect embedded design complexity significantly, components, allowing partners to especially in multi LED Light Embedded controller contribute their technologies. Engine (LLE) luminaires. LLEs and Embedded Sensors need The resulting modular, Plug-and- a controller to bring the luminaire to Play architecture facilitates future Embedded sensors, such as life. From a software perspective the luminaire upgrades. It also enables temperature, light level or absence controller is the most complex ‘late stage’ luminaire configuration, sensors, increase control module. Fortunately, all EnLight either during production or effectiveness as they are typically luminaires share the same controller installation. Finally, an easy, co-located with the luminaire. software, so development cost can exchangeable modular concept This also simplifies installation be spread over many luminaires. reduces potential cost-of-non- and commissioning. quality, and decouples the lifecycles The “Decision Engine” is the of independent technologies. The embedded controller implements embedded controller’s brain and the The schematic diagram in figure 6 the decision engine and logical attached memory contains a set of depicts the components of the luminaire. The communication rules which determine the luminaire’s architecture’s key building block: module connects the embedded behavior. Rules are programmed the intelligent luminaire. controller to the ‘Lighting Control over the “Luminaire Control Interface” Network’ (LCN). and stored in persistent memory.

Figure 7: LED light engine block Decision engine & rules diagram In general there are two methods for implementing decision logic: scripting or rules. The consortium chose a rule-based solution as most lighting scenarios map well onto rules. Rules are also simple and inherently parallel, so lighting designers are not forced into the sequential thinking of programmers. The decision engine evaluates rules upon receiving an event. Rules are kept relatively simple to allow implementation on low cost Figure 8: Embedded controller hardware. While specified in XML, block diagram rules are programmed and stored in binary format and consist of three parts: Trigger Event, Condition and Action(s). The Trigger Event specifies the event (type and source address) that will trigger the rule. If an event matches the rule’s trigger event, its condition is tested; if true the specified actions are executed. Table 4 lists the supported actions.

Logical luminaire The logical luminaire understands Table 4: Rule actions Action Explanation “priority levels”, with all settings (some actions require applied on a certain priority level. LevelActivation Activates or deactivates a priority level arguments, comprising New settings only become visible if the event’s parameters SetVariable Set the content of a variable the specified level is activated. and variables - If more priority levels are active Figure 9) LuminaireSetting Change a light setting of a LED Light Engine simultaneously, the highest level SetTime Set the local time of the luminaire settings will be used. The level GenerateEvent Generate an event concept offers a powerful means to prioritize conflicting settings. The “LevelActivation” action is used Table 5: Luminaire commands Luminaire Setting Explanation to activate or deactivate priority levels. As shown in the example On Switch the light on (Figure 9), a level’s activation can Off Switch the light off have a timeout and when the timer expires, the level returns to its SetColor Set the color original state. This feature is often SetBrightness Set the dimming level used to make rules more robust for Apply the settings according to the temporary communication flaws. ActivatePreset specified presets The most important luminaire SetLightLevelControl (De-)activate the closed loop light level control commands are listed in table 5. SetColorFadeTime Set the time to go from one color to the other

SetFadeTime Set the time to go from one dim level to the other The “SetLightLevelControl” command activates the ‘closed loop light level SetPowerMode Set the high power supply mode: on, off or auto control’, often used for daylight harvesting. The luminaire will try to The decision engine can be are executed. Typically, an action realize the specified amount of light triggered by both internal (ILB) and results in a luminaire command that as measured by the light level sensor. external events (LCN). Each time an is passed to the logical luminaire. event is received all the decision This component translates a The logical luminaire also takes care engine’s rules are evaluated, and if a luminaire command into ILB of presets and “Level Definitions”, rule is triggered one or more actions messages to control the LLEs. which can be configured and stored

Figure 9: in persistent memory. Presets define XML presentation each LLE’s brightness, color and of a rule - The event on/off state, and can be recalled “SceneSelected” is with the “ActivatePreset” command. generated by a 6 button panel. Similar to a preset, Level Definitions The event comes allow default luminaire settings to with one parameter be overridden at power-on. representing the pressed button number. This parameter Event generation is passed to the A luminaire can generate its own “LuminaireSetting” virtual events and the generic command “ActivatePreset”. implementation of this feature So the shown rule makes it very powerful. Events can will activate a preset be generated instantly or after a depending on which specified time. This effectively button has been pressed implements a one shot timer, commonly used in lighting applications. For scheduled events, which require an absolute time and The EnLight architecture scales Informing as opposed to controlling date, the luminaire’s real time clock smoothly from a single luminaire to a luminaire implies that sensors and ensures the event occurs at the many hundreds. This makes the controls don’t require any correct time. Finally, the event module luminaire best place to host the knowledge of the system’s can be configured to generate intelligence (decision logic) of a luminaires. Embedded sensors in events on a periodic basis. lighting system as the amount of combination with local intelligence intelligence in the system grows allow simple and robust granular Key specifications: linearly with the amount of luminaires. control, but a well thought-out • Local rule based engine, communication framework is up to 250 rules Using a standardized intra luminaire needed for the effective development • Up to 250 presets bus enables luminaire diversity of such a system. In this case, • Color control: CCT, xy, HSV, RGB based on a limited amount of the use of a publish/subscribe • Up to 16 priority levels standardized modules from design pattern results in very • Embedded sensors: different vendors. The consortium efficient communication and PIR / Light Level / realized 14 types of luminaires, combined with the use of prioritized Temperature / Switch all based on the same building control (levels) delivers a very • Closed loop light level control blocks. For these luminaires, powerful solution for lighting a simple yet powerful decision systems with multiple sensors engine (+ZigBee stack) was and controls. Conclusions implemented on a low cost The consortium was a unique microprocessor (16 MHz RISC, collaboration with partners and, 32 kB Ram, 256 kB flash). Further, sometimes, competitors. the ILB framework showed that The following conclusions are based software reuse is possible when on scientific and technical results. moving from modular hardware Commercial feasibility has not been to fully integrated hardware addressed and is not taken into (cost down for high volume). account in the conclusions.

If luminaires designed for traditional light sources are simply retrofitted with LED light sources like it occurs in the so-called “1st wave of LEDification”, they will always fall short of expectations in many points. Herbert Weiß and Thomas Noll from Osram GmbH, Martin Möck from the University of Erlangen-Nuremberg, Martin Creusen from Philips Lighting, and Friedhelm Holtz from Insta Elektro GmbH explain why these shortcomings were addressed and which solutions were developed in the EnLight project.

One thing that all shortcomings Examples for the minimizing absorption of the of the “1st wave of LEDification” Shortcomings of Retrofit reflected light by the light source have in common is that a Solutions itself. With these technologies it sustainable solution implies is possible to realize light output resolving fundamental Screw base as disabler for ratios of up to 90%. The problem contradictions which are based minimizing junction arises when a linear LED retrofit on the fact that the retrofit temperature lamp is used as a 1:1 replacement. lamp does not fit the luminaire It is quite obvious that incandescent The LED light source whose light since it was originally designed lamp designs like those with an distribution is now far from for another technology like Edison screw base cannot fulfill one rotationally symmetric no longer incandescent, halogen or of the elementary LED lamp design fits the luminaire design. As a fluorescent lamps, but not criterions, namely to minimize the consequence the reflector might for LED lamps. LED junction temperature. One key have no effect at all. Light design aspect of the Edison socket distribution that is not desired by has been to keep the heat in the the user occurs or the luminaire system. The heat transfer path glare rating is out of specification. actually ends at the Edison lamp base. In contrast, for LED lamps and luminaires optimization of the heat Wall switch/dimmer not in transfer from the LED to the line with customer environment is essential for high expectations efficacy and lifetime. Retrofitting a luminaire also means that classical user interfaces - like the common wall switch or dimmer Luminaire optics are not used to switch or dim the lamp - suitable for light shaping of are generally maintained. retrofit If we consider, for example, a troffer On the other hand LEDification and luminaire using linear fluorescent digitalization of luminaires open up lamps, it is an important design far more possibilities for interaction. aspect for luminaire manufacturers Automatic adjustment triggered by to optimize the light output ratio sensors or remote adjustment of by use of highly reflective materials light and light scenes by various for the reflectors and also by use user interfaces like a customized of specially shaped reflectors. app via a smart phone are A classical example is an evolvent examples. Retrofits will never meet design, which allows for guiding the customer expectations arising from reflected light around the lamp and these possibilities for control.

Figure 1: Office Luminaires “PowerBalance” For office applications, the focus luminaire with 2 x 8 is traditionally on high luminous reflector cups (left). efficacy, short return of investment Mini-“PowerBalance” luminaire with 2 x 2 and long maintenance factors. reflector cups (right) In this project emphasis was put on high light quality, i.e. high color rendering, pleasant appearance, the possibility for color and color Figure 2: temperature adjustment and exact EnLight architecture control of the light distribution. of the “PowerBalance” All luminaires were built as intelligent luminiare luminaires, letting each individual luminaire make lighting decisions based on presence, occupancy events or ambient light information detected by its own integrated sensors, or events and information from other nodes in the network.

The following luminaire prototypes were designed accordingly.

Figure 3: Instalight Glow Intelligent “PowerBalance” luminaire The “PowerBalance” luminaire family from Philips consists of state-of-the- art energy-efficient office-norm compliant LED luminaires (Figure 1). These luminaires offer good-quality lighting solutions for direct replacement of T5 luminaires in most indoor office applications. The two form factors applied in and controller board). All mentioned and more smooth and classical the demonstrator installations, components were connected in a appearance. Four LED and lens a standard troffer size with daisy-chain configuration (Figure 2). modules are arranged at each end 2 x 8 reflector cups and a mini- of the 1500 mm long luminaire. “PowerBalance” with 2 x 2 cups, This task light component is contained tunable-white EnLight Intelligent “Glow” available in color temperatures compatible LED Light Engines In contrast to the flush mounted 3000 K or 4000 K. It provides (LLEs), and an embedded PowerBalance recessed luminaire, > 3100 lumens and a color temperature, light and PIR multi- the intelligent instalight Glow rendering index of > 85. The overall sensor from Valopaa. The outer luminaire contributed by Insta luminous efficacy of the task light dimensions were 1200 x 300 mm2 Elektro GmbH is a linear pendulum component is 87 lm/W. and 300 x 300 mm2, respectively. luminaire with direct / indirect LED The 4-channel LLEs (warm white, light output. The light distribution of Separately dimmable indirect cool white, blue and amber LEDs) the direct outlet is controlled by illumination was provided by RGBW using high power LEDs were driven lenses which resemble big drops of LED modules concealed on the by two 3-channel UBA3077 driver water protruding from the luminaire. back side of the luminaire. The user boards from NXP. The tunable white This notable design makes the was free to choose from the entire light output for the 2 x 8 cups luminaire suited not only for the RGBW color gamut range. “PowerBalance” (at 350 mA LED illumination of workplaces but current) was >3000 lm for warm especially for reception areas, The luminaire complies with white and >4000 lm for cool white lobbies and conference rooms. standard EN 12464-1 regarding with an overall luminous efficacy omnidirectional glare reduction. of 105 lm/W. The Intra-Luminaire The drop-shaped optics of 80 mm Bus (ILB) was used for internal diameter is made of clear acrylic The luminaire had embedded communication between the glass. Optics is optionally available sensors for motion, illuminance different embedded components in an internally satined version that and color temperature control. (i.e. LED driver, multi-sensor gives the luminaire a less technical The luminaire architecture followed

the same concept as depicted in rooms deep inside a building. to the outside by a white sheet with figure 2 but with different numbers Due to its very large light emitting predominantly diffusive reflectivity of of LED and driver boards. The Glow surface this luminous door allowed about 99%. Thermal management luminaire had a one-channel LED for the creation of a wide set of was highly efficient since LED board for direct and one four- scenes like sunrise or favorite boards as well as heat sensitive channel LED board for the color patterns for mood lighting. driver components were coupled to indirect light output. The physiological impact can be the metal door frame which had a used for light therapy such as large cooling surface. alleviating jetlag or treating seasonal Luminaires for Hospitality affective disorders. Glare was not an Applications issue despite a very high maximum “Wedge” luminaire For a hospitality environment luminous flux up to 10,000 lm A luminaire developed by OSRAM EnLight provided much more than depending on color temperature or which served as a platform for a just conventional luminaires. color settings. The maximum wide range of room lighting and Prototypes demonstrated in this luminance was 4000 nits (cd/m²). decorative designs was dubbed project proved that, by exploiting the “Wedge” for its wedge shaped design freedom enabled by LED, The door was equipped with design. Light was emitted at the luminaires can be realized which embedded PIR sensors from wide edge of the “Wedge” which is provide more than just illumination Valopaa for interaction with a ideal for mounting the luminaire on for a visual task. They became preconfigured light level and varying vertical surfaces to light a desk not only the actual creative element colors and patterns. One sensor (task lighting), on the ceiling or just but even merged into building was placed near to the door handle. for a wall-wash effect. With a structures and took over part of Luminaires or other devices in the maximum height of only 25 mm the their functional properties. room were thus activated as soon luminaire was exceptionally flat and as someone was using the door required little mounting space. handle. In the same way sensors in The unobtrusive appearance made “Luminous Door” the room checked for occupancy the luminaire almost disappear, The luminaire with the highest when the door handle was touched and directed the user’s attention to functional versatility and functional upon leaving the room. the light and the illuminated object. integration into building components realized in this project was a Another option was to use the Similar to the luminous door, luminous door (Figure 4) developed luminous door for showing a hotel multicolor LED modules consisted by OSRAM. Both back and front guest the way to his room by raising of warm white, red, mint and blue sides emitted light and could be light output, or tuning color. LEDs for full color tunability. controlled individually, including LEDs were placed in a highly individual control of all four frame The luminous door was made of reflective mixing chamber which parts (top, bottom, left, right). linear multicolor LED boards, which was optimized for high light output, Colors and color temperatures were hosted inside the doorframe. homogeneous color mixing and could be varied within a large gamut Their light was guided into the prevention of direct glare from direct range, which is achievable with edges of special PLEXIGLAS® view into the LED light source. warm white, red, mint and blue sheets which homogeneously Since the housing was made of LEDs. The door was virtually coupled the light out of the sheet’s metal, it was effectively used for mimicking a window and is thus surface. Light exiting towards the heat spreading and cooling of LEDs ideal for places like windowless inside of the door was redirected and electronic components. In order

Figure 4: Luminous door with two light emitting sides. Examples of homogeneous daylight as well as of a colored pattern is shown

Figure 5: to enable emission and reception “Wedge” luminaire and of radio signals within the wireless luminaire architecture EnLight communication network a plastic window was inserted into the metal housing just above the radio antenna.

“Wedge Wall” The side emitting design of the “Wedge” luminaire was especially suitable for light arrays, where multiple panel configurations allowed design freedom. Together with the variability of color temperature and color combinations an infinite number of scene settings can be achieved. A selection of different settings, which Figure 6: were chosen for the installations, is “Wedge Wall“ scene shown in figures 6 and 7. settings at the office demo at VTT, Finland Similar to the luminous door, the “Wedge Wall” allowed glare free illumination and mood lighting. Indirect lighting was dynamically tuned and adjusted. The wedge wall and the luminous door substantially contributed to vertical lighting. Horizontal lighting is a mainly functional property requested by standards with regard to the execution of a visual task on multiple components and luminiares The “Wedge” luminaire panel horizontal surfaces. Vertical lighting (Figure 8). The entire “Wedge” panel was installed in different is more and more recognized as was regarded as a single luminaire configurations with 8 “Wedge” a vital prerequisite for spatial which is composed of modular luminaires at the office demo at experience. The wedge and door building blocks. For the hospitality Philips, Netherlands and with luminaires not only enabled the demo shown in figure 7 a total of 16 “Wedge” luminaires at VTT, architectural construction of spaces 12 “Wedges” were used in one Finland (Figure 6). In these cases with light but also provided a panel. Three 75 W power supply branches of 4 “Wedge” luminaires pleasant experience where people units supplied the entire panel. were simply removed from and came to meet and talk. With a high Wireless communication from added to the configuration in component of vertical lighting, outside the panel was done by figure 7, respectively. faces were well illuminated and ZigBee to the luminaire controller. not obscured by shadows. If the intra luminaire communication The “Wedge” wall concept bus, developed in the course of the demonstrates how an apparently project, was used for communication complex intelligent luminaire can be “Wedge Wall” architecture from the luminaire controller to the configured by just “stock-picking” The “Wedge Wall” provides a good LED driver controllers, luminaires, ingredients” from the building block example of how the modular sensors and user interfaces could inventory (Figure 1 in the “EnLight architecture can be employed for be readily added or removed without Intro-Overview”) without a special most flexible configuration of further need of re-commissioning. need for customized development.

Figure 7: “Wedge Wall” scene settings at the hospitality demo at Osram GmbH, Germany

Figure 8: Architecture of the “Wedge Wall”- a panel with 12 “Wedge” luminaires is shown in this example

Luminaire for Accent luminaires can be given thrilling 6 mm was used. The étendue Lighting designs to which we had not been which governs the size of the used to in traditional lighting entire optical system was thus Spotlight luminaire systems. Spotlight luminaires very small. In combination with A spotlight luminaire suitable for designed for the use with legacy a Fresnel TIR lens, which was track light mounting was developed light sources are usually associated optimized for maximum flatness for the purpose of adding accent with elongated cylinders and long the whole luminaire aspect ratio lighting to EnLight installations. parabolic reflector shapes. For the represented the extreme opposite This luminaire demonstrated that luminaire an extremely small LED of conventional designs. with the use of LED technology light kernel with a diameter of only Lighting module and track light

Figure 9: The light distribution of a spotlight on a projection surface (left) and the measured light distribution graph (right)

Figure 10: EnLight spotlight luminaire

body were both cubically shaped As with all other EnLight luminaires, LED technology. LED light source which gave a consistent style and color and color temperature tuning efficacy was optimized by harmonic overall appearance. was implemented. Electronics driver thermal management concepts, and control components were which minimize the LED junction Efficacy was not sacrificed by this placed in the track light body. temperature by making use of design. The flat design rather functional and design structures of improved thermal management. the luminaire without adding bulky The light kernel was mounted Conclusions cooling bodies. High light output directly on a heat sink at the back of The project partners developed ratios added to the overall luminaire the luminaire and an open structure various luminaires that followed the efficacy by means of optical designs allowed for air flow through the same modular building block which fully take into account the lighting module and enforced concept of the EnLight component light source properties and the convective cooling. inventory. These luminaires were desired luminaire light distribution. integrated into the office and The high lens optical efficiency hospitality installations. All luminaires New form factor luminaires led to a light output ratio of close demonstrated that this new luminaire were demonstrated that break to 95% for the used light kernel. system architecture with a high completely free from conventional The total luminous output was degree of modularity and designs and take the notion of a 500 lumens with an overall extensibility, enabled by the luminaire to a level that would have luminous efficacy of 80 lm/W. intra-luminaire communication bus, hardly been considered with is working. The new level of freedom traditional light sources. The light kernel provided a red, in configuration and combination blue and mint color combination. was used to realize concepts which Light mixing was done by a diffuser would have been much more cast on the light kernel level. complex and less configurable In combination with the lens optics in the past. a perfectly homogeneous light distribution of beam angle In contrast to the retrofit approach, FWHM = 30° was achieved EnLight luminaires widely exploited (Figure 9 - right). design possibilities dedicated to

The EnLight consortium came to the conclusion that to provide cost effective solid-state lighting products there are several aspects in which a modular approach seems to be advantageous. Tim Böttcher and Lucie Chandernagor from NXP, Philippe Maugars from PMC, Hannu Vihinen from Helvar, Mark Coopmans from Philips Lighting, Olli-Pekka Jokitalo from PKC Electronics, Raimo Ontero from Valopaa, Christian Paul from Infineon, and Rafael Jordan from Fraunhofer IZM explain how the new approach works.

The EnLight Lighting System limited set of hardware, In order to give as much design was based on a modular even coming from different freedom to the luminaire design hardware approach, which was partners. The functionality of as possible, it was intended to founded on a Plug-and-Play the individual luminaire was have very compact and energy hardware bus and distributed then only realized in software efficient modules. Besides the intelligence of the individual and no hardware change was small size, this allowed the heat Figure 1: communicating luminaires. required. An example of the sinks to be reduced in size or Set of four different luminaire types build This modular approach allowed variety of building blocks inside to use parts of the luminaire on the same set of realizing the required large one luminaire is illustrated housing as heat sink. hardware variety of luminaires with a in figure 1.

Figure 2: Diversity Management Bus system inside an In order to connect all the individual intelligent EnLight modules, a novel bus system was luminaire, connecting developed. Since several partners LED driver and sensor boards contributed to the hardware platform, the bus system was required to be highly flexible and simple to adapt to the actual hardware requirements. In the following section the hardware and the software parts are illustrated. integration if required for BOM. One of the applications is a controller As illustrated in figure 3, the ILB implementing the intelligence in ILB hardware bus system framework forms a platform for the form of a decision engine, which The EnLight luminaires were based functions that need to communicate takes input from sensor applications on LED driver and communication to one another, where a function and drives lamp applications. modules, which were connected (e.g. presence sensing) typically through a standard I²C bus. The bus consists of a hardware part and a During power up, an address driver was modified in such a way, software part. In ILB the software requesting service queries the that the plug-and-play operation of part is referred to as an application. address assignment service for a modules is possible. Within one unique I²C hardware address to be luminaire, one distinguishes the Intra Technical features of ILB are: assigned. Similarly for the module Luminaire Bus (ILB) and the LED • Reusable and exchangeable ID service after a hardware module driver bus. The ILB bus system is building blocks was assigned a hardware address. connecting the individual modules • Abstraction from implementation The controller is the only module on hardware basis to an intelligent technology (e.g. PIR vs. that is found on a fixed hardware luminaire controller. The LED driver Ultrasound for motion detection) address. All other modules are bus purely operated in master-slave • Application software integration assigned a hardware address mode in order to distribute commands into combined hardware (and also module ID) dynamically. to the PWM generator on the LED execution platform driver board. All modules and boards • Multi-master mode enabling were designed to allow the daisy low standby power Hardware Modules chain connection of boards, • Plug and Play The implementation of the actual thereby simplifying the wiring in total. • Portability to different physical hardware was guided by the An example of such a luminaire communication layers luminaire requirements, which, configuration is shown in figure 2. (e.g. I²C, RS485) in particular constrained the possible volume and the heat management of The decision engine was placed When partitioning the system in the modules. Here, the key modules in the intelligent controller module, hardware modules, a function may are described by example. which was commonly connected migrate from one hardware module to the ZigBee or area network. to another, depending on the most Based on the programmed rule set appropriate implementation for Power supply units in use, the controller translated the that system. To support such a The Power Supply Units (PSUs) rules into module commands on the migration, the ILB framework were AC/DC converters designed ILB network. The behavior of the abstracts the physical location for this new architecture. Each PSU luminaire as a whole was then only and routes messages between contained two separate power defined by the rule set programmed modules as applicable. supplies: high power supply (HPS) into the intelligent controller. for LED drivers and low power Accordingly, it was possible to use The ILB framework is a shared supply (LPS) for ILB devices. standardized and small LED driver software component that: To address all luminaire needs, modules to operate the LED strings, • Provides address resolution and two different PSU versions with a which were connected on the ILB physical communication between power of 75 W and 20 W were bus in order to build luminaires hardware modules developed. The main criteria for of all sizes. • Provides an interface for the PSUs were high power factor, applications to exchange high power conversion efficiency messages and low stand-by power. The power ILB software bus system • Associates an application with the factor corrector was based on a The main concepts behind the Intra appropriate hardware module boost topology with quasi-resonant Luminaire Bus (ILB) are to introduce • Provides a managed message set control, which results in a power modularity, yet allow an easy factor of up to 0.97.

Figures 3: The ILB framework controller. As illustrated in figure 6, as platform for the setting from the intelligent communicating luminaire controller was translated applications by the LED driver controller into a set of required PWM signals. The related commands are then given to the PWM expander, which independently generates the PWM signals for the DCDC converter at the LED strings.

One DCDC LED driver for short Figure 4: The block diagram of strings was designed for an average the power supplies LED current up to 0.7 A (Infineon ILD6070). Switching and conduction losses of the IC were minimized to achieve a high efficiency. LED driver switching frequencies up to 1 MHz enable the use of low inductance inductors keeping the board size small while achieving high slew rates of the LED current. The high slew rate together with the short PWM delay time of the IC allowed high contrast ratios in each LED string. For long LED strings, Figure 5: Embedded sensor boost DCDC LED driver boards block diagram were designed accordingly.

Intelligent controller and ZigBee communication A combined CPU and ZigBee transceiver for all EnLight building The 75 W HPS used a LLC resonant people, prevailing ambient light blocks was chosen (NXP JN5168). topology with synchronous level and temperature inside the On most of the modules, secondary side rectification sensor. The sensor boards a connection slot was reserved so (NXP SSL4120T). The 20 W HPS accommodated sensor controller, to be able to plug a standard CPU / was driven by a quasi-resonant PIR sensor, and ambient light ZigBee module flashed with the flyback controller (NXP TEA1755T) sensor and temperature sensor. relevant firmware when necessary. with synchronous secondary side They were powered from 5 V DC Although the communication rectification. The LPSs of both PSUs supply, delivered via ILB bus function was not needed in all were based on a flyback converter connector and from which power modules, the same controller chip that enters the burst mode at low consumption below 10 mW is was chosen so as to have full load to ensure low losses. achievable. The functional block flexibility for reuse of the embedded The functional block diagram of diagram is presented in figure 5. SW blocks without any redesign. the units is presented in figure 4. The sensor boards were designed in two form factors to fit into The dynamic smart lighting Also, up to 4 pieces of the PSUs different luminaires. requirements from EnLight require a can be combined to form high major extension of the hardware and power luminaires. When the LED software capabilities. A new ZigBee load was switched off completely, LED driver boards stack was developed, enabling up to the main power supply was The LED driver boards were 250 nodes in a single network. switched off as well via the ILB-bus. designed to operate autonomously The radio receiver, optimized for once a defined setting is better efficiency allowed lowering the programmed through the ILB. standby consumption below 100 mW, Embedded ambient sensor This was achieved through a pulse thus meeting the future targets. Embedded sensor boards were width modulation (PWM) expander The chip will feature a full Multi designed to provide luminaire level (NXP PCA9685), which had an Master I²C bus that improved the information on movement of I²C interface to the LED driver performances of the ILB bus

Figure 6: described above. A full function Hardware bus system JTAG debugger allowed easier and inside one LED driver faster real time software development, board connected to and a larger flash memory will enable the ILB seamless over the air re-flashing. The block diagram of the new chip is displayed in figure 7.

Miniaturization To go beyond the given size constraints from the chosen EnLight luminaires form factor, the miniaturization of modules was evaluated further. Here, different integration of the module in the foot technologies and the thermal pad aspects such as board design of the lamp, which was not possible was insulated from the electrical and LED design were addressed. with the two-stage design. connections, illustrated in figure 9.

The assembly process of the Compact single stage PSU Integrated LED light engine packages was chosen in a way for simple luminaires with hermetic package that no step would re-melt prior Most EnLight luminaires featured Another component for the modular interconnections and that the final several LED strings, or even several luminaire was a spotlight with about package would withstand process LED Light Engines; therefore, 1000 lm out of a 20 mm² package temperatures up to 270°C. Known the two-stage topology with surface. As the project partners and new technologies like eutectic central PSU previously described, always focused on forward looking bonding, anodic bonding, transient was chosen. However, for some solutions, this module had to be liquid phase bonding and more were simple luminaires a single stage hermetically sealed to withstand chosen the way that no polymeric or approach is more appropriate, humidity as well as harmful gases other permeable interfaces are built. since this allowed a more compact and other harsh environments. Therefore, the package is completely electronic module and lower To achieve this goal, a completely hermetic and highly reliable. standby power consumption. new approach was launched, starting from thermal and thermo- Such an application was developed, mechanical simulations, developing Energy Efficiency tested and demonstrated (NXP a complete 8” wafer level packaging The project achieved the energy SSL5511). Figure 8 shows the mains process and assembly of prototypes. efficiency targets, in particular, interface, the manual switch, The packages were designed for through intelligent control of the the Jennic module with printed flexible configurations with pure illumination on the basis of highly antenna and the connections to white LEDs, RGB-LEDs or even efficient modules in the system the LED module. The compact additional sensors. The footprint is electronics. Examples of this work size (10 x 7 x 2 cm) allowed the compatible with standard board are illustrated in the following,

Figure 7: Block diagram of the JN5169, a CPU / ZigBee chip based on the project findings

Figures 8 & 9: Compact Supply/ Driver/Communication module (left). A hermetic package housing red, green and blue LEDs. The background shows the wafer on which the LED light engine was manufactured (right)

Figure 10: The efficiencies of the The wake-up radio was designed PSUs as a function of in CMOS technology and operates the output power on its own supply source at 3.3 V. In standby mode there is no power drain on the main supply.

When a user presses the command switch, an activation message at 433.92 MHz is emitted. This wake-up message is Manchester encoded at 25 kbit/s. The 24 bits address it contains is programmable where components designed for the The complete LED driver in an by SPI bus. If the expected code is specific requirements of intelligent EnLight luminaire with 25 V DC received, the wake-up radio lighting are described. supply voltage (including losses provides a pulse that drives an of inductor, current sense resistor electrical relay connecting the main and Schottky diode) achieved supply to the application. This pulse PSU and LED driver efficiencies above 95% driving is delivered with a maximum latency efficiency 6 LEDs at the rated current of time of 125 ms. The wake-up radio The efficiencies of the PSUs at full the IC. In PWM dimming down to achieves a - 55 dBm sensitivity that load were about 93.5% (75 W PSU) 1% duty cycle the efficiency of the allows for a 10 m range in indoor and 90% (20 W PSU). However, LED driver was better than 81% due conditions when using a standards even more important is the good to the low power consumption of regulation compliant 10 dBm emitter. efficiency throughout the entire load the IC, which is a prerequisite for range in a system where the energy intelligent lighting with its intense The wake-up receiver is compatible consumption is minimized by usage of dimming and color control. with a ZigBee transceiver. Indeed, dimming or shutting down the LEDs. it is therefore suitable for use at In figure 10 the efficiencies are 868 MHz or 2.45 GHz. ZigBee plotted as a function of the output Wake up radio transceivers are able to generate the power, showing the efficiency above Even if the ILB cuts off the main wake-up message subject to 82% even at the lowest load. power supply, the receiver still software modifications. drains power on the order of The 75 W PSU was able to receive 100 mW. The wake-up radio is an commands on the ILB bus, such additional receiver only in charge DCDC choice of the flyback that the high power output can be of the activation of the application diode in the LED driver switched on/off in order to optimize (Figure 11). As a net result, In the chosen low cost non- load and losses. The standby power the standby power use of the synchronous LED driver loss was then down to 160 mW. whole application was reduced to architectures, Schottky diodes However, the standby losses the power consumption of the were used due to their low forward depended on the quantity of devices wake-up radio. This consumed voltage during conduction and connected to the ILB-bus. The low only 100 µW, i.e. a thousandth of the fast switching. However, power output is always on and it the standby power consumption. choosing an optimal diode for the provided the power to the control Setting a lower operation rate at the application was not straightforward circuitry of the system. cost of a higher latency time can due to the loss contributions arising reduce this consumption further. from forward conductance,

Figure 11: Schematic diagram of the wake up radio application

Figure 12: leakage current and switching. Power loss The peak efficiency of the buck contributions in the DC-DC converter exceeded 95%, flyback diode of the and by choosing the correct DCDC LED driver Schottky diode the efficiency can be increased to 96%. At low load conditions, the efficiency improvement can even be as high as 5%. This does not seem impressive, but it translates to a reduction of the losses by more than 20%, easing the requirements on the thermal design. Since the I-V and C-V characteristics intelligent lighting with its intense One might think that a Schottky of Schottky diodes could be well usage of deep dimming and color diode with lower forward voltage described by SPICE models, control is supported by the power drop VF would always result in it was possible to evaluate the total electronics, which were designed better efficiency. This is based on loss of the Schottky diode in this to deliver high efficiency at full and the assumption that the losses due application in the design phase partial load. Embedded sensors to the leakage current and the and even to predict the and the distributed presence of switching are negligible. It is valid operating temperature. controller modules enable the as long as the conversion frequency intelligent control. is not too high. Once the board operates in the range above 100 kHz Conclusion To conclude, the modular as for the EnLight design, This Chapter detailed the design of architecture supports future lighting the switching losses become the modules inside the intelligent system upgrades facilitating the shift relevant for the system. and energy efficient EnLight of the current linear economy to a Figure 12 shows details of the architecture. It was shown that it is more sustainable circular economy. loss contributions for an LED driver possible to build a large variety of Easy exchangeable (modular) with 6 LEDs, operating at 300 kHz. luminaires on the basis of few lighting systems, as opposed to Except for the ultra-low VF hardware modules from different “sealed-for-life” systems, are required PMEG3050EP that has a very high suppliers, which are seamlessly to realize this circular economy. leakage current, loss due to reverse integrated via the smart usage of leakage is negligible as compared to reusable software on top of I²C bus the switching loss and the forward architecture. This Intra Luminaire conduction loss. Interestingly, Bus is fully plug-and-play from a the smallest diode with the highest hardware and software perspective, forward voltage PMEG4020EP gives enabling the easy and secure the highest efficiency due to the replacement of modules inside one smaller switching loss. luminaire. The application of

The EnLight project looked for greatly improved energy efficiency and user comfort in lighting applications. Werner Weber from Infineon Technologies, Lex James from Philips Research, Arjan van Velzen from Plugwise, Bruno Vulcano from Legrand, Micha Stalpers from AME, Arend van de Stadt from Eagle Vision Systems, Jens Döge from Fraunhofer IIS/EAS, and Wilfried Rabaud from CEA Leti explain how a closer relation between the user and provided light made it happen.

The closer the relation between Figure 1: Building blocks the user and his requirements developed for sensors in terms of light provided in and local user controls space and time, the better the during the project comfort. These demands were fulfilled by advanced sensors and EnLight’s distributed rules- based intelligence concept. Various physical parameters are important and need to be measured to allow proper decision-making such as occupancy, position of people in a room, level of outside lighting and temperature. The sensors developed and implemented into the lighting control network as well as the user controls are summarized in figure 1. Those peripheral devices are connected to the Lighting Control Network schematically shown in the illustration.

Sensors and User the system to react on a sensor a hierarchical group structure. Interfaces signal from a domain that is not The size of the group can vary from Before the different sensors are lighting related, e.g. smoke alarm just a few luminaires in a toilet to a discussed one-by-one, the role of provided by a CO2 sensor: large number of devices within the sensors and controls in this project whole building. In each group, is highlighted. The context was In this context so-called “virtual modules can be added and presented in general terms in the sensors” are possible. For example, removed and specifics like vendor EnLight architecture paper in a luminaire with a decision engine name and hardware version can be this article series [1]. Here, a few can generate an event stating the set. If a group is selected in the app examples shall clarify the concept. presence of persons, rule-based on a list of all its modules and a list of the information from various subgroups pops up and if a module The sensors discussed in this paper presence sensors in a certain area. is selected, the tool shows in which provide information but they do not groups the module is present and make decisions. Decisions are only Another example of a virtual event the groups that a module belongs to made in the luminaire. In this is a peak load-limiting signal coming can be added, removed and saved. architecture on the one hand, from the smart grid to request the sensor is acting independently temporary power reduction. As background information it is of the way its output is used and on Luminaires can be provided with important to understand that the the other hand the control in the rules that react to such an event commands are executed by a set of luminaire is rather flexible in the use so the lighting system can rules (based on an Excel file), which of different sensor data depending respond to the request. are triggered by events; an event on the application. Flexibility is might be initiated for example by largely enhanced by this architecture In the following chapters a user someone walking in the office. which uses a standardized process interface tool for commissioning The rules contain different levels of in the publication of data (e.g. by application in EnLight systems, priority and the execution of a rule the sensor) and subscription to the a specific local user control, may result in new “luminaire settings” receipt of data (e.g. by the luminaire). and different presence sensors/ and “level (de-)activation”. Only the cameras are discussed based on settings of the highest active priority In order to exemplify the context the different technical concepts and level are displayed, when no level is user can press a button on a panel considering the privacy aspects. active the luminaire is switched off. with two buttons. The button has no knowledge of what it means when it Each device has its own set of is pressed. The user knows what User Interface Tool rules and thus every QR code the pressing of a button means and Plugwise developed the contains its own set of rules. the luminaire acts on rules to commissioning tool, which mainly A standard set of rules is applied interpret the information. moves toward improved usability of to each added module, which the luminaires (Figure 1, top) [2]. means that when presence is The pressing of button ONE The application provides a large detected all the electricity turns on can mean variety of use cases; for example, in the specific group and if absence • Luminaire 1 to dim-up it can easily change the colors of is detected, all electricity switches • Luminaire 2 to increase the the luminaires with only one click on off. In this way energy consumption color temperature the color palette on an iPad or other is reduced, which was one of the • HVAC to increase the temperature iOS- or Android-driven devices. great challenges of the project. Furthermore, the app makes it and the pressing of button TWO easy to set up a schedule for the can mean luminaires so they provide varied Local User Control • Luminaire 1 to dim-down light colors and intensities in Legrand developed a local user • Luminaire 2 to decrease the color each specified time frame control in order to give capabilities temperature, and (e.g. 30 seconds purple, 30 seconds to locally provide input to the • HVAC to decrease temperature orange). The data can be put in luminaries (Figure 1, top). manually, but a Bluetooth QR- In any case, the button itself scanner may also be used to Two kinds of ZigBee end device only provides the information that scan the data of the luminaires. systems were introduced: a certain button is pressed. The QR codes may be printed or The luminaire can interpret this just shown on a computer screen. • A wall switch able to be installed information by a rule-based action. and fixed wherever the end user The app is not only able to give wants This example illustrates the decoupling commands to one single luminaire; • A table remote control of domains (sensors and luminaires there is also an option to group in this case). The decoupling allows multiple luminaires and create

Both run on batteries. In addition to People Tracker interface to external systems makes the ZigBee EnLight Profile Eaglevision developed a people it possible to process the tracks embedded in these devices and tracker system [3] (Figure 1, and other detected events. compared to other solutions on the bottom). This EagleGrid system is a market, Legrand improved ZigBee marker-less 3D People Tracking The camera images are processed commissioning management System. It is a scalable network of on the local processor and do reliability within the proposed small, people detection sensors, not need a central server. architecture. called EagleEyes, which are This architecture avoids heavy connected. These sensors cover network load and supports the Modifications done on the large areas including complete “privacy by design” principle commissioning sessions floors in buildings. No tags like because server image storage were as follows: RFID, Bluetooth or other badges is not required. In collaboration • Return to factory configuration are needed. The system is based with our application partners functionality: allows deleting all on stereo vision and advanced complete applications and bindings which are initiated 3D imaging. The open network solutions are implemented. between the ZED (ZigBee End Figure 2: Standing/sitting Device) and its ZigBee Router (ZR) detection demonstrator. • Auto Remove functionality: after a The lighting situation commissioning session, products adapts automatically are working in a normal use when a person is sitting down or standing up mode. In case a ZR is not able to join, after several attempts, the ZED removes the ZR address from its binding table. As soon as this ZR has been removed from the binding table, the ZED sends a Subscribe Announcement signal to allow new ZR’s to join or to allow the ZR which has been excluded from the binding table to re-join. This algorithm allows for an automatic clean-up of the binding table in case a ZR is broken or has been removed. It also allows a solution for RF communications issues which may occur • Child - Parent Management: In terms of the ZigBee vocabulary, a ZED is the child and a ZR is the parent. Each ZED communicates with the ZigBee network through its parent. It is not mandatory that a child is bound to its parent. In case a parent is not seen by a child, the child has to manage a way to find another parent to talk with the ZigBee network. Moreover, the child also has to manage situations in which its previous parent is returning into the network. These situations are encountered when a power outage occurs during an installation

As a consequence of these measures communication reliability was increased.

The tracking system can be used Motion Detector and in all indoor places where people Temperature/Humidity The temperature/humidity need to be tracked and safety Sensor sensor offers: events are automatically detected. Existing motion and temperature/ • Subscription on periodical The system respects people’s humidity sensors from Plugwise/ reporting of temperature and privacy by design because the AME were adapted to support humidity measurements in images are processed locally. the EnLight functionality and the form of EnLight events ZigBee communication protocol [4] • Reporting conditionally based With the EagleEye stereo cameras (Figure 1, bottom). The sensors on a change in measured values 3D images are acquired and were battery powered devices for temperature and humidity. processed. By advanced and therefore act as sleepy end For example, the temperature algorithms individual persons are devices according to the ZigBee is only reported in case the tracked in 3D and their route and specification. They rely on the measured temperature deviates poses over larger areas (including luminaire in the neighborhood to more than 5°C from the multiple cameras” field of view) are act as their ZigBee “parents”. previously reported value measured. Based on this method The sensors are in deep sleep of tracking data, many applications (no radio) as long as there is no are available such as direction detection of an EnLight event. CMOS Camera sensitive counting of people in As soon as a relevant event occurs, Within the scope of the project, broad passages, detection of a i.e. detection of movement or a timer Fraunhofer IIS/EAS developed a fallen person, counting the exact for reporting, the sensor wakes-up, low-power presence detector, number of persons in a room gathers the event data (typically light, based on an image-sensor system- (for example for access control), motion temperature or humidity on-chip (SoC) [5]. In contrast to measurement of queues and measurements), switches on the traditional solutions, such as passive service times, and monitoring of ZigBee radio and sends the event infrared (PIR) sensors, this system human behavior (detection of via its parent luminaire over the air to processes the image in the visible elderly persons wandering in the subscribers. Please note that and near infrared spectrum, unsafe situations). this fits seamlessly in the EnLight and derives texture features from model as described before. visual information. A self-learning Within the project an office multi-modal algorithm analyzes the demonstrator was developed. Both the motion detector and scene at a frame rate of up to ten The demonstrator reacts to human the temperature/humidity sensors frames per second. People can be behavior as follows: in an office offer the following common localized within the field of view and setting the lighting is modified functionalities: distinguished from technical objects automatically (in color and intensity) • Leave the old network and join according to the active area and based on the pose of the person(s) new network upon network typical motion. In contrast to in the illuminated neighborhood. button press (> 7 seconds) gray-scale algorithms the chosen In the demonstrator the lighting • Announce to other devices in approach is highly tolerant to color moves from “reddish weak” the network upon a button brightness variations occurring to “blueish intense” when the press to allow configuration due to incoming sunlight or person is standing up, for example and subscription switched luminaires. to give a presentation (Figure 2). • Configure operational parameters With this lighting configuration, such as “reporting period”, We performed tests using a the attention of the other attendees “humidity delta reporting hardware / software prototype will be optimal and focused on the threshold” or “absence timeout” based on a commercial image presenter. As soon as the person • Report measured data on a sensor as well as an FPGA- sits down again, the lighting returns periodical basis in the form implementation of the processing- to the original situation for a more of EnLight events pipeline (Figure 3, left), and soft evaluation discussion. simulations. They show the The motion sensor offers: reliability of the method. Moreover, This demonstrator stands for a • Subscription on presence events, the experiments demonstrate that a large variety of possible use cases absence events high-dynamic-range image of the EagleEye as smart sensor • Subscription on periodic acquisition increases the integrated in an intelligent lighting reporting of light measurements effectiveness even further, system, creating a very smart and presence especially for mixed lighting with building. Application areas are • Notification of presence and the inclusion of sunlight or shadows. office, hospitality, retail, security absence (no presence for a and (home) care. configurable amount of time) These findings, as well as the to subscribers algorithmic approach, contributed to the development of the new

Figure 3: Demonstrator of the presence sensor (left) and image sensor SoC with integrated low power data processing (right)

presence sensor with a novel After installation of the sensor, detectors (PIR, thermopiles, etc.) smart high-dynamic-range image various regions in the room are and the high-price - high pixel size sensor SoC (Figure 3, right). configured in the software so that, IR imagers (µ-bolometers). It features a linear-logarithmic depending on the location and characteristic with more than characteristics of recognized The new IR µbolometer based 120 dB dynamic range, and was movements, events are issued. presence sensor was developed on developed using Fraunhofer’s By their logical combination it is two parallel tracks: the first one is proprietary charge-based mixed- possible to detect whether a door the development of low complexity signal sensor-processor platform [6]. was opened, whether somebody detection algorithms (low-level and The integrated application-specific entered or left the room, high-level), and their implementation instruction set processors (ASIP), where movement is located and on the demonstrator that was and the column-parallel processing how intense it is. The different specifically developed for the units have therefore been enhanced scenarios are used to control the project. In this prototype the for the extraction of texture features. illumination and window shading detection algorithm provides according to user requirements. semantic descriptors to the output, The internal image-processing has At a desk close to a window, preserving intrinsic privacy. a number of advantages for the glare can be avoided, and the The low-level algorithms were presence sensor. The on-chip lighting adjusted depending on designed to avoid thermo-electrical feature extraction leads to a what the user is doing; for example coolers. They enable shutter-less significant reduction of data to reading or working with the operation of the sensor with fixed be transferred and reduces the computer. In a domestic pattern noise removal. They are computational effort for the external environment, the color temperature robust to environmental temperature general-purpose processing unit. can be adjusted according to the variation, and self-commissioning. A reconstruction of original images movement and the time of day. The high-level algorithms allow very outside the image sensor is In addition, adjustment is possible low complexity target detection: rendered impossible. of the intensity and distribution of the result of the detection process light depending on whether the is provided at the output by Three key benefits: residents are eating, sleeping semantical descriptors. The result • “Privacy by design” or watching TV. of such detection is illustrated in • External processing effort is very figure 4, where each square stands low so that a small micro- for the detection of a person controller can be used Infrared Presence Sensor through a dedicated android • Thus the total power In the frame of the project a new application developed for consumption is very low kind of presence sensor was the project. developed by CEA Leti (Figure 1, For the sensor with optimized bottom). It is based on a thermal IR The second track was on the software components on both (Infrared) sensor that is able to development of a specific integrated the image sensor SoC and the detect presence under arbitrary circuit. The application specific micro-controller, a total power lighting conditions (daylight, night, integrated circuit for autonomous consumption of 100 mW is realistic etc.) [7]. Detection considers both low-cost, low-power steady without restricting functionality still and moving people. This presence sensing and counting was and comfort. development fills the gap between successfully fabricated on a the low-price - low pixel size general-purpose 130 nm technology

Figure 4: from Altis semiconductors. The wafers were post- Results of the detection processed in the MINATEC clean-room facility for the process; each square implementation of IR bolometers MEMS. The integrated stands for a detected circuit with the IR bolometers built on top forms the person sensor focal plane array. The latter is a 128x128 pixel matrix with 128 SIMD RISC processors and 128 application-specific ADCs (patented). A general purpose instruction set is implemented inside the processors which allows a broad range of applications and reduces system cost. Moreover, on-chip processing avoids image transfer and saves power.

The circuit proved its ability to perform privacy- compliant fully-digital thermal image acquisition and on-the-fly processing. Benchmarking with latest commercial products and articles in literature show a power consumption reduction of more than ten times using this new, dedicated integrated circuit (around 0.5 µW/pixel).

Conclusion/Summary All sensors for the Enlight system that were discussed in this paper concentrate on the important question of presence of people to provide the correct amount of light at low cost and by avoiding impact on privacy of the persons in the room. The technical concepts are different and range from motion sensors, via Infrared presence detection up to cameras in the visible light. In the demonstrators, the interface to the system was based on wireless ZigBee technology. In principle, wired implementations are also possible, and may be used in future applications. Information from the sensors is provided to the network by ‘events’ The Enlight architecture is, of course, not limited to generated by the sensors, but no decisions are made presence detection. Indeed, it provides a very powerful at this level. This information may be used and decisions means for control of home environments in general, indeed made on the amount and color of light provided in times when energy saving is an important topic by any luminaire or other device in the network. and electronics for control purposes becomes extremely inexpensive.

References: [1] “System Architecture for Distributed Intelligence”, Alex James, Martin Creusen and Micha Stalpers; LED Professional Review, Issue 48, 2015. Page 72 [2] Plugwise: https://www.plugwise.com [3] Eagle Vision Systems bv (www.eaglevision.nl): the EagleEye people tracker [4] Plugwise/AME: https://www.plugwise.com/ [5] Fraunhofer IIS/EAS, http://www.eas.iis.fraunhofer.de/ [6] Jens Döge, „Ladungsbasierte analog-digitale Signalverarbeitung für schnelle CMOS-Bildsensoren“, Dissertationsschrift, TU Dresden, Dresdner Beiträge zur Sensorik, 32, Dresden, 2008. [7] CEA Leti: http://www-leti.cea.fr/

While the last generation of LED lighting products is already very advanced with respect to energy savings, quality and end-user experience, these are still important topics and therefore also parameters on which the EnLight project needs to be evaluated. Eveliina Juntunen from VTT, Frank van Tuijl from Philips Lighting, Herbert Weiß from Osram, and Ambali Talen from Philips Research provide insight on the results of the demonstration installations in comparison to current state-of-the-art lighting systems.

In the course of the project, Description of Demos The largest demonstration pilot real-life demonstration pilots The real-life demonstration pilots was built by Philips at the High of intelligent lighting systems focused on office and hospitality Tech Campus in Eindhoven, were developed in three applications with a broad range of the Netherlands, with more than locations in Europe. In this functionalities in indoor lighting 120 luminaires along with other article these implementations scenarios. The implementation relies dedicated infrastructure elements, of the EnLight intelligent lighting on control system intelligence to such as external sensors, system are described. The provide the right light in the right user controls, and energy meters. performance was evaluated amount at the right place and at The demo area consisted of an by comparing the installations the right time. The energy-saving open plan office, corridor and with a baseline of state-of-the- strategies applied in the project meeting room. The demo area art lighting systems. Validation are summarized in (Table 1). was well populated with office concentrates on measuring The general energy-saving strategy employees and had good access the energy consumption was to adjust the lighting according to natural light with big windows, and illumination at the pilot to the presence of people and the especially in the open plan office installation sites. In order to available amount of daylight. space (n=24). validate the light quality, end With wireless communication and user acceptance was evaluated multiple sensors integrated into the The VTT Technical Research Centre with user surveys. The goal of demo space, people’s presence and of Finland also built an office pilot in the project was to achieve 40% the availability of daylight could be its multifunctional meeting, working energy reduction compared to detected locally and with a granular and lounge space in Oulu, Finland. today’s LED retrofit systems ‘light only when needed’ strategy, Compared to the office pilot in without compromising light significant energy savings was Eindhoven, the implementation was quality and user comfort. The achieved. Experiments with smaller with 43 luminaires among main results are discussed circadian rhythm lighting were also other infrastructure needed for in this article with some done in both the office and the sensing and control. The occupancy considerations for future hospitality environment. Additionally, in the VTT pilot space in Oulu was development. personal lighting control with push lower and there was less natural buttons and desk lights was light available than in Eindhoven, implemented for energy-saving which provided a diversified and user comfort reasons. perspective for the office demonstrations.

Table 1: Task Time Daylight Load Energy-saving Application tuning Personal control Occupancy schedule harvest shedding strategies of the demos (“-”: Feature not Local Local available) Ambient / occupancy Sunrise Open office Desk light constant √ task tuning sensing with a rhythm lux light bubble

Scene selection Local Meeting 5 scenes with a push occupancy - - - room OFFICE button sensing

Scene selection Global Lounge 4 scenes with a push occupancy - - - button sensing

Local occupancy Office Corridor - - - √ sensing with a hours BOTH light bubble

Scene selection Local 4 scenes and and CCT tuning Guest room occupancy - - - CCT tuning with a push Sensing button

CCT selection Local 4 color Rest room with a push occupancy - - - temperatures button sensing HOSPITALITY Local Lobby - - occupancy - - √ sensing

Figure 1: The hospitality demonstration pilot office workers enabling them to do Demo areas: Open was built by Osram in Garching, their daily tasks. In the corridors the plan office at Philips, Germany. The demo comprised a same concept was used for Eindhoven (top), guest room, a corridor, a restroom, reducing energy consumption while multifunctional office space at VTT, Oulu and lobby areas. The lighting system maintaining the impression that the (middle) and hospitality was also of significant size with corridor lighting is always on. guest room at OSRAM, nearly 100 luminaires, controls and Garching (bottom) monitor components installed in The following control strategies total. The demo area had no access were applied when implementing to natural light except for the guest the light bubble concept: room which had only a small • A light bubble around the window with limited daylight luminaires that detect the contribution. Test persons frequently presence of people used the installation, in particular the • A low background lighting level guest room for making a break, is applied if there is someone relaxing, chatting or working. present in the area However, no overnight stays like in • Smooth brightness transitions a real hotel could be hosted. with low fade rates are used to hide differences in the brightness of luminaires Saving Energy through • In the office use case, personal Distributed Intelligence control is facilitated by a desk The intelligence in the EnLight light, which can be activated system was based on a granular, manually when the user wants location-specific approach to to increase the light on the sensing with high local accuracy. work surface As an example, a ‘light bubble’ • In the corridor use case, the ends concept was developed for lighting of the corridor are lit to suggest the open plan office and the that the lighting in the corridor is corridors. In the open plan office use always on. Also, external presence case, the primary design objective sensors are applied to turn on the was the reduction of energy lights before the user arrives in the consumption while providing good empty corridor and sees it quality and comfortable lighting to completely dark

Figure 2: Simulation of the corridor with a light bubble control concept

Figure 3: Measurement grid (left) and illuminance map (right) in the meeting room in the office demo

Figure 2 shows a snapshot of User Comfort - The photometric measurements the simulation of the light bubble a Matter of Quality showed that the developed lighting in the corridor. The bubble was In this project, it was not an option system gave functional and nicely used to create a smooth transition to compromise the quality of light in distributed illumination in the pilot from 100% brightness towards order to increase energy efficiency. office and hospitality environments. background level (20%). The luminaire Therefore both photometric The measurements also showed that detects the presence of people measurements and user surveys that the proposed new system can sets its brightness to 100% on a were carried out at all the pilot sites provide the same light level and light high priority level. The neighboring to guarantee user acceptance of distribution as the baseline of luminaires were set to 70% on a the developed lighting system. state-of-the-art lighting systems lower priority level and the far used as the reference in the neighbors have an even lower performance comparison. priority level for setting their Photometric measurements brightness to 50%. In case of To evaluate the lighting on flat overlap the highest level will win. surfaces, such as a table or floor, End user feedback In the real-life demos, in most illuminance in the demo areas The overall user experience was cases the bubble was hardly was measured with a lux meter. evaluated with validated visible because in practice A grid defining the specific questionnaires made available several bubbles overlap. measurement points over the to the users of the pilot areas. demo area was used as shown The questionnaires focused on The bubble turns to background in an example in (Figure 3). visual comfort, room appearance brightness (20%) after 2 minutes The illuminance is indicated and personal control in the demo of not detecting motion. with colors (lx) shown in the space. In addition, face-to-face The measurements in the demo color palette at the right. interviews were carried out to installations showed significant Other photometric quantities collect more detailed feedback of energy savings with this kind such as CCT, CRI and color the installation. An example of the of granular control strategy. coordinates could be recorded results is shown in (Figure 4) below. For example, in the office during the measurement as well. application 30% energy savings In addition, luminance in the open In general, the quality of light was was shown in the corridor office pilot was measured using evaluated to be at a good level compared to a traditional system a luminance camera with a fish in all the demonstration pilots. with global presence detection. eye lens.

Figure 4: Although statistically significant User rating of the improvements in comfort were only hospitality installation. shown for some particular aspects, The rating scale ranges qualitative analysis showed an from 1 (very bad) to 5 (excellent) increase in user comfort compared to state-of-the-art lighting systems used as a reference. In particular, non-conventional LED luminaires (“New Form Factor Luminaires and New Light Effects” - article) scored especially high in user preference in the hospitality environment. Thus, based on photometric measurements and user tests carried out in the project, it was concluded that the energy savings were not attained at the expense of light quality.

The user studies revealed that good communication and awareness of the benefits are important when introducing for example, was well appreciated Energy Savings: Metrics new lighting control systems. because it enables a user to adjust and Measurements In conclusion, the majority of end the amount of light according to The Lighting Energy Numeric users preferred the new system personal preferences when needed. Indicator (LENI) described in the over the state-of-the-art reference EN 15193: Energy performance of for saving energy and maintaining After becoming accustomed to buildings - Energy requirements for a good quality of light. the algorithm and understanding it lighting standard was used as the as an effective way to save energy, indicator of the energy performance. Furthermore, taking care of smooth almost none of the users LENI describes the annual energy fading times is essential, since complained about the smart consumption of the lighting (kWh/m2, noticeable changes in the lighting control causing darker spots in per year) taking into account the settings were experienced as the demo area when only a few power of the luminaires and the disturbing. User control with people were present. The light parasitic systems. modern push buttons and desk bubble in the corridor was only lights was discovered to be noticed by those who arrived first The energy savings were validated important for user acceptance early in the morning or left late in by comparing the developed system in the office because, in general, the afternoon. The feedback was with the baseline installation of people like to have control over positive as they were charmed by state-of-the-art lighting technology changes. The desk light, this energy-saving approach. in an identical demo area.

Figure 5: Energy consumption of lighting in the baseline system (dark) and the EnLight system (light) recorded on an hourly basis

Figure 6: LENI results measured The power consumption was for both test measured and the LENI was installations in the calculated for both the baseline and office application the EnLight installation. Examples of measurement data in the office demo are shown in (Figure 5). The occupancy and daylight supply in different spaces with variable control strategy were also taken into account in the LENI calculations. Thus, it was possible to find out the differences in the energy performance in different situations.

Overall Energy Saving Results The main goal of the project was to Normative LEED EnLight achieve more than 40% energy benchmarks EN15193 ASHRAE 18 pnt Granular saving compared to state-of-the-art LENI [kWh/m2, a] Office ** 90.1 credit Title 24 control Table 2: Energy benchmarks of lighting in real-life demonstrations. Open office 37.6 20.3 25.4 20.3 the office installation This target was accomplished in both the office and hospitality Corridor 23.0 12.4 25.2 4.8 applications. Furthermore, Meeting room 25.7 13.9 7.7 the energy performance was Total building 45.5 27.1 12.4 compared against regional building energy performance benchmarks [1, 2, 3, 4] to bring the results in measured difference in the the total office area was reduced a wider perspective. illumination and occupancy between to 12.4 kWh/m2 per year from the systems, the energy data were 22.3 kWh/m2 per year shown for corrected. The measurements were the LED retrofit baseline. Office conducted in the period from The baseline reference for an calendar week 24 (June) to week The EnLight system energy office application was a lighting 44 (October) in 2014 and were performance was compared to installation which used retrofit LED extrapolated to yearly energy use the regional energy building lamps, such as TLED, LED Spot, without seasonal corrections. performance standards and LED bulb, retrofitted into EN15193:2007 [1], LEED [2], traditional office luminaires The office pilot demonstrated total ASRAE 90.1 [3], Title24 [4]). designed for incandescent and energy savings ranging from 37% The results are summarized in table 2. fluorescent lamps. No daylight for the meeting room to ~50% for All energy values were calculated regulation was exploited, but a the corridor and open office, from the measured occupancy data commonly used automatic on/off compared to the state-of-the-art and the applicable Lighting Power control strategy based on global retrofit LED lighting systems as a Densities given by the standards. occupancy sensing per area with reference. Thereby, the contribution In conclusion, the LENI results a switch-off delay of 15 minutes of the granular control strategy (i.e., 20.3 kWh/m2 per year) were was used in the baseline. ranges from 26% (meeting room) approximately 20% better than the to maximum 37% (open office) Title 24 Lighting Power Density The meeting room and open improvement. The overall lumen (25.4 kWh/m2 per year) in case of office measurements of the baseline efficacy on luminaire level has large office areas. Compared to the and the EnLight installation were improved with more than 20% ASHRAE requirements, the results running in parallel in twin areas from 76 lm/W to 96 lm/W. were more than 46% lower which with identical room characteristics results in a maximum LEED score and occupancy. The corridor As the resulting energy saving for of 18 points. The current European measurements were alternated in the total installation was 44%, EN15193:2007 standard provides time between the EnLight and the the goal of the project was the least stringent performance baseline system in the same accomplished. Figure 6 shows the benchmark figures with values installation area. The task light absolute LENI numbers measured almost 400% higher than the illuminance levels for both test for both systems for the open office, demonstrated LENI performance. systems were designed to be corridor and meeting room areas. the same - in case of a small With EnLight, the LENI number for

Figure 7: Hospitality LENI results of the Like in the office demonstration EnLight hospitality pilot, the baseline reference to which installation. For the the EnLight luminaires and their data without intelligent control, occupancy energy consumption in the factors given in EN hospitality application was compared 15193 are assumed consisted of LED lamps retrofitted into traditional luminaires designed for incandescent and fluorescent lamps. Non-conventional luminaires described in the “New Form Factor Luminaires and New Light Effects“ article were exploited in the demo. Such luminaires make full use of design possibilities which arise with LED technology and can thus hardly be realized in a retrofit approach. Nevertheless, state-of-the-art lighting technology retrofitted with Table 3: LED lamps with only on/off control EN15193 Energy benchmarks of was assumed as a basis for the Normative Hotel LEED hospitality installation benchmarks Quality ASHRAE 18 pnt estimation of baseline performance. LENI [kWh/m2, a] Class *** 90.1 credit Title 24 EnLight

Energy measurements were carried Corridor 37.9 20.5 26.0 15.4 out over several weeks in a similar Restroom 22.6 12.2 30.5 10.9 way as for the office installations. Guest room 38.7 20.9 52.2 29.4 Test persons used, interacted, and judged the whole installation. Usage Lobby 58.1 31.4 60.1 50.6 hours which are relevant for deriving Total hospitality area 108.1 36.7 20.2 LENI numbers were nearly the same as given in the EN 15193 standard [1]. Energy monitoring measurements of basic control. However, using the Similar to the office demo, the the EnLight installation revealed an interactive and granular control, hospitality installation compared well overall energy consumption of the light was adjusted to the right with the most stringent international 20.2 kWh/m2 per year (Figure 7). level at the right time and energy standards. The installation Compared to the LED retrofit was drawn only as much as performed 45% better than the baseline, this corresponds to required by the users’ needs. Title 24 standard for hospitality savings of 81% which is largely applications and exceeded ASHRAE above the target. Even if savings Compared to energy savings 90.1 requirements by an average of compared to the LED retrofit demonstrated with the EnLight office 46%. A LEED score of 18 points baseline with only on/off control installation, the savings shown with was therefore achieved. Table 3 (savings of 42% in Figure 7) would the hospitality demo were especially gives an overview of the LENI have been overestimated, 67% high. This is due to the fact that for benchmark in detail. savings were still gained exclusively decades a strong focus in office due to intelligent control. luminaire development has been on highest efficacy levels. This is not Recommendations and Broken down into the different areas true for hospitality applications in Future Work of the hospitality demo, the savings which a large focus is still on It was shown by the validation by control amounted to about 50% decorative elements that often results that the right metric for in the corridor and restroom. In the counteract good efficacy. Dedicated energy consumption of lighting lobby, no savings could be realized, designs as they were applied in this systems should be based on actual since luminaires had to run all day project provided large efficacy gains. energy usage per area and per year long in this area. Most significant (i.e., kWh/m2 per year). Therefore, savings, namely 80%, were realized Also, the lighting power density the Lighting Energy Numerical in the guest room. In order to provide installed in hospitality environment Indicator (LENI) is a more suitable a large range of scene and light level is usually much higher than in office energy performance metric than setting options, the installed lighting areas. Consequently, there is good commonly used installed lighting power density was especially high potential for energy savings with power (W/m2). The validated energy in this area. This would be highly intelligent control as demonstrated savings are an important stepping detrimental for installations with with these results. stone to realize the EU directive

2010/31/EU of the European However, end-user acceptance Summary Parliament and of the Counsel for a of high-end ‘activity’ sensors will In the EnLight project, near zero energy performance of require corresponding algorithms to intelligent lighting systems for buildings in 2020. More stringent enable unobtrusive implementation. office and hospitality applications LENI benchmark numbers than have been developed that in the current EN15193:2007 In the future, companies should demonstrate significant energy standard would be instrumental further strive to limit energy savings of 44% - 81% compared to achieve that goal. consumption of stand-by power, with state-of-the-art LED retrofit ahead of future legislation. systems while maintaining, At the moment, dynamic lighting Joint activities in standardization or even increasing, user comfort. systems are relatively new to the bodies may guide to a stable market These results have been achieved lighting industry. Development of acceptance and therefore growth. by using sophisticated energy- dynamic lighting systems requires Also, further research and validation saving strategies, such as a combination of automated and of effects of human-centric lighting task tuning, personal control, personal control. Introduction of on health impacts of dynamic and granular occupancy sensing. novel granular lighting control and lighting - e.g. impacts on sensors embedded in luminaires productivity in office lighting and facilitate significant energy savings also on psychological stability - and user comfort enhancements. should be addressed.

Figure 8: “Wedge Wall“ luminaire, CCT tuned to neutral white and warm white

References: [1] EN 15193:2007 Energy performance of buildings — Energy requirements for lighting [2] Leadership in Energy and Environmental Design (LEED) [3] ANSI/ASHRAE/IES Standard 90.1-2007 [4] http://www.energy.ca.gov/2012publications/CEC-400-2012-004/CEC-400-2012-004-CMF-REV2.pdf

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Imprint Next LpR LED professional Review (LpR), ISSN 1993-890X Costs & Processes Issue 49 - May/June 2015 - Short Overview Publishing Company Luger Research e.U. Institute for Innovation & Technology TECH-TALKS BREGENZ Moosmahdstrasse 30 Daniel Doxsee - Deputy Managing A 6850 Dornbirn, Austria / Europe Director at Nichia Chemical Europe phone +43 5572 39 44 89 Nichia is arguably the company with fax +43 5572 20 60 70 the longest history of manufacturing info(at)lugerresearch.com white LEDs. Recently, however, www.lugerresearch.com new competitors, especially from China, have started challenging Nichia’s market share. Nichia’s role, in solid-state lighting Publisher strategic and technical issues, past, Siegfried Luger +43 5572 39 44 89-70 present and future, were discussed. s.luger(at)led-professional.com

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