41 Photometry Standardization Measurement with Integrating Spheres Standards for Smart Lighting Voltage Limits for PWM Operated

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Review LpR The leading worldwide authority for LED & OLED lighting technology information Jan/Feb 2014 | Issue 41

Photometry Standardization Measurement with Integrating Spheres Standards for Smart Lighting Voltage Limits for PWM Operated LED Drivers

EDITORIAL 1

Safety & Quality

Experience shows that early adoption of many new technology developments into the market goes hand in hand with a lack of quality, and in some cases, a critical lack of safety. There are several reasons for this: One is the balancing of test time and test conditions against proven data before entering the market. Another reason is that every new technology and/or technical system displays “unexpected” or “unknown” behaviors under certain conditions. Third of all, international standards are lagging behind the rapidly changing technologies. Standardization bodies need input and experiences as well as concrete problems in order to be able to adapt and/or expand their standards. Everyone seems to be confronted with a more or less “insecure” situation where quality and safety issues may arise and possibly target LED technology in general.

When looking at lighting systems or luminaires, all components and modules are important and somehow related to safety and quality. In addition to that, the combination and integration of different parts can have unforeseen effects. There is an article in this issue of LED professional Review which covers one aspect of this: How specific conditions in real applications may lead to critical operation behaviors in regards to safety in the PWM mode of LED drivers.

The electronic circuit design can be seen as a very relevant topic for guaranteeing the necessary quality and safety levels. Tests performed in our lab with GU10 LED lamps from different manufacturers, ordered through prominent online shops and labeled by well-known companies showed that about 50% of the lamps were defect due to faulty electronics within 6 months. We also came across E27 socket-based lamps that broke into two parts when we tried to screw them out of the sockets. In this case, the mains voltage was directly touchable.

Performance increase, design and cost optimization are important areas that need to be further developed in LED and OLED technology. In parallel, a lot of effort in research and industry should be made to evolve the quality and guarantee the safety of LED and OLED based lighting. In this respect test-lab activities, state-of-the-art approvals and continuously updated standards are needed to support the market with valuable products.

One of our main objectives this year will be to raise up new quality issues, discuss safety boundaries and get information to you with articles and lectures about state-of-the-art design methodologies for safer lighting products.

This first issue of the year covers the topics of performance, testing and safety issues.

Please let us know if there are additional areas you want to have covered in subsequent issues related to safety & quality.

Have a great read.

Yours Sincerely,

Siegfried Luger Publisher - LED professional

Content Advertising Index

Epistar C 1

Cirrus Logic p 3 EDITORIAL p 1 COMMENTARY p 4 IMPRINT p 60 NEWS - PRODUCTS p 6 Bicom Optics p 5 NEWS - RESEARCH p 22 Toshiba p 9

LedLink p 13

Konica-Minolta p 17

Honglitronic p 19

Lackwerke Peters p 21

LED Lighting Taiwan p 23 STANDARDIZATION Photometry Standardization Developments for OLEDs and LEDs p 24 Signcomplex p 23 by Tony Bergen & Peter Blattner, CIE Division 2 Auer Lighting p 28

New EC Regulation – How to Measure Directional Light Sources p 30 Instrument Systems p 29 by Christian Krause, Viso Systems Aps Refond p 33

Supertex Inc. p 42

INTERVIEW - SIMON DEN UIJL Honglitronic p 42 About Wireless Standards for Smart Lighting p 34 OTTI p 43 by Siegfried Luger & Arno Grabher-Meyer, LED professional LED China p 43

Sontronic p 51

TECHNOLOGY LpS 2014 - Call C 3 Optimization of SSL LED Devices p 38 by Ralph Bertram & Alexander Wilm, Osram Opto Semiconductors Lextar C 4

ELECTRONICS Safety Issues for LED Drivers with PWM Operation Modes p 44 by Siegfried Luger, Luger Research & John Showell, Product Approvals

MEASUREMENT Using Integrating Spheres Correctly to Measure LEDs p 48 by Mikolaj Przybyla, GL OPTIC / Just Normlicht GmbH

APPLICATION Lighting Mona Lisa with LEDs - Details Concerning Innovating Techniques p 52 by Marc Fontoynont et al., Interdisciplinary Development Team

ARTICLE INDEX 2013 p 58

COMMENTARY 4

MEASURE THE EXACT BRIGHTNESS AND COLOR OF LEDS AND OBTAIN VALUABLE ADDITIONAL INFORMATION

Due to its multiple advantages, the LED the sub-indices R1 to R15. The has found its way into many significance of the sub-indices is often applications, where traditional light underestimated and the Ra is relied sources such as incandescent or gas blindly upon. But who isn’t familiar with discharge lamps were previously used. the white LEDs with an Ra of more As a result, completely new than 80 and poor color rendering in requirements have arisen, such as red? The sub-index R9 shows up such sophisticated thermal management, deficits mercilessly. As currently which must be dealt with during the discussed, a good color rendering development of new luminaires. But could have an Ra of more than 85 and even when the aim is to correctly an R9 of more than 40 for a white LED. measure the brightness and color of I would like to mention the scotopic Eric Schwabedissen the light emitted by LEDs during quality value as another example. For a lux Following his physics assurance tests or on-site, there are meter this value states the illuminance, now fundamental differences to the as it is perceived by eyes that have degree at the Technical measurement of traditional light adapted to night-time vision. For street University of Munich, Eric sources to be taken into consideration. light manufacturers especially, this Schwabedissen has value is a great possibility to disprove Often, measuring devices, such as lux the supposed superior energy gained 20 years of meters and colorimeters, are already efficiency of sodium vapour lamps in professional experience in available. These devices tend to be comparison with LEDs, which is based constructed from one or three light on the photopic value, and therefore the field of measurement sensors, each with an optical filter relates to the light sensitivity of eyes engineering. Between fitted in front. As only the highest- that are adapted to day-time vision. quality and as such costly devices are It should be indisputable that carrying 2007 and 2012, he worked adapted with the maximum level of out evaluations of a street light based in sales at Instrument precision to the provided spectral on night sensitivity is more practical Systems GmbH, a market transmission curves, glaring measuring than using day sensitivity as a basis. errors can occur in connection with the In addition, what bin an LED belongs in leader in complete narrow-band peaks in the spectrum can be seen immediately from a solutions for light that are typical to LEDs. Especially spectrometer. All these functions are those users, who have previously been now integrated into handy, portable measurement technology. completely satisfied with their spectrometers which even satisfy the In 2012, he moved to measurement of traditional light quality grading B in accordance with sources, such as incandescent lamps, DIN 5032-7 for premium manufacturers. Konica Minolta, the parent did not anticipate this effect. Not only do they have a nominally high company of Instrument measuring accuracy of light intensity Systems, where he is a Spectrometers elegantly avoid these and color coordinates, they also satisfy causes of error. As they determine the a variety of practical requirements. Key Account Manager in spectral distribution of the radiance charge of sales for the with a high resolution of wave length, In light of the measuring errors possible they do not need a filter. The required with conventional photometers and Light & Display product refinement of the collected signals can colorimeters as well as the valuable segment in Germany, take place purely mathematically in the additional information that can be Austria and Switzerland. device, which means the filter as a provided by a spectrometer, there decisive cause of error can be should be at least a spectrometer removed, making measuring accuracy available as a reference device for possible for LEDs and many other measuring LEDs. If necessary, existing narrow-band light sources. classic photometers and colorimeters can often be calibrated by users on the In addition, as well as information such basis of the reference values supplied as photometric value, color by the spectrometer. However, please coordinates, color temperature, note that the achieved calibration will distance to the Planck curve, color only supply reliable measurements for saturation and dominant wave length, the spectrum of the LED type current spectrometers also provide measured as part of the calibration. other important information which is The more variable the measured not provided by devices based on filter spectrum, the greater the measuring technology. An example of this is the error will appear. general color rendering index Ra and E.S.

NEWS PRODUCTS 6

New LED Module The design of Xicato’s Vibrant Series light is to that encountered in lighting applications based on original research conducted in the within buildings, in everything from spotlights Development for lighting laboratory at the Instituut to retrofit light sources. Lichtontwerpen in Amsterdam, by Colette Retail at Xicato Knight, Ph.D., an independent lighting Osram has optimized the heat dissipation of Xicato, a leading developer of superior light application specifier and researcher. Color the Oslon Square to allow an increase in the quality from LED modules, announced that it scientists at Xicato were able to use the junction temperature. “With our new has expanded its Vibrant Series offerings to feedback of more than 60 subjects to design conversion technology, we can produce include both a 1300 lumen and 2000 lumen a new light emission spectrum that makes significantly thinner converter layers. The option alongside its 3000 lumen module. whites, blues and reds, in particular, appear thinner layers better dissipate the heat, thus Introduced in July 2013, the Vibrant Series richer and more vibrant. It adds visual depth enabling the higher temperatures in the LED,” has been quickly adopted by designers, to textures like denim, leather or lace. says Ivar Tangring, SSL Product Development merchandisers and brand managers to at Osram Opto Semiconductors, explaining support their efforts to differentiate and create the advantages of the innovative technology. compelling experiences for customers. With that, the Oslon Square can reach a Osram Opto lifetime of considerably more than 50,000 hours even at high temperatures of up to Improves Oslon 135°C in the LED. Square for Longer Customers benefit from the properties of Lifetime at High the new Oslon Square: Measuring and binning at operating Temperatures temperatures of 85°C is of great significance Excessive heat generation is one of the main to customers who further process the reasons why light-emitting diodes fail. With light-emitting diodes into luminaires. They

Xicato’s Vibrant Series light in LETO luminaires the Oslon Square, Osram Opto receive precise information on parameters highlight the naturally vivid colors of fruits and Semiconductors presents an LED that such as luminous flux or color stability, which vegetables withstands high ambient temperatures they need to optimally define the properties of particularly well. their products. “With Xicato’s Vibrant Series we’ve discovered a previously unfulfilled need for Furthermore, the improved temperature light that is crisper, brighter and makes behavior leads to higher luminous efficacy in colors really sing,” said Rolf Hurbin of Senso the application. “This luminous efficacy, Lighting in Canada. “With the new light meaning the ratio of luminous flux to applied output options it will be easier to create electrical power, helps our customers to tailored environments and focus attention significantly optimize the price/performance exactly as desired by our clients.” ratio of their luminaire solutions,” Tangring emphasizes. Thanks to the higher permitted The new 1300 and 2000 lumen modules junction temperatures, fewer large heat sinks are fully backward compatible with other Osram Opto’s new Oslon Square - better heat are required, and this simplifies the design of Xicato XSM modules. This means that if a dissipation, stable color uniformity and a longer lamps and luminaires, because they can be luminaire currently uses a 1300 lumen lamp life even at high temperatures smaller and therefore less costly. Standard Series module, the new Vibrant Series module can be directly swapped for Technical data (@ Tj = 85°C): Application in interior lighting: it without re-engineering which gives the • Housing dimensions: 3 mm x 3 mm The Oslon Square is particularly suitable for manufacturer a path to instant expansion • Beam angle: 120° the various applications in buildings. With a of their product line. • Typical voltage (at 700 mA): color temperature ranging between 2,400 and 2.9 V – max. 3.2 V 5,000 Kelvin, it can generate either warm- or “A portfolio of ‘light’ has become essential for • Current: max. 1.8 A (previously 1.5 A) cold-white light. The color rendering index is designers and specifiers, particularly those • Typical brightness (at 700 mA): over 80 and the luminous flux is an impressive working in retail environments where we see 202 lm (at 3,000 K) 202 lumens (lm). Product variations with a the rapid integration of light, sound, visuals • Color rendering index (CRI): min. 80 different color temperature spectrum and and intersection with the connected world,” • Thermal resistance Rth: higher color rendering indices are to follow. At said Joanna Brace, VP Marketing at Xicato. 3 K/W (previously 3.8 K/W) present, the new LED is undergoing extensive “Our color scientists and engineers work • Color temperature: 2,400 – 5,000 K quality testing: The certification process under closely with the lighting, design and retail the LM-80 long lifetime standard is underway. communities to design and produce high To ensure that the colors of several LEDs in a The results of the 3,000 hour test are quality light that supports their needs and luminaire remain uniform even at higher expected at the end of the year, those of the accelerates business growth.” temperatures, they are measured and binned 6,000 hour test in spring 2014. at 85°C, a temperature that comes very close

Plessey Releases standard 3020 package. With a drive current Key Applications: of 60 mA, the PLW114050 has a typical • Downlights New Generation of forward voltage of 3.2 V. A full datasheet is • High Bay & Low Bay available on the Plessey website. Plessey also • Indoor Area Lighting GaN-on-Si LEDs supply the blue LED PLB010050 in sawn- • Lamps Plessey announced availability of its next wafer die form. Additional package options • Outdoor generation GaN-on-Silicon mid-power LEDs. will be made available. The product family doubles the efficacy of “We use the term ‘extreme efficacy’ because Plessey’s first generation MAGIC™ of the remarkable performance customers (Manufactured on GaN-on-Si I/C) products can expect from these emitters,” said released in February 2013. Using standard Philips Lumileds New Hartnett. “For instance, outdoor fixture silicon semiconductor production techniques, manufacturers who need 4000 K at 70 CRI Plessey is able to achieve high flux output High-Flux Emitters are taking advantage of the LUXEON TX LED products at substantially lower cost. The Transform Directional 360 lm output @1.0 A and 85˚C to decrease PLW114050 is the first in a family of entry level overall system cost, but have the ability to LED lighting products that will be released. Luminaires drive the same part @350 mA to deliver 155 lm/W LED efficacy and enable streetlights Philips Lumileds introduces LUXEON TX with a system efficacy of more than 120 lm/W.” emitters. This next generation of high-power emitters delivers the highest luminous flux The LUXEON TX platform is available in a available, with maximum efficacy, for a variety range of CCTs and CRIs to satisfy the most of directional and omnidirectional lighting exacting requirements of downlights, high bay applications. “These emitters are truly and low bay lighting, indoor area lighting, transformative in that they enable customers outdoor lighting and replacement lamps. In to achieve performance metrics - such as a addition, for improved design flexibility, Philips true 50 W equivalent MR16 lamp at 2700 K Lumileds has added a minimum 85 CRI

Plessey’s new PLW114050 is a 3020 type PLCC that meets ERP/DIM2 requirements - which option so designers can further differentiate packaged LED with 60 mA nominal drive current LEDs simply could not meet previously,” said their product lines. Kathleen Hartnett, Product Line Director at “We have made great strides forward in Philips Lumileds. “Designers have typically had to choose refining, productizing and improving our between the lower efficacy associated with a patented MAGIC™ technology,” said Dr. Keith 90 CRI LED or the poorer color rendering Strickland, Plessey’s Chief Technology Officer. associated with an 80 CRI LED. Now LUXEON “We have a roadmap that puts MAGIC™ TX 85 CRI emitters bridge that gap by ahead of the efficacies achieved by sapphire- providing high CRI with increased efficacy in a based LEDs and, thereby, sets a new full CCT range from 2700 K to 5000 K. milestone in terms of Lm/$ performance. By approaching efficacy parity, we are For applications that require a minimum accelerating the widespread adoption of 90 CRI, LUXEON TX delivers up to 100 lm/W GaN-on-Si LED-based lighting products. Our warm white light (3000 K CCT, 90 CRI and

MAGIC™ LED products have a cost Philips Lumileds’ new LUXEON TX promises 700 mA at 85˚C). This level of efficacy at advantage over comparable sapphire-based highest luminous flux without compromising 90 CRI enables superior performance for LEDs as we use 6-inch, high yield, standard, efficacy in a very compact dimension luminaires that must adhere to increasingly automated silicon manufacturing technology.” stringent lighting standards such as the CEC’s Features: California Quality LED Lamp Specification. Dr. Jose Lopez, Plessey’s Chief Commercial • Compact 3737 package

Officer, said, “Customers are delighted that a • Typical Vf of 2.8 V European company is committed to • Thermal resistance of 3 K/W developing and manufacturing world class • Hot tested at T = 85°C j Latest Edison Opto GaN-on-Si LEDs. The market currently has • Freedom from Binning – 3 & 5 SDCM many suppliers of LEDs but the quality and • Exceeds ENERGY STAR lumen COB HM Series reliability can be variable. Plessey is a trusted maintenance requirements Meets the CEC brand with a 50-year plus track record of • UL-recognized component [E352519] with manufacturing products to the highest level 4 enclosure consideration Specification standards. Our aim is to light the world with MAGIC™ LEDs.” Benefits: With the keen competition of the LED market, • High luminance for directional applications products of different qualities have flooded The PLW114050 product is available in a CCT • Optimized for extreme efficacy the industry. Every manufacturer states that range from 6500 K to 2700 K, with a • Excellent color consistency the lifespan of their products can be up to Lambertian distribution in an industry • Proven reliability tens of thousands of hours and their efficacy

is extremely high. But without specification, MacAdam ellipse. And that means Edison The integrated package is the first to bring the real performance of those products is Opto has achieved the goal of color together SemiLEDs vertical, white chip, and doubtful. In view of this phenomenon the consistency. Those products are particularly ceramic packaging technologies. Measuring California Energy Commission (CEC) suitable for applications requiring high color just 6.3mm on a side (39.7 square mm/.06 developed the quality LED lamp specification homogeneity, such as gallery, printing factory square inch), the compact multi-color LED in 2012. The CEC specification focuses on six and stage lighting. opens the door to arrays with cumulative key quality attributes for LED lamps, including lumen-densities in excess of 6000 lumens per color temperature, color consistency, color square inch. Beyond just the size and rendering, dimmability, lifetime and light potential for high-lumen densities, the square distribution. The CEC standard requires that SemiLEDs Introduces footprint also greatly simplifies color mixing all lamps have color rendering index (CRI) ≥ and integration with secondary optics, 90 and R9 > 50. This specification will 10 W Integrated including narrow beam spotlights which become effective in January 2014. RGBW LED benefit from the symmetry and depend upon minimized source sizes. When compared to a SemiLEDs Corporation, a world leader in strictly RGB source, the addition of discrete vertical LED technology solutions, announced white to the color changing LED architecture the introduction and release of the 10-Watt enables a broader spectrum and more natural M63 RGBW integrated 6363 LED. The white palette to be projected. The white 4-channel M63 RGBW delivers over 410 total source in the M63 RGB delivers 100 lumens lumens of combined red, green, blue and per watt at a correlated color temperature white light output. The compact 6.3mm x (CCT) of 6300K to 8000K. By its nature, an 6.3mm dimensions enable the M63 RGBW to RGBW LED should include a cool-white fit in a wide range of color-changing source to compliment the additive nature of applications, including entertainment (stage the colors in the integrated device. Edison Opto’s latest COB HM Series meets the lights, backdrops and spotlighting), large scale California Energy Commission (CEC) displays, and color-adjustable luminaires for “Every current technology trend is towards specifications which will become effective in building façades, wall washing or specialized higher integration, both to reduce component January 2014 interior luminaires. count and simplify the final design, and that To satisfy market demand, since its carries with it a ripple effect that continues establishment, the Taiwanese leading LED into process engineering and manufacturing,” manufacturer, Edison Opto, has dedicated continued Dr. Cokgor. “As a result of its broad itself to promote a better living environment technology offering, SemiLEDs is in a and never stop creating high efficacy LED somewhat unique position to reliably deliver products. By virtue of seven years of these higher levels of integration, as reflected experience in COB development, Edison Opto in our new M63 RGBW. High quality LED has introduced the high efficiency EdiPower II manufacturers will continue to differentiate HM series which has attracted the attention of and add value to the industry by driving industry. Recently, in order to respond to increasing integration at both the component market demand, Edison Opto upgraded the and subsystem level,” he concluded. CRI value of HM series up to 90 and met the SemiLEDs M63 RGBW can be driven with requirement of R9>50. This breakthrough up to 10 W makes the HM series a preferred choice of museum and hospital lighting where high CRI “The M63 RGBW demonstrates a new level New “Tunable White” light sources are required to present the of LED product integration from SemiLEDs”, actual color of objects. commented Dr. Ilkan Cokgor, Executive VP LED With High CRI - of Sales and Marketing for SemiLEDs. “By Not Just for Medical With high quality standards, Edison Opto’s combining three colors, plus an independent COB components can keep pace with phosphor-coated white emitter, onto a single Applications international manufacturers’ products. LED package, our customers will be able to To help customers and lamp designers to better optimize the optical and thermal When it launches the new Osram Ostar distinguish product chromaticity, Edison Opto properties of their design, while minimizing Medical, Osram Opto Semiconductors will be refers to the specifications of Energy Star and the manufacturing complexities of their introducing the first LED component with a adjusts the original BIN group. At present, the luminaires or large scale displays. This high color-rendering index (CRI) of 95 and the COB products are grouped in 3-Step and integrated approach is enabled by our possibility of adjusting the temperature of the 5-step MacAdam ellipse. The new BIN group well-validated and robust metal vertical LED color white. This makes it ideal for medical makes CCT control more accurate and thus product portfolio, which can be reliably applications – for instance in operating rooms, improves the product homogeneity. 98% of driven harder to deliver higher than average where a precisely controlled chromaticity Edison COB products are within a 3-Step lumen density and increase the lumens per coordinate and high natural color rendering MacAdam ellipse and 90% are within a 5-step dollar,” Dr. Cokgor added. are crucial.

the components ordinarily used. The product Lextar COB provides: owes its compact design to the flat, antireflex- • Complete series from 4 W~120 W coated glass cover with which the LED is for all kinds of applications equipped instead of the usual lens. • Light emitting surface compatible with ZHAGA standard “Compact luminaires prevail in the modern • High efficacy medical lighting sector and the low height of • Offering 3 step binning with the new Ostar Medical makes it the ideal CRI 70, 80 and 90

product,” explained Wolfgang Schnabel, who • Low Rth, good heat dissipation is in charge of marketing the product at Measuring just 5.9 mm x 4.8 mm x 1.2 mm, the Osram Ostar Medical has a very Osram Opto Semiconductors. “The Application suggestion: compact design component is standardized, which means that • Down light customers can use the commonly available • Par20, Par30, Par38 Main Features: lenses.” As with other members of the LED • Track light • Footprint: 5.9 mm x 4.8 mm family, the Osram Ostar Medical is simple to • Flood light • Height of housing: 1.2 mm install with standard soldering processes. • High / Low bay

• Thermal resistanceRth: 1.8 K/W • Typical brightness: 80 lm (at 4,000 K) The COB has recently been widely adopted 325 lm (at 5,000 K) thanks to its quality light and no multi shadow, • CRI: Ra/R9 greater than 95 Simplify Your Design low thermal resistance and good uniformity. It brings benefits to manufacturers with its The new Osram Ostar Medical comprises four with Lextar’s High simplified luminaire design and reduced different LED chips in the colors warm white, Quality COB assembly costs. ultra white, verde and amber. This permits customers to set the shade of white emitted Lextar has a whole COB product – the The Lextar Nimbus COB series is offered by the LED according to their individual “Nimbus” series. Its wide coverage ranges in a range of light outputs from 400lm to requirements within a color temperature range from 500 to 10000 lm and is applicable for 10,000 lm. We provide whole high quality of between 3,700 and 5,000 Kelvin – and at a bulbs, par lights, down lights, track lights, solutions for general lighting including down high overall CRI of 95. This combination of streetlamps and high bays. lights, spotlights, track lights and industrial precise chromaticity coordinate control and lights. With its high quality standards, the excellent CRI is particularly important for Lextar Nimbus COB series complies with the lighting in the medical sector. When optimized specifications of Energy Star, offering a CIE for the red spectrum (RaR9), the CRI remains bin with 3-step and 5-step MacAdam ellipses at around 95 so that red shades are to keep the best color consistency for designs particularly true-to-life – ideal for light systems that use single light source COB. in operating rooms. The Lextar Nimbus COB series is available Compact dimensions, simple to install: with CCTs of 2700 to 5700 K and color quality With a footprint of just 5.9 mm x 4.8 mm and (CRI) levels of 70, 80 or 90 for different kinds a housing height of 1.2 mm, the design of the Lextar’s new “Nimbus” COB series LEDs are of designs and applications. For applications Osram Ostar Medical is very compact. available in various CCTs with different LES such as museum or commercial lights that Indeed, it is only about one-quarter as high as and as High CRI version require a minimum 90 CRI, the Lextar Nimbus

1500 and Nimbus 2000 COB deliver up to efficiency of approximately 90%, up to double Lux Magazine for Light Source Innovation of 100-lm/W warm white solution (3000K CCT, that of competitive edge-lit solutions. the Year and recognition by the Illuminating 90 CRI and R9>50). Engineering Society (IES) in its Progress The modular light tiles can be produced in any Report featuring the most promising new For better optical solutions costs, the shape or size up to 1m, offering up to 20,000 lighting products. light-emitting surface (LES) of the Lextar lumens per square meter. Designers will Nimbus COB series is designed as 9, 13.5 benefit from single or double sided Linear light sources are in widespread use for and 23 mm which comply with the Zhaga illumination and with LEDs distributed across illuminating commercial and industrial standard. the panel, applications are not inhibited by the applications worldwide. Office lighting and need for external thermal management. other commercial applications have been In addition, the substrate design of Lextar challenging for white LEDs previously because

Nimbus COB with low Rth (Thermal As standard the tiles are supplied with LEDs of the need to diffuse the point sources, resistance,K/W) provides an advantage over a offering a color temperature range from warm reducing system efficacy. The ChromaLit mechanical design for a luminaire. It provides white to cool white (3000 K – 7000 K) and Linear product delivers naturally uniform, better heat transfer and improved reliability of Color Render Index (CRI) >85. Options are high quality light with conversion efficacy of the lighting system. also possible for single or mixed colors as well up to 215 lumens per radiant watt or up to as a range of low voltage or constant current 163 lumens per system watt when used with drive solutions. the most efficient blue LEDs available.

Design LED “ChromaLit Linear transforms industry thinking about LED linear lighting and remote Products Launched Intematix Introduced phosphor,” said Julian Carey, Senior Director Revolutionary Flexible of Strategic Marketing at Intematix. “We can Three New Remote forget about low efficacy and pixelation LED Light Tile Phosphor Products because this product enables high light output, smooth uniformity, white off-state and Design LED Products is using Lux Live 2013 for LED Lighting new possibilities for applications from as the launch pad for its revolutionary flexible under-cabinet to troffers to high bay lighting.” LED light tile technology, offering designers Intematix Corporation, a leading manufacturer the opportunity to use light in new and of phosphor solutions for LED lighting, The ChromaLit Linear remote phosphor unconventional ways. The highly efficient tiles announced the commercial availability of solution offers flexibility of length. Surface can be designed to be modular and scalable ChromaLit® Linear. Just three weeks before, lumen density scales from 500 to 2500 lumens and are ideal for uniform backlighting they announced the volume shipments of their per linear foot and the system presents new applications and directional lighting remote phosphor componentfor 150 W design directions not possible with fluorescent applications requiring low profile, curved or equivalent LED retrofit lamps, after having and white LEDs. Intematix has also changed irregular shapes. announced beginning of November the how designers think about remote phosphor development of a remote phosphor-based because ChromaLit Linear has dramatically LED lighting module with 203 lumens per watt improved the off-state appearance and efficacy, which was done in cooperation with illumination quality. ChromaLit Linear offers Philips Lumileds. 3 SDCM color consistency as standard and color temperature options from 3000 K to 5000 K and CRI of 80.

Remote Phosphor and Reference Design for 150 W LED Retrofit Lamps: This production release for 150 W equivalent

One of the big advantages of Design LED LED retrofit lamps adds to the product family Products’ new flexible light tile is that it can already enabling 40 W, 60 W, 75 W and provide up to 20,000 lm per square meter 100 W bulb replacements all using a similar without the need of an external thermal omni-directional form factor. management system Intematix’s latest product is the ChromaLit® Linear remote phosphor that allows the design As global government regulations phase out Design LED’s patented technology embeds of products with a system efficiency of up to incandescent lamps, these remote phosphor LEDs into a thin, flexible transparent film with 163 lumens per watt components streamline access to high quality, printed surface optics to create a lightweight, efficient lighting in these popular lumen output integrated and modular light engine. The ChromaLit Linear Remote Phosphor: ranges for use in residential and commercial pattern and form of the surface features ChromaLit® Linear is a remote phosphor applications. In addition, this innovative form governs the illumination uniformity and beam offering uniform luminance over any length, factor delivers an incandescent-like 325° light angle control for lighting and backlighting high flux density and a sleek, white off-state distribution pattern in contrast to many LED requirements. The solution offers high optical finish. This product received the Lux Award by replacement bulbs on the market.

“By applying this remote phosphor technology 11° to 45° Zoom & When equipped with the Moving Lenslet Array to the high end of the light bulb output range, (MLA) PL1564, the newest accessory we show 38% higher lumen output than bulbs Autofocus Lenses designed by Khatod, the lenses execute available today,” said Julian Carey, Senior Zoom and Autofocus performances in a wide Director of Strategic Marketing at Intematix. from Khatod range of applications. The MLA and the lens “We are already seeing newly available, Zoom & Autofocus Lenses, available in Ø 45 fit perfectly as they are complementary; have 2200-plus lumen LED light bulbs worldwide mm are equipped with a Moving Lenslet Array the same diameter and Lenslet Array. using this technology.” (MLA) that execute zoom and autofocus performance in a wide range of applications. Place the MLA on the top of the lens and 150 W equivalent LED light bulbs utilizing The beam angles vary in a range of an 11° make it slide over the lens along the optical Intematix’s patented ChromaLit remote beam when the MLA is nearly in contact with axis: beam angles will vary in a range from phosphor are now available at major US retail the lens, up to a 45°wide beam when the 11°, when the MLA is nearly in contact with outlets. MLA is made sliding over the lens. Reach a the lens, up to 45°, when the MLA is made high optical efficiency over 90% by preserving sliding over the lens. The beam variation is Remote Phosphor LED Lighting Module a perfect light layout in the full range of the obtained along 5 mm distance. Delivering 203 lpw: beam angles, also in color mixing It is believed that this module represents the applications. These lenses perform an optical efficiency over highest level of efficacy among LED-based 90% and preserve a perfect light layout in the light sources commercially available for full range of the beam angles, also in color production in the market today. mixing applications using multi-color LEDs.

“This result is a significant step along our The combination of the lens and the Moving innovation roadmap for phosphor solutions,” Lenslet Array allows zoom and autofocus said Yi-Qun Li Chief Technology Officer at applications by just sliding the MLA on top Intematix. “Remote phosphor architectures of the lens. Zoom & Autofocus Lenses from Khatod provide lower cost, increase efficacy and improve light the designers of lighting fixtures with unique quality in many of the consumer, commercial, optical solutions that far exceed the normal industrial and outdoor area lighting performances of standard lenses applications commonly deploying LED New Mains- technology today.” Lens - PL1590WI Benefits: • Available with PL1564 Moving Lenslet Array Dimmable LED Lamp The LED lighting module uses a commercially (MLA), enabling Zoom from 11° to 45° beam Driver from Diodes available, 26 mm diameter dome shaped angle range remote phosphor developed by Intematix that • Innovative design Diodes Incorporated, a leading global converts blue light to on-the-black-body-line • High optical efficiency over 90% manufacturer and supplier of high-quality 6000 K daylight spectrum and 70 CRI with • Robust Mounting application specific standard products conversion efficacy of 267 lumens per radiant • Perfect uniform flux within the broad discrete, logic and analog watt. The design is applicable for round and • Shadows or glare totally eliminated semiconductor markets, introduced the linear module configurations and is offered in • Easy fixing onto the PCB AP1694, an AC-DC controller providing a color temperatures ranging from 2700 K to universal high-performance driver solution 6000 K with CRI values from 70 up to 98. Moving Lenslet Array- PL1564 Benefits: for a variety of mains-dimmable LED lamp • To be used with PL1590WI Lenses designs. Suitable for both 120 V and 230 V This groundbreaking lighting module uses • Innovative design AC inputs, while supporting non-isolated Philips Lumileds LUXEON T/TX family of royal • Zoom Range 11° to 45° buck, buck-boost and isolated flyback blue LEDs, achieving industry leading wall • High optical efficiency over 90% topologies, this part enables between 10% plug efficiencies of 76%. • Shadows or glare totally eliminated and 50% reductions in total BOM costs. • MLA and lens fit perfectly as they are “We’re very proud of this landmark complementary, have the same diameter performance of 203 lm/W as this was and Lenslet Array achieved using our latest commercially available LED technology and Intematix’s Typical Applications: remote phosphor,” said Jy Bhardwaj, Senior • Architectural Lighting Vice President of R&D at Philips Lumileds. • Stage Lighting “This marquee performance simplifies a wide • Entertainment & decorative variety of thermally constrained applications • Shop windows, halls & entrances such as 100 W A19 bulbs and high lumen • Downlights candle lamps, and enables downlights with • Flashlights Typical application circuit using Diodes’ AP1694 LED driver the highest efficacy in the industry.” • Border/contour • Lamps, etc.

Features: Triple Output High power from a nominal 12 V input with • Primary side control for output current efficiencies as high as 93%. Each of the regulation without opto-coupler Current LED Driver three channels is operated by an • Boundary conduction mode (BCM) independent True Color PWM™ signal, Operation to Achieve High efficiency Controller Drives over enabling each channel to be dimmed to • High PF and low THD 250 W of LED Power ratios as high as 3000:1. Each channel also • High efficiency without dimmer offers both robust open-LED and short- • Wide range of dimmer compatibility Linear Technology Corporation announces circuit protection in boost mode, providing • Dimming curve compliant with NEMA SSL6 the LT3797, a triple output DC/DC controller high safety and reliability designs required in • Low start-up current designed to drive three independent channels automotive applications. A frequency adjust • Tight LED current of LEDs. Its fixed frequency, current-mode pin enables the user to program the • Tight LED open voltage architecture delivers constant, accurately frequency between 100kHz and 1MHz to • BJT transistor driver regulated LED current over a wide range of optimize efficiency while minimizing external • Dynamic base driver control supply and output voltages. Its 2.5 V to 40 V component size. Its thermally enhanced 7 • Valley-mode switching to minimize the input voltage range with transient ride through mm x 8mm QFN package provides a highly transition loss to 60 V makes it ideal for automotive compact solution footprint for 20 W to 250 • Easy EMI applications as well as a wide range of W LED applications. • Internal protections: industrial applications, RGB lighting, billboards • Under voltage lock out (UVLO) and large displays. The LT3797 is designed so that each • Leading-edge blanking (LEB) channel can use the most suitable • Output short protection configuration to drive its LED string, whether • Output open protection step-up, step-down, and SEPIC or a • Over temperature protection combination of these. Its high-side current • Flexible for design with small form factor sense enables each channel to be used in and very low BOM cost the same or different configurations while rail-to-rail current sense enables outputs The controller uses Diodes’ patented PFM from 0 V to 100 V, offering a wide range of technology to tightly regulate LED current design flexibility. Other features include and achieve a high power factor and low overvoltage and undervoltage lockout, 20:1 total harmonic distortion. By operating in Linear Technology’s new triple output LED analog diming via the CTRL pin and external boundary-conduction mode, the AP1684 driver allows high power applications in a synchronization. also assures high efficiency and low EMI compact footprint driver characteristics. As a primary side controller, this part removes the need for Summary of LT3797 Features: opto-coupler and secondary-side control • Three Independent LED Driver Channels Supertex Introduces circuitry, and being inherently stable, • Wide Input Voltage Range: 2.5 to 40 V with eliminates the need for loop compensation. VIN Transient Ride-Through up to 60 V Dimmable Low Cost • Rail-to-Rail LED Current Sense: 0 to 100 V LED Driver Solution The AP1694 delivers a 5% initial LED current • 3,000:1 True Color PWM™ Dimming accuracy, meeting the requirements of most • TG Drivers for PMOS LED Disconnection for Bulbs and Tubes mains-dimmable LED lighting applications • Operates in Boost, Buck, Buck-Boost, and is compatible with a wide range of SEPIC or Flyback Topology Supertex, a recognized leader in high voltage different dimmers, including both leading • Open-LED Protection analog and mixed signal integrated circuits edge and trailing edge types. It achieves • Short-Circuit Protected Boost Capable (ICs), introduced PS30, a constant frequency deep dimming down to 1%, complies with • Fault Flags for Independent Channels (67 kHz), constant duty cycle LED driver the NEMA SSL6 standard for dimming • Programmable VIN optimized for dimmable off-line LED bulb/tube curves and meets the requirements of the • Undervoltage & Overvoltage Lockout applications, providing high power factor IEC6100-3-2 harmonic standard. • Adjustable Switching Frequency: correction (PFC). 100 kHz to 1 MHz Provided in the small form factor SO-8 • Synchronizable to an External Clock package and requiring only 26 external • CTRL Pins Provide Analog Dimming components in buck topology, the AP1694 • Programmable Soft-Start driver controller offers designers of mains- • 52-Lead QFN Package dimmable LED lamps a higher power density with a simpler and smaller total Each of the LT3797’s channels can drive a circuit footprint. The device also integrates wide range of LED power in either step-up, comprehensive protection features, step-down or SEPIC topologies. In a boost including open-load detection, over-voltage, configuration, it powers three channels of Supertex’s new PS30 LED driver is compatible short-circuit and overtemperature up to 90 V of LEDs with LED currents in with leading and trailing edge dimmers, as well protection. excess of 1 A, delivering over 250 W of as two-wire digital dimmers

NEWS PRODUCTS 14

PS30 is intended to drive a single switch, Designers can evaluate the new LYTSwitch-4 single inductor power converter (flyback for LED-driver IC family using a new high-line isolated version and buck-boost for non- LED lighting reference design that has been isolated version) directly from AC line, 110 V or co-developed with Cree. DER-396 describes 220 V, for power levels up to 20 W. PS30DB1 a PAR38 spotlight LED driver design. demo board provides a 6.3 W design solution, achieving 93% PFC and greater than 81% efficiency with ±4% current accuracy. It can be modified for other power levels up to 20 W. ISSI Announces

PS30 offers smooth dimming to extinction for Single Stage High a wide variety of dimmer types such as Power Integration LYTSwitch™-4 LED-driver IC family - typical schematic Power Factor AC/ leading edge dimmers, trailing edge dimmers, and dimmers with microprocessor controls. It Main Features: DC LED Controller for implements a PFC LED driver solution, • Better than ±5% CC regulation operating from a 10 V shunt regulator derived • TRIAC dimmable to less than 5% output Retrofit LED Bulbs from the power supply snubber, and provides • Fast start-up Integrated Silicon Solution, Inc., a leader in for a simple design by eliminating feedback • <250 ms at full brightness advanced memory and analog IC solutions, components and the optocoupler typical in • <1s at 10% brightness announced the IS31LT3932, a high isolated solutions. It minimizes line induced • High power factor >0.9 performance universal AC input LED brightness variation, and protects against • Easily meets EN61000-3-2 Controller for the solid-state lighting (SSL) open circuit failure with over voltage protection. • Less than 10% THD in optimized designs market place. With a universal input voltage • Up to 92% efficient range from 85 to 265 VAC, a Power Factor Two unique features enhance the value and • 132 kHz switching frequency for small Correction greater than 0.97 and a typical performance of PS30. It is designed to magnetics output current accuracy of +/-3%, the implement a simpler, lower cost open loop IS31LT3932 is ideally suited for a wide range solution. The potential limitation of open loop LYTSwitch-4 ICs feature a combined PFC of offline LED retrofit lamp solutions including design is that the output choke tolerance and CC single-stage converter topology E26, GU10, PAR and T8. This true constant normally results in variation in output current resulting in a power factor greater than 0.95 current LED controller can support LED amplitude across product builds in and efficiencies of over 90% in typical lighting solutions of up to 30 W with a minimal production. PS30 includes proprietary control applications. Designs based on the new number of external components. techniques that largely mitigate this output drivers easily meet EN61000-3-2C current variation. It also includes proprietary regulations for total harmonic distortion dimming circuits that ensure proper operation (THD); optimized designs deliver less than with different triac dimmers. It controls the 10% THD. Regulation is better than +/- 5% timing of the power stage and activation of across load and production spread, auxiliary loading to eliminate concerns of reducing the need for over-design to meet erratic SCR firing and the resultant flickering. minimum luminance targets, cutting system Its circuitry ensures stable operation during cost. The devices’ high switching frequency light load conditions and a consistent starting (132 kHz) enables smaller, lower-cost point for the zero crossing phase detection. magnetics to be used, and frequency ISSI’s new IS31LT3932 LED driver IC is a single stage high power factor AC/DC LED controller jittering reduces EMI filtering requirements. for retrofit LED bulbs These factors enable LED-driver designs to fit easily into space-restricted bulb styles. The IS31LT3932 utilizes a patent pending PI Adds High-Line average current mode control scheme to Comments Andrew Smith, senior product maintain inductor current regulation Parts to LYTSwitch-4 marketing manager for Power Integrations: regardless of variation of input and output LED-Driver IC Family “LYTSwitch-4 LED-driver ICs have proven voltage. The device implements a Pulse very popular since the initial launch of the Frequency Modulation (PFM) technology Power Integrations, a leader in high-efficiency, low-line parts, due to a combination of without an optocoupler and secondary side high-reliability LED-driver ICs, added devices efficiency and excellent dimming control or loop compensation circuitry optimized for high-line applications, performance. Even when used with dramatically reducing the bill of material completing the roll-out of its LYTSwitch™-4 leading-edge and trailing-edge TRIAC (BOM) and overall cost. The controller can LED-driver IC family. LYTSwitch-4 ICs deliver dimmers, and at low conduction angles, be configured to operate in a Non-Isolated accurate output current and high efficiency. designs comply with NEMA SSL-7. Start-up Buck or Buck Boost mode or Isolated The devices simplify design and reduce cost is very fast, typically less than 500 ms, even Flyback mode. The device’s unique while ensuring that lamps deliver uniform light when dimmed to less than 10% light output, architecture continuously monitors the output output and provide exceptional performance and pop-on is virtually eliminated.” voltage and adjusts the operating frequency in TRIAC-dimmable applications. to maintain high LED current accuracy.

The IS31LT3932 has special input power SmarteXite, based on fully configurable annual growth rate for LED bulbs units to be line sensing and output voltage sensing logic, is the first LED driver technology sold between 2012 and 2016, with more circuits operating in primary feedback mode to directly and easily support wireless than 2.6 billion units to be sold in 2016.” to deliver highly accurate current regulation connectivity, light sensor control and to the LED load. The IS31LT3932 allow easy integration into lighting SmarteXite supports final stage digital incorporates many features found in more control systems. calibration on the production line where the complex controllers such as soft-start, Vcc bulb manufacturers can reconfigure the under-voltage lockout with hysteresis, and The first device from the smarteXite family, illumination calibration settings like protections against output over-voltage, the iW6401, supports multiple dimming brightness and color via the A/C mains output open and short circuit, primary side interfaces, including digital dimming via a terminals. This allows lower tolerance LEDs over-current and thermal shutdown with simple mains on/off switch, the new to be used with less binning or waste of hysteresis. In addition, the versatile high Ledotron™ digital dimming protocol and LED’s. Additionally, using this final stage voltage gate drive of the IS31LT3932 will toggle-switch based dimming. calibration feature, the adjustment of the support a wide range of low-cost power LED currents can be done even in the MOSFET devices. All dimming-curves can be memory- installed state making the smarteXite configured to enable a highly optimized platform also ideal for Zhaga compliant “The IS31LT3932 expands our LED end-user lighting experience. The integrated power supplies. The iW6401 can be controller offering for the retrofit lamp digital load line transmission (DLT) receiver configured to actively manage lamp market,” remarked Ven Shan, ISSI VP of in the iW6401 supports the Ledotron IEC temperature using either on-chip or off-chip Analog products. “Lighting manufacturers 62756-1 dimming protocol making it the temperature sensor and a configurable state will benefit from the versatility offered by a world’s first single-chip plug-and-play temperature control. high power-factor, universal AC input and Ledotron solution. constant current output because one LEDs are especially suitable to be dimmed design will support multiple LED array load Using a standard I2C digital interface, the in a wide range. Unlike CFLs and other configurations. With design re-use, our iW6401 can serve as a powerful frontend for discharge lamps, LEDs can be set to almost customers can truly maximize their wireless communication modules like zero current by applying digital control design efforts.” low-energy Bluetooth, Wi-Fi or ZigBee. principles. With smarteXite, intelligent Additionally, intelligent sensor devices control algorithms can be employed and enabling color- or proximity-sensing can be configured to provide a wide dimming directly connected. When such a peripheral range. Additionally, the smarteXite platform Revolutionary device is used, the integrated power offers a range of protection and supervision management unit in the iW6401 provides a functions, which can be customized for the SmarteXite stable power source, reducing the external different bulb requirements. Technology Driver component count and cost. Platform from Dialog Combining Dialog’s strengths in configurable power management with state-of-the-art AVX’s New Vertical Semiconductor digital signal processing design, the iW6401 Dialog Semiconductor announced its is the world’s first programmable AC/DC Top Mount SMT smarteXiteTM platform, enabling a new retrofit LED lamp driver IC, which allows Connector for SSL generation of highly flexible, programmable engineers to design and configure the bulb LED driver ICs for smart lighting applications. design via software with an optimized bill of Wire-to-Board Market material (BOM) versus a time intensive iterative hardware design process. This AVX Corporation, a leading manufacturer greatly reduces the time to market and of passive components and interconnect allows a smarteXite-based design to support solutions, has introduced the first vertical, many different global configurations and top mount, SMT, wire-to-board connector lighting requirements. specifically designed to meet the configuration, performance, and cost “Solid state lighting components and goals faced by industrial and solid-state manufacturing costs have fallen to a level lighting design engineers. Featuring AVX’s enabling LED bulbs to be sold in retail industry-proven dual-beam, 3 mm, high stores for under 10 dollars; this price point spring force box contacts packaged in a drives consumers to adopt the technology protective insulator, the new 9296 Series and retrofit their homes,” said Mark Tyndall, vertical, top mount, poke home connectors The tiny iW6401 smarteXite LED driver IC VP Corporate Development & Strategy and provide maximum mechanical stability and supports dimming options with multi-interface GM Power Conversion Business Group at wire retention in addition to simple strip solution and multi-stage programming Dialog Semiconductor. “Market analyst firm and insert wire loading and twist and McKinsey predicts a 57 percent compounded pull wire removal.

Tape and reel packaged for automatic The IceLED Xtra 550 is a fan-cooled model assembly, each 9296 Series vertical top that performs up to 10,000 lumen or 100 mount connector is supplied with a small watts of heat dissipation, while the IceLED kapton tape on the top to aid with the pick Xtra Ultra goes up all the way to 20,000 and place process. Post-soldering, the tape lumen. With a weight of just 400 grams should be removed and discarded. designers can make major improvements on the overall weight of their high and low bay designs.

The modularity of the ModuLED and IceLED AVX’s new wire-to-board connector allows Mechatronix connecting 18-26AWG wires directly through designs are reached through making all the the connector’s top aperture Launches ModuLED needed mounting holes immediately in the Xtra and IceLED Xtra extrusion profile. In this way the LED Designed to surface mount on the top of a modules can be mounted without any after PCB, the new one- to six-way 9296 “The whole idea of developing the ModuLED work by self-tapping screws. connectors allow users to insert solid or Xtra and IceLED Xtra LED coolers was to stranded, plated or un-plated, 18-26 AWG create a limited number of products which Overview of all LED COB’s and LED wires directly through the connector’s top fitted with all the newest LED modules and modules which are standard foreseen on aperture and are ideal for a variety of COB’s which came on the market in the last this “Xtra” series: industrial applications, including: LED year” according to Ken Yang, Chief Designer • Zhaga Book 2 compliant LED engines: lighting, smart meters, building controls, at MechaTronix. Megaman Teco, Philips Fortimo TDLM fire and security systems, and industrial and Tridonic Talexx Stark DLE twist motor controls and drivers, among others. • Zhaga Book 3 compliant LED Spot Light modules: “We designed our new 9296 vertical top Edison Edilex SLM, Osram PrevaLED, mount SMT connector to satisfy a Philips Fortimo SLM, Tridonic Talexx Stark significant gap we identified in the industrial SLE, Vexica Lumaera and Vossloh and solid state lighting wire-to-board Schwabe Luga Shop markets,” said Tom Anderson, product • LED COB’s for which Zhaga Book 3 LED manager at AVX. “No other vertical top holders are available: mount connectors designed to provide Bridgelux ES rectangular LED array, robust performance in industrial grade Citizen CitiLED CL-L030, CL-L032, applications are currently available and, C L- L 0 4 0, C L- L 0 42, Cree XLamp CXA18xx, CXA25xx, Mechatronix’s intention when designing moreover, many of the vertical through- CXA30xx, ModuLED Xtra and IceLED Xtra LED coolers board options that exist are not robust was to create a limited number of products for Edison Opto HM16 and HM30, LG enough to satisfy the unique demands of all the latest LED modules Lighting MCP 10-24W, industrial applications. With this latest Osram Soleriq E30, Philips Lumileds addition to the 9296 Series, AVX now offers “Bridgelux came out with the Vero LED Luxeon 1204, 1205 and 1208, Luxeon K12 vertical top mount, bottom mount, and modules, Philips Lumileds created a whole and K16, through hole poke home connectors that family of Luxeon COB’s, Vossloh Schwabe Prolight Opto PABA 10-50W, provide reliable off-the-shelf solutions developed a new 10,000 lumen high bay LED Sharp Mega Zenigata and Tiger Zenigata, specifically designed to meet the configuration, engine with the Luga Industrial, and that’s just Tridonic Talexx Stark LES 17 cost, and performance requirements for a 10% of all the new developments our ECO • Zhaga Book 5 compliant LED engines: broad range of industrial applications.” partners reported us in the last twelve GE Infusion LED modules M1000, M1500, months. Also a lot of new ECO partners M2000, M3000, M4500 AVX’s 9296 Series vertical top mount applied for making standard LED heat sinks • Zhaga Book 6 compliant LED engines: connectors feature RoHS-compliant for them, like GE for their Infusion series, LG Toshiba E-Core LED Light Engine LED coppery alloy contacts with tin over nickel Innotek, Lustrous, and TSMC. LEV11 and LEV16 plating and are rated for 300VAC, five-cycle • Bridgelux Vero 13, 18 and 29 LED engines durability, and temperatures ranging from Making dedicated standard LED coolers for • Edison Opto SD, HS, HV and HR COB -40°C to +125°C. Available in one to six each of those separately would probably take • Lustrous X5, DX5, TX5 and XL5 COB positions, each connector will accept the us two years, and by that time the LED world series entire wire gauge range for either solid or would look already completely different.” • Philips Lumileds Luxeon 1204, 1205 and stranded wires at varying current ratings 1208 COB series supported by each wire size; and, once The ModuLED Xtra passive LED coolers come • Prolight Opto PABA COB series inserted, wires can be easily removed or in 50 and 80 millimeter height and give a replaced by twisting, unscrewing, or using a cooling performance for spot and down light With regards to thermal performance small blade extraction tool. designs from 700 lumen up to 4000 lumen. MechaTronix runs thermal validation

programs from each brand and LED GlacialPower package in combination with the LED cooler and publishes this data online. In Announces Two this way the lighting designer has immediately an accurate idea of the New Drivers For temperature the Tc/Tp point will reach in 9-57 V Indoor LED his design, what can save a tremendous amount of time during the design stage. Lighting GlacialPower, a division of Taiwanese technology manufacturer, GlacialTech Inc., is pleased to announce two new Star Heat Sinks Cool GlacialPower LED drivers for constant voltage (CV) and constant current (CC) LED High Power LEDs lights – GP-RS26P and GP-RS35P – Advanced Thermal Solutions, Inc. (ATS) available in several options ranging from 9 V has added a series of Star LED heat sinks DC to 57 V DC. The drivers are also designed for convection cooling of high available with a 3 in 1 dimming heat flux LEDs to its portfolio. Each of the (1-10 V/PWM/Resistor) function. 32 heat sinks provides enhanced heat transfer for effective LED cooling without fans or blowers. Cooling performance reaches more than 60 K (∆Ths-ambient) at 50 W of power dissipation, depending on model.

Optionally, both new LED drivers offer GlacialPower’s 3 in 1 dimming function

Features: • Class 2/II plastic housing design

ATS’ new line of Star heat sinks is made from • Double insulated wiring lightweight aluminum • Universal AC input 90~305 VAC • Constant current and constant voltage The Star heat sinks are made from operation lightweight aluminum in a round profile • Built-in active PFC (Power Factor that fits common LED applications. Correction) function Cooling fins are arrayed in a round, • 3 in 1 dimming function (optional) star-like cross section that optimizes • Protection: OVP / SCP / OTP thermal performance in local air flow. A flat • IP67 approved base at one end allows secure, direct • Operation from -20°C ~50°C at full load mounting of LEDs. Integral threads on the base perimeter allow attachment of Both of the drivers are ideal for any indoor brackets and other hardware. An inner LED lighting solutions, as the robust IP67 thread on most models allows convenient approved plastic housing protects the attachment of LED lens mounts. drivers from possible dust or water damage such as rusting. In addition, the ATS Star heat sinks are available in double insulated wiring design ensures lengths from 25 to 1,000 mm (0.98 to that if the wire is pulled externally, the 39.37 in). Standard diameter is 45 mm strain relief bushing to the circuit board (1.77 in). Each heat sink features a will not be exposed, preventing possible black anodized finish that provides electricity leakage. corrosion resistance, electrical insulation, and improved thermal performance. The GP-RS26P and GP-RS35P LED drivers All heat sinks within the series are offer a range of different options for indoor RoHS compliant. LED lighting needs. The output voltage of NEWS PRODUCTS 18

the two LED drivers range from 9 V DC to designed in these new power units. Beside 57 V DC. The GP-RS26P LED drivers deliver standard functions of protections for short up to 25.2 W and the GP-RS35P LED circuit, over voltage, overload, and over drivers up to 36 W of power to the LED. For temperature, HVG(C)-65 comply with global LED driver producers — safety standard certificates of lighting regulations. They are certification UL8750 Class 2/II has been very suitable for LED lighting applications applied for and is currently under review, that require high input voltage range. however these drivers’ specifications fully satisfy the criteria of the UL1598 fixture safety standard. These specifications Mean Well’s HVG(C)-65 LED driver is the latest combined with a two stage design that member of the HVG(C) series Mean Well Introduces prevents flicker, as well as durable plastic housing and cables makes these drivers Both series are built-in two-stage PFC New Boost Type DC/ excellent options for practically any constant function, so that they can meet the harmonic DC Constant Current voltage and constant current LED indoor current limitation per EN61000-3-2 Class C lighting needs. (>60% load), and they also fulfill PF>0.9 if LED Drivers loading over 60% (>70% load under 480 VAC). These two new LED drivers offer safe and In addition, they possess 4 kV surge immunity After the launch of the DC/DC Buck type reliable power. In addition to the IP67 (EN61000-4-5) ability which complies with the LED converters (LDD series), Mean Well approved plastic housing the drivers have requirements of lighting industry. further introduced the new Boost type DC/ three different protections: Over Voltage DC constant current LED drivers~LDH-45 Protection (OVP), Short-Circuit Protection Features: series. The new drivers possess 9~18V DC (SCP) and Over-Temperature Protection (OTP). • Wide range input 180~528 VAC input for LDH-45A-X models and 18~32 VDC • Aluminum case and potted by glue, comply input for LDH-45B-X models. GlacialPower’s R&D team developed these with IP65 / 67 LED drivers with the aim to eliminate the • Output voltage and current adjustable need for electronic transformers and to • Meet 4 kV surge immunity level provide more energy-saving and (EN61000-4-5) environmentally-friendly LED products. • Built-in active PFC function GlacialPower’s LED driver technology is • 90.5% high efficiency expected to lead a new trend in innovation • Cooling by free air convection and become an essential feature for all LED • Protections: Short circuit / Overload / Over lighting products. Besides the GP-RS26P voltage / Over temperature and GP-RS35P, GlacialPower also offers the • Certificates: GP-RS45P and GP-RS60P for higher HVG-65: UL / CUL / FCC; HVGC-65: UL / wattage applications. CUL / ENEC / CB / FCC / CE • Dimension(LxWxH): 189 x 61.5 x 36.8 mm Mean Well’s new LDH-45 series possess high • 5 years warranty efficiency up to 95%

Mean Well Extends HVG(C)-65 has three options (A/B/D type) in Features: different mechanisms and functions for your • Step-up design Its HVG(C) Series selection. In A type of HVG-65, users can • Constant current (C.C.) mode output with the HVG(C) 65 adjust DC current range from 60% to 100% • 95% high efficiency and output voltage ±10% by removing the • Built-in EMI filter After the launch of the high input voltage rubber stopper on the cover. In A type of • Built-in PWM and Analog dimming LED power supplies~ HVG(C)-100/150 HVGC-65, users can adjust DC current range function series, MEAN WELL announced the from 60% to 100%; B type models equip with • Cooling by free air convection extension of its HVG(C)-65 (65W) series. three-in-one dimming function (0~10 VDC, • Working temperature: -40~+70°C Featuring with 180~528VAC wide range AC PWM, resistance) while D type models • Protections: Short circuit, over voltage, input, HVG(C)-65 series are not only fit for (optional) equip with “multiple stage timer input under voltage the general 230 VAC main input, but also dimming” function that can be customized by • UL94-V0 level plastic case can be operated under 277 / 347 / 440 / request. In addition, these new series possess • Approval: CE 480 VAC input in USA, Canada, and Japan. up to 90.5% of high efficiency, so they can be • Package type: Pin style and Wire style cooled by free air convection from -40°C to • 3 years warranty Designed with constant voltage (C.V.) plus +70°C ambient temperature. constant current (C.C.) mode, HVG-65 Both series feature with 350 mA / 500 mA / series are low voltage output models In order to fit in with the outdoor harsh 700 mA / 1050 mA output current. In (54 VDC max.) while HVGC-65 are high environment, aluminum case with fully addition, LDH-45 series are built-in PWM voltage output models (186 VDC max.). potted by glue (IP65/67 structure) are also and Analog dimming function, thus,

the ON/OFF remote control and the output current adjustment can be realized by connecting the external PWM signal or 0.25~1.3 VDC analog voltage, which can satisfy the demand of various energy- saving dimming design of lighting fixtures.

LDH-45 series possess up to 95% of extremely high efficiency and can operate between -40~+70°C of ambient temperature by only free air convection. All series are potted for providing better ability of heat dissipation, anti-dust, and anti-moisture. Furthermore, they offer two kinds of input/ output packages like pin style or wire style for selection. Built-in EMI filter, these LED drivers comply with EMI requirements per EN55015 lighting regulation without connecting any external EMI restraint components. Other standard The ILT950 comes standard in two ranges, functions include short circuit, over ILT950 with a spectral range of 250-1050 nm voltage, and input under voltage and the ILT950UV with 200-450 nm protections. Suitable applications include street lighting, landscape lighting, tunnel Main Features: lighting, household lighting, and all kinds • Two Versions of off-grid LED garden lights or LED street • ILT950: 250-1050 nm lights that powered by solar charger. • ILT950UV: 200-450 nm • NIST-Traceable/ISO17025 Accredited Calibration • ILT950 Applications include ILT Introduces characterization of solar simulation • Accelerated weathering New Portable • Photostability testing Spectroradiometer • UV curing systems • Photobiology and photochemistry Systems • LED illumination and color analysis

New ILT950UV / improved ILT950 is now The new higher pixel SONY CCD array is equipped with a higher pixel CCD array for upgraded for improved performance improved performance including nearly including nearly 50% more sensitivity over 50% more sensitivity and higher S/N ratio the entire spectral region, and higher S/N increased from 200:1 to 300:1 with larger ratio increased from 200:1 to 300:1 with quantum well depth. This most cost- larger quantum well depth. This, combined effective, fully integrated, CCD-based with the new software features included in spectroradiometer family is available with our powerful SpectriLight III, makes the ISO17025 accredited calibration. ILT950 a top performer in the CCD array spectrometers available on the market. The ILT950 is equally at home on the production floor as well as the laboratory To make ordering easy, ILT offers pre- combining high performance, accuracy, configured complete measurement ease of use, and a wide array of features systems which include everything you will all in a rugged, compact, and portable need to take accurate, calibrated light design. measurements: • ILT950 Remote Optic Irradiance System The excellent performance of the ILT950 includes the ILT950 spectrometer, has been improved even further with the FFOSMA2UV1000 2 meter long fiber addition of a new machined optical bench optic, W2 wide eye diffuser, single source for reduced stray light and improved calibration from 250-1050 nm, thermal stability for 2014. SpectriLight III software, Tripod and NEWS PRODUCTS 20

carrying case. (For UV use: ILT950UV through pop up windows, menus and Boasting the same shape and size as the version with W diffuser and dual source cal toolbars. Absolute Irradiance and chromaticity popular A19 traditional bulb, the Cree LED 200-450 nm) are calculated instantly. 75-watt Replacement Bulbs can be placed • ILT950CR Clean room “NO UV” verification in most lighting fixtures in the home. system includes the ILT950 spectrometer, Unlike many low-priced LED bulbs, WD direct mount diffuser, Short pass 500 Cree’s omni-directional LED bulbs turn on nm filter, Dual source calibration from Cree Expands LED instantly and are easily dimmable with most 250-500 nm, SpectriLight III software and standard incandescent dimmers. The carrying case. Used to verify the UV Bulb Portfolio with high-performance bulb is illuminated by blocking filters use in clean room an A19 Size 75-Watt Cree LED Filament Tower™ Technology environments.. and provides a compact optically balanced • ILT950RAA Colorimetry/Right Angle Replacement Bulb light source within a real glass bulb to irradiance system includes the ILT950 deliver consumers the warm light they spectrometer, SC600 600 um fiber optic Cree, Inc. marks another milestone in LED love and want. light guide with RAA4 right angle diffuser, lighting with the introduction of the new Single source calibration from 250-1050 Cree LED 75-watt Replacement Bulb. nm, SpectriLight III software and carrying The game-changing Cree LED Bulb now case. With the new enhances colorimetry shines even brighter with the 75-watt option. Green Creative’s features such as Metamerism calculation The revolutionary bulb looks and lights this is an excellent configuration designed like a traditional incandescent bulb but it Crisp Series High for testing lamp output in light booths used uses 82 percent less energy and is CRI Lamp Is the First in the graphic arts industry. (For UV use: designed to last 25 times longer. ILT950UV version with RAA4 diffuser and Conceived from the start to make quality LEDA Tier 2 Qualified dual source cal 200-450 nm) LED lighting accessible to all, the new • ILT950P Power/Flux Measurement System Cree LED Bulbs retail for $23.97 – MR16 Lamp includes the ILT950 spectrometer, delivering consumers a higher output Green Creative, the commercial grade LED FFOSMA2UV1000 2 meter long armored LED bulb in a standard form factor that’s lighting manufacturer proudly announces its fiber optic, INS125 5” integrating sphere, priced less than competing 75-watt MR16 7W High CRI lamp as being the only Single source calibration in Watts/Lumens replacement LED bulbs. Tier 2 qualified MR16 lamp in the Energy from 250-1050 nm, SpectriLight III software, Solutions LED Accelerator Program in Tripod and carrying case. For total flux California. Featuring a typical CRI 95, R9 95 measurements of LED’s and many other and R13 95, the MR16 7W High CRI lamp is types of miniature lamps. (For UV use: perfect for applications that demand ILT950UV version with INS125 integrating excellent color rendering. sphere and dual source cal 200-450 nm) • ILT950R Luminance/radiance Measurement System includes the ILT950 spectrometer, FF0600SC 600 micron 1 meter long fiber optic, R3 Spot luminance optic, A706 light source, Single source calibration for radiance/luminance from 250-1050 nm, SpectriLight III software, tripod and carrying case. (Not recommended for dual source cal/UV measurements) Cree’s new 75-Watt replacement bulb delivers more light in the convenient A19 size with Green Creative’s new LEDA certified MR16 unmatched energy savings The new spectroradiometers come with ILTs 7 W High CRI lamp has exceptional R9-R14 SpectriLight™ III control and analysis values software, a LabView™ based software “Driving to 100-percent adoption of LED package for Windows that allows acquisition lighting requires continuous innovation to Unlike most high CRI LEDs, the Crisp Series of spectral and color data. Analysis of the meet even more customer needs,” said MR16 delivers outstanding color accuracy data is calculated instantly within the same David Elien, Cree vice president, marketing without sacrificing efficiency. With a typical program - no exporting required. and business development. “The new Cree 465 lumens, this 1:1 halogen form factor LED 75-watt Replacement Bulb gives lamp has an extremely high 66 lpw efficacy. SpectriLight™ III provides easy setting of all consumers even more options and yet This is over 50% more efficient than any operating controls of the ILT950 spectrometer another reason to switch to LED lighting.” other high CRI 45-50 W replacement MR16. with an integrated data analysis package This innovative lamp has already been making your spectral analysis fast and simple. Cree LED Bulbs are the ideal replacement selected by the Illuminating Engineering Wavelength range, integration time, scan for energy-wasting 75-watt incandescents Society to appear in the prestigious 2013 average and other controls can be easily set and compromise-laden CFL lighting. Progress Report.

Funded through PG&E, the California LED strong demand for this, and now Green guarantees safety for industrial usage. Accelerator Program (LEDA) works with LED Creative has clearly set itself apart from the ALTLED® street lights are also IP68 and have manufacturers and multi-site PG&E competition with this high CRI MR16.” passed the salty-spray test; a new feature is customers, primarily in the retail, grocery, they have a CRI of 95, which is unheard of in restaurant and museum/art gallery sectors, by the lighting industry. The new ALTLED® street providing incentives for the replacement of lights not only provide uniform brightness for traditional lighting sources with the latest in ALT Announced improved nighttime vision, but also bring out high-performance LED products. In addition the true colors of the objects and to providing incentives for high-volume retrofit New High-Wattage environments illuminated. projects, LEDA also offers lighting energy Floodlights & Street audits, economic analysis, product ALT developed a new 4-inch 20 watt demonstration, technical product selection, Lights downlight with a brightness of up to 2,000 and product specification assistance. lumens (true white). The product aims to On the first day of the 2013 Hong Kong replace traditional halogen downlights. The In order to qualify for the LEDA Program, International Lighting Fair, Aeon Lighting ALTLED® downlight utilizes ALT’s patented lamps must meet a set of rigorous Technology (ALT) announced the new heat dissipation technology for efficient heat specification requirements. The lamps are development of several LED lighting products transfer which ensures LED stability and then separated into two tiers, with Tier 2 for specialized markets, including those lengthens product life. This newly developed products achieving a higher performance engineered for extreme environments and downlight has an option of CRI 98, exceeding standard than Tier 1. Green Creative has the high wattage LED floodlights and streetlights. industry standards. CRI and efficiency are most qualified products on the PG&E trade-off factors, but ALT has managed to LEDA list, with a combination of ten PAR maintain high efficiency with a wide range of and MR models. color temperatures between 2,200 K and 6,500 K. As with all ALTLED® products, the The MR16 7W High CRI lamp is the only Tier downlight also comes with a 3-year warranty. 2 qualified MR16 on the list which features products from over ten participating Aiming for a luxury niche market, a special manufacturers. This lamp exceeds LEDA’s edition of gold MR16 and gold chandeliers CRI 90 and 50 LPW efficacy requirements, were displayed during the product launch. both of which are more stringent than Energy Paired with 2,200 K color temperature, these Star. Green Creative’S MR16 7 W High CRI ALT’s new Floodlights can replace HID gold and luxurious MR16s and chandeliers LEDA qualified lamp model comes in 2700 K luminaires up to 1,000 W, delivering 42,000 lm can create a golden-colored ambience for a CCT and a NF beam angle. more regal effect. Furthermore, ALT has Introducing All New ALTLED® Lighting developed a 10 watt Grande chandelier light “It’s impressive that we have hit the Tier 2 ALT announced the T200 and T500 floodlight, which has lumen output up to 1,200 lumens. mark with our MR16,” says Green Creative’s brightness reaching 42,000 lumens. These The Grande chandelier light has an option of Utility Program Manager, Erik Bluvas. “The high wattage LED floodlights are expected to 2,200 K or CRI 98, which is perfect for Tier 2 standards were designed to push the completely replace traditional HIDs that are oversized chandeliers in grand halls, market, and I don’t think PG&E expected a over 1,000 watts. Completely waterproof, mansions and six or seven-star hotels. The manufacturer to reach it so soon. The color dust-proof, and anti-corrosion, the T200 and luxurious section is tailored for those who quality levels are also exceptional. In my years T500 are rated IP68 and have the option of have an eye for beauty but are also of field auditing there has always been a installing an anti-fall device, which further environmentally conscious.

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UC Santa Barbara: over traditional incandescent or fluorescent As LEDs become brighter, for example when lighting. LEDs use less energy, emit less they are used in vehicle front lights, they also Optimizing heat, last longer and are less hazardous to tend to get warmer, and, inevitably, this the environment than traditional lighting. impacts phosphor properties adversely. Phosphors Using Already utilized in devices such as street Simple Guidelines lighting and televisions, LED technology is “Very few phosphor materials retain their becoming more popular as it becomes efficiency at elevated temperatures,” Brgoch Improves Efficiency of more versatile and brighter. said. “There is little understanding of how to choose the host structure for a given activator Solid-State Lighting According to Seshadri, all of the recent ion such that the phosphor is efficient, and By determining simple guidelines, researchers advances in solid-state lighting have come such that the phosphor efficiency is retained at UC Santa Barbara’s Solid State Lighting & from devices based on gallium nitride LEDs, at elevated temperatures.” Energy Center (SSLEC) have made it possible a technology that is largely credited to to optimize phosphors - a key component in UCSB materials professor Shuji Nakamura, However, using calculations based on white LED lighting - allowing for brighter, more who invented the first high-brightness blue density functional theory, which was efficient lights. LED. In solid-state white lighting technology, developed by UCSB professor and 1998 phosphors are applied to the LED chip in Nobel Laureate Walter Kohn, the such a way that the photons from the blue researchers have determined that the gallium nitride LED pass through the rigidity of the crystalline host structure is a phosphor, which converts and mixes the key factor in the efficiency of phosphors: blue light into the green-yellow-orange The better phosphors possess a highly rigid range of light. When combined evenly with structure. Furthermore, indicators of the blue, the green-yellow-orange light structural rigidity can be computed using yields white light. density functional theory, allowing materials to be screened before they are prepared The notion of multiple colors creating white and tested.

This illustration demonstrates how bright blue may seem counterintuitive. With reflective LED light, shone through its complementary pigments, mixing blue and yellow yields This breakthrough puts efforts for high- yellow phosphor, yields white light green; however, with emissive light, mixing efficiency, high-brightness, solid-state such complementary colors yields white. lighting on a fast track. Lower-efficiency “These guidelines should permit the incandescent and fluorescent bulbs - which discovery of new and improved phosphors Art to science: use relatively more energy to produce light - in a rational rather than trial-and-error Until recently, the preparation of phosphor could become antiquated fixtures of manner,” said Ram Seshadri, a professor in materials was more an art than a science, the past. the university’s Department of Materials as based on finding crystal structures that act well as in its Department of Chemistry and as hosts to activator ions, which convert the “Our target is to get to 90 percent efficiency, Biochemistry, of the breakthrough higher-energy blue light to lower-energy or 300 lumens per watt,” said DenBaars, contribution to solid-state lighting research. yellow/orange light. who also is a professor of electrical and The results of this research, performed computer engineering and co-director of the jointly with materials professor Steven “So far, there has been no complete SSLEC. Current incandescent light bulbs, DenBaars and postdoctoral associate understanding of what make some by comparison, are at roughly 5% efficiency, researcher Jakoah Brgoch, appear in phosphors efficient and others not,” and fluorescent lamps are a little more The Journal of Physical Chemistry. Seshadri said. “In the wrong hosts, some of efficient at about 20%. the photons are wasted as heat, and an LED lighting has been a major topic of important question is: How do we select “We have already demonstrated up to 60% research due to the many benefits it offers the right hosts?” efficiency in lab demos,” DenBaars said.

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Photometry Standardization Developments for OLEDs and LEDs

Since the introduction of Solid State Lighting the challenges for manufacturers to provide constant high quality light have changed completely. Compared to conventional light sources, many aspects of the characteristics of an LED light source are different. Never before have the characteristics between light sources of the same type differed as much as they do now. Never before was the influence of external parameters as significant for a measurement result as it is now. For this reason, the review of existing standards and, when necessary, their revision, must be done stringently. Tony Bergen, Technical Director of Photometric Solutions International and Secretary of CIE Division 2, and Peter Blattner, Head of the Photometric Laboratory at the Swiss Federal Institute of Metrology and Director of CIE Division 2, introduce the challenges and report about the ongoing work and the expected revision of TC2-71 - the most important measurement standard.

Solid state lighting (SSL) various areas relating to testing representing the best authority on the devices such as LEDs and and measurement of SSL subject and as such is recognized by OLEDs have rapidly developed devices. This article looks in ISO as an international standardization in recent years and are now detail at some of the issues body for the field of light and lighting. rivalling traditional light sources relating to the photometry of The Commission is organized in seven as the predominant choice of SSL products and the work being divisions covering all topics of light and lighting type for new lighting done by the CIE solving these lighting. Division 2 deals with aspects installations. Their efficiency, challenges. of the physical measurement of light versatility and robustness offer and radiation. It identifies an incredible range of benefits measurement problems associated and opportunities. But with Introduction of CIE with new sources, detectors and these opportunities also The International Commission on materials and gives best practice come challenges: Illumination – also known as the CIE guidance on measurement techniques from its French title, the Commission and the application of these techniques • Challenges with testing and Internationale de l´Eclairage – is in practical situations. The new lighting measurement devoted to worldwide cooperation and technologies also have an impact on • Challenges with harmonization the exchange of information on all measurement procedures and and standardization matters relating to the science and art instrument requirements. • Challenges with product quality of light and lighting; color and vision; and reliability photometry; lighting applications; photobiology; and image technology. Measurement Issues The International Commission on With strong technical, scientific and with LEDs Illumination (CIE) has risen to cultural foundations, the CIE is an LEDs have many interesting properties. these challenges and will soon be independent, non-profit organization They are highly efficient, can be publishing an International that serves member countries on a modulated, may change their spectral Standard Test Method for voluntary basis. behavior and allow a high degree of photometry of LED Lamps, LED freedom in the geometric design of Luminaires and LED Modules. Since its inception in 1913, the CIE has lamps and luminaires. The Additionally, the CIE has other become a professional organization measurement of the photometric Technical Committees working on and has been universally accepted as parameters such as luminous flux or

Beside the technical committees cited in the article about developing an international standard test method for LED lighting products, there are several additional activities going on. The other Division 2 TCs are currently working specifically on different aspects of LED photometry. Some TCs are not specifically relating to LEDs but also contribute with very relevant work for the Solid State Lighting community.

TCs Relating to LED TC2-75: Photometry of Curved and calibration of imaging-photometry-based Photometry Flexible OLED and LED Sources near-field goniophotometers and for (Chair: Hsueh-Ling Yu, TW) determination and conversion of photometric TC2-50: Measurement of TC2-75 is working on preparation of a CIE data of lamps and luminaries for both near-field the Optical Properties of recommendation on methods for and far-field applications. LED Assemblies characterization of the photometric and (Chair: Richard Distl, DE) colorimetric quantities of curved and flexible TC2-72: The Evaluation of TC2-50 is working on a technical report to give sources: especially for OLEDs and LEDs. The Uncertainties in Measurement of recommendations for laboratory measurements aim is to make measurements accurate and the Optical Properties of Solid of optical properties of LED assemblies such as repeatable and to include measurement State Lighting Devices, including LED modules and LED light engines. This traceability. It includes aspects such as Colored LEDs includes environmental conditions, power terminology; luminance; uniformity; luminous (Chair: Richard Young, GB) supply and control equipment, and pre- flux; color; viewing angle; and reflectance. The CIE recently published CIE 198:2011 measurement precautions. It will give guidance Determination of Measurement Uncertainties in for measurement of Luminous Intensity; TC2-76: Characterization of Photometry, which provides guidance on how Luminous Intensity Distribution; Total Luminous AC-Driven LED Products for to model measurement procedures in a Flux; Partial Luminous Flux; and Luminance. SSL Applications measurement equation, combine uncertainties (Chair: Pei-Ting Chou, TW) in a budget and convert to the presentation of TC2-63: Optical Measurement TC2-76 is preparing a technical report dealing expanded uncertainty and it has a wide of High Power LEDs with methods and procedures for testing and selection of examples. TC2-72 is working on (Chair: Yuqin Zong, US) calibration laboratories to characterize expanding the supplements of CIE 198:2011 to The measurement results of high-power LEDs AC-driven LEDs for physical quantities related include further principles and examples for depend strongly on their thermal conditions. In to lighting including electric, photometric, evaluation of the uncertainties associated with order to achieve reproducible results with small colorimetric, and radiometric quantities. It is the measurement and testing of LEDs and other uncertainties it is critical to accurately set and focused on those properties influenced by the solid state lighting devices. Examples include control the junction temperature of an LED effect of flicker, and there is also a distribution photometry, spectral measurement during the time for optical measurement. This corresponding reportership (i.e.: a detailed and derived quantities, goniospectroradiometry TC is working on a technical report to describe study) within CIE Division 2 that is looking at and other priority measurements as advised by the methods and procedures for measurement flicker measurement and a flicker index study industry. of high-power LEDs under DC operation to on solid-state lighting. acquire photometric, colorimetric, and TC2-74: Goniospectroradiometry radiometric quantities at a specified junction of Optical Radiation Sources temperature. TCs Relating to Measurement (Chair: Jiangen Pan, CN) Instruments and Laboratory LEDs frequently display a spatial and angular TC2-64: High speed Testing Practices non-uniformity of chromaticity – i.e., they Methods for LEDs change color with angle. So it is usually not (Chair: Günther Heidel, DE) TC2-51: Calibration, sufficient to take a single color measurement in The report to be produced by TC2-64 is Characterization and Use of a single direction and assume it to be intended to extend CIE 127:2007 (Measurement Array Spectroradiometers representative of the total light source like could of LEDs) for precise, high speed testing of large (Chair: Richard Young, GB) often be assumed with other traditional light numbers of single LEDs, including high-power TC2-51 is working on a technical report for the sources such as incandescent and fluorescent LEDs. It is primarily focused on the calibration of detector array spectroradiometers, sources. Thus goniospectroradiometry is measurements during LED production, which is such as CCD spectroradiometers, primarily for becoming increasingly important in where the LEDs are binned. It is being prepared the determination of colorimetric and characterization of SSL devices. This TC will in collaboration with TC 2-63. The fact that all photometric quantities. It includes performance produce a technical report on optical and electrical parameters of solid state characteristics, evaluation of these goniospectroradiometry, including light sources are highly dependent on the characteristics, calibration methods and measurement principles for evaluating temperature makes some definitions for the test guidance in the application of methods for the radiometric, photometric and colorimetric environment and driving conditions necessary determination of uncertainty. quantities and related traceability. to get results which can be reproduced in other laboratories with low uncertainty, and can be TC2-59: Characterization of TC2-78: Goniophotometry used to calculate optical values for the later Imaging Luminance of Lamps and Luminaires applications. Measurement Devices (Chair: Tony Bergen, AU) (Chair: Udo Krueger, DE). This TC is updating CIE 070:1987, CIE 121:1996 TC2-68: Optical measurement TC2-59 is preparing a Technical Report on and the relevant parts of CIE 084:1989 relating methods for OLEDs used for methods for the characterization of imaging to goniophotometry. It will produce an lighting luminance measurement devices (i.e. CCD up-to-date technical report on goniophotometry (Chair: Thorsten Gerloff, DE) cameras used to measure luminance). These including the absolute goniophotometry of LED TC2-68 is producing a Technical Report on the devices are important for applications such as lamps and luminaires. measurement methods of the optical properties measurement of the luminance distribution of and the terminology of OLEDs used for lighting. LEDs and LED arrays; measuring the uniformity This includes effects such as temperature, of OLED panels; glare evaluation; and TC2-79: Integrating Sphere orientation of operation and current density and measuring the luminance of lighting installations Photometry and Spectroradiometry measurement effects including uniformity such as roadway and tunnel lighting. (Chair: Dong-hoon Lee, KR) (homogeneity) and a comparison of TC2-79 is updating the relevant parts of CIE measurement in integrating sphere with TC2-62: Imaging-Photometer- 084:1989 Measurement of Luminous Flux that goniophotometry/goniospectroradiometry. It is Based Near-Field Goniophotometry relate to integrating sphere photometry and currently working on a technical note for terms (Chair: Walter Steudtner, DE) spectroradiometry. It will take into account and definitions that are hoped to be released in This TC is working on a CIE recommendation current day techniques, practices, test late 2014. on the methods for characterization and geometries and light sources. STANDARDIZATION PHOTOMETRY 26

Figure 1: luminous intensity distributions isn’t Typical errors that could be fundamentally different to traditional encountered when light sources. However, several measuring white aspects need closer considerations. LEDs as a function of the quality of the photometer Spectral aspects All photometers, for example, illuminance meters (lux meters) and luminance meters, need to have a spectral responsivity which is the same as the “standardized” human eye – the relative spectral luminous efficiency function known as the V (λ) curve which is defined in CIE S010/E:2004. Deviations from this ideal spectral response results in what is referred to Figure 2: as spectral mismatch errors. Depending Example of errors encountered for on the quality of the photometer, the 120 photometers match to the reference curve can of different quality range from very poor to very good. when used to measure a variety For traditional white light sources, such of single-color LEDs as incandescent, fluorescent and HID lamps, the relative measurement error due to the spectral mismatch for very good photometers is typically less than 1%. For more general-purpose photometers this error is still typically less than 3%. The spectral distribution of LEDs, however, may be quite different from traditional sources. In particular it is possible to generate white using the RGB-technology, i.e. the light is emitted at three spectrally narrow wavelengths. For this type of white light source the error is about double to that of traditional white light sources.

CIE S023/E:2013 defines a quality index, f1’, which is a measure of the Even for very good photometers, the Temporal aspects spectral mismatch of a photometer to error due to the spectral mismatch can The light waveforms of LED lighting the V (λ) curve. An f1’ of 0 is a perfect be in the order of 10%, while for and signaling products are often match (ideal and not achievable in general-purpose photometers the error deeply modulated depending on the practice) and a higher number can be more than 50%! This is shown design of the LED control gear, for indicates a poorer match. Generally in figure 2, where the error is shown for example, the use of pulse width speaking, an f1’ < 1.5% is considered a range of photometers of different modulation. As the rise and fall time of an excellent match and f1’ < 3.0% is a quality and each with a range of LEDs is very short, the light output is very good match. While not directly a different colored LEDs. effectively fluctuating very quickly measure of error, a photometer’s f1’ between fully on and fully off. Care has can be used to have an idea of the Measuring the luminous flux of blue therefore to be taken when measuring magnitude of spectral mismatch error and red LEDs is therefore challenging these devices. The integration time likely to be encountered in practice, as and spectral mismatch corrections should be considered according the shown in Figure 1. need to be made according to CIE modulation period of the light source. S023/E:2013. For this purpose the This is particularly true for imaging The situation is even worse for spectral distribution of the light source luminance measurement devices single-color LEDs as they emit light and the spectral response of the (luminance cameras) and over one narrow spectral region only. photometer need to be known. spectroradiometers where very short

integration times are possible. If by develop a unified global Standard for situations. For example, the standard coincidence the device measures harmonization of testing of LEDs and condition for ambient laboratory during the “off” time of the pulse then SSL products. temperature is 25°C, but in practice it wrong results are possible. is allowed to be in the range 25 ± 1°C. TC2-71 has been developing the If the boundary condition is not met Standard in conjunction with CEN- then a correction must be made to Thermal aspects TC169-WG7, and the Standard will be correct the measured value to the It is well known that the photometrical technically identical to the CEN standard condition. For example, say a performance of LEDs depends on their Standard EN13032-4 which will be test is made with an ambient junction temperature. The junction released soon. The TC comprises 37 temperature of 23°C, which is outside temperature depends on many members from 16 countries in 5 the range 25 ± 1°C, then an additional aspects including the injected electrical continents and has a good test must be made (e.g. with the device current, the thermal connection to the representation from different industry in a temperature-controlled chamber) heat sink, the thermal capacity and sectors such as public testing to correct the measured value to what inertia of the heat sink, etc. It has been laboratories; LED/lighting it would be if the test were performed found that depending on the design manufacturers; laboratory test at 25°C. Likewise there are the thermal conductivity of the lamp/ equipment manufacturers; regulatory requirements for the properties of the luminaire holder can also have an bodies; and National Measurement electrical supply and electrical influence on the junction temperature Institutes. In fact, the very diversity that measurement equipment. For example, and thus also the luminous flux of the is needed to ensure that all interests the test voltage at the supply terminals LEDs. Laboratories also need to be and stakeholders are represented itself must be within ± 0.2 % of the rated careful that they don’t attach any creates difficulties: the TC has needed circuit voltage for RMS AC or within thermally conductive mechanical to balance different expectations. 0.1% for DC. support structure to the heat sink Aspects that have caused the greatest because that may also affect the discussion include whether or not test In reflection of the increasing demand output of the LED device under test. parameter boundary conditions should worldwide for measurement quality be imposed; the stringency of and accountability, the Standard also requirements for some test requires that all test results be Other aspects parameters; whether reporting of accompanied by a statement of the In addition to the points mentioned measurement uncertainty should be uncertainty of measurement. To assist above, many new quantities have to be mandatory or not; and the possibility of laboratories unfamiliar or inexperienced determined for LEDs. In particular, including default uncertainty values for with this, a TC2-71 subcommittee is spectral measurements will increase laboratories new to evaluation of currently preparing a Technical Note significantly in the coming years as measurement uncertainty. that will provide guidance on the important quantities such as the color determination of uncertainties of rendering indices or correlated color TC2-71 has met in person four times: in measurement for photometry and temperatures need be determined. CIE South Africa; China; France; and spectroradiometry of SSL devices. Division 2 addresses these points by Slovenia, as well as several online Furthermore, the measurements must drawing up technical recommendations Webex meetings. Because the be traceable: all equipment must be and measurement standards. Standard is being developed in properly calibrated and the traceability conjunction with CEN-TC169/WG7, chain must be maintained back to a several TC2-71 members from outside national laboratory (National Development of an of Europe have also attended some of Measurement Institute). International Standard the CEN-TC169/WG7 meetings as Test Method observers when they have been It is expected that the Standard will be Currently there is no single international discussing the standard. While there published in draft form in the first half standard test method for photometry have been a large number of of 2014. of SSL devices. This creates trade disagreements and revisions over the barriers and difficulty in comparing course of the development of the results obtained for testing at different Standard, it is now nearing completion Uncertainties laboratories. In response to this and has near-unanimous agreement As mentioned above, the CIE gives deficiency, in 2011 CIE Division 2 amongst the TC members. special attention to the evaluation of established a new Technical measurement uncertainty. This is for Committee (TC) to develop an The Standard defines standard test good reason, since the understanding International Standard Test Method for conditions for operating the LED of the measurement process has LED Lamps, Luminaires and Modules. device under test. Some of these changed over the past two decades. This new TC, TC2-71, is chaired by conditions have boundaries that take It needs to be recognized that no Yoshi Ohno (US) and its aim is to into account practical laboratory measurement is exact. When a

quantity is measured, the outcome typically defined through a tolerance Conclusion depends on the measuring system, interval. In order to minimize the risk of We have seen in this article that Solid the measurement procedure, the skill putting a product on the market which State Lighting devices pose significant of the operator, the environment, and is outside the specification, the challenges for photometry and many other effects. It is therefore an producers will define an acceptance spectroradiometry and that a lot of integral part of a measurement interval which is smaller than the work is going on to create accurate, process that dispersion of the quantity tolerance interval. In order to quantify repeatable and transferrable value is determined and stated. It gives the risk of wrong decisions the measurements of a wide variety of an indication of the quality of the producer needs to know the types of these devices and their measurement and measurement uncertainty of the measurements that applications. Uncertainty of devices and allows people to judge if have been performed. measurement and measurement two measurements done by two traceability are becoming more and different laboratories are compatible. CIE Division 2 has published a more important as there is greater fundamental document on emphasis on labs taking responsibility Measurement uncertainties play a measurement uncertainty evaluation in for their quality of measurement. The central role in quality assessment and photometry (CIE 198:2011) and CIE continues to take a leading role in quality standards. In conformity continues to generate guidelines and the development of these standards assessment, a measurement result is recommendations on practical aspects and testing methods. used to decide if an item of interest of measurement uncertainties. conforms to a specified requirement

Annotations: All information in regard to the Standard is correct at the time of writing this article.

Many of the Technical Committees mentioned in this article will be meeting at the next CIE Division 2 annual meeting, which will be held in conjunction with the CIE 2014 “Lighting Quality and Energy Efficiency” conference in Kuala Lumpur, Malaysia in April 2014. For more information or to join one of these Technical Committees, please get in touch with your National Committee of the CIE or see www.cie.co.at.

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STANDARDIZATION EC REGULATION FOR DIRECTIONAL LAMPS 30

New EC Regulation – How to Measure Directional Light Sources

In many ways LEDs are a game-changer for the lighting industry and even more so for the end-users. Especially the latter now need to deal with light intensity values like lumens and even candelas that are confusing for them. A new EC regulation regarding the measurement of directional light sources promotes lumens as the only value. Christian Krause, director of Viso Systems Aps, explains what this regulation means to manufacturers and gives an example.

Figure 1: In September the EC introduced Measured in Why Measuring Within 90° cone (a), a new regulation as part of a Cone measured in 120° regulation No. 1194/2012 for This new method of specifying the cone (b) directional light. This means lumen value only within a cone might that the common method of not make sense at first glance but one measuring light sources has to be of the reasons for measuring reviewed because only luminous directional light sources in this way is flux within a fixed beam angle, or to make it easier for the end user to more correctly – within a cone, understand light output of directional should be defined; whereby the light sources. Because the lumen amount of luminous flux that value would be defined as a exists inside the cone is what directional value, in a sense it would should be measured. eliminate the need for the peak candela values. The new regulation means that the common measurement Peak candela and beam angle values method using an integration are currently the most common way of sphere is rendered invalid for defining the intensity of a directional directional light sources, as light source. But having two different directional light sources should light intensity values (lumen and be measured within a 90° or 120° candela) to represent the amount of cone instead. light confuses many customers. Therefore, the new regulation promotes the lumen value as the only value. Figure 2: Definition of directional lamp Furthermore, you would expect a according to the directional light source to be new EC regulation “directional”. Therefore the light being measured within a 90° or 120° cone will give a more accurate lumen value because non-directional light would be discarded from the measurement and thus allow for a more accurate efficiency number to be calculated.

Table 1: What Is a Directional Correction factors Scope of the correction Corrected power (Pcor ) to calculate P Lamp? cor Lamps operating on external halogen lamp for EEI = P / P The definition of a directional light P rated × 1.06 cor ref control gear source in the regulation No 1194/2012 is defined as a “lamp having at least Lamps operating on external LED lamp P rated × 1.10 80% light output within a solid angle of control gear π sr (corresponding to a cone with an Fluorescent lamps with a 16 mm diameter angle of 120°)”. (T5 lamps) and 4 pin single capped P rated × 1.10 fluorescent lamps operating on external fluorescent lamp control gear Calculating the EEI Other lamps operating on external fluorescent P rated × (Energy Efficiency Index) lamp control gear Furthermore, the efficiency of a Lamps operating on external high-intensity directional light source will no longer P rated × 1.10 discharge lamp control gear be labeled as “lumen/watt”, but rather, it will be replaced by the EEI (Energy Compact fluorescent lamps with a color P rated × 0.85 Efficiency Index). This may cause rendering index ≥ 90 confusion because the lower the EEI value, the higher the efficiency and Lamps with anti-glare shield P rated × 0.80 vice versa. In addition, the type of light source The regulation is being launched in The EEI is calculated based on and how the driver gear is connected three steps: measurements made in a 90° or 120° must be defined. A table (Table 1) is cone. Luminous flux / lumen should provided to select the right correction • The first step took effect in be measured within a 120° cone if the values for calculating the EEI. September 2013 beam angle of the light source is • The second step will be launched in

equal or above 90°, otherwise Pref can then be calculated as September 2014 luminous flux should be within shown below: • The last step will come into effect in the 90° cone. September 2016 For models with Φ use < 1.300 lumen: The measured luminous flux [lm] For general LED spots such as the √ Pref = 0.88 Фuse + 0.049Фuse is called Фuse, indicating the useful GU10, the requirements will be: lumens. For example is Ф90 is the amount of lumens in a 90° cone and For models with Φ use ≥ 1.300 lumen: • Sept. 2013: EEI must be below 0.50 Ф120 is the amount of lumens in • Sept. 2014: EEI must be below 0.50 120° cone. Pref = 0.07341Φ use • Sept. 2016: EEI must be below 0.20

Figure 3: (This regulation may differ for non-LED Beam angle light sources, e.g. halogen spots) defined at 50% intensity Defining the Beam Angle To make the EEI calculation, is it necessary to measure the beam angle. The angular distribution from a goniometer measurement can be used to define the beam angle. The beam angle is defined when the light intensity has reached 50% of the peak value, as shown in figure 3.

Measurement Example GU10 LED The measurement example of figure 4 shows a typical LED GU10 lamp measured using the EC standard. The lamp has been limited to a 90° cone as the beam angle is 22°. Furthermore, the measurement shows that quite a

Figure 4: Furthermore, goniometer LED GU10 with EEI at 0.27 measurements are also necessary for measuring the beam angle of the light source.

A goniometer typically measures the intensity of the light radiated at different angles. The intensity values are represented as candela values for a certain number of angles. These candela values can then be used to calculate the complete luminous flux of a lamp, eliminating the need for the integration sphere to measure luminous flux / lumen.

Adding a spectrometer to a goniometer system would basically mean measuring all light source photometric data including CRI, color temperature, color deviation and much more. This would make it possible to eliminate the integration sphere altogether. lot of light is wasted as 33 lumen out Future of Measuring Light of a total of 181 lumen is considered New methods must be used to LED light sources also have more wasted light. The optical design of the measure directional light sources. uniform light distribution compared to lamp is important to ensure a low This raises a lot of questions as to the old-fashioned tungsten source. amount of wasted light. how measurements should be made This means that even fewer in the future since the conventional measurements are necessary to make The result for the example lamp is method of using an integration sphere sufficient accurate measurements, as follows: will no longer meet the requirements. thus making goniometer measurements competitive and fast • Sept. 2013 EEI must be below 0.50, At the same time, the integration compared to previous methods. therefore the result is “OK” sphere doesn’t give a high accuracy • Sept. 2014 EEI must be below 0.50, value when measuring directional therefore the result is “OK” light sources. This is because a Conclusion • Sept. 2016 EEI must be below 0.20, high amount of light concentrated There is no doubt that the new therefore the result is “FAILED” into one location is not always regulation introduced by the EC completely equally distributed along might raise a lot of questions by The measurement shows that the the surface inside the sphere. lighting manufacturers but new GU10 lamp will fail EEI requirements innovations will also change the way in September 2016. This indicates The use of a photo goniometer is light is being measured. This will spur that it will mostly be halogen type therefore necessary to measure the new light measurement technologies, directional light sources that will be angular distribution of light in order to making it easier and faster to measure affected by the steps in 2013 and define the amounts of luminous flux light by using smarter goniometer 2014 and LEDs will mostly be affected within the 90° or 120° cone. systems in the future. by the step in 2016.

INTERVIEW STANDARDIZATION FOR SMART LIGHTING 34

About Wireless Standards for Smart Lighting

Smart Lighting is an increasingly important issue, clearly bolstered by the maturation of LED lighting. Both wired and wireless controls are available with each based on very different and often incompatible technologies. This confuses consumers and curbs market introduction. LED professional talked with Simon den Uijl, Secretary General at The Connected Lighting Alliance, about their first proposal, technologies, future plans and strategy to endorse the proposed wireless standards.

LED professional: TCLA is a relatively is facing the problem of becoming residential area where it could offer young organization. Could you please fragmented and the user is uncertain new functions and opportunities give us an idea of why TCLA was which system to choose (Figure 1). for consumers. But in order to be founded, why it is necessary to have accepted in this market a common another lighting organization, and what TCLA aims to minimize these risks standard and interoperability the mission and goals of TCLA are? by proposing and promoting wireless are required. connectivity based on an open Simon den Uijl: TCLA was founded in standard. The open standard is LED professional: Can you name the August 2012. It was established very important because it is developed benefits and reasons that influenced when six leading lighting and controls in a cooperative process and any party the decision to focus on the residential companies realized that LED lighting that wants to use it can. Meanwhile 20 area in more detail? could benefit from smart controls members are supporting these goals. options and especially wireless Simon den Uijl: Among the exciting controls. They also found that the LED professional: Initially TCLA and beneficial new functionalities framework conditions were not ideal. announced its proposal for residential are easy switching, dimming, lighting. Why is TCLA focusing on colors changes and making group There are currently different several this area? color settings. But there are also incompatible wireless connectivity value added benefits like reduced standards being implemented in Simon den Uijl: The TCLA members energy consumption or integration lighting products. Due to these saw the biggest need and benefits into the complete home automation different “ecosystems”, the industry for a wireless infrastructure in the as well as reduced installation effort.

Figure 1: All the products shown here offer wireless control but they are all based on different technologies. This hinders interconnectivity and therefore limits usability for customers

Figure 2: The selection process is clearly defined and guarantees the best results while providing a high level of agreement amongst the members

It is also very important to mention Simon den Uijl: The first question to done. These candidates had to meet that the technology used to provide answer is, “what are the market some boundary conditions. They had these advantages is now mature and requirements” – in this case for to be open standards and they had to a very low cost target can be reached. residential applications. So first the have been available and ready for market demands are ascertained. implementation. LED professional: TCLA is promoting These are requirements like the number ZigBee Light Link for residential of nodes that the standard has to At that point the tough work (the lighting. Why and how did TCLA select support, security, energy management evaluation) could start. The experts this standard? options, or ease of installation. had to meet a number of times in order to be able to come to a Simon den Uijl: I think this is a very The latter is of extraordinary conclusion. The first thing they did important point. To obtain a broad importance for the residential was to score the different candidates. acceptance for a standard it needs application. In fact, this market The goal was to achieve a consensus. to be the best possible solution. requires that an installation can be In order to be able to come to a To ensure this, TCLA has set up its made without any technical skills. common recommendation, a deeper Technical Advisory Working Group. Ideally, even a grandmother should be analysis was carried out category by This group evaluates existing open able to buy the product and install it. category. This sometimes led to longer standards and selects the ones And then it has to work. discussions before an agreement was best suitable for the given area. reached. In the end the scores were The evaluation is done using objective System simplicity is another important averaged and these averaged scores criteria. The criteria are weighed point. This helps to hold costs and were accumulated per candidate. depending on their importance in the failure rates down. In the case of a residential application market. Finally, the technology with it meant that all in all, the ZigBee Light the best overall score is selected. The entire work group had to agree Link had the best score. on the evaluation process and the LED professional: How did you define influence of the different parameters The decision-making in June 2013 at a the parameters to guarantee the correct before the selection of the possible meeting in Osaka, to promote ZigBee selection? What about the process? candidates for the evaluation was Light Link for residential lighting

Figure 3: The TCLA Technical Advisory Working Group recognized that ZigBee Light Link, while offering the best overall match for the defined requirements, also has some potential to improve

applications was a real milestone, fragmented, it is, in fact, even worse discussions are going on it’s too because it showed that the members for the professional indoor market. early for details about things like are willing to set aside their differences This makes the evaluation task more how to connect. in order to benefit the customer. demanding and challenging. In the first stage we will again focus on the LED professional: You just mentioned LED professional: Can you give a market requirements. that existing standards for other comparison between ZigBee Light Link building management systems and and its competitors? At the first meeting in November we home appliance networks have to be concentrated on the question of how taken into account. Therefore I assume Simon den Uijl: Unfortunately not. to define the professional indoor that compatibility, or at least I cannot disclose details because market. The outcome of this discussion connectivity, to these systems was an it is our policy to point out the positive determines if subcategories with important criterion for evaluation. But properties of the promoted standard different requirements need to be how important was it? And how well is and not to talk badly about or show defined, or if it is possible to find a ZigBee Light Link performing regarding the weaknesses of other, alternative common view and define common this requirement? standards. But I can show you where requirements. This clear definition is ZigBee Light Link scored well and crucial for evaluating the existing Simon den Uijl: This question can be where it was not a top scorer. You can standards and deciding if there is an answered by looking again at the see that the results shown on your appropriate existing standard available outcome of the analysis (Figure 3). We screen clearly demonstrate we found or if a new standard needs to be have found that ZigBee Light Link has ZigBee Light Link to performs very created. In such cases TCLA only been developed specifically for lighting well in most requirements, especially gives their input to other purposes, but the drawback is that on the highly priorized lighting standardization bodies like IEEE to connectivity to home appliances is not features, scalable and affordable for create the desired standard. guaranteed. However, it is expected to consumers. Furthermore it is easy to be improved in future versions. The install for users at home (Figure 3). LED professional: If I understand you TCLA members believe that in the correctly, the first thing you look at are future lighting will become a part of a LED professional: While you are not existing wireless systems and fully connected home. The second task allowed to show a detailed comparison, standards. In many professional indoor currently set up for the Technical can you tell us something about other lighting cases there are still wired Advisory Work Group is to address this tasks and plans of the Technical systems like KNX, LON or BacNet issue. To put it precisely, this activity Advisory Working Group? available. Do you take these wired aims to enhance interoperability standards and the interoperability into between ZigBee Light Link and ZigBee Simon den Uijl: Of course. We have account as well? Home Automation. The request to started a new activity that focuses on enhance interoperability between these the indoor professional lighting Simon den Uijl: Connectivity to two profiles has also been forwarded to market, which will be a huge task. existing building management the ZigBee Alliance, and they have When I said before that the wireless systems has to be taken into account already responded that they have market for residential is very for our proposal. But while started to work on the matter.

Another activity is to provide when the Promotion Work standard that is mandatory. interoperability with ECHONET Group takes over. They plan, This may not even be desirable. lite, a global standard that is coordinate and perform the What we can and will do is very popular in Japan, which different promotional activities. make all the different parties in offers connectivity to various the value chain aware that home appliances - LED professional: These are ZigBee Light Link is the best especially energy management two different tasks. We should option for this field of with demand response. probably discuss both. Maybe application. To succeed it is Functions that are currently not you could give us an idea about very important not only to covered with ZigBee Light Link. why someone should become a inform about the lighting member. From the time TCLA industry, but also to include the LED professional: These promotes an open standard the different sales channels and to activities suggest that while most critical information is make the end-user aware of it. being the best overall solution, available for everybody, like now Once, for instance, retailers and ZigBee Light Link may not with ZigBee Light Link so what consumers realize that ZigBee completely satisfy all demands; types of memberships are there Light Link based residential Simon den Uijl especially demands in the and what are the benefits for a lighting solutions offer the best future. Does it already cover all member? promise for future interoperability, Simon den Uijl is the Secretary requirements regarding light they will demand such General of The Connected Lighting control? Or are there current or Simon den Uijl: Companies products. We believe this will Alliance, and a Standardization future additional requirements can become regular or motivate an increasing number Director with Philips. Simon holds a that need to be satisfied? And is associated members. of manufacturers to provide MSc. in Business Administration there space to prepare for Regular members can be part differentiating, but interoperable from Rotterdam School of future demands? of the work groups whereas the products using this standard. Management, and has published associated members receive several articles on standards in top Simon den Uijl: The group information about what’s We believe that it is a strong ranked academic journals. Before defined “SHALL requirements” going on, on a regular basis. and convincing argument for joining Philips, Simon co-founded and “SHOULD requirements”. Members get all the reports the industry that the leading Epyon, a company specialized in ZigBee Light Link covers all and information available. lighting companies, as member fast charging lithium-ion batteries currently defined must have They receive a detailed analysis of TCLA, are endorsing a which was acquired by Swiss requirements for residential of the competing standards, common open wireless multinational ABB. lighting. These are, for instance, the complete scores and other connectivity standard. on/off, dimming, CCT and color results that are not available to control, individual control, group the public. They also see the To promote our control, scene control and real pros and cons of the selected recommendations, we will time control without any delay. standard in detail and not just a attend the major events around summary. In addition, they are the world, like Light+Building in The ZigBee standard is currently informed much earlier about Europe, LightFair in the US and being updated. One of the big what is going on. Therefore, Hong Kong Lighting Fair in Asia, advantages of ZigBee is that the they are better able to handle and the LED professional standard is tight enough to these issues. Symposium +Expo in Austria, guarantee interoperability, just to name a few. but most importantly, allows LED professional: That brings manufacturers to differentiate on us back to the promotion of LED professional: Thank you products without compromising selected standards. At the very much for your time. interoperability. current stage your standards All these explanations sound are a kind of recommendation very reasonable. We’d like to LED professional: While these, from an industry consortium for wish TCLA success with partly early stage, ongoing the industry. How will TCLA their activities. activities are being carried out, manage to become accepted? the ZigBee Light Link standard Is it a viable way of bringing Simon den Uijl: Thank you! that the members agreed on is these proposals to an ready to be promoted. How is international standardization that done? body to make it mandatory? Or what is your strategy? Simon den Uijl: Correct, the standard for residential Simon den Uijl: There are lighting is ready for promotional several reasons why it is almost work, and that is the moment impossible to make it a

Optimization of SSL LED Devices

There are different levers to improve LED performance. Ralph Bertram, application engineer for SSL products, and Alexander Wilm, key expert in the SSL application engineering department at Osram Opto Semiconductors, have a look into the device itself and explore the principal limitations of the different contributors to device efficacy. They show how to balance driving current and chip size to define the right LED, and explain the impact on performance and system costs of LED packages for the intended lighting task approaches for lighting strategies.

The performance of LEDs The most prominent and also the most in these parameters. It is reasonable to depends on different parameters important performance parameter is assume all efficiencies to be at 90% such as electrical efficiency, the efficacy of an LED. Although LEDs (except that phosphor conversion internal quantum efficiency and are small, there are lots of cannot exceed around 80% due to package extraction efficiency. technological challenges inside and Stokes Shift). Multiplying all these All of these aspects have many small steps lead to constant contributions yields an efficiency of limitations in principle that have improvements in LED efficiency. 52% for a white LED, which is a value to be examined to optimize LED that can be achieved by R&D level performance. The right balance When assessing the efficiency of an LEDs already. between driving current and LED, we need to consider what is chip size is the key to reconciling known as the efficiency chain, which is Typical spectral efficacy of white LEDs efficacy and cost targets. Other shown in figure 1. It consists of five is 330 lm/W, meaning that the radiated parameters such as luminance parameters, namely electrical spectrum of one watt optical power and package sizes must also efficiency (ηelectr), internal quantum contains 330 visible lumen. This results be taken into account when efficiency (ηint), extraction efficiency in a total efficacy of 172 lm/W for the identifying the right LED for the (ηextr), phosphor conversion efficacy complete LED if all efficiencies are at intended lighting task. and package extraction efficiency 90 percent. As always, extracting the (ηpackage). Every LED manufacturer last few percentage points from a possesses strengths and weaknesses parameter requires a tremendous effort.

Figure 1: Features of an LED including the efficacy chain

Figure 2: The maximum achievable spectral efficacy of an LED for different CRIs

Paths of Optimization in an LED, taking part in the p/n refractive index difference resulting in a To improve the performance of LEDs junction of the diode. ηint depends high amount of total internal reflection several levers can be used. largely on crystal quality. The key for that hinders light from getting out. best quality is the elaborated crystal Strategies to improve light extraction growth process using MOVPE epitaxy. include structuring of surfaces,

Electrical efficiency η( electr) The thickness of the active layer is introduction of mirrors or diffuse All electrical contacts and conductive defined by the doping profile in the reflecting surfaces. Also, the geometry parts are ohmic resistors that heat up semiconductor. Structures to trap of the chip plays an important role: upon current flow. For better electrical electrons and holes together in the Volume emitting chips have larger efficiency the conductivity of current- crystal area (“Quantum Wells”) facilitate surfaces to enable light to exit in conducting layers and interfaces the recombination process and different paths. The reduction of between different materials has to generate high quantum efficiencies. refractive index differences by using be improved. The conductivity of So optimizing these structures has high-index silicones helps light to exit transparent conduction layers, the greatest impact on the efficacy the chip. Only the right combination of in particular, is a field for constant of an LED. all these improvements will significantly optimization. A trade-off between enhance light extraction ηextr. transparency and conductivity is

therefore needed, typically using Light extraction efficiency η( extr) Indium Tin Oxide (ITO) as the Once the photons are generated they Light conversion efficiency conducting material. need to get out of the semiconductor. In terms of phosphors, there is also However, the refractive index of GaN room for improvement. Part of the blue (gallium nitride, used for blue and light from the LED chip is converted to

Internal quantum efficiency η( int) green LEDs) is about 2.5 and GaAlP’s yellow, green and red wavelengths to Another path of optimization is index (gallium aluminium phosphide, generate white light. Here, efficient increasing the internal quantum used for yellow and red LEDs) is about phosphor materials must be developed efficiency ηint. The conversion of 3.5. Together with the typical refractive and embedded in suitable materials to electrons and holes to photons index of the encapsulating material of enhance the conversion efficiency. (“recombination”) is the central process around 1.5 it forms a interface of a The converted light is emitted in all

directions, including back to the engineering”), the right mixture of efficiency and, to a lesser extent, chip and to all package surfaces. phosphors needs to be found. resistive losses, deteriorate with Engineering the whole system to Concentrating the light in the green increasing temperature. Proper thermal recycle as much of this light as part of the spectrum where the eye is management of the LED chips as well possible before it hits absorbing most efficient, and reducing the red as phosphors therefore help to surfaces is essential to improve the and blue content results in higher maintain high efficacy during operation. conversion process. Although the spectral efficacies. However, a color To facilitate thermal design, LED photon conversion process itself can target on the Planckian locus (“white manufacturers are working on chips be very efficient (near unity), around light”) is desired as well as good color and phosphors that can be operated 20 to 30 percent of the light energy is rendering. A trade-off between efficacy at higher temperatures as well as on irrecoverable due to the inevitable loss and light quality is therefore needed. packages with enhanced stability. of photon energy in the conversion In figure 2, the maximum achievable LEDs with an efficacy maintenance process. The exact amount depends spectral efficacy is shown for different of more than 95 percent at 100°C on the color target. Warm white and CRIs, calculated for a theoretical compared to 100 percent at 25°C will high-color rendering LEDs need plenty optimum light spectrum. A realistic soon hit the market and enable tight of red light, having higher losses. spectral efficacy for the widely used packing with minimum efficacy impact. CRI 80 is 300-330 lm/W. Up to now, only physical parameters have been addressed. In order to In addition to all the issues mentioned The Importance of match the light spectrum to the above, parameters such as internal Current Density sensitivity of the human eye (“spectrum quantum efficiency, phosphor The biggest lever in LED efficacy, however, is the current density. Figure 3: The reduction in the number of LED efficiency as a function of current electrons and holes in the device density (droop) results in stronger confinement of charge carriers in the active region. Because of this, there are few ways for them to escape without generating a photon. LED efficacy consequently increases at lower currents. Below a certain threshold there are not enough electrons and holes to recombine, so efficacy drops again at extremely low current densities. The loss of efficacy with increasing current density is known as “droop” (see figure 3).

The latest research results Figure 4: demonstrated the physical effect Impact on cost and efficacy by responsible for the droop. Although the underdriving/ physical mechanism of the droop overdriving typical effect has been well understood, it is LEDs far from being overcome. However, the scope of future research projects can now be narrowed, with the focus particularly on measures to eliminate the Auger effect. In LEDs based on the indium gallium nitride (InGaN) material system, the “bipolar Auger effect” is limiting the efficiency that converts charge carriers into light.

By using a bigger chip surface for a required lumen package, the LEDs can be driven in the low current density regime (“underdrive”) to greatly improve efficacy with respect to standard currents. This is most obvious in the following diagram showing the requirements in cost (lm/$) versus LED

efficacy (lm/W) of an LED retrofit lamp. provide white LED light. In the case sizes or, alternatively, to volume-emitter The different points that are located of phosphor-converted LEDs, CoBs, a reduction of the LES to 19 mm around the black line symbolize one two different concepts prevail in can be achieved, enabling 24° optics LED driven at different currents. the market: to be smaller than 100 mm. Located top left, the LED is overdriven As discussed above, only direct to get more light at the expense of • The first concept uses many mounting of surface-emitters on a efficacy. If the LED is located bottom volume-emitting blue chips mounted metal core board enables tighter right, it is underdriven. This means that on a mirror, embedded in a spacing of the chips. This results in a greater efficacy is possible, but also phosphor-filled silicone matrix. the same flux at 13 mm in diameter, that more LEDs are required to achieve Since light from volume-emission is enabling the optics to be 60 mm or the same light output. also directed to the sides, the chips tighter beam angles to be achieved. cannot be packed closely but need Due to the space required for the Knowing this, an LED chip space between them to allow the placement and wire-bonds, they are manufacturer has two ways to light to escape and be converted by still not packed with maximum density. improve the efficacy of LEDs: the phosphor. This fundamentally Further improvements in chip assembly Either by improving the LED efficacy limits the luminance achievable with and connection technologies have itself at a given current density or by this type of LED. been developed at a research level reducing production costs to get • The second concept is based on and 4,400 lm from an LES of 9 mm more chip surface for the same price, surface-emitting blue chips with a has been demonstrated recently. allowing underdriving to achieve phosphor-containing layer on top of acceptable efficacy. the chip. Almost 100 percent of the light is emitted from the top surface The Right LED Package for Evidently, both ways need to be used only. Here, the single chip has the Each Application in parallel, but the focus may lie more highest luminance achievable and, With this overview of the factors that on one or the other side for different for example, embedded in influence LED efficacy right now, manufacturers and applications. automotive headlamps they are there is still a variety of packages to Most renowned LED manufacturers driven at extremely high current choose from. In order to decide on offer several variants of LED packages densities to generate even higher the perfect solution, the following containing different chip sizes to luminance. However, in general questions have to be answered: enable the customer to choose their lighting applications many of these optimum operating conditions and chips have to be closely packed and • Is the focus more on efficacy or light output. driven at normal current densities in on cost? order to maintain sufficient efficacy • Are there special requirements with and high light output. regard to optics? LEDs with High Luminance • Are high operating temperatures There are applications where Both volume and surface emitters are and/or is long lifetime important? underdriving is not reasonable, available in SMD LED packages; • What is the required level of simply because a lot of light has to high-power LEDs in both concepts use robustness? Are extreme conditions come from a very small source. Chip-on-Board technology (CoB). expected (humidity, pollution, Examples are LEDs used for tight high temperature differences)? spotlights, and LEDs embedded in As an exemplary calculation, for a • Are there restrictions to the automotive headlamps or in street 4,000 lm light source 42 packaged assembly process? Is SMD lighting applications, where luminance LEDs with a common chip size are soldering an option? and controllability of the light necessary, covering a light emitting distribution are even more important surface (LES) of 28 mm in diameter. Starting from the easiest conditions, than luminous flux. But how can the To achieve a 24° beam angle, a if there are no special requirements luminance be improved? There are reflector of 120 mm in diameter would Sapphire-based volume emitters several technologies available to be necessary. Moving to larger chip currently perform best in terms of the

Figure 5: Light emitting surfaces (LES), when using different LED types, indicated by dashed lines – from LES 28 to LES 19 down, to LES 13, and to the LES 9 lab demonstrator (from left to right).

cost/efficacy ratio. Built into high- are present, they show no signs of increases at lower currents but may volume backlighting packages there is corrosion. Unlike volume-emitter chips, not fall under a certain threshold almost no match in lm/W versus lm/$. they do not need a highly reflective because of the droop effect. Better Is it really? Currently, multi-chip SMD mirror below the chip, which is usually LED efficacy can therefore also be packages can save even more on both made out of corrosion-sensitive silver. achieved by reducing production costs package costs and assembly costs. Instead, the complete LED is made to get a greater chip surface for the Delivering up to 500 lm from one from inorganic material such as same price. On the other hand, the package, they are more cost-effective ceramics and silicone, and the best package for an LED is needed to than most CoBs. In addition, the electrical contacts are gold-plated. get the best performance. For up to package material is more stable and 500 lm one can choose a multi-chip can withstand higher temperatures, package that is more cost-effective and they achieve longer lifetimes. The Best Ways to Improve than most CoB LEDs. For higher LED Performance luminous fluxes or to avoid SMD If higher luminous flux levels are As already stated, there are many assembly, CoB LEDs are the right required or SMD assembly is not an levers that can be used to improve LED choice because of their excellent option, CoB LEDs are the right choice. performance. On the one hand by optical properties and standardized They also offer good optical properties improving LED efficacy using physical accessories. For maximum lifetime and and many accessories such as holders parameters such as electrical harsh conditions there is no alternative and lenses that are available as efficiency ηelectr and phosphor to ceramics-based packages. standard components. conversion efficacy ηpackage that influence LED efficacy. These As can be seen, there is no one way to However, if it comes to very long parameters get worse with increasing optimize LED performance, but many, lifetimes and rough conditions, there is temperatures so manufacturers are depending on the applications and the almost no alternative to ceramics working on LED chips and phosphors conditions. One can therefore focus on based high power LEDs. These exhibit that can be used at higher operating one or two parameters or exploit as almost perfect stability against outdoor temperatures. The most important many as possible to get the best conditions, and even in tunnel lighting aspect for improving LED efficacy is performance from the LEDs. applications, where corrosive gases the current density: LED efficacy

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ELECTRONICS SAFETY ISSUES IN LED DRIVERS 44

Safety Issues for LED Drivers with PWM Operation Modes

In many cases LED drivers manage their output power with PWM controlled switched mode power supply-topologies. The output voltages are filtered and normally DC voltages with low ripple apply at the output connectors of LED drivers. During dimming these circuits can behave very differently and therefore safety issues may arise. Siegfried Luger, CEO at Luger Research e.U. and John Showell, Product Safety Consultant at Product Approvals Ltd. have a closer look at those operation modes and the requirements on voltage limits.

Figure 1: LED lighting technologies are Typical AC to DC LED driver developing very quickly. As topology with the light-sources themselves a single-stage evolved, new sophisticated flyback converter and enhanced electronic concepts were developed to drive and control LEDs. These developments are very important for fulfilling market requirements but safety and standardization aspects are lagging behind. One issue related to LED drivers concerns the output voltage limitations for LED drivers. The following Basic LED Driver Topology Therefore the feedback circuit has to considerations summarize the LED drivers can be categorized into be isolated to sense the LED string latest developments and point DC to DC converters and AC to DC cur-rent. This might be done through out possible safety issues. converters. Where AC to DC an optocoupler but more advanced converters are concerned, in most sensing schemes use the primary side cases, they operate directly from the of the transformer or an additional

mains (e.g. 240 Vrms / 50 Hz). AC to DC sensing winding to detect the output converters for mains applications LED current. consisting of an EMI filter, a bridge- rectifier and a single-converter stage, The switching frequency of the flyback are mostly built up as a flyback converter may vary between 10 kHz converter to transform the rectified AC up to some MHz. To control the output voltage into a constant DC current to power/current for dimming the light perform the powerfactor-correction output, PWM schemes are used. and to isolate the output LED circuit from the mains. Finally the output Nowadays, to reduce flickering and current is also rectified and the energy stroboscoping effects on human eyes, is stored in an output capacitor the PWM frequencies are chosen above (Figure 1). LED strings in serial or in some hundred Hertz (e.g. 300-500 Hz). serial/parallel are connected to the Under standard operation conditions LED driver output poles. the PWM signal will not be seen at the output, because of the rectifying and The output stage of such an AC to buffering output circuit. Figure 2 shows DC converter is galvanically isolated the output voltage (Ch2) as a DC through the flyback-transformer. voltage with a small part of AC ripple.

Figure 2: DC output voltage Possible Safety Issue - of an LED driver Chopped DC (Ch2, approx. Assuming that the LED driver and the

55 VDC) overlaying output stage are designed as an SELV with a small (Safety Extra Low Voltage) converter it part of AC ripple is allowed to touch the output lines, voltage (approx. bridging the positive to the negative 4 Vpp). Ch1 shows the pole of the output with the human high-frequency body impedance. ripple-current from one output When operating in dimmed modes pole to earth (10 mA/Div). Time (power reduction), the energy delivered base is to the output storage capacitor is 20 ms/Div reduced. Touching the output lines under this condition can lead to a change in the output voltage signal from a DC voltage to a chopped DC voltage in which the PWM frequency can be seen at the output (Figure 3). This might happen especially when sensing the output current similar to the concept shown in figure 1. Figure 3: Bypassing the sensing resistor with the Measurement of an LED driver load of the human body would not lead output under to a regulation of the LED driver system. 2kOhm load and 50% duty-cycle. Under this condition critical operation Ch2 showing the modes for these LED drivers may voltage above the output terminals. occur when the driver is not designed Ch3 showing the for additional low ohmic loads, e.g. too LED current low capacitor values and/or insufficient regulation algorithms.

The main topic is that the change from “pure DC” output voltages to alternative voltages, here chopped DC signals means that the safety voltage limits for these drivers may change automatically to lower values due to the change of the voltage signals!

Backgrounds - Human Body Model Figure 4: There are different impedance models Perception / Reaction network for the human body available and also (according to defined in international standards. IEC 60990, 1999 - The model shown in figure 4 known Figure 4). as Perception / Reaction network is The human defined by a resistive load of 1.5 kΩ body model with perception / and 0.5 kΩ in series and a capacitor reaction network of 220nF in parallel to the 1.5 kΩ is the most resistor. The input impedance at realistic test 50 Hz is 1,990 Ω, at 500 Hz 1,433 Ω method, but and it drops down to 476 Ω at 1 MHz. usually just applied if a The output stages of an SELV LED standard test with driver, therefore, might be bridged 50 kOhms fails with a human body impedance lines. This “load” is responsible for The touch current limits are between 1.5-2.0 kΩ under real changing the output signal from a measured across the 500 Ω resistor

conditions, when touching the output DC voltage to a chopped-DC voltage. Rb (voltage U1). The measuring

Figure 5: network R and C showing in figure 4 Let-go thresholds 1 1 and dangerous are used for a weighted touch current limits current. So the measuring voltage U2 as a function of does include frequency ependencies frequency (C.F. as well. The variation of the threshold Dalziel, “Electrical of perception, for example, Shock”, Advances in Biomedical is increased by the factor of 1.5 Engineering, between 50/60 Hz and 500 Hz, edited by J. H. U. the base operation frequency of Brown and J. F. PWM drivers (see IEC TS 60479- Dickson III, 1973, 2:2007 - Figure 1 for further details). 3, 223-248) Earlier studies, as shown in figure 5, were the basis and documented the principle relationship between the thresholds and the frequency.

Safety Issues - Consequences of Changing the Mode of Operation As described above LED drivers might change their mode of operation when touching the output terminals. With the human body model this behavior can be tested with LED drivers, bridging the Please note that in brief, Class 2 The values for chopped DC or output. The question which then arises circuits are isolated and have interrupted DC signals as proposed in

is: “What does this mean to safety?” maximum voltage ratings of 60 VDC, UL 8750 (Table 1) are based on studies

30 Vrms, maximum current ratings of done by W. B. Kouwenhoven in 1936. There are various US and EN standards 8 A and maximum power ratings of He found out that the peak voltage which answer this question. In regards 100 W. Electrical systems obeying limits for fibrillating currents at 60 Hz to safety the maximum or peak voltage Class 2 specifications may afford has to be lowered by the factor of 1.69 level is interesting, because of the ability additional design freedom that compared to alternating currents. of the voltage to drive current through includes the selection of material to √ the body - which is the mechanism of address flammability concerns and 50 Vrms * 2 = 70.7 Vpeak

the electric shock. There are some accessibility of other circuits. 70.7 Vpeak/1.69 = 41.7 V differences between voltage Such affordability makes Class 2 (max. interrupted DC voltage) magnitudes for DC and AC signals. compliance popular among LED Peak voltage is commonly referred to, luminaire designers and manufacturers. A. Mörx who found out that the such as quoted in the LED professional Table 1 shows reduced maximum reduction of the human body Review (LpR) article Issue 39, e.g. voltages for wet locations compared to impedance has to be considered for

42.4 Vpeak (30 Vrms) is a common UL dry/damp locations defined in UL 8750 higher voltages performed a further figure but not universal across UL for the risk of shock. analysis for safety voltage limits. standards. The differences come in because of US UL standards and those Maximum Voltage of UL standards which are based on an Dry and Damp Waveform Type (a) Wet Locations IEC standard and have some Locations commonality with EU voltage levels. Sinusoidal AC 30 Vrms 15 Vrms Non-Sinusoidal AC 42.4 V 21.2 V The UL standard groups for LEDs peak peak DC (b, c) 60 V 30 V recognize the guidance needed for certain scenarios. As such, UL 8750 Table 1: Reduced maximum voltages for wet locations compared to dry/damp locations defined in UL 8750 for the risk of shock: (other UL end-product standards may a) For a combined ac + dc waveform, the wet location voltage limit shall be the apply) covers products intended for non-sinusoidal ac limit where the dc voltage is no more than 10.4 V, and shall be (16 installation on branch circuits of + 0.45*dc voltage)V where the dc voltage is greater than 10.4 V. The dry and damp 600 V or less. UL also noted that many location voltage limit shall be twice these amounts LED products are designated for b) If the peak-to-peak ripple voltage on a DC waveform exceeds 10 percent of the DC voltage, the waveform shall be considered a combined waveform per Class 2, which refers to supply footnote above characteristics specified in Article 725 c) DC waveforms interrupted at frequencies between 10-200 Hz shall be limited to of the National Electric Code (NEC). 24.8 V in dry and damp locations, and 12.4 V in wet locations

Table 2: A B Conclusion Column A shows SELV UL 8750 Output lines of SELV/Class-2 LED the SELV limit proposal proposal voltages acc. Waveforms Voltage limits Voltage limits Notes drivers are allowed to be touched. IEC 60449:1973 Depending on the operation mode, DC ave Standard definition calculated based 120 V 60 V the LED driver design and the used on Kouwenhoven 10% ripple voltage DC voltage limit component values, LED drivers may studies. Max. voltage peak DC max including the ripple voltage “switch” from DC output mode into Column B shows 140 V 70 V the UL proposal 10% ripple voltage Udc_max= AC output modes, mostly with U (1+0.1*√2) for Class-2 dc_ave chopped-DC signals. Since AC power supplies RMS voltage limit AC sinusoidal 50 Vrms 30 Vrms voltage limits are below the DC in reference to equivalent to the DC value voltage limitations, the safety NFPA 70 - 2011 AC non-sinusoidal 84.9 Vpeak 42.4 Vpeak Peak voltage (*√2) (Note: The 30 V requirements of these drivers are rms Interrupted DC (iDC_l) 41.7 V 24.8 V “Kouwenhoven limits” limit in UL 8750 10-200Hz changing with the operation mode. corresponds On the other hand, LED drivers “Kouwenhoven limits” to 25 V limit Interrupted DC rms 62.6 V 37.2 V increased by frequency operating with PWM control are using according to EN (iDC_h) 500 Hz factor 1.5 for 500 Hz higher frequencies then the 61347-1 (10.4)) PWM mode - reduction standards normally cover. Instead of DC /iDC_l factor 2.88 2.42 ave factor DC, 50 or 60 Hz they are operating the PWM at some hundreds of Hertz According to IEC TS 60479-1:2005 the would fall immediately out of the safety (e.g. 500 Hz).

impedance at 50 VDC is 2900 Ω and limits when changing the output mode

drops down to 1625 Ω at 125 VDC. from DC to chopped DC because the The global discussions going on These recognitions are not covered in limit for DC falls from 60 V to 24.8 V about these limits are important in details within this report but may be (frequencies between 10 - 200 Hz)! respect to safety to cover all critical important for further analysis. conditions which might occur in Higher frequencies would help because applications. For manufacturers of Table 2 shows the different voltage the limits for higher frequencies go up. LED drivers it is important to know limits in a comparison between the UL On the other hand, new research on that the limits for PWM controlled

and IEC for 120 VDC and 60 VDC levels the human body model also works LED drivers might be reduced and and gives indications for possible “new against this. Therefore, it’s a very tested under given conditions and voltage limits” which are in consideration undefined and unclear situation. that the limits might be lowered

right now. The 120 VDC value shown in In general, it can be stated that the against the pure DC limits by a factor table 2 is valid for single pole touchable change from DC to AC will lead to a of 2.4 - 2.9. New designs should take SELV. It is important to recognize that reduction of the limits to some extent. care of this fact and even if further an SELV LED driver, for example, This is an important issue for designing investigations have to be made to

designed with 60 VDC voltage limit, safe LED drivers for the future. define the correct limits.

References: [1] http://www.comm-2000.com/ [2] Mr. Bahram Barzideh, PDE Manager, Lighting from Tom Blewitt’s group in Melville, New York [3] Wirkungen des elektrischen Stromes auf Menschen und Nutztiere - IEC/TS 60479-1:2005 + Corrigendum Oktober 2006 (VDE V 0140-479-1) [4] Berührungsspannungen für Gleichstrom, Mörx, August 2012 [5] Electrical Safety, Walter H. Olson, 2008 [6] Guidelines for Limiting Exposure to Time-Varying Electric, Magnetic, and Elekctromagnetic fields (up to 300 GHz), Health Phys 75(4):442; 1998 [7] Berufsgenossenschaftliche Vorschrift für Sicherheit und Gesundheit bei der Arbeit. Unfallverhü-tungsvorschrift - Elektromagnetische Felder, 2001 [8] Normen für DC-Technik / DC-Netze, Dirk Barthel, DKE, 2012 [9] Touch Current Basics, Ronald Vaickauski, UL, 2010 [10] IEC 43/191/CDV, IED 62493 Ed.2: Assessment of lighting equipment related to human exposure to electromagnetic fields [11] Technical Report IEC/TR 62493-1 Ed.1 Part 1: Results of the EMF measurement campaign from the VDE Test and Certification Institute and ZVEI, the German Electrical and Electronic Manufacturers’ As-sociation [12] IEC 62493 Edition 1.0 2009-12 [13] Proceedings of the IEEE, William B. Kouwenhoven, Vol. 97, No.12, December 2009 [14] IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromag-netic Fields, 3 kHz to 300 GHz [15] Maximum Permissible Touch and Step Voltages Assessment in High Voltage Systems (>1 kV) [16] Residual Current Devices in LV, Schneider Electric, 2006 [17] Personenschutz und Fehlerstromschutzschalter für LV DC-Netze, Rik W. De Docker, 2012

Using Integrating Spheres Correctly to Measure LEDs

LEDs have opened up new dimensions of design freedom, allowing architects and designers to give free rein to their creativity. Light-emitting diodes permit manifold design solutions as a light source in illumination products. However, a suitable measuring method for comparing key technical data is required in order to get the best out of the diversity of illumination products available. Mikolaj Przybyla from GL OPTIC, a Just Normlicht GmbH division, explains crucial product requirements and what to take care about when calibrating a measurement system.

A generally reliable and suitable and mixed inside the integrating emission. With this method it measurement method for a wide sphere before being decoupled is possible to obtain reliable range of lighting products is to for measurement by a detector. results for many different types measure the luminous flux and In practice the test object is of light source and to take all radiant power with an integrating secured at the center of the designs, illumination angles and sphere. A high-resolution sphere so that the luminous types into account. Integrating spectrum analyzer can be used flux can be quantified in all spheres are used successfully to measure transmission and directions. The overall energy for measuring incandescent emission spectra, but the so- emitted by a source can thus and electroluminescent light called integrating sphere can be determined regardless sources. They are also suitable determine the radiant power or of the source’s structure or for characterizing light sources luminous flux of light sources. the spatial distribution of the comprised of LEDs or OLEDs. Therefore the integrating sphere, Figure 1: Typical also known as the Ulbricht sphere measurement after its inventor, is among the setup with a large most important instruments used integrating sphere in spectrometer applications calibrated with a (Figure 1). laboratory grade spectrometer German engineer Richard Ulbricht was commissioned to construct a three-phase power station for the train stations in the city of Dresden. In connection to this, he also became involved with the illumination of the stations. For his photometric investigations Ulbricht utilized the multiple reflections produced by light, and it was in the course of this work that he developed the integrating sphere. Essentially, the integrating sphere is a hollow sphere whose inner surface is coated with a diffuse reflecting material and is completely opaque and closed on all sides. The radiation is fully integrated

Figure 2: Typical measurement plot of a cold white LED, with the required figures: Lumen output, rendering indices R1 - R15 and Ra (CRI), Color coordinates and correlated color temperature. Additionally radiometric value of radiant power [mW] is calculated

The Right Detector – candela, cd/m² or lumen, In this case, the detector is influenced Photometer or Spectrometer spectroradiometric measuring by different illuminants, with high An integrating sphere is just one part equipment is capable of indicating energy in several wavelength ranges of the overall measuring system – additional parameters such as and lower or near-zero signal strengths a detector is also required to quantify the dominant wavelengths, peak in other ranges. LEDs have a the intensity of the signal. The detector wavelengths, bandwidth, CCT (color somewhat gaseous spectral is a measuring device that is connected temperature), and CRI (color rendering distribution pattern with a specific peak to the sphere. An integrating sphere index). Spectral measurements achieve wavelength and a halfwidth of fewer and photometer were typically used to very accurate results because they than ten nanometers. Blue, red and measure conventional incandescent quantify the spectral power distribution white LEDs, in particular, are affected light sources that emit a continuous of a light source. Luminous flux is by pronounced deviations in luminous spectrum across a broad spectral measured by a spectrometer in intensity and the dominant wavelength range. With the help of photometry it is conjunction with a diffuser and a due to the relatively poor adaptation of possible to determine the energy- suitable cosine corrected head. the filters to the defined flanks of the efficiency classes and average service The spectrometer is connected to the V(l) function. For example, error rates of life of lamps as well as the spatial integrating sphere and it measures the several hundred percent are not distribution of light. A photometer integrated signal level in lumen [lm]. uncommon for blue LEDs. In the case mounted to the inner wall measures The application software installed then of white LEDs, on the other hand, the light level inside the sphere. This calculates the photometric and correct evaluation of the blue peaks is device frequently comes with an colorimetric values that cannot be extremely important for the accuracy of optical correction filter (V, λ) that ascertained with a traditional the color coordinates. Another problem adapts the sensitivity of the device to photodetector. The basis for the is that different photometers deliver the characteristic sensitivity of the measurement data continues to be different results depending on the human eye. Measuring the integrated the energy emitted by a source. respective filter parameters and optical radiation accordingly provides a basis This measurement method also correction (V, λ). A precision for assessing how the light source will eliminates the errors that can result spectroradiometer avoids this pitfall be perceived by the human eye. when a detector incorrectly renders the because a computer-based analysis of sensitivity of the human eye across the spectrum (Figure 2) uses precisely For the measurement of LEDs and different wavelengths. defined functions in accordance with other light sources that emit a the CIE 127:2007 standard issued by non-continuous spectrum, a spectral This aspect is especially important for the International Commission on measurement device must be used. LED measurements, as these sources Illumination (CIE). Spectroradiometers While photometric measurement emit light in a limited wavelength range are therefore the recommended choice systems specify parameters in lux, that contains sharp and narrow peaks. for measuring LED light sources.

FACTBOX: The Appropriate Sphere It is important to choose an appropriate The inside of an integrating sphere is sphere diameter when designing a What is luminous flux? coated with a special material measurement setup (Figure 3). Luminous flux describes the total designed to diffuse the reflected light. Specific requirements prohibit the light output perceived in relation to Barium sulfate (BaSO4) is often used maximum physical size of a light the spectral sensitivity of the for this application. Optical PTFE source from exceeding 10% of the human eye. (polytetrafluoroethylene) offers ideal inner diameter of a sphere. reflection characteristics across a Until recently, this meant that a sphere broad wavelength range, and a gold with a diameter of at least 1 meter had How is it measured? coating is applied for infrared radiation to be used to measure a source Luminous flux is measured using a values in excess of 700 nm. spanning 10 cm in diameter. spectrometer connected to an The coating used in older spheres Accordingly, a 4-meter sphere was integrating sphere. With this had a light reflection coefficient of required to measure objects of 40 cm method it is possible to determine 80%, which produced good results in size, and so on. By compensating the total amount of energy emitted in conjunction with the detectors of for self-absorption, it is now possible in all directions by the light source. previous generations. A spectrometer to measure light sources twice as Luminous flux is specified in allows materials with a light reflection large without compromising lumens [lm]. coefficient of 97% to be used. measurement accuracy. The results This enables better integration and also depend on the shape of the higher signal strength at the detector source. In a sphere with a diameter of What is the significance of entry point, and it makes the 500 mm, objects measuring up to this measurement method? measurement results much 16 cm x 16 cm can be measured. This method is very practical for more accurate. A sphere with a diameter of 2,000 mm quantifying the total light output or can therefore be used to measure radiant flux of a light source or An important CIE requirement is to sources of up to 60 cm x 60 cm illumination system so that the consider the self-absorption. The in size. In the case of fluorescent energy efficiency or power rating of methods used should be able to lamps, the length of the source can lamps can be determined and determine which part of the signal have a diameter that is almost as lamps with sufficient illumination emitted by a specific source is also wide as the sphere itself. can be chosen for a given room. absorbed by this source. The absorption can be due to the housing or to all the elements within a sphere that are used Calibrated Measurement to install a sample. The CIE Setup requirement can be met by installing To guarantee the desired level of an auxiliary source in the sphere to reliability, the instrumentation used measure the absorption of the tested must be calibrated. Every measurement light source. This is then factored into system comprising an integrated the final measurement results. sphere and a spectrometer requires

Figure 3: Small integrating spheres are also used in high quality handheld instruments for single LED measurements

calibration. The calibration source is Since the blue spectral component in Summary a reference lamp with known spectral halogen lamps accounts for only about The combination of longevity and distribution and luminous flux values. 10% of the energy available along an extremely robust internals as well as These light sources are calibrated 800 nm wavelength, it is frequently the high light output expected of LEDs by certified laboratories that use an recommended that a corresponding makes this illumination technology truly ideal black body radiator and a LED be used for absolute calibration unique. It therefore comes as no monochromator as a reference for when measuring white LEDs with a surprise that the requirements for a determining the spectral distribution pronounced blue component in their color consistency are very high when and luminous flux of a reference light. This should avoid calibration LEDs are being binned into the color lamp. The manufacturer normally errors that can occur in conjunction groups. Adding to this is the increasing calibrates measurement setups, with the scattered light of a white LED. need to optically characterize LEDs, which should be repeated every since their illumination characteristics 12 months. However, this is not required for are critical to safeguarding compliant devices that feature optical stray light product quality. Integrating spheres Spectrometers are calibrated in reduction (OSR) that are used in high have proven to be versatile and three steps: quality spectroradiometers. Applying effective measuring tools and are even • Wavelength calibration suitable filters and mathematical essential for some applications. • Spectral calibration models reliably prevents calibration • Absolute calibration errors caused by stray light.

References: [1] CIE Technical Report CIE127-2007 Measurement of LEDs, ISBN 978 3 901 906 58 9 [2] Zong Y., Uncertainty analysis of stray – light correction, 2010 CIE Expert Symposium, Bern, Switzerland

Lighting Mona Lisa with LEDs - Details Concerning Innovating Techniques

As part of Toshiba’s patronage of the Louvre Museum, it was decided to develop a new, very high performance lamp in order to add complementary lighting to the Mona Lisa. A special development team was formed and the company ARKANZ dealt with the execution of the product. The new LED lighting equipment was installed on June 4th, last year. In the following article, Marc Fontoynont, Jean Pierre Miras, Marco Angelini, Jean Chanussot, Christophe Marty, Grégory Duchêne, Leonid Novakovski, Kazuaki Makita and Tokayoshi Moriyama present the solutions developed by this team.

An LED lamp was designed This is realized without producing and to the surrounding luminous exclusively with the purpose of any infrared or ultraviolet environment, and for obtaining providing the Mona Lisa in the radiation. A smart command the best rendering. Louvre Museum in Paris, with system was developed which the highest possible quality of allows the Louvre Museum to Finally, the lamp benefits from lighting. The Japanese company, adjust the spectrum of the light an extremely powerful cooling Toshiba, financed the innovative (deviation Duv), with an easy and system that stabilizes the mixing design. The new lamp is installed precise process. of color and offers a life of 80,000 in a shelf designed by the room’s hours. Owing to the use of the architect (Lorenzo Piqueras, These changes are mainly useful last generation of LEDs, this lamp 2005) and works upward. It is for adjusting the coloration consumes only about 20 watts composed of 34 LEDs (single caused by the protection glass when operating. chip and multi chips) and Figure 1: replaces the former lamp from Toshiba lamp 2013 with 34 LEDs 2005, containing 7 LEDs. Three designed to light optical systems have been the Mona Lisa developed in order to obtain a high uniformity of luminance on the painting: primary optics on the LEDs, a “Scheib” mixing the colors, and a third system consisting of a double lens with an integrated filter, focusing the light on the painting and regulating its quality. A framer was also incorporated. The other aim of this lamp is to freely control the color temperatures, keeping a high CRI (>95) with a maximum Gamut Area (in relation to the scientific research of the International Lighting Commission).

Original Lighting In 2013, lighting techniques have The development of the new lamp, Principles and Functional progressed, so did knowledge in managed by Arkanz Lighting in close Requirements of the colorimetry. Consequently, it has cooperation with Toshiba Lighting, New Lamp been possible to push the challenge has called for innovative technological Marc Fontoynont, Consultant, Professor, even further: solutions: 34 LEDs are positioned in a Aalborg University, Copenhagen, • With LEDs of high luminous efficacy, star configuration in order to ensure Danemark and better spectral distribution chromatic homogeneity across the In 2005, Architect Lorenzo Piqueras • With more precise optics to painting. The spectral distributions of was in charge of the renovation of the significantly improve uniformity of the LEDs have been carefully chosen “La Joconde Room” at the Louvre illuminance distribution over the in order to achieve a very high Color Museum and Marc Fontoynont was painting Rendering Index (CRI) of up to 98 on responsible for the lighting. It had • With an integrated framing with the required temperature color range. been decided that the Mona Lisa sharp edges The cooling of the lamp is ensured should not be lighted in an • With an integrated color adjustment by a massive copper heat sink in ostentatious way, and that the way it system, to allow simple and precise combination with a fan to limit the is represented should closely spectral adjustment chromatic variations as much as resemble the one used for the • With an increase of “Gamut Area”, to possible and to guarantee the neighboring paintings. The painting’s extend quality of display (based on spectrum over the required lifetime. position on a specific wall and behind CIE work) a thick plate of laminated glass • With a selection of techniques which One of the major challenges was to required a lighting system providing could be deployed to all museums mix colors over a very short 12 cm color adjustments to be added. The distance. This was made possible by upward lighting from the shelf allows Partner Company Fraen srl integrating the lamp to be hidden and avoids A State-of-the-Art Lamp a Scheib optical fiber mixer in the risks of reflections. that Draws on the Best mixing and projection optical system. Available Technology and (See following articles). In the renovation conducted in 2005, Know-How we realized that a lighting system Jean–Pierre Miras, CEO, Arkanz Lighting The current driving system was based on multiple LEDs could GmbH / Sklaer GmbH, Frankfurt, designed by the company DEF srl Germany efficiently provide the chromatic (Lombardy, Italy). DEF was also corrections needed (optimal rendering The first lamp developed for La responsible for the assembly and the of colors, compensation of coloration Joconde by Sklaer GmbH (an quality management with UL due to the thickness of the glass plate Arkanz affiliate) in 2005 had 7 LEDs, International Italy. Two D-LED Push and the need to take into account the a FOCON type color mixer-converter type constant current DALI drivers surrounding lighting). Designing an (Fiber Optics Converter), and an have been used for color mixing and LED lamp short enough to be inserted active cooling system using a interference free dimming. The Push is in the shelf was a major constraint. permanently functioning fan. a very compact multi-channel current The lamp designed in 2005 was Each channel was driven individually driver specially adapted for LEDs composed of 7 LEDs and had already in constant current. It operated for lamps; it has a DALI or 0-10 V interface been the subject of a detailed over 70,000 hours without failure. and an overheating control loop. colorimetric study.

Figure 2 (left): Lamp with 7 LEDs developed by Arkanz-Sklaer GmbH in 2005 (Project - Arch. L. Piqueras / Lighting - M. Fontoynont)

Figure 3 (right): Upward lighting principle of Mona Lisa developed in 2005 (Architect Lorenzo Piqueras, Lighting Designer Marc Fontoynont)

Figure 4: The new Toshiba Optical Optimization for an Mona Lisa Excellent Uniformity across projector, Design the Painting Vittorio Ferri, 2013 Marco Angelini, MD & CTO, Fraen Corporation Srl, Italy In the former 2005 LED lamp model, the projection lens was a single aspheric lens with a 0.8 numerical aperture. The shape of the beam was created using a fiber optics converter with a trapezoidal output whose rectangular projection coincided exactly with the painting of La Jocund.

For the new 2013 LED lamp, the main multi-sources structure has been retained although the spatial distribution has been improved to increase the homogeneity of both color and intensity.

The number of LEDs has been increased from 7 to 34, set up as 7 “single-chips” and 3 “multi-chips” each one consisting of 9 chips.

Figure 5: Details of the The color mixing is achieved through color mixing three successive steps: optical train • The first “pre-mix” step is based on that guarantees specific Fraen optical components lighting uniformity for LED color mixing (Fraen - across the screen FCM-M1+FCX Patent Pending Appl. N. WO2010US23071 20100203) • The second step uses a “Scheib” optical system (see colors/Scheib mixture section) • The third step uses a special (SF)3 diffusing filter

A “Pre-mix” optical system allows the A CP64-LX-C standard controller from have chosen the following three beam from the 34 LED-source to the Company AELSYS (PACA region, parameters: color temperature, focus on a disk that creates a France) is used to control the drivers luminous intensity and deviation from high-homogeneity luminous spot. and store the scenarios. Aelsys the black body locus. AELSYS has The dimensions of the luminous spot develops and manufactures DALI and developed an application on Windows are optimized in relation to the size of DMX controllers that can be interfaced 8 to link the CP64-LX-C with a the La Jocund painting. with external sensors as light control Toshiba tactile PC/Tablet, via Wifi and presence detectors. In Le Louvre, or an USB3 link. Downstream of the “Scheib” mixer the controller is connected via an we have chosen to position a Ethernet link to the main bus of With this „concept lamp” Arkanz trapezoidal cut-off diaphragm in the the Museum Lighting and its partner companies focal plane of the projection system. have studied and implemented a This allows a rectangular-form spot The configuration software (WINCIP) number of technological solutions to be projected on to the screen has been modified to integrate a that are the subject of patents and plane that is not orthogonal to the colorimetric module; this module can open the way for new, powerful optical axis of the lamp. automatically set the levels in the and high-performance museum 7 groups of LED modules once you projectors.

Figure 6: Asymmetric LED Color Mixing - projection doublet Technology Using Fiber- guarantees Optic Parallel-Sided Plate uniform light Leonid Novakovsky, Pharos-Alef, distribution Moscow properly shaped Color mixing of 34 LED sources in the on the screen new spotlight for the Mona Lisa is carried out by means of the device that enables the spotlight size to be reduced. It represents a fiber-optic parallel-sided plate (“Scheib”) and uses the same principle of operation as in the FOCON of the previous spotlight, but with more sophisticated diaphragms. It consists of a bunch of optical fibers with both a high fill factor and a high angular aperture which is Figure 7: 4 mm thick. The big aperture (0.5) The light measurements on allows LED modules to be arranged in the painting show a wide cone of +/- 32°. Testing this a uniformity of device shows that color mixing of very 0.85 with the lamp high quality takes place there, and as a alone and 0.92, result of that the uniformity of taking the ambient light into account illumination would run close to 95%.

The fiber-optic plate (“Scheib”) is used for light beam transmission and image shaping when an application demands precise light distribution in a small space. This elegant technology is successfully used for shaping a mobile light beam pattern in original headlight designs and is the subject of a patent application submitted by Pharos-Alef Ltd. and Sklaer Gmbh (patent N 2283986).

Figure 8: The former lamp used an aspheric The uniformity of the screen lighting Fiber-optic plate “Scheib” (Photo single projection lens. The new lamp is one of the most noticeable spot by Sklaer GmbH) is equipped with a special-design performances of the 2013 model. aspheric-symmetrical doublet. This doublet has a numerical aperture Because the lamp optical axis of 0.7. The design of this new two-lens forms an angle of approximately system was necessary to eliminate the 60 degrees with the normal painting distortion on the upper side of the plane, the risk was to have the lower asymmetrical projection of the beam. part significantly brighter than the This resulted in obtaining a very well upper part. To avoid this problem, defined rectangular spot on the in addition to the pre-mix, the Scheib painting. Furthermore, careful and the doublet systems, it was fine-tuning of the system offers the necessary to develop an additional Total Control of Spectra possibility of monitoring the contrast special filter, named (SF)3, to balance and Luminous Power between the illuminated part (the more precisely the distribution of light Christophe Marty, Gregory Duchêne, painting) and its frame. on the painting. This (SF)3 filter can INGELUX, Lyon, France be designed for a wide variety of Two different pilot modes were To manage the luminous fade from angles of incidence along both X,Y suggested: the first one dedicated to the illuminated area to the dark area, directions and for different optical colorimetric adjustments before the the team decided not to light up the specifications. final on-site delivery and the second frame but to make a slightly fuzzy one for current operation, and “cut-off edge” to create a “soft” profile. interfaced with the DALI protocol employed in the Louvre Museum.

Figure 9: b) because the general lighting The specific Mona Lisa light was The controlling system offers the conditions are inappropriate and need expected to be replaced in June 2013 highest quality a localized chromatic correction. together with the luminaires of the Red of lighting for all Room. The lighting in the Napoleon the operating Hall will be renovated before mid-2014. points situated on a wide range of The Highest Quality LED temperatures. A Lamp in the World At the beginning Toshiba had planned high Gamut Area Kazuaki Makita, Toshiba Corporation, to design a new lamp to replace the is reached with Chief Specialist specific lamp developed in 2005 by a large number The Toshiba group started new the German company Arkanz-Sklaer of LEDs (34). activities regarding lighting in April that lights the Mona Lisa. They The navigation on the diagram 2010 in order to create a new decided to develop an innovation is made by the worldwide “lighting culture”. Within lamp based on the latest technology Ingelux designed the framework of the first renovation of LEDs and benefiting from pilot, based The first aspect was particularly project of lighting outside the progresses in optics. Toshiba then on established relevant concerning innovation. museum, we signed a contract in launched a project to gather the best knowledge partnership with the Louvre Museum available technologies to develop a We have designed a colorimetrical (from June 30, 2010 to December 31, lamp of the best possible quality. tool, in line with the ongoing research 2013). The lighting of the Pyramid, of the International Council of the Pyramidions and the Colbert Museums (ICOM) and the International Pavilion was replaced by LED lamps Close Monitoring of the Lighting Commission (CIE). This tool on December 6, 2011, whereas the Technical Team allows us to navigate in the LED retrofit lamps at the Cour T. Moriyama, Toshiba Lighting & colorimetric space, to freely control Napoléon were installed on May 24, Technology Corporation, Senior Specialist the chromatic coordinates of emitted 2012. Today, the work is progressing light while disposing at any time of a in order to deliver the Cour Carrée Toshiba began to investigate the light with an optimal quality (high lights by the end of 2014. possibility of developing a new lamp to Color Rendering Index and maximal light the Mona Lisa in 2012. To improve Gamut Area). The development of this This renovation project of external the performance of the former lamp we software has required spectral lighting is not limited to a simple conducted a feasibility study that ran calibration of each color channel, technological support job, but has for two months after June 2012, corrections due to optical systems, maintained a worldwide cultural together with the German company using an integrating sphere. heritage in a “more sustainable and Arkanz GmbH, and we began to nicer way”, to achieve the “fusions of launch technological developments on However, the conservation department arts and technology” and to reduce the following points: of the Louvre Museum had to make electrical consumption to 73%. • Assess possible technologies to final decisions concerning these control fluxes, CCT, Duv and CRI adjustments. We have elaborated a The Louvre Museum acknowledges • Investigate technical solutions to protocol for on-site adjustment in front that we have succeeded in improve uniformity of illuminance of of the Mona Lisa. The final adjustment combining the “reduction of the Mona Lisa, as well as the was decided by the curator, Vincent environmental charges and the uniformity of spectral distribution Delieuvin, assisted by the architect of revalorization of arts”. This explains over the painting the “La Joconde Room” Lorenzo why we could sign a new partnership • Investigate solutions to provide a Piqueras, under mixed general lighting contract on the renovation project perfect framing at the edge of the conditions (fluorescent light with a little dealing with the lighting of the interior rectangular painting bit of natural light). of the Museum in May 2012. • Identify ways to limit drastically any production of UV radiation and It is essential to insist on the This time, a series of lights will be infra-red light innovative process, allowing the replaced by LED lamps, starting with curator to adjust the light and colors the lights of the Mona Lisa, called the In January 2013 a prototype was built. on a painting, to render with high treasure of the Louvre Museum, The operation of the lamp was tested fidelity, the exact colors of the work. the ones in the “Red Room” where in real conditions in front of the Mona we find famous large-scale paintings Lisa with the participation of the The process that we elaborated would (for example the Couronnement de curator of the XVIth century Italian deserve to be in many museums, l’Empereur et de l’Imperatrice). painting, Vincent Dieulevin, and the at least where the art curators would We will also replace the light situated Architect of the “Salle de la Joconde”, like to adjust the lighting: at the entrance of the Napoleon Hall, Lorenzo Piqueras. In February, the final a) because of the deterioration of more precisely at the entrance of spectral distribution of the lamp as well the painting, the Museum. as the luminous flux was determined through on-site tests.

Table 1: Performances of Statement by the Curator Parameters Specifications TOSHIBA Lamp the Toshiba lamp of the XVI Century Italian Adjustable from 2700 K 2700 to Paintings CCT with high CRI until 3800 K - 3800 K Vincent Delieuvin, Louvre Museum 3200 K selected for Mona Lisa In the Louvre Museum, particular Color shift from locus N/A Adjustable from -0.02 to 0.01 attention is paid to the lighting so that Luminous Flux (lm) 88 lm selected from Mona Lisa every object of art receives proper N/A lighting. Each painting deserves to be (can be boosted to 400 lm) looked at in the best conditions of CRI between 95 and 98 CRI > 90 lighting which, in turn, might be when on locus useful for understanding the pictorial > 95 for Mona Lisa Color Quality Scale technique of the artist or to admire > 85 > 85 maintained for various CCT (CQS) the subtlety of his palette. between 2700 K and 3800 K Ultra Violet radiation < 5 μW/lm < 3 μW/lm However, the lighting has to adapt Infra-Red Radiation < 0.1 W < 0.05W to multiple constraints. For example: time could have deformed the Uniformity on painting 0.85 (with 16 points) > 0.6 structure, altered the pigments or Emin/Eaverage > 0,92 with ambient lighting damaged the varnish. Vertical Uniformity on > 0.9 0,93 E over E painting half top average Furthermore, the glass protection of 100-250 lx 180 lx on glass / 108 lx on painting Average Illuminance certain pieces of art, necessary for spot + ambient (spot only) their security, can disturb the visibility Luminous Flux projected < 1% < 0.5% if the surrounding space reflects into outside frame the glazing. Lamp Life > 50,000 hours ~ 80,000 hours More or less all these constraints are present in the case of the Mona Lisa and in a very acute manner. We are delighted that the painting If in 2005 a new modern spot for the has benefited from the latest Mona Lisa was designed for the Over the past 500 years the wooden innovations in the lighting domain, reopening of the Salle des États, panel has lost its shape and taken a thanks to the partnership with today it is thanks to Toshiba’s convex form. As a result, a complex Toshiba. This approach is part of the involvement, famous specialists gather network of cracks has appeared, spirit of experimentation and the again. We are delighted to present the damaging the subtle work of spirit of Leonardo de Vinci. painting showing the benefits of the Leonardo da Vinci. The different latest of lighting technology. coats of varnish laid down on the painting had oxidized, darkened and Statement by the Director The authors are thankful to Jean-Louis yellowed the color range. Finally, of the Architecture Bellec, Chief of Service at the the protective glazing, particularly Sophie Lemonnier, Louvre Museum Architecture Department of the Louvre thick for this painting, adds a colored The building of the Louvre Museum is Museum, for his careful monitoring of filter, which lighting has to Compensate. in permanent change. Even today, the project and his active participation the special design of the new lamp for in the exchanges. The Louvre Museum would like the Mona Lisa is the result of an this major artistic world heritage to interactive collaboration between benefit from the best available renowned specialists. lighting techniques.

References: Marc Fontoynont, Consultant and Professor, Aalborg University, Copenhagen, Danemark Jean-Pierre Miras, CEO, Arkanz Lighting GmbH - www.arkanz.com, www.sklaer.com DEF S.r.l., Paolo de Vecchi - www.defsrl.it Aelsys Sarl. Jean Chanussot - www.aelsys.fr Marco Angelini, CEO Fraen S.r.l.Italy - www.fraen.com Leonid Novakovskij, CEO Pharos-Alef, Russia - www.pharos-alef.ru Christophe Marty, Gregory Duchêne, Ingélux Lighting Consultants, Vaulx en Velin Lyon - www.ingelux.com Kazuaki Makita, Chief Specialist, New Lighting Systems Division, Toshiba, Tokyo, Japan

Annual LED professional Review (LpR) Article Index 2013

Events LED Acceptance in the Global Lighting Market Continues to Grow LpR 35 | Jan/Feb 2013 p 26 by Alan Mills, LED professional LED Lighting Taiwan Review - Focus on Taiwan’s Key Players in the SSL Market LpR 38 | July/Aug 2013 p 30 by Arno Grabher-Meyer, LED professional LpS 2013 - A Comprehensive Program, Trends, Innovations and New Product Launches LpR 40 | Nov/Dec 2013 p 22 by Arno Grabher-Meyer, LED professional

Interviews Zhaga – A Successful Strategy for Luminary Manufacturers LpR 35 | Jan/Feb 2013 p 30 by Siegfried Luger, LED professional Optics Production Technology for Customizing LED Luminaires LpR 36 | Mar/Apr 2013 p 34 by Siegfried Luger & Arno Grabher-Meyer, LED professional Digital Driver IC Chip Designs for Retrofit Bulbs LpR 37 | May/June 2013 p 38 by Siegfried Luger & Arno Grabher-Meyer, LED professional In-Line Process Control and Yield Management in LED Manufacturing LpR 38 | July/Aug 2013 p 38 by Siegfried Luger & Arno Grabher-Meyer, LED professional Status of Micro- and Nanostructured 3D LED Technologies LpR 39 | Sept/Oct 2013 p 34 by Siegfried Luger & Arno Grabher-Meyer, LED professional Light Quality and Standardized Measurement LpR 40 | Nov/Dec 2013 p 32 by Siegfried Luger & Arno Grabher-Meyer, LED professional

Applications An Economical Omnidirectional A19 LED Light Bulb LpR 36 | Mar/Apr 2013 p 52 by Chen-Peng Hsu, Industrial Technology Research Institute (ITRI) FL Replacement LED Tubes - Challenges and Technologies LpR 37 | May/June 2013 p 32 by Arno Grabher-Meyer, LED professional Handheld Photometry Supports LED Lighting Design LpR 38 | July/Aug 2013 p 56 by Norbert Harkam, SalesLink GmbH / UPRtek Contactless LED Technology LpR 39 | Sept/Oct 2013 p 40 by Alain Guimont, HEICO lighting Light Quality and Appropriate Light Measuring Methods in Demanding Applications LpR 40 | Nov/Dec 2013 p 56 by Rich Rosen, Litepanels

Technology Copper Bonding Wires - A Feasible Solution for LED Packaging LpR 35 | Jan/Feb 2013 p 34 by Dominik Stephan & Alon Menache, RED Micro Wire How Silicones are Evolving to Meet the Growing Needs of the LED Lighting Industry LpR 36 | Mar/Apr 2013 p 40 by F. de Buyl, M. Beukema and K. van Tiggelen, Dow Corning New Optical Lithography Method for Advanced Light Extraction in LEDs LpR 37 | May/June 2013 p 42 by T. Uhrmann & H. Solak, et.al, EV Group & Eulitha AG OLED Technology in Lighting Applications - Current Status and Outlook LpR 38 | July/Aug 2013 p 42 by Franco Musiari, ASSODEL New MOCVD Platform for Cost-Effective Production of GaN-based HB LEDs LpR 38 | July/Aug 2013 p 48 by Shiping Guo, Advanced Micro-Fabrication Equipment Inc. High-Index Nanocrystals - Key to Next Generation Advancements in Lighting LpR 38 | July/Aug 2013 p 52 by Gregory Cooper, Pixelligent Technologies LLC Reliability Oriented Design of LED-Based Light Sources LpR 39 | Sept/Oct 2013 p 52 by Matteo Meneghini et al., University of Padova, LightCube SRL LED and Lens Degradation Through Volatile Organic Compounds LpR 39 | Sept/Oct 2013 p 58 by Edward Steinke, Cree Corp.

Annual LED professional Review (LpR) Article Index 2013

Electronics EMI Problems in TRIAC Dimmable LED Drivers LpR 35 | Jan/Feb 2013 p 38 by Bianca Aichinger, RECOM Lighting Protecting LEDs from Electrical Overstress Faults LpR 37 | May/June 2013 p 58 by Joe Dinkel & Spencer Guo, TE Circuit Protection LED Converter With High Dimming Performance LpR 40 | Nov/Dec 2013 p 38 by Giulio Borsoi, Mathias Burger & Christian Nesensohn, Tridonic Intelligent Over Temperature Protection for LED Lighting Applications LpR 40 | Nov/Dec 2013 p 46 by Bernd Pflaum & Hakan Yilmazer, Infineon Technologies

Thermal Management Reliable Thermal Management of High-Power LEDs LpR 35 | Jan/Feb 2013 p 42 by Stefan Hörth, Haeusermann Thermal Management for LEDs Beyond Thermal Conductivity Values LpR 37 | May/June 2013 p 48 by Jade Bridges, Electrolube Choosing the Appropriate Heatsink for an Application LpR 37 | May/June 2013 p 52 by Jürgen Harpain, Manager of Development at Fischer Elektronik Natural Design for Heat Sinks LpR 39 | Sept/Oct 2013 p 64 by Ch. Herbold & C. Neumann, Karlsruhe Institute of Technology

Characterization The Influence of LED Emission Characteristics on the Efficiency of Lighting Systems LpR 36 | Mar/Apr 2013 p 46 by Roland Schulz, Osram Opto Semiconductor HD-Retina LED Technology - Light Quality Beyond CRI LpR 40 | Nov/Dec 2013 p 52 by Giulio Vezzani, Martini Light

Standardization Labeling and Certification Testing Issues LpR 36 | Mar/Apr 2013 p 30 by Arno Grabher-Meyer, LED professional The Challenge of Designing Safer LED Lighting Products LpR 39 | Sept/Oct 2013 p 46 by John Showell, Product Approvals Ltd.

Manufacturing Lacquer Systems for PCBs – Optical Requirements and Performance in Applications LpR 35 | Jan/Feb 2013 p 46 by Dr. Manfred Suppa & Johannes Tekath, Lackwerke Peters The Necessity and Feasibility of Production Testing for LED Lighting Products LpR 39 | Sept/Oct 2013 p 70 by Bernie Chang, Chroma ATE Manufacturing Silicone Lenses and LED Packaging LpR 40 | Nov/Dec 2013 p 60 by Tarik Karsandik, Tengifts Technology

Special Topics DC-Grids - Challenges and Chances for LED Lighting LpR 35 | Jan/Feb 2013 p 52 by Arno Grabher-Meyer, LED professional Trends in LED Lighting Design and Function LpR 38 | July/Aug 2013 p 60 by Mick Wilcox & Aaron Merrill, Bridgelux Solid-State Lighting Considerations LpR 39 | Sept/Oct 2013 p 30 by Siegfried Luger, LED professional Key Technologies – Drivers of the (LED) Lighting LpR 40 | Nov/Dec 2013 p 64 by Arno Grabher-Meyer, LED professional

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