EyeOnElectronics Recent developments in automotive offer safety, reliability and styling enhancements—but at a cost. Question is, will motorists ante up?

he uses of electronic subsys- the output of the . The use of tems in automobiles are well halogen was a major step forward in reliability documented, and over the last and precise control of where light could actu- couple of years, electronics has ally be directed. Mike Dale been moving into vehicle light- The next big advance came with the introduc- ing systems. High-intensity dis- tion of HID lighting in Europe in the early ’90s. charge (HID) lighting is with us now in small With HID lighting, there’s no filament to break volumes. Using HID as a base, electronically or burn out. A high-voltage igniter is used to Tcontrolled is on the way. These form an arc inside the light-generating tube. developing systems This tube is filled with xenon gas and has two will bring added safe- closely spaced electrodes. Once the arc is lit, an ty, improved reliabili- electronic ballast controls the voltage and cur- ty and new approach- rent needed to feed and stabilize it. Xenon is su- es for styling engi- perior to mercury vapor in that it warms up neers. There is also much more quickly. opportunity for the The result of the HID concept is a system aftermarket, as fash- that produces three times as much light as a ion-conscious drivers halogen bulb while using only 65% of the en- are retrofitting their ergy. Because there’s no filament, the bulbs vehicles with HID are rated at 3000+ hours of service. It’s systems. thought that these bulbs can be made to last Since the early ’70s the life of the vehicle. The color of the light vehicles have been is also different. Halogen bulbs produce a using halogen head- light with a distinctive yellowish color. HID’s , in which the bluer light more closely approximates the col- tungsten filament fits or temperature of natural daylight, which inside a quartz helps visibility. envelope filled with The downside of HID has been and contin- one of the gases from ues to be cost. In Europe, the buyers of high- the halogen group. As end vehicles have been paying in excess of the filament is heated $1500 to get these lighting systems on their electrically, some of vehicles. Here in the U.S., HID is about 6% of the tungsten evapo- the new- market, with expectations that it rates. Unlike a regu- will grow to about 10% over the next couple of lar light bulb, the years. In the long term, it’s hoped that the tungsten combines benefits of HID will cause more consumers to with the halogen gas want HID, and be willing to pay for it. and is redeposited The cost of HID lighting has not slowed

Illustration courtesy Hella North America courtesy Illustration onto the filament. down the aftermarket. OSRAM Sylvania, Hel- The job of any lighting system is to put light on This allows the fila- la North America and other suppliers offer kits the road so the driver can see what’s in front ment to last much to convert existing vehicles to HID lighting. of him. Electronically controlled lighting will longer even at higher Sylvania’s XENARC HID X2010 kit, for exam- shape and direct the beam for the best vision temperatures. Raising ple, is designed to fit the Ford F-150. It retails based on what the needs are—such as seeing the temperature of for $899. Other kits are in the $500 to $1000 around curves in the road, as shown here. the filament increases range. If that seems like a lot of scratch, don’t continued on page 16

14 July 2002 Eye On Electronics

forget that many owners routinely ducted studies “to find out what the a different way that creates differ- spend similar money for color- drivers would really like the lighting ent patterns of projected light. As matched caps or fancy sets of wheels. system to do for them. What we many as five different beam pat- Studies show that, on average, Gen- found is that drivers would like to terns can be produced. Based on in- eration Y young people are willing to have front lighting that can automat- formation detected by the sensors, spend up to an additional $2500 to ically adjust the lights to different the computer controlling the VarioX make their new rides stand out from road and light conditions. Intelligent headlamp system can direct the the crowd. front lighting should be able to ad- light in the pattern producing opti- The opportunity for the service in- just for daylight, twilight or night- mum visibility. dustry is in the sale and installation of time conditions. The lighting should While computer-controlled head- the HID kits. The wiring and installa- also be able to uniquely adjust for lamp systems have some government tion will be more work than many tunnels, rain, or . Better problems to overcome, expectations people will be willing or qualified to lighting that adjusts for bends in the are that they’ll be ready for produc- do on their own. Typical kits include road, that adapts for fast highway tion by 2005. An interim step that the xenon gas light source, an ignit- speed and that gives im- should be ready for next year are er/ballast for electrical control and proved lighting of curbs and ditches headlights that know when the vehi- new reflectors or projectors. was also found to be desirable.” cle is turning, then project the light To be street-legal in Europe, a in that direction. As a mechanical fea- headlamp-leveling and washer sys- A Smart Lighting System ture, this has been tried before by tem must be added. There has been Hella’s answer is called Varilus, a both Citroen and Tucker. The elec- much concern about oncoming driv- smart lighting system based on sen- tronic version uses a servomotor to ers being blinded by the headlights sors connected to an in-vehicle data move reflectors inside the headlamp of a car loaded heavily at the rear. network. Existing sensors, such as the assembly to change the direction of The headlamp-leveling system uses sun sensors of the a/c system, speed the light. a sensor to determine the position sensors, turn angle sensors and the HID lamps can also make use of of the headlamp relative to the like, will be used to detect what the another concept currently being de- ground. Servomotors are used to ad- operating circumstances of the vehi- signed into new vehicles—distributed just the angular position of the light cle are. New types of sensors along lighting. This concept takes a single source. with computer algorithms will be source of light, located remotely from Of course, there are always those used to recognize different lighting where the light will shine, and con- who’ll try to take advantage. A quick conditions (day, night, twilight, tun- ducts it there by fiber optic cable. A check on the Internet and with local nels, bridges). Then the body or single source of light can be made to parts houses shows a variety of com- lighting computer will know what the shine in multiple locations without panies offering halogen lights with best lighting should be for a particu- the need for wiring, connectors and blue glass. The true advantage of lar set of circumstances. bulbs. This can also aid styling be- HID is not there, but the color of the The key is implementing the cause the light can be generated light makes it look like an expensive changes in real time so the driver can where there’s room and then be con- upgrade has been done. have the benefit of the improved ducted through these so-called light True HID is what’s called an en- lighting when it’s needed. As a first pipes to where it’s needed. This abling technology. Once you have the step, Hella is showing carmakers should allow designers unique ways additional light available, there are something called the Bi-xenon lamp. to shape the front and rear ends of more things that can be done with it. Today’s HID systems use halogen vehicles without having to allocate HID will make the next generation of bulbs for high beams and xenon space for conventional headlamp or lighting systems possible. lamps for low beams. In the Bi-xenon taillamp assemblies. “We have been working with the system, a movable shield is placed And so, electronics has come to ve- University of Paderborn in Europe between the light source and the pro- hicle lighting systems. When GM did to study the physiology of light and jection lens. In one position, the full the Precept experimental car as a how it affects people,” Jason Bonin, light of the lens is allowed for a high part of the government’s Partnership Vice President of Lighting Technolo- beam; in the other, the shield reduces for a New Generation of Vehicles, gy at Hella North America, told me the shape and amount of light output they found that HID allowed them to recently. “One thing we learned is for the low beam. cut the electrical demand for the that people’s eyes are not as sensitive Hella’s VarioX headlamp system lighting system from 170 watts to 94 to orange light. We can mount read- uses a motor-driven cylinder placed watts, which produced a fuel saving ing lights in the headliner of a vehi- between the light source and the of 1.5 mpg. Put that together with the cle that allow the passenger to read projection beam. The outside shape safety improvements to be gained without disturbing the vision of the of the cylinder is not round but from improved lighting, and you see driver.” sculpted. At each rotational posi- why electronics and lighting systems Bonin went on to say they’ve con- tion, the light is partially blocked in are a good match.

16 July 2002