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Eye on electronics

Motor, Jul 2002 by Dale, Mike

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

The uses of electronic subsystems in automobiles are well documented, and over the last couple of years, electronics has been moving into vehicle lighting systems. High-intensity discharge (HID) lighting is with us now in small volumes. Using HID as a base, electronically controlled smart lighting is on the way. These developing systems will bring added safety, improved reliability and new approaches for styling engineers. There is also opportunity for the aftermarket, as fashion-conscious drivers are retrofitting their vehicles with HID systems.

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Since the early '70s vehicles have been using halogen headlights, in which the tungsten filament fits inside a quartz envelope filled with one of the gases from the halogen group. As the filament is heated electrically, some of the tungsten evaporates. Unlike a regular light bulb, the tungsten combines with the halogen gas and is redeposited onto the filament. This allows the filament to last much longer even at higher temperatures. Raising the temperature of the filament increases the light output of the headlamp. The use of halogen was a major step forward in reliability and precise control of where light could actually be directed.

The next big advance came with the introduction of HID lighting in Europe in the early '90s. With HID lighting, there's no filament to break or bum out. A high-voltage igniter is used to form an arc inside the light-generating tube. This tube is filled with xenon gas and has two closely spaced electrodes. Once the arc is lit, an electronic ballast controls the voltage and current needed to feed and stabilize it. Xenon is superior to mercury vapor in that it warms up much more quickly.

The result of the HID concept is a system that produces three times as much light as a halogen bulb while using only 65% of the energy. Because there's no filament, the bulbs are rated at 3000+ hours of service. It's thought that these bulbs can be made to last the life of the vehicle. The color of the light is also different. Halogen bulbs produce a light with a distinctive yellowish color. HID's bluer light more closely approximates the color temperature of natural daylight, which helps visibility.

The downside of HID has been and continues to be cost. In Europe, the buyers of highend vehicles have been paying in excess of $1500 to get these lighting systems on their vehicles. Here in the U.S., HID is about 6% of the new-car market, with expectations that it will grow to about 10% over the next couple of years. In the long term, it's hoped that the benefits of HID will cause more consumers to want HID, and be willing to pay for it.

The cost of HID lighting has not slowed down the aftermarket. OSRAM Sylvania, Hella North America and other suppliers offer kits to convert existing vehicles to HID lighting. Sylvania:s XENARC HID X2010 kit, for example, is designed to fit the Ford F-150. It retails for $899. Other kits are in the $500 to $1000 range. If that seems like a lot of scratch, don't forget that many owners routinely spend similar money for color-- matched caps or fancy sets of wheels. Studies show that, on average, Generation Y young people are willing to spend up to an additional $2500 to make their new rides stand out from the crowd.

The opportunity for the service industry is in the sale and installation of the HID kits. The wiring and installation will be more work than many people will be willing or qualified to do on their own. Typical kits include the xenon gas light source, an igniter/ballast for electrical control and new reflectors or projectors.

To be street-legal in Europe, a headlamp-leveling and washer system must be added. There has been much concern about oncoming drivers being blinded by the headlights of a car loaded heavily at the rear. The headlamp-leveling system uses a sensor to determine the position of the headlamp relative to the ground. Servomotors are used to adjust the angular position of the light source. Of course, there are always those who'll try to take advantage. A quick check on the Internet and with local parts houses shows a variety of companies offering halogen lights with blue glass. The true advantage of HID is not there, but the color of the light makes it look like an expensive upgrade has been done.

True HID is what's called an enabling technology. Once you have the additional light available, there are more things that can be done with it. HID will make the next generation of lighting systems possible.

"We have been working with the University of Paderborn in Europe to study the physiology of light and how it affects people," Jason Bonin, Vice President of Lighting Technology at Hella North America, told me recently. "One thing we learned is that people's eyes are not as sensitive to orange light. We can mount reading lights in the headliner of a vehicle that allow the passenger to read without disturbing the vision of the driver."

Automotive Industry

Eye on electronics

Motor, Jul 2002 by Dale, Mike

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