rides

Light-emitting diodes [LEDs] are common for brake lights and signal lights in many cars, but only a handful of elite cars and trucks offer LED headlights - such as a couple of Lexus hybrids, and Cadillac Escalade SUV. LED headlights are an option on the relatively inexpensive Toyota Prius. However, like any other technological breakthrough, LEDs are expected to be made available on less expensive rides.

As Viren Merchant, electronics engineering manager for exterior lighting at Visteon Corp., a major supplier to the world’s automakers, explains, “They’re especially desirable for hybrid and full electric vehicles. With electrification of the vehicles, where power generation or power storage costs money, using less power gives you less storage [requirement] or more range. That’s what’s driving it and there’s a lot of interest from [manufacturers] in that regard.”

Early cars used headlamps fueled with acetylene gas. Next came tungsten-filament sealed beam headlights [an old school light bulb for use on the road]. Tungsten-filament bulbs made way for Halogen bulbs [which are still the primary light source for most rides]. However, Halogen bulbs have more recently been replaced by high-intensity discharge (HID) lamps. You can distinguish a HID bulb when you see one due to its bluish-white light source. They work by passing electricity through xenon gas.

In Merchant’s estimation, about 15 percent of the world’s vehicles now are equipped with HID lights. Currently, we are up to LEDs. LEDs have been used since the 1960’s for readouts on electronic equipment and more recently on things like Christmas lights.

Merchant says automotive engineers and designers love LEDs mainly for three reasons: long life, low power consumption and new styling and function possibilities. LEDs may stacked or arrayed in different patterns.

“With a bulb you have a single light source and there’s only so many things you can do with it - a certain size, a certain area and a certain cone that you have to play with. LED takes 70 or 80 per cent less power compared to incandescent sources. The power savings is a significant driver,” says Merchant.

As well, there is a good chance LEDs will last the life of the vehicle thus they may need never be replaced.

Rainer Neumann, a researcher at Visteon’s Germany division, says HID bulbs last about 3,000 hours, while LEDs offer a 15,000-hour lifespan.

The reason all cars are not already equipped with LEDs is purely fiscal. A bulb is powered by 12 volts from a battery and it is on. LEDs are not cheap to begin with. They require electronic controls and a cooling system because excessive heat can lead to premature failure. Add these two components together, and you have a highly engineered product. You have expensive sources, and you have expensive controls.

As usage increases, however, there will be an economy of scale on controls, as well as on LEDs, and that should bring the price down, at least to HID levels or lower in the future. On the downside - damaged LEDs lights will cost more to replace because they are a sealed unit.

In conclusion Merchant also notes that HID lights with all their bells and whistles such as built-in washers and motorized self-leveling projector lenses, have already been pushing up prices. When the dusts settles, it will be LEDs that will be emerge as the standard light source.

Source: The Daily Gleaner