The simplicity in design and small packaging make LED lighting systems very attractive to engineers when designing different types of illumination. They can be so compact that stylist find it simple to put LEDs in new locations. Look at the side view mirrors on many of our cars and light duty trucks that have turn signal LEDs in them. 

Invented by a General Electric engineer in the early '60s, it took a while before the little glowing red (the first ones invented were red in color)  would be able to be rugged and economically suitable for automotive applications. Depending on some applications, you can have as many as 10 to 30 LEDs in a taillight. Using 30 LEDs to replace one bulb means a huge increase in the manufacturing of these devices which helps to drive down the cost. 

Some of the other major benefits that LEDs have are that they can be less taxing on the electrical system and offer greater spectral efficiency as well as the faster rise times mentioned before. The chart below offers some of the hard data.

Spectral Efficiency

One other feature I did not mention yet was the fact that LEDs, using much less power, generate much less heat. This is significant as prior to LEDs, the amount of heat certain bulbs emitted had a direct effect on where those bulbs could be used. With virtually no heat coming from LEDs, the choices on where they can be implemented is almost boundless. Remember in the early years of Center High Mounted Stop Lamps, the bulbs would generate so much heat that on some instances the housings would melt or on IP lighting where the sockets would be fused to the printed circuit due to some unwanted plastic fusion? No longer a problem with LED technology.

In the near future, LEDs may be getting a seat at the front of the vehicle...
As scientific research and automotive engineers move forward on creating a white light LED, you may see them heading for headlight applications! Though it appears that the right combination has been found to make a pure white light LED, cost and "luminous flux" or light output are still a factor. Even though we are using more HID lighting strategies, (they may start to be used in Back Up Light Systems) there is a debate over the "glare factor" (see the page on HID lighting) which would not be a factor if LEDs were to be perfected for this application.

Mik Stubing Lead Instructor - Northeast Region