A thread about white LEDs got me wondering – I’ve seen some very bright white LEDs, especially in newfangled flashlights. Have any car companies been creating LED-based headlights? They require a fraction of the electricity required by conventional incandescent lights for the same amount of light. Seems like a good idea to me.
The ones you see require a “fraction of the electricity” because they only emit a fraction of the light. You will need a lot of them to get the same amount of light as a conventional bulb. But the LEDs should last longer.
A headlight emits light, which reflects off an object and still have enough intensity fro the drive to easily see it.
I think you will find commercial brake lights and turn signals before long. Those don’t need to be as big since they only need to be bright enough for people looking at the light to notice them.
Many commercial vehicles already have LED brake and turn-signal indicators. I’ve noticed them on big-rigs, box vans, flat beds and busses.
Interestingly I’ve also noticed that often a fair number of the LED’s in the array are not functioning. Anyone aware if this is a quality control issue, a susceptibility to vibration / shock, or something else my feeble mind lacks the comprehension to identify? At what point should / must the array be replaced (25% failure, 50% failure, complete failure)? Are there any regulations concerning this?
Two problems I would imagine could happen with LED headlights:
LEDs, because of the way that they are packaged, are quite difficult to focus using a reflector arrangement - in LED torches(flashlights) a beam with a soft edge is produced - in headlights this could mean that other drivers were dazzled by the beam edges (or if the beam were more tightly focused, it would mean that visibility at the beam edges could be dodgy).
LEDs are effectively a ‘point source’ - this means that, although their total output may be less than that of an incandescent source, they are dangerous to look at directly because all of the light that reaches the eye is concentrated on a very small piece of retina - could be a problem for oncoming motorists.