ProtoConVert

Question: Would an array of LED bulbs arranged in such a way as to cover the front area of a headlight cluster draw more or less power or amps from the battery? How is this sort of hting measured, power or amps? Would any wiring modifications like steppers ors omething like taht be necessary?

wakeech

measured in power, i think.

i'm super rusty on my electoronics, and of course it would depend on what your LEDs are like, but you'd probably have to step it down.

just a question: because there is so very little, not to mention EXTREMELY diffuse, light that comes from LEDs, why would you want to cover your headlights with them?? tail lights would look cool (like a semi-truck/bus... a lot of reflectors are going that way stylistically) but again, the visibility problem... what's the deal??

gazita123

It would depend on the LEDs that are used.

Currently, there are new ones under development that are for this exact kind of application, so it isn't exactly like taking a bunch of those key chain lights and taping them to the front of your car.

There are some pretty big power discharge LEDs now, look at the ones that are used in the larger flashlights where the power output is in W and not mW. And, since they tend to be more efficient, the light output is higher too, per watt.

If someone wanted to do an array of current technology LEDs, it would take a PWM controller to go between the power and the LEDs themselves, which doesn't dim the lights, but allows them to run brighter without burning them out and makes them more efficient.

But, like wakeech said, the output isn't quite there with the current generation. It may be possible to have a very large number and it be effective, though.

P.S. - We had a contractor at work that did the design for one of the LED flashlight manufacturers, so I had to listen to how the future is LEDs for a while.

wakeech

ahahaha... "The future is..."... how many times have i heard that phrase?? jesus...

anyways, i do remember seeing some older Citroen concept car that had EVERYTHING shaped like an eye (it was weird as hell) that used LED headlights (i think), but didn't seem to work so well... looked cool, but yeah, this is something which would be rediculously expensive to manufacture and make-work.

Farsyde

LED's are pretty cool and they may be "the future." More like 10+ years. I don't see why anyone would use them. Do headlights really draw that much power that LED's need to replace them? I can see how LED's could possible use a smaller alternater and the fact that high output lights could be a problem in electic/fuelcell cars that need all the power they can get, but for now it just seems like something that doesnt need to be done.

Of course i'm sure someone once said the same thing about rotaries and look where we are today! Rotary heaven this summer.

gazita123

It is both a factor of power consumption and lifetime. LEDs would almost never need replacement.

Farsyde

im curious, is anyone working on an LED as a single "bulb" or would the headlights be a collection of focused LED's?

gazita123

The concepts that I've seen seem to be using several bulbs. Which would make some sense. That way, a lighting pattern could be defined without having to resort to a reflector.

Farsyde

that would make sense but i think they would still use reflectors so on coming traffic isn't blinded by the bulbs directly. Since LED's have such a narrow band (kinda like HID's only they could be worse) and are very efficient for their size in lumens. They could make the lens over the LED subtely diffuse to scatter some of the light. I bet cattilac is the first company to go for LED headlights.

wakeech

...unless there are "reflectors" painted onto the LED's, wouldn't the light be rather diffuse in the first place, as in, emitting raidially from the diode in the little plastic bulb?
... i really don't know much about this newer concept...

oh, a question: would producing LED headlamps be concievably cheaper than HID units, which i know are made with (high pressure?) rarish noble gases, big heavy ballasts, and cost a bloody fortune...??

Farsyde

i know that LED's are the cheapest form of lite for the cost and brightness (lumens). You can buy a bag of like 200 LED's for like 10 bux. The problem is, LED's (at least the one's i've seen) currently aren't "bright enough" to send a beam that conforms to the DOT standards (i think they are beam must project 200ft and cover 50ft wide). i haven't seen any current research on them which is why i still think we are a ways off. After all, it took like 5 years for engineers and physicists to develope a stable blue LED.

TerenceT

how about these LED brake lights? (wrx wagon)

http://community.webshots.com/photo/...75471926tDIvbl

or these LED night vision illumination? (inspired by Audi, then Porsche, then TSX)

http://community.webshots.com/photo/...75472005lFUXOM

gazita123

If you look very closely at even the normal LEDs that are on the market, there is a reflector behind the IC, which is in the middle of the plastic.

LEDs would be cheaper, as long as the IC cost is cheaper, which is the part that is relatively expensive right now.

Farsyde

are we talking about the cost of high output LED's??? Cuz right now the on e-bay you can buy 200 for about $10.

gazita123

The existing high output LED's are weak in comparison to what is in the pipes. Output in watts vs. mW.

Efini 8

I personally have PIAA White LEDs and they are really cool. They are not extremely bright, but bright enough. They emit a color unlike any halogen bulb, it is a purplish tinge with blue around it also. Its a CLEAN white with a bit of purple. I use it in my headlight assemblies and side markers.