Thread: LED Headlight
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Old 01-25-2010, 03:45 AM   #37 (permalink)
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I would like to hear other's thoughts too but I would like to try it.

I know with a light bulb, light goes out in all directions. The housing is a parabola shape and collects whatever spills backwards and sends it all directly forward. The light that doesn't reflect off the housing can still go all which ways out the front of the lens. So I would think the diffuser in front of the bulb would send all that forward light backward to the housing so ALL the light ends up going directly forward. It's either that, or the diffuser in front of the bulb is there to avoid there being a really bright spot in the center of the beam, rather it spreads that light out over a wider area to reflect off the housing.

With LEDs it would already solve the problem of having to collect the light going backward, since there would be none.

If the diffuser in front of the bulb is there simply to avoid a bright beam center, and the light is OK to go out to the sides some, then LEDs alone would be fine since it would be an even light output over the entire square.

If the diffuser in front of the bulb is there to block the light that can go all directions and focus ALL the light directly forward, then filing the LEDs would so the trick. Seems like the best way would be to solder them all in place, then run the LED board over a flat sanding block.

Without filing the LEDs, light would go +/- 20 degrees according to the LED specs. That may or may not be a good thing, one would have to try it both ways.

Not sure about DOT approval. However my thought was use stock headlight bodies for a built in diffuser, an easy mount, keeping weather out, stock appearance, and easy reversal if needed. I would think that law enforcement wouldn't hassle you as long as they're aimed correctly, and according to calcs they should be a similar light output to other approved headlights. They would probably just look like the whiter lights of more expensive cars. I think what the cops are looking for is people who are using those super bright off road lights.

I do have one question. You wire four 3.3v LEDs in series so 13.2v is needed, which is close to alternator output. So why do you need a resistor?

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Last edited by wagonman76; 01-25-2010 at 03:52 AM..
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