Thread: LEDs
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Doug Dotson
 
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I've seen quite a number of White LED driver chips on the market.
Apparently they are boost converters that output 32 volts to drive
2 to 8 LEDs from a 3.3 to 5.5V supply. Apparently the flash in my
cellphone camera is a white LED.

Doug
s/v Callista

"Jim" wrote in message ...
Terry Spragg wrote:
removed
Each LED consumes about 80 milliamps at 1.6 volts or so.


I think you're mistaken here. If I remember correctly, most LED's
require a minimum voltage of 1.7v just to conduct current across the
diode. (Someone help me here if my terminology is incorrect as well as my
lack of electronics knowledge.) You would have a hard time seeing an LED
running at that low of a voltage. I believe most white LED's require a
minimum voltage of 3.6 volts, at least all of the ones I've dealt with.
Sometimes they are driven at a higher than rated voltage to get more or
rather brighter light, as in some flashlights, but the LED's that are
overdriven like this will typically be heatsinked(sp?).

If anyone is looking for a reasonably priced supplier in the US, check
out superbrightleds.com. They seem to have some of the brightest LED's
and their prices are, or at least were, the best I've found for LED's.
They also have LED lamps.

-Jim