On June 24, 2004 01:37 pm, Harold Hallikainen wrote:
>I'm loooking for a two terminal constant current device that could be put
>between an LED and a variable DC supply to hold the LED current at 5mA as
>the supply varies over a 0-10V range (recognizing we're not going to get
>it at 0V, but I'd like the widest range possible). So far i've found the
>Central Semiconductor CCLM5750 which is a nominal 5.750mA, but it takes
>4.5V to get 80% of the rated current. Anyone have other ideas?

Haven't tried this, but the theory seems okay.
Put the LED in parallel with a 1N4001 diode.
then put the both of them in series with your circuit.

The LED is expecting more than .7v to run full brilliance, so it will
probably run a bit on the dim side.
The 1N4001 should be able to handle 1amp and acts like a 0.7v clamp on the
LED.

Select something bigger than a 1N4005 if you need to deal with more
current.

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