Help with ISOPOD PWM Circuit

[cjh]

I would like some help with a PWM Circuit.

I am trying to use one of the PWM outputs as
a dimmer for a 12v LED Luxeon.

the 12v would be external from the ISOPOD and the PWM output should be the only connection to this circuit to the isopod.

Thanks.

[Dave]

In looking at some of the Luxeon LED modules, it does not appear that they have a 12 volt forward voltage, but are in the 2 to 4 volt range. Are there any specs for the units being used?

If trying to use the PWM as a dimmer, it might be possible to make a sort of "averaging" circuit with a resistor and capacitor that in turn drives the base of a transistor. In this way, the current capability of the Pod outputs (about 20 mA) could possibly average different levels up to 350 mA through the gain of the transistor. It might need to be a transistor in a TO 220 case since the Luxeon LED modules appear to be rated up to that 350 mA level. Your circuit should probably also limit the current to that level with a resistor to keep from burning out an expensive LED module.