> The 317 is a linear solution. What I'm trying to avoid is 
> blowing away significant power in a resistor, or other linear device.
> 
> PWM is fine, but I don't have much space or time to spend 
> getting there.

Check the datsheets of standard SMPS chips like the lm2575 for
constant-current mode. Or maybe google for LED drivers. Makeing it
adjustable should not be too difficult.

Wouter van Ooijen

-- -------------------------------------------
Van Ooijen Technische Informatica: www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: www.voti.nl/hvu
 
 


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