Quote Originally Posted by mister_e View Post
Weird idea this Zener Z1 so far...

But yeah i'll second the PWM idea.. maybe just remove the LM317 as well and use a Mosfet/Transistor instead and do everything in software. a 12F683 would be perfect for that.

1 current senses
1 voltage sense
1 PWM and
remaining pins for leds and maybe other safety inputs.
Hi,

I didn't remember it at first ... but the 317 can be used as a "switching transistor" for PWM !!! ... just do not use too high a PWM frequency and it will work rather pretty ...

YES ... the "off" state voltage will be 1.25 v ... but, here, no issue with that !!!

do not laugh ! ... I have the proof ... it was ... 18 years ago, for a model train controller !!!

Alain