On Mon, Mar 21, 2011 at 2:30 AM, IVP wrote: > Hi all, > > could I have suggestions for controlling an LM317 please > > In the attached diagram, the 10k pot is used to set the voltage > of the HV PWM outputs > > What I need to add is a modulation control, which simulates > the pot being rotated left and right. The pot will stay, modulation > is just another mode > > IF I'm right assuming that ADJ can't be directly voltage-controlled > (correct me if I'm wrong) then adding modulation will require either > grounding the pot through a FET, so that it can be switched out, or > paralleling it with some resistive element > How much modulation (in terms of output voltage) do you need? Could you use digital pot, e.g. AD5290, with existing pot in series? --=20 Mark Rages, Engineer Midwest Telecine LLC markrages@midwesttelecine.com --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .