Report 0-30V Stabilized Power Supply in Projects Q/A Posted September 27, 2017 Sorry for not getting back, been out of town. Turned out the Op-Amp was defect; put a fresh one in and it worked like a charm. Thanks for the help Now, another question: As audioguru says above, the voltage pot just feeds 0-11.2 V to the right Op-Amp. I wanted to try to control the voltage from another source, which I can't really get to work as I want: From 11.2~8.2V it works fine and the output adjusts down perfectly. However, no matter how much lower I try to feed it, it won't get lower, actually stopping the input source from going any lower. As soon as I shut the supply off or disconnect it jumps back down. Interestingly, with a multimeter set for Voltage measuerment between pin 3 (Non-inverting in) and pin 4 (ground) it does suddenly work as expected and adjusts all the way down to 0, as soon as I remove it it's back to ~8.2. I'm sure I'm missing something obvious here..