Atten PPS3005S DC Power Supply Fix
Channel: bobski3333
Date: 2011-06-25

I bought one of these supplies last week and after a mixup with the seller, finally got it on Friday. When I plugged it in and tried it out, I found the controls and current limiter were a bit... Sluggish.
I figured the controller (an ATMEGA88PA) might be having a hard time keeping up, so I tried swapping out the 8 MHz crystal for a 16 MHz I had on hand (the controller can handle up to 20 MHz). This had zero effect on the supply's behavior. I figured it  should have had SOME change, so maybe the controller was mis-configured and ignoring the crystal. The manufacturer conveniently provided an ISP port, so I hooked it up and checked. Sure enough, it was using an internal source. I flipped it to external, hit program and problem fixed.