I would like to build a variable DC voltage output power supply. It does not need to be very accurate, but it needs to start at 0 volts and go to about 15 volts and be capable of about 20 amps. I have seen some projects listed out there. With that high of amps, they tend to be fixed voltage. Some cannot go any lower than 1.2 volts. I haven't given up searching, but I decided to put a query out in the forum and see what help is available.