Ductapemaster

Ahhhhhh that makes sense. I was wondering how that all worked, but now its clear. Thanks! I'm in the process of scrounging up parts for this (I would like to make a dual rail one for +/- supply needs). Hopefully it all goes well. -Dan

I'm in the process of deciding on a design for a lab power supply, and this one seems to fit the needs that I have. However, I have been reading some of the forum replies and I have a question. Why are you guys using OP amps that aren't rail to rail? If you used a rail to rail amp, it would eliminate the need for the charge pump negative voltage generator and make life a whole lot easier. Am I just missing something, or is there a reason for using non-rail to rail OP amps? Thanks, Dan