Does anybody have a current ARRL membership? If so, there is a PDF file at http://www.arrl.org/ for a 13.8-V, 40-A Switching Power Supply. Seems like this would be ideal for running peltiers. I don't know about you, but I've seen prices of $200 or more for a similar device at most of the major websites for electronics surplus. The only downside is that the complete PDF file is part of the members only section of the website. A partial file with the schematic and pcb layout is at http://www.arrl.org/notes/hbk-templates/13v40aps.pdf. If I get the time, I might just go to the National Semiconductor website and design my own.