I made a 12 volt supply out of an ATX PSU to power some stuff when "on the grid". It was pretty straight forward but there were a couple of things I had to track down like which wire to connect to get it to turn on and the fact that you need a load on the 5 volt rail to get the 12 volt rail to produce good power.
See: http://www.vonslatt.com/bus-tron.shtml
and the rest: http://www.vonslatt.com
See: http://www.vonslatt.com/bus-tron.shtml
and the rest: http://www.vonslatt.com

