i scrap out old, dead computers so there's always a pile of the old "at" power supplies around here. one is almost always running. fans, speakers, testing anything that draws a low enough amperage. if anyone knows how to step to different voltages i'd appreciate the feedback. i'd like to replace the half dozen transformers i've got running at 6, 7.5, and 9 volts with a single "at" power supply.