Variable power supply

Well i was originally going to mod an ATX power supply for a benchtop one. I need a power supply to run the PIC microcontrollers which require 5 volts. But after talking with some guys in the High voltage chatroom i decided to use the power supply for coilgun parts. So i went on a quest for a cheap variable power supply. I finally decided on the 0-12 volt one from Chaney electronics. It was small, and reliable. (http://www.chaneyelectronics.com/products/power-supplies/c6724.htm). here are some pics of the build. you can get an idea of what the finished thing looks likbe so i dind't include a final pic. I had a problem with the fan though, it was a 12 volt fan and i tied the power leads to the binding posts for the output. only problem was that at around 5 volts it would start to draw power. and would make the output voltage oscilate from 5 to 4.3 volts. If that happened while working ona pic the Pic would brownout every time the voltage dropped below 5 volts. so i had to add a switch to turn off the fan while working on PIC microcontroller. I'm not too worried about overheating the power transistor at 5 volts, but it starts to get hot at around 8 volts.