Inside every PC is good quality switching power supply. The exact details depends on the PC, but you can expect to find regulated 5V and 12V often at 200W or more of power. Modern PCs rarely consume that much power, so there is plenty of spare juice for your projects. The problem is how to get to it. In this article I'll show you a quick and easy way to gain access to your PCs power supply.
Construction is very simple.
Just remove an unused drive plate. These plastic plates cover the holes where you would install a floppy disk or a disk drive. I used a 5.25 inch cover, but if you only have a 3.5 inch cover open, that should work just as well. Using a center punch, mark 4 holes in the plate equally spaced. Then drill out the holes to fit 4 binding posts.