Step 5: Test it!
After you had built your power supply, test it with your multimeter to make sure they are no solder bridges.
After you tested it, put it in a plastic box or something to protect you from shocks.
But do not operate the power supply like I did, it is very dangerous because of the mains voltage on the transformer, you or somebody will get badly shocked!
My power supply has 11.73v output, not too bad, I don't need it to be exactly 12v...