Things that you will need to make this power supply is...
- Piece of veroboard
- Four 1N4001 diodes
- LM7812 regulator
- Transformer that has an output of 14v - 35v AC with an output current between 100mA to 1A, depending how much power you will need. (I found a 16v 200mA transformer in a broken alarm clock.)
- 1000uF - 4700uF capacitor
- 1uF capacitor
- Two 100nF capacitors
- Jumper wires (I used some plain wire as jumper wires)
- Heatsink (optional)
You should be able you get most (maybe all) of the parts at Radio Shack or Maplin.