Power supply

The Power supply

As the power supply only needs to supply 5v, I decided to use a standard 7805 regulator circuit.

Theory

This is a standard 7805 power supply capable of supplying up to 1A at +5v. It is basically straight from the datasheet.

To keep it simple, i enclosed the whole lot in a plastic box. This keeps the high voltage bits nicely away from the rest of the computer. The heatsink is bolted on the outside.

Schematic

Testing

Testing consists of plugging it in and seeing if we get 5V at the output. Its a good idea to see if the LED lights up as well.

If this doesnt work, disconnect immediately

Parts list

• Active
  • 7805 regulator
• Passive
  • 100uF Capacitor
  • 1n4001 diodes x4
  • Transformer, 9v primary
  • Switch
  • Power socket
  • Plastic case
  • Led
  • 330 ohm resistor.