This very simple circuit will turn off anything when you shutdown your computer. It works by using the power of the usb port to turn on a relay. When your computer is off the usb port has no power and the relay opens the circuits to the devices that are plugged in.
- 1 Relay:
- power cord and socket, you can use a power strip
- USB Cable
- Cut the usb cord, keeping the computer side long.
- i.e. cut the B-plug off
- Strip the +5 and ground wires
- the 1 and 4 wire, probable black and red. See USB pinout below
- Solder wires to the coil of the relay.
- Cut one of the power cords wires and solder one end to normally open (NO) and the other end to common.
- Designed and published by User:ZyMOS