Automatic Power Control of PC Peripherals

The power from a USB port drives a relay. When the computer is powered up, the USB's 5 volts turns on the relay. The relay contacts switch 120 VAC for all peripherals. In this way, the peripherals power up when the PC is on and power down when the PC is off. No more forgetting to manually turn them off.

You will need a relay able to be powered by 5V that can switch 120VAC. A scrap USB cable and a power cord plus an outlet complete the list. Put it in either a plastic box or a metal box. If metal, connect ground to it for safety.

Cut the USB cable and isolate the red and black wires. Connect these to the coil of the relay. Connect the relay contacts so they switch power from the power cord to the outlet.