This power supply switch for ATX PC power supplies allows ATX PSUs to be switched on and off safely even without a PC mainboard attached or without bridging the power-on signal.
The power-on signal provides 5 V SB via a pull-up resistor. If this green cable is bridged to ground (0 V, the potential of the PC case), the power supply can be switched on.
This switch takes over this function. The illuminated button switch shows the current status of the power supply.
