Control device for power switch, control method for power switch and electronic display system

A control device for a power switch, comprising:

• an acoustic sensor, configured to sense an acoustic signal generated by an acoustic generator and generate a switch control signal according to a frequency of the acoustic signal in a standby mode;
• and
• a switch, coupled between a power supply and an external electronic device, and configured to turn on or turn off a path for the external electronic device to receive the power supply according to the switch control signal,
• wherein, in the standby mode, the acoustic sensor periodically and actively performs a generating operation of the switch control signal,
• wherein the acoustic sensor determines that the acoustic signal has a composite frequency composed of a plurality of frequencies to generate the switch control signal,
• wherein the frequency of the acoustic signal falls at 15 kHz or more.