This switch uses four CD4013 BE dual flip-flops, an inverter, and an optoisolator to drive a triac. The circuit can switch 25-A ac load current. A standard 4x3 telephone keyboard is used to enter a 6-digit code. In case of a wrong code, a signal is available to activate ah alarm.
The disarming method is a secret reset button that can be any number on the keyboard.