Household appliance protector circuit schematic

LC03-3.3 SOP8 TVS Static Protection 3.3V

Photocoupler

IC1 (555) is connected to the RS trigger mode. When undervoltage and overvoltage occur, Kl is set and its 3 pin is high. IC2 is reset, the 3 pin is low level, the SCR is cut off, and the load is powered off. When the power is turned off and then called again, since the terminal voltage on C4 cannot jump, the 2 pin is added with a peak high potential, so that the output of IC2 is low, and when the C4 is charged, the potential of the 2 pin is lower than 1/3VDD. IC2 is set and the load is restored. The charging time of C4 is the protection time, and the protection time of the graphic parameters is about 6 minutes.