Rice cooker automatic rice cooking controller circuit

How the circuit works: The controller is actually an AC timing switch. As can be seen from the figure , the dotted box contains the electronic watch circuit
with alarm function . Part of the alarm time electrical signal taken from both ends of the piezoelectric buzzer piece BC of the electronic watch passes through the capacitor C. Coupled to the control end of the unidirectional thyristor vs, it directly triggers the conduction of vs, causing the relay K to be electrically closed, and its normally open contact K. Turn on the power of the rice cooker, and the rice cooker will be automatically powered on and cooked at a scheduled time without any operation . In the circuit, the 220 V AC mains power is stepped down by the transformer T, and after half- wave rectification by the diode VD and filtering by the capacitor C, a DC stable working voltage of about 12 V is provided to the control circuit.