Large drum type washing machine electric controller circuit principle

As shown in the figure, the electric control circuit of the large drum type washing machine. The controller is composed of a pulse generator, a counter, a relay control circuit, a step-down rectifier circuit and the like. The buck rectifier circuit provides a DC voltage to the entire controller.
The pulse generator is a multivibrator composed of IC1 (555) and R2, R1, C1, etc., and its oscillation period is T≈0.693 (R1+R2)C1. The counter IC2 adopts a decimal counting/pulse distributor CD4017, which The output pulse of IC1 is used as the clock signal. The output cycle of the IC1 is continuously cycled at the same high level as the counting pulse cycle at the Y0~Y9 terminals. The output Y0, Y4, Y5, and Y9 sequentially switch the BG1, BG2, and BG3 to start the relay. J1, J2, J3, thereby controlling the contactors 1C, 2C to turn on the three-phase AC motor power supply, and complete the washing function according to the washing machine timing.
The controller can realize the same function of forward rotation → stop → reverse → stop of the mechanical contact type controller.