AC contactor power-saving silent operation circuit (1)

As shown in the circuit in the figure, when starting the motor, press the start button ST, the AC contactor KM will be closed, the auxiliary contact of KM will be closed, release ST, the normally closed contact of ST will return to the closed state, and the diode VD and KM will be connected. The coils are connected in parallel, connected to the power supply through the capacitor C and the KM self-locking contact, and the KM converts to DC operation. The capacitor C plays a voltage-reducing role in the circuit and causes the alternating current to flow through the coil from top to bottom in both positive and negative half-waves, causing the AC contactor to operate in direct current. The noise is extremely small during DC operation, so it is also called AC contactor silent operation.