Electromagnetic relay working principle:
Close the switch S in the low-voltage control circuit, the current passes through the coil of electromagnet A to produce a magnetic field, which produces a gravitational force on the armature B to make the movable and static contacts D and E in contact, the working circuit is closed, and the motor is working; when disconnecting the low-voltage switch S, the current in the coil disappears, and the armature B is under the action of the spring C, making the movable and static contacts D, E Disconnect, the working circuit is disconnected, the motor stops working.