Electromagnetic relay is a switch that uses an electromagnet to control the on-off of the working circuit.

(1) Structure: The main components of Electromagnetic relay are electromagnet, armature, spring, moving contact and static contact.

(2) The working circuit can be divided into two parts: the low-voltage control circuit and the high-voltage working circuit. The low-voltage control circuit includes the Electromagnetic relay coil, the low-voltage power supply, and the switch; the high-voltage working circuit includes the high-voltage power supply, the motor, and the contact part of the Electromagnetic relay.

(3) Working principle - close the switch in the low-voltage control circuit, and the current passes through the coil of the electromagnet to generate a magnetic field, thereby attracting the armature, making the moving and static contacts contact, the working circuit is closed, and the motor works; when the low-voltage switch is disconnected When the current in the coil disappears, under the action of the spring, the armature disconnects the moving and static contacts, the working circuit is disconnected, and the motor stops working.