What role does the relay play?

What role does the relay play?

A relay is a device in a circuit that is often used as a switch.According to the type of control voltage required by the coil, it can be divided into ac relay and dc relay.The specification of the relay is expressed in terms of coil control voltage and contact current. Normally, when the load current is less than 10A, the contact of the relay can be directly used to connect or disconnect the circuit.If the load current is too large, it can be used as an indirect control device.

In the central air conditioning control system, the relay is often used as the switch of the power circuit such as compressor, fan motor, water pump and four-way valve.When in use, connect one end of the control coil of the relay with the power supply and the other end with the output end of the control part. Through the output control signal of the control part, the potential difference between the two ends of the control coil of the relay will be generated and the current circuit will be formed to generate electromagnetic force.Under the action of the electromagnetic force and the inherent elastic force of the relay reed, the relay contact is attracted or released to connect or disconnect the circuit of the electrical load power supply, so as to control the operation or shutdown of the relevant equipment.