Relay and its main function

Relay is an automatic switch element with isolation function, which is widely used in remote control, telemetry, communication, automatic control, electromechanical integration and power electronic equipment, and is one of the important control elements.

 

... generally, the relay has an induction mechanism (input part) that can reflect certain input variables (such as current, voltage, power, impedance, frequency, temperature, pressure, speed, light, etc.); an actuator (output part) that can realize "on" and "off" control of the controlled circuit; Between the input part and the output part of the relay, there is also an intermediate mechanism (driving part) for coupling isolation of the input quantity, functional processing and driving the output part.

 

.... As a control element, in summary, the relay has the following functions:

 

.... 1) expand the scope of control. For example, when the control signal of the multi-contact relay reaches a certain value, the multi-channel circuit can be switched on, disconnected and connected at the same time according to different forms of the contact group.

 

.... 2) zoom in. For example, sensitive relay, intermediate relay, etc., with a very small amount of control, can control a large power circuit.

 

.... 3) integrated signal. For example, when a plurality of control signals are input into a multi winding relay in a prescribed form, a predetermined control effect is achieved through comparative synthesis.

 

.... 4) automatic, remote control and monitoring. For example, the relay on the automatic device, together with other electrical appliances, can form a program control circuit to realize automatic operation.