What are the main functions of relays
Relay is a kind of "automatic switch" used in automatic control circuit, which uses small current to control large current operation. Relay is an electrical control device, which has the interaction between the input circuit and the output circuit. It plays the role of automatic adjustment, safety protection and conversion circuit in the circuit.
Generally, relays have induction mechanism (input part) which can reflect certain input variables (such as current, voltage, power, impedance, frequency, temperature, pressure, speed, light, etc.); There is an actuator (output part) which can realize "on" and "off" control of the controlled circuit; Between the input part and the output part of the relay, there is an intermediate mechanism (driving part) which can couple and isolate the input, process the function and drive the output part.
As a control element, relay has the following functions
1) Expand the control range: for example, when the control signal of the multi-contact relay reaches a certain value, the multi-channel circuit can be changed, disconnected and connected at the same time according to different forms of the contact group.
2) Amplification: for example, sensitive relay, intermediate relay, with a very small amount of control, can control a large power circuit.
3) Integrated signal: for example, when multiple control signals are input into the multi winding relay in the specified form, the predetermined control effect can be achieved through comparison and integration.
4) Automatic, remote control, monitoring: for example, the relay on the automatic device, together with other electrical appliances, can form a program control circuit to realize automatic operation.
Relay is an automatic switch element with isolation function, which is widely used in remote control, telemetry, communication, automatic control, mechatronics and power electronic equipment.