A relay is a component that produces a predetermined jump in one or more of its output when the input reaches the specified conditions. The electromagnetic relay can be simply understood as a switch that applies a specified electrical signal at the input end and turns on and off the controlled circuit at its output end. Relays generally have a sensing mechanism (input part) that reflects a certain input variable (such as current, voltage, power, impedance, temperature, pressure, speed, light, etc.); it can realize "on" and "off" for the controlled circuit Controlled actuator (output part); in the input part and output part of the80a latching relay, there are also intermediate mechanisms (drive part) for coupling and isolating the input, functional processing and driving the output part. As a control element, in summary, the relay has the following functions:

A) Expand the control range. When the control signal of the multi-contact relay reaches a certain value, it can switch, break and connect multiple circuits at the same time according to different forms of contact groups;

B) Amplification, such as sensitive relays, intermediate relays, etc., with a very small control quantity, which can control a large power circuit;

C) Integrated signal, for example, when multiple control signals are input to a multi-winding relay in a prescribed form, they are relatively integrated to achieve a predetermined control effect;

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