Main role of relay
The relay (English name: relay) is an electric control device, which is an electric appliance that causes a predetermined step change in the controlled output amount in the electrical output circuit when the change in the input amount (excitation amount) reaches the prescribed requirement. It has an interaction between the control system (also known as the input loop) and the controlled system (also known as the output loop). Often used in automated control circuits, it is actually an "automatic switch" that uses small currents to control large current operation. Therefore, it plays the role of automatic adjustment, safety protection and conversion circuit in the circuit.
The relay is an automatic switching element with isolation function, which is widely used in remote control, telemetry,
Communication, automatic control, mechatronics and power electronics are among the most important control components.
Relays generally have an inductive mechanism (input section) that reflects certain input variables (such as current, voltage, power, impedance, frequency, temperature, pressure, speed, light, etc.); it has the ability to "pass" and "control" the controlled circuit. The actuator (output portion) of the control unit is disconnected; between the input portion and the output portion of the relay, there is also an intermediate mechanism (drive portion) that couples the input amount, functions, and drives the output portion.
Main role of relay
As a control element, in summary, the relay has the following effects:
1) Expanding the control range: For example, when the multi-contact relay control signal reaches a certain value, it can switch, disconnect, and turn on multiple circuits at the same time according to different forms of the contact group.
2) Amplification: For example, sensitive relays, intermediate relays, etc., with a very small amount of control, can control a very high power circuit.
3) Integrated signal: For example, when a plurality of control signals are input to a multi-winding relay in a prescribed form, the comparison is integrated to achieve a predetermined control effect.
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 achieve automatic operation.