1. What is a general purpose relay
General-purpose relays refer to relays that can be used in a certain field or in many fields. A relay is an electrical appliance that makes a predetermined step change in the controlled quantity in the electrical output circuit when the change of the input quantity (excitation quantity) reaches the specified requirements.

2. Working principle of general relay

Relay (English name: relay) is a kind of electrical control device. The main working principle is: when the change of the input quantity (excitation quantity) reaches the specified requirements, the controlled quantity will undergo a predetermined step change in the electrical output circuit. - an electrical appliance. It has an interactive relationship between the control system (also known as the input loop) and the controlled system (also known as the output loop).

Usually used in automated control circuits, it is actually an "automatic switch" that uses a small current to control the operation of a large current. Therefore, it plays the role of automatic adjustment, safety protection, and conversion circuit in the circuit.

Relay is an automatic switching element with isolation function. It is widely used in remote control, telemetry, communication, automatic control, electromechanical-integration and electrical and electronic equipment. It is one of the most important control elements.

The relay generally has an induction mechanism (input part) that can reflect a certain input quantity (such as current, voltage, power, impedance, frequency, temperature, excitation, speed, light, etc.); between the input part and the output part of the relay, there are also There is an intermediate mechanism (drive part) that couples and isolates the input, processes the function and drives the output part.
 
Relay is an automatic switching element with isolation function. It is widely used in remote control, telemetry, communication, automatic control, mechatronics and power electronic equipment. It is one of the most important control elements.

Relays generally have induction mechanisms (input parts) that can reflect certain input variables (such as current, voltage, power, impedance, frequency, temperature, pressure, speed, light, etc.); Between the input part and the output part of the relay, there is an intermediate mechanism (drive part) that couples and isolates the input quantity, processes the function and drives the output part.