Facing the complex modern small general relay products, how to choose and use them reasonably and correctly is the key problem that directly affects the performance and practical reliability of the whole machine. Of course, this is also a practical problem that the whole mechanical design and development personnel pay attention to and must give priority to.

1. Control relays are widely used in power transmission, program control, automatic regulation and detection, household appliance systems, general relays, etc.

2. Composition of control small general relay

The control relay is mainly composed of two parts, one is the control system, the other is the control system. The reason why the control relay plays a control role is that when the input signal of the control system, such as electrical, magnetic, thermal, optical and other physical quantities, reaches a certain value, it can change the control quantity of the controlled system (also known as the output circuit) from zero to a certain value or from a certain value to zero, so as to realize the functions of control, protection, transmission and conversion of information. Using small current to control large current is the characteristic of control relay.

3. Use and classification of control relays

The control relay is an automatic device, which is suitable for the remote switching of switch AC /dc small capacity control circuit, as well as the control, protection and signal conversion in the power transmission system. The input of relay is usually electric quantity such as current and voltage, as well as non electric quantity such as temperature, pressure and speed. The output is the change of electrical signal or parameter of output circuit when the contact moves. The characteristic of relay is that when its input changes to a certain program, the output will gradually change.