In the use of electrical equipment, there is a commonly used electrical equipment made of silver contacts: contactors. The function of a contactor is to connect a high current circuit device, which usually operates next to the motor. The contactor mainly has the function of connecting and disconnecting the circuit, and has a low voltage release protection function. When the motor is in use, due to the effect of AC power, the current is not as stable as DC, and the negative electricity transmitted in the circuit can easily destroy the entire circuit, which is not conducive to production. Therefore, a wire and switch are needed, The protection of the trinity device comes from the contactor, which has a silver contact switch. The silver contact switch includes a normally closed switch and a normally open switch. The meaning of this name is like that normally closed is A, normally closed is B. In normal use, the silver contact switch A is equal to a wire, playing the role of conventional circuit connection; When a circuit needs protection, the silver contact switch A will open, the conventional circuit will close, and the switch B will be connected, and the load device will start to protect the main electrical device from damage. It can be said that contactors are a major security factor in circuits and are often used in high current circuits. The key to the quality of a contactor lies in its load capacity and the sensitivity of silver contact switches. Currently, domestic production technology can meet most of the electricity consumption needs.

Another function of a contactor is segmented connection, which can be understood as a switch with many lines. When line A needs to be operated, the A contact switch is connected, and the rest are disconnected; When B needs to be operated, the B contact switch is opened and the rest are disconnected; And so on. This setting is to meet different production effects. For example, when operating item A, if the motor power is A and the running time is A, line A can meet the requirements, while line B cannot; When it comes to item B, only line B can meet the requirements, while other lines cannot. The multiple connection methods of contactors also enable the use of motors to achieve multiple goals, greatly improving flexibility and reducing costs.