A contactor is an automatic switcher that is used to connect or disconnect the AC and DC main circuits or large-capacity control circuits with loads. The contactor is to control the motor and it is also used for other electrical loads, such as electric heaters, electric welding machines, lighting equipment. Contactors are very important device in industrial field, especially the high voltage DC contactors . They can not only connect and cut off the circuit, but also have a low voltage release protection. The contactor has a large control capacity, is well suitable for frequent operation and long-distance control and is one of the important components in the automatic control system. The DC contactor relay is generally used to control the DC electrical equipment. The coil is supplied with DC current. The working principle and structure of the DC contactor are basically the same as that of the AC contactor. What is the working principle of a DC contactor? When the contactor coil is ener