Abstract:

In order to improve the breaking current capacity of the traditional electromagnetic contactor and solve the disadvantages of high closing power consumption, large impact force of the moving iron core and serious wear of the iron core under large contact gap, a contactor with controllable contact gap is designed. Through structural improvement, the gap of the contact that can be opened at the structural level of the traditional AC contactor is increased. The control circuit based on the single-chip microcomputer is used to identify the breaking current, and the pulse current with different width is applied to the excitation coil during the breaking process, so that the contactor has different gap under different breaking current. After the breaking, the contact returns to the balance position of small gap. Through experiments, it is verified that the designed contactor has the function of controllable contact gap.

Key words: electromagnetic contactor, control circuit, controllable contact gap, breaking current