Influence of electromagnetic pulse on electromagnetic relay by using equivalent circuit model

Research on anti-interference capability of electromagnetic relay under electromagnetic pulse (EMP) is very important for assuring its reliable operation. In this paper, equivalent circuit of the relay was obtained, considering parasitic capacitance, inductance and resistance of electromagnetic system and contact system. The equivalent circuit is applied in a certain relay to analyze how the EMP interferes with inner structures, including coil, movable reeds and static reeds. The conclusion is valuable for improving the anti-interference capability of relay under EMP.