The invention discloses a double-coil undervoltage tripper. The double-coil undervoltage tripper comprises an EMC filter circuit, a rectifying circuit, a sampling circuit, a PWM circuit, a first switch circuit, a power supply circuit, a comparing circuit, a bolt circuit, a differentiating circuit, a second switch circuit and a double-coil undervoltage
electromagnet, wherein the EMC filter circuit is used for bidirectionally inhibiting interference signals generated by a
power grid and an internal circuit; the double-coil undervoltage
electromagnet comprises a stabilizing winding, a strong starting winding and a movable iron core. According to the double-coil undervoltage tripper, the reliable pull-in when the
voltage of the
power grid is higher than 85% of rated
voltage is guaranteed, and the reliable
tripping when the
voltage of the
power grid is lower than 50% of the rated voltage is guaranteed; by virtue of relatively high power of the strong starting winding and relatively low power of the stabilizing winding, the high-reliability pull-in can be achieved, and the low-power operation is simultaneously considered, so that the heating of the
electromagnet is avoided. Besides, after a power supply circuit of the double-coil undervoltage tripper is connected to the second switch circuit in series, the energy efficiency of the circuit is effectively improved when the integral circuit is adequately simplified.