Undervoltage circuit breaker with an electromagnet

摘要

An undervoltage circuit breaker has an electromagnet for triggering a switching device and a driver circuit that supplies power to the electromagnet. The driver circuit contains a pulse generator for generating a holding current for the electromagnet and a capacitance dimensioned so that delayed triggering of the electromagnet is possible. Due to the variable pulse duty factor of the pulse generator, the energy content of the capacitance is utilized favorably. An elevated operating voltage can also be selected and therefore a smaller capacitor may be selected to advantage.