EARTH-LEAKAGE CIRCUIT BREAKER

摘要

[Subject] The present invention provides an earth leakage circuit breaker which can prevent the failure of an embedded power supply circuit by blocking the earth leakage circuit breaker even when an overvoltage is consecutively applied to an AC circuit at a withstand voltage test, etc. [Solution] The earth leakage circuit breaker comprises: a rectifier circuit which converts an AC voltage supplied from the AC circuit (1) into a DC voltage; a second constant voltage circuit (53) which drops an output voltage of the rectifier circuit; a second Zener diode (54) which detects an overvoltage from the output voltage of the rectifier circuit; a second resistor (55) which boosts the output voltage of the second constant voltage circuit (53) when the second Zener diode (54) detects the overvoltage; a third Zener diode (56) which absorbs a surge current when the output voltage of the second constant voltage circuit (53) reaches a first certain value; and an overvoltage detecting circuit (9) which operates a trip device by detecting the arrival of the output voltage of the second constant voltage circuit (53) at a certain value.