ELECTRIC LEAKAGE DETECTOR

摘要

PROBLEM TO BE SOLVED: To provide an electric leakage detector capable of correctly determining an electric leakage even when increasing an applied voltage of a coupling capacitor to improve detection accuracy.

SOLUTION: An electric leakage detector 100 has a booster circuit 3 for applying a pulse voltage boosted to a coupling capacitor C. A reference voltage is generated by a reference voltage generation circuit 4 on the basis of an output voltage of the booster circuit 3, and converted into a pulse voltage by switching the reference voltage by a switching element Q. A pulse output from the switching element Q charges the coupling capacitor C. An off-set voltage generation circuit 7 generates an off-set voltage which is lower than the pulse voltage on the basis of the output voltage of the booster circuit 3. An arithmetic circuit 8 outputs a voltage obtained by subtracting the off-set voltage from the voltage of the coupling capacitor C. A CPU 5 determines whether there is an electric leakage in a load power source 10 on the basis of a result of comparison between the output voltage of the arithmetic circuit 8 and a threshold.

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