| 摘要 |
PURPOSE: An apparatus for monitoring insulation of a non-grounded power line is provided to prevent the dangerous condition due to a poor insulation of the non-grounded power line by measuring continuously an insulation thereof. CONSTITUTION: A relay(RY1) is connected to a rectifying section and operates a leakage current detecting unit(15) by connecting a relay contact point as the power is supplied. A constant-voltage device(ZCV) is comprised of Zener diodes(Z1,Z4), a diode(D1), and a plurality of distribution resistors(R2-R7) and receives the power from the rectifying section to supply a DC(Direct Current) power. A differential amplifying unit(11) amplifies output voltage of the constant voltage device(ZCV) and the leakage current detecting unit(15) to compare the amplified output voltage with a reference voltage. An alarm detecting IC(Integrated Circuit)(U102) delays the output of the differential amplifying unit(11) during a predetermined time to output the delayed output to a speaker. A meter driving unit(14) receives the output of the leakage current detecting unit(15) to supply the received output to a meter and is comprised of resistors(R11,R12) and a capacitor(C10).
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