| 摘要 |
PROBLEM TO BE SOLVED: To provide a small-sized tanδmeasuring device superior in portability, capable of highly precisely measuring tanδwithout using any standard capacitor as the device remains grounded. SOLUTION: A voltage dividing circuit is connected between the secondary side terminals of an insulating transformer 1 for generating test voltage not exceeding 100V and 110Hz, and a voltage signal evs proportional to applied voltage is obtained by a voltage buffer amplifier 11 connected to the intermediate thereof. An output signal eio proportional to the leak current of a device to be measured is obtained by a current buffer amplifier 12 connected to one terminal of a power source and a 90 deg. phase shift circuit, and direct current proportional to tanδis obtained from first and second waveform shaping circuit 5, 6 for converting the output signals evs , eio into rectangular waves at the zero cross points of respective waveform and respective reverse coincident signal components of output.
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