| 摘要 |
PURPOSE:To enable to obtain active component and reactive component of leakage current simply and at high accuracy by using a general-purpose clamp type leak meter and adding a simple additional circuit. CONSTITUTION:The body of a leak meter LM amplifies and rectifies secondary side current of a current transformer CT and an indicating ammeter is also unified. Tertiary winding and a bias coil La to let flow bias current is wound on a transformer CT. An adapter AD adjusts bias current to a coil La to a specified value. A neutral point (t) is provided in a descending transformer Tr and secondary low voltage side. Secondary side of the transformer Tr is connected to a bridge by a three-terminal variable resistor VR, and a resistor R and coil La are connected in series between the neutral point t and the sliding terminal of the resistor VR. As secondary side of the transformer Tr is loaded by resistance of a high value, bias current becomes the same or reverse phase to the phase of power source voltage. The phase can be reversed and the value of bias current can be changed by changing the resistance VR.
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