| 摘要 |
PURPOSE:To shorten the time of response for detection of a defective insulation of the electric wire to be tested, by comparing the change component of the charging current with the reference voltage which is set according to the test voltage. CONSTITUTION:A detecting means including the reference circuit 11, detecting circuit 12 and comparator 14 is important. The circuit 11 produces an output of I=KE+C (K>=0, C>=0) to the test voltage E. The circuit 12 consists of a charging current DC converting circuit 18, charging current storage circuit 20 which performs a sampling storage and substractor circuit 22 which calculates the difference of outputs between the circuits 18 and 20. Thus the change component of the charging current is delivered from these circuits and then compared with the reference value through the circuit 14. And in case the output of detection is larger than the reference value, the control output circuit 24 is actuated. In such way, a malfunction can be eliminated for the detecting action. Then the time of response is reduced to increase the sensitivity greatly. |
