| 摘要 |
<p>PURPOSE:To prevent the influence of an external noise and to determine the absolute amount of an inner corona by outputting the difference of the outputs of a pair of sensors as a signal, and inhibiting an output when the polarities of the outputs of current sensors are the same. CONSTITUTION:A pair of sensors 2a, 2b and 2c, 2d grounded at a position not disconnected in a circuit manner by a circuit breaker 22 are provided, and subtracting means 4 for outputting the difference of the pair, and polarity identifying means 5 for producing an output when the polarities of the outputs of the pair are the same are provided in a trouble diagnosing device body 3. When the means 5 produces the output, the output of the means 4 is blocked by gate means 6. Except it, this output is input to discriminating means 7 through a multiplexer 15 and A/D converter 16 to measure the absolute amount of an inner corona.</p> |
