| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an accident detecting device, which can detect a short- circuit accident with higher sensitivity and keeps constant the detecting sensitivity regardless of the rated gas pressure. SOLUTION: An accident detecting device 2 of a gas insulating electric apparatus is provided with an input means 3 for inputting a signal of a pressure sensor 1, a delay circuit 10 for outputting a delayed signal, an amplifier 7 for amplifying the difference between the gas pressure signal and an output signal of a delay circuit, an A/D converter 6 for inputting the output of the amplifier and a determining means 8 for determining the occurrence of an accident based on an output of such an A/D converter. A change between the current value of gas pressure voltage and a value before the predetermined period becomes almost zero in the normal condition priorto the occurrence of an accident. Immediately after the occurrence of an accident, change becomes almost identical to the rise of the gas pressure. Consequently, since the amplifier amplifies only a voltage signal, which is identical to rise of gas pressure immediately after occurrence of an accident, the large gain of the amplifier can be set.</p> |
