| 摘要 |
<p>PURPOSE:To enhance measuring accuracy, in an electroscope apparatus for detecting the zero phase voltage and current of a three-phase line, by always taking in power supply from the line to make said apparatus operable and digitally converting a signal to a digital signal and further converting the digital signal to a light signal to transmit the same. CONSTITUTION:Electroscopic means 14, 19 are respectively provided to three- phase lines 1A-1C and the outputs thereof are respectively connected to light emitting diodes through A/D converters 16, 20 and E/O signal converting circuits 17, 21 to be transmitted to light receiving parts 29A-29C, 28A-28C through optical fiber cables 4A-4C. The signal received by the light receiving parts 28A-28C is connected to a current synthesizing circuit 30 and the signal received by the light receiving parts 29A-29C is connected to a voltage synthesizing circuit 31 to respectively detect a zero phase current and zero phase voltage. These circuits are constituted so as to be always operated by a current transformer 22 and a DC power source circuit 23. By this method, this apparatus is made always operable and the effect of the variation in the intensity level of a light signal can be prevented.</p> |
