| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the manufacturing cost of a ground fault detection apparatus by eliminating a unit and a part of the ground fault detection apparatus, and to improve the reliability of the ground fault detection apparatus by providing a function for monitoring the soundness of a principal circuit in a transmitter at all times. <P>SOLUTION: The ground fault detection apparatus includes both the transmitter connected to a transmission line and a detector connected to the transmitter to receive and analyze a detection signal from the transmitter. The transmitter includes an input part for inputting a fault current of the transmission line as a detection signal, a DC superposition part for superposing a prescribed DC voltage on the detection signal, a voltage/frequency conversion part for converting a DC superposition signal into a pulse signal, an electricity/light conversion part for converting the pulse signal into a light signal, and a stabilized power source for stabilizing the power source of the transmitter. The detector includes a light/electricity conversion part, a frequency/voltage conversion part, and an arithmetic processing part for analyzing the detection signal to specify a section in which a ground fault has occurred. In the transmitter, the DC superposition part superposes a DC voltage in such a way as to output all waves of input waveforms of the detection signal. <P>COPYRIGHT: (C)2011,JPO&INPIT |
