| 摘要 |
PURPOSE:To enable to discriminate the disconnection and wear state of a current collector in the state that a load is operated by superposing a high frequency wave oscillation output through the collector on a supply wire, and discriminating the disconnection and wear state of the collector by the output of a demodulator connected to the supply wire. CONSTITUTION:A load 4 is energized through a current collector 3 by a supply wre 1. At this time, a high frequency wave signal from an oscillator 6 is superposed through a modulator 7 and the collector 3 on the wire 1. A demodulator 8 demodulates the high frequency signal of the wire 1 and inputs it to an integrator 10. When the collector 3 is disconnected, the output level of the integrator 10 decreases, and a signal is outputted from a level comparator 11. A display circuit 13 counts the output of the comparator 11, and displays the wear state of the collector 3. |
