| 摘要 |
<p>PURPOSE:To make detection of the monitor signal possible only at the fault occurrence time, by operating the monitor circuit of the repeating installation to transmit the natural freqency to the terminal station by increasing the steady state current value of power transmission when the fault of the transmission system is confirmed in the carrier-frequency terminal station. CONSTITUTION:When a fault occurs, the feed current is increased by the steady state current value. Zener diode 20 is so designed that V=V1 and V1<VZ (the breakdown voltage of Zener diode 20) are true when the current of the steady state current value is flowed. When the current is increased more than the steady state current value at the fault occurrence time, V=V2 and V2>VZ are true, and the current is flowed to resistance 22 to operate transistor 21. Oscillating circuits 11 and 12 for monitor are operated by voltage V2 between A and A' to transmit the monitor signal to carrier-frequency terminal station 1 or 2. As a result, the faulty repeating installation is confirmed.</p> |
