| 摘要 |
<p>PURPOSE:To discriminate a faulty section momently and easily by detecting a difference of arrival time between feeding currents, which are propagated from a faulty point in both directions, in a loop-shaped feeding circuit to detect the faulty point. CONSTITUTION:When taking notice of currents I1 and I2 flowed to feeding device output terminals L1 and L2 of the loop-shaped feeding circuit, I1=I2 is true as long as the loop is closed. If a trouble such as a cable disconnection or the like occurs at a certain point of the loop and feeding is broken, step currents which have the same magnitude and have polarities opposite to each other are generated at the faulty point, and these step currents are propagated in both directions and reach feeding-side terminals L1 and L2 with a difference of arrival time corresponding to the difference between transmission lengths from the faulty point. Consequently, this difference of time is measured to discriminate the faulty section.</p> |
