| 摘要 |
<p>PURPOSE:To detect a fault by detecting a duty difference signal when at least one line of balanced double current interchange lines connected to a balanced double current interchange circuit is faulty. CONSTITUTION:A reception signal (a) from the balanced double current interchange circuit 1 is a signal having a period T and retarded by a time (t) by a delay circuit section 2. Then a fault detection pulse (c) obtained from a gate 3 ANDing the reception signal (a) and a delay signal (b) retarded by the delay circuit section 2 is given to a signal fault detection circuit section 4, which detects whether or not the reception signal (a) is in error and gives an output a fault information signal (d). If either one of the balanced double current interchange lines 5a, 5b is opened, the received signal a' is retarded by a time (t) by the delay circuit section 2, outputted as a delay signal b', but a fault detection pulse c' ANDed by the reception signal a' and the delay signal b' is not outputted as a pulse, and the signal fault detection circuit 4 outputs the fault information signal (d) as a fault.</p> |
