| 摘要 |
PURPOSE:To obtain a folding circuit which is small in size and high in performance and reliability by constituting the function for regenerating and repeating a pulse code modulating PCM signal, and the function for turning back a specified bipolar PCM signal for indexing a faulty position of a transmission line, of a logical circuit. CONSTITUTION:In case of executing a usual regenerative repeating by a bipolar turning-back circuit 7, a control signal 5 goee to in advance an H level, and a PCM transmitting signal inputted from SIN is decomposed to RZPCM signals 1, 2 of the positive side and the negative side, turns on transistors TRQ1, Q2, respectively, by switching circuits 9, 10, and outputted to SOUT through a coil L1. A PCM receiving signal from RIN is decomposed to RZPCM signals 3, 4 of positive and ngative, and outputted to ROUT through switching circuits 11, 12 TRs Q3, Q4, and a coil L2. At the time of a folding operation for locating a faulty position, the signal 5 goes to an L level, the circuits 9-12 are controlled by a signal from an NOT circuit 8, the signal from SIN is outputted to ROUT through the TRs Q3, Q4, and the signal from RIN is outputted to SOUT through the TRs Q1, Q2, and the coil L1. |
