| 摘要 |
PURPOSE:To eliminate the B position relay to make it possible to simplify the constitution of the telephone exchange repeater by performing a connection to change the operation state of the C position relay. CONSTITUTION:Before an originating telephone set is driven, the C position relay is normally operated due to the path through the earth, contacts a, s and t, the C position relay, and a - battery. After the telephone set above is driven, the A position relay is operated to break the preceding circuit, and the C position relay id released solwly. Continuously, when a dial pulse has come, the A position relay repeats release and operation and the C position relay starts operation again at the first release. Then, when the A position relay is released due to on-hook, the C position relay is normally operated. Therefore, the B position relay can be eliminated to simplify the constitution of a telephone exchange repeater by changing the operation conditions of the C position relay. |
