| 摘要 |
PURPOSE:To realize a detection for the incoming signal even with a key telephone set, by connecting a call signal closing/connecting circuit in parallel to a telephone circuit in an AC way in a queuing mode for reoutging. CONSTITUTION:In case the called subscriber is busy or has no answer after a transmission of the dial number through an automatic outoging operation, a circuit switching circuit 5 is controlled. Then a terminal 2 is connected to a terminal 3, and a telephone circuit is opened to secure a reoutgoing queuing mode. In this case, a control circuit 12 gives a control to close a switching circuit 10 and connect a call signal closing/connecting circuit 9 to the terminal 3. In other words, the circuit 9 is connected to the telephone circuit in parallel in an AC way. Thus the call signal current flows to a call signal detecting circuit 6 via the circuits 9 and 10 when the call signal arrives. The circuit 12 detects the currents to discontinue a repetitive outgoing. |
