| 摘要 |
PURPOSE:To report the length of a call time by starting time counting in response to the detection signal which is obtained when a telephone set is connected to a central office and issuing a recognizable signal, which indicates that the counted time exceeds a preliminarily determined time, to both of an originating subscriber and a terminating subscriber when the counted time exceeds the preliminarily determined time. CONSTITUTION:A switch 5 is connected to a central office 6. A connection detecting circuit (DET)7 is connected to the output of a dial mechanism 4 of this telephone set, and a time counting circuit (TIM)8 is connected to the output of this circuit 7, and a sound synthesizing circuit (SYN)9 is connected to the output of the time counting circuit 8. When a speaker hooks off the receiver, the switch 5 is turned on; and when the connection is detected by the detecting circuit 7, the time counting circuit 8 starts time counting, and the speaker dials. When the counted time of the time counting circuit 8 reaches a prescribed value, the sound synthesizing circuit 9 is started to synthesize and transmit a prescribed message signal. This message signal passes a mixing circuit 10 and reaches the dial mechanism 4 and a hybrid circuit 1 of the originating telephone set and is outputted from the receiver of the originating subscriber. The message signal is outputted from the telephone set of the terminating subscriber through the mixing circuit 10, the switch 5, and the central office 6. |
