| 摘要 |
PURPOSE:To enhance the function of the key telephone system by securing the cordless part between the main device and the telephone of the key telephone system as well as to having multiplication of the signal. CONSTITUTION:The call signal which is transmitted from the main device to the telephone not shown in the diagram is transmitted via hybrid 5, interruption circuit 6, modulator 7 and antenna 11. And the call signal sent from the telephone is received via antenna 12 and demodulator 17. The information of the circuit display, the individual calling and the like given from telephone circuit control circuit 2 is encoded by circuit condition conversion circuit 3 and via clock 4 and then transmitted with interruption to the call signal through interruption circuit 6. On the other hand, the button information and the like given from the telephone side are also interrupted to the call signal and then isolated by isolation circuit 18 to be supplied to control circuit 2 via circuit condition demodulation circuit 20. |
