| 摘要 |
PURPOSE:To secure a connection among systems via an exclusive line, by using the specified AC signal for the control signal and at the same time using the holding/ transfer means incorporated into the key telephone system. CONSTITUTION:With push down of the key of the key telephone 17 in the system A, the signal is supplied to the main control circuit 3. Thus the telephone 17 is connected to the talking link 32. After this, with a dial operation of the telephone 17, the dial signal drives the oscillating circuit 4. And the output signal is sent to the reception circuit 8 of the system B via the exclusive cable 34. The control circuit 15 processes the signal, and the talking becomes possible between the telephones 17 and 18 via the talking links 32 and 33 plus the cable 34 each. Then with push of the holding key of the telephone 18, the circuit 15 and the holding circuit of the main unit 2 work to make a talking possible between the telephones 18 and 19. Thus the telephone 19 knows the incoming call. And the relevant key is pushed to open the circuit 16 to make a talking possible between the telephones 17 and 19. |
