| 摘要 |
PURPOSE:To miniaturize of a simultaneous transmitter of voice data, by forming a device circuit to a band stop filter in an on-hook state and therefore miniaturizing the band stop filter. CONSTITUTION:When the call of a telephone 6 is over, the output of an on-hook detecting circuit 14 is applied to a control part 15. Thus each contact between changeover switches SW1 and SW2 is connected to the side (b) by the control of the part 15. For a band stop filter 11, the connection is turned off to a private exchange 5, and the telephone 6 is connected to the exchange 5 via by-pass lines l1 and l2. Then a manual switch SW3 is pushed when a call is established between the telephone 6 and a telephone of the remote side. Thus each contact between the SW1 and SW2 is connected to the side of (a), and the filter 11 and a BPF12 are connected to the telephone of the remote side. Then the transmission of data is possible simultaneously with a call. |
