| 摘要 |
PURPOSE:To dial even if an additional telephone is hooked off, by short-circuiting an additional telephone and a monitor circuit at a pulse dialing time and disconnecting the additional telephone at a tone dialing time. CONSTITUTION:A telephone line is connected to terminal 25 and 26, and the additional telephone is connected to terminal 27 and 28. When pulse dialing is performed, a switch 33 is turned on to short-circuit both ends of the additional telephone, and both ends of a monitor and tone signal circuit 34 are short- circuited by switches 32 and 33. When tone dialing input is performed, the switch 33 is turned on, and the switch 32 is turned off, and the additional telephone is disconnected from the telephone line, and thus, tone dialing is possible without hindrance of the transmitter of the additional telephone even if the additional telephone is hooked off. |
