| 摘要 |
PURPOSE:To realize the automatic sending for the dial of the trasfer destination by detecting the dial tone sent out from the call-back trunk after sending automatically the hooking pulse or the special number. CONSTITUTION:When subscriber selection button 11b is pushed for the transfer operation, output 50 is delivered from control circuit 9 to actuate main wire switching relay 2. Thus the loop of telephone 1 is switched toward the main device. After this, the transfer pulse is sent out by driving relay 3 with output 51 of circuit 9. Then the dial tone sent from the station is detected by tone filter 7, and the output starts circuit 9 to read out the subscriber telephone number memorized in memory circuit 10. The signal is then exchanged to the aural frequency signal by multi- frequency signal generation circuit 5 via circuit 9 to be sent out to main wire L through matching transformer 4. When this sending is over, circuit 9 detects the end code read out from memory 10. As a result, relay 2 is released to thus release the talking loop. |
