| 摘要 |
The device includes a detector which determines unhooking of the telephone receiver and generates a first signal. A generator produces a second signal which controls line use. A processing circuit verifies access to the network on simultaneous reception of the first and second signals. The processing circuit is controlled by a time switch after a predetermined time and a relay connected in series with the telephone line is switched to connect or disconnect the receiver handset. When the handset is hung up, the line is returned to its initial state and is ready for a new call. |
