摘要 |
<p>The system being used in connection with a telephone set and comprising means (9) for storing at least one preselected telephone number sequence and means for encoding (3) a telephone dialling audio signal into a multiple-bit sequence, is characterized by initializing means (2, 5) activated by a voltage drop occuring upon lifting a receiver of said telephone set or the like, means for comparing (4) each of said multiple-bit sequences corresponding to one digit of a telephone number sequence with said preselected telephone number sequences and means for providing an output signal (6) upon positive match of the dialled telephone number sequence with one of said preselected telephone number sequences, said output signal being used as an activating signal for a device (7) capable of decoding said output signal . <IMAGE></p> |