Electronic padlock for a subscriber telephone line.

摘要

The description relates to an electronic padlock which provides the presence of a sensor (SS) adapted to render available a signal (S) whose level expresses the condition of the telephone line. When the subscriber engages the line the sensor (SS) determines the insertion, in parallel with the telephone terminal (TL), of an inhibiting electric branch (T1). This latter is adapted to prevent the switching exchange (CT) from detecting the digits dialled by the subscriber, thus causing the shifting of a predetermined current. Such digits are however detected, via the said sensor (SS), by a logic unit (UL) that compares the same with a combination stored therein and turns the inhibiting electric branch (T1) off in case of positive result.