LONG-DISTANCE CALLS, INTERNATIONAL AND VOICETEL RESTRICTION DEVICE

摘要

the invention relates to a device for restriction of long-distance, international, voicetel, which, in the case of a call certain numbers, interrupt the call for a telephone set (1),the device having the composition an interface (2) through which the selection from the telephone (1) is provided, on the one hand,a binary counter (4) which address a prom memory (6) and, on the other hand, a monostabil restriggerabil, (3)bound by a decimal counter (5) at the entrance of validation of the prom memory (6) which, in the case of a call to a restricted number, order, through a monostabil (9),the opening of a contact (k) of a relay (7), disrupting the conversation.