Telephone number identifier with cascade of gates - each assigned to one place in numbers with its own counter and coincidence gate

摘要

The telephone number identifier, for self-dialing systems, has an electronic counter for marking. Each place in the the telephone number has its own counter and coincidence gate. The gates only operate when a marker is also present. The gates form a pyramid-type circuit whose end or 'peak' gate operates a switch if all places in the number are marked. The coincidence circuit includes an electric comparator with a control criterion and a marking system associated with bistable switching circuit using AND gates.