Call distributor unit for telecommunication exchange - utilises matrix of nodal points to connect calling and subscriber lines and has auxiliary loop circuits

摘要

The major components of the telephone exchange are a matrix of nodal points (1) for the junctions between the calling lines (2) and the subscriber lines (3). Each subscriber line is connected with an operator call point (4) and supervisor unit (5). In parallel with the matrix are control circuit (6) auxiliary circuit (7) and, for the latter, an optical survey unit (8). Each calling line and subscriber line is connected to logic circuits which include mainly flip-flops, AND gates and NOR gates, so that each end of the circuit may receive a reply signal and search for an alternative line in case the first route selected is engaged. The matrix nodes include an AND gate, transistor, relay and diodes.