GB819454A - Improvements in or relating to circuit arrangements for marking selector contacts intele-communications installations - Google Patents

Abstract

819,454. Electric selective signalling systems. SIEMENS & HALSKE A.G. March 6, 1957 [March 6, 1956], No. 7515/57. Class 40 (1). [Also in Group XXXIX] A selector is controlled by a circuit in which code signals are stored, a first group of leads in a cross-connection panel corresponding to storage elements while a second group of leads is allocated to the selector contacts, the two groups of leads being connected together by rectifiers so that a potential applied to a number of leads in the first group by the storage elements is cancelled out by application of a counter potential through a wiper of the selector when the selector is set to the appropriate lead of the second group. Operation of one of keys Tl-TO, Fig. 5, sets up a digit in code form by energizing one or two of four storage relays A-D, Fig. 6. The operated storage relays close the related contacts 1a-7d, Fig. 1, to apply resistance battery to one or two of four leads 11-14 and also to the related rectifiers GI1-GI4. As the selector brush d steps round battery remains on one of these rectifiers until the selected terminal is reached when earth from brush d cancels out battery on the marked rectifiers and tube R fires. Relay P then energizes to stop the selector. Second embodiment. Operation of one of the keys of Fig. 5 passes current through one or two of the transformer primaries shown in Fig. 7 to induce current in the corresponding secondaries, Fig. 2, so firing the related one or two of tubes RA-RD. As in Fig. 1 the rectifier network GI1-GI4 is backed off until the selector brush reaches the selected lead when tube R fires. Third embodiment. Each storage relay A-D, Fig. 6, controls through its contacts, such as 1a, 2a, a pair of leads, such as I1, I2. Otherwise the operation is as in Fig. 1. Fourth embodiment. Leads 15-18 are permanently connected to resistance battery which is shunted out on one or two leads at operation of the related storage relays A-D, which connect resistance battery to the associated lead or leads 11-14 at the same time. At the appropriate position of the selector brush earth is applied to four of the rectifiers GI1- GI8 simultaneously and R fires. Modifications. Tube R may be replaced by a relay in series with resistor W5. Rectifiers GI1-GI4, Figs. 1-3, or GI1-GI8, Fig. 4, would then be replaced by low resistors. Relays RA-RD may form part of a register set up in any manner.