Patent GB-753357-A (GB)
Title: Improvements in or relating to electric code translators
Inventor: HARTLEY GEORGE CLIFFORD
IPC: H04Q3/42
Filed: 1954-01-13
Abstract: 753,357. Automatic exchange systems. STANDARD TELEPHONES & CABLES, Ltd. Jan. 7, 1955 [Jan. 13, 1954], No. 1005/54. Class 40(4). In a translator of the type in which a jumper designating an exchange code is threaded through a number of magnetic toroids in accordance with the translation to be effected, the jumper being pulsed to produce outputs from windings on the toroids, at least one end of the jumper is connected to one of a plurality of static electric switches located at the cross points of a plurality of groups of wires, one wire from each group being energized in accordance with part of the code to be translated. Arrangements may be provided in the outputs of the toroids either to take account of the polarity of their outputs, or not. In one embodiment, Figs. 2, 3 and 4, one of ten tubes A(1) . . . A(0) and one of ten tubes B(1) ... B(0) are fired in accordance with the A and B digits respectively when a start potential to the tubes is applied by relay KS. The outputs from the cathodes of these tubes operate a resistance-rectifier gate to fire one of 100 tubes T(11) ... T(00) in accordance with the first two code digits. One of ten tubes TO(1) . . . TO(0) is fired in accordance with the C digits. The anodes of the tubes T and the cathodes of the tubes TO are connected by jumpers such as 220 over rectifiers which are normally back-biased. When the two tubes are fired, however, the rectifiers conduct and the change in current in the jumper 220 causes pulses to be produced in the output windings of such toroids CA ... FE as the jumper is threaded through. As shown, the translator may consist of four digits each of which is represented by a two-out-of-five code on a row of toroids. In a modification, Fig. 9, suitable for 900 codes (the value 1 for the A-digit not being used), coordinate arrays are provided at both ends of the jumper. Thus 30 points TSA are provided corresponding with 10 horizontal co-ordinates for the B-digits and 3 vertical co-ordinates indicating a group of three digits containing the A digit. Likewise 30 points TSB are provided corresponding to ten horizontal coordinates for the C-digits and three vertical coordinates corresponding to the position of the A digit in its group of three. In another modification, Fig. 8 (not shown), a 20 X 50 arrangement is shown. In an output circuit for the toroids of Figs. 2, 3, 4 a full-wave rectifier may be interposed between the output winding and the firing electrode of a gas tube feeding a translator utilization circuit, Fig. 10 (not shown). This enables the jumper to be threaded upwards or downwards indiscriminately through the toroids. Alternatively account may be taken of the direction of threading of the jumper in which case four toroids per digit may be used to provide eighteen combinations in a two-out-of-eight code. This may be restricted by threading the jumper once upwards and once downwards still giving twelve combinations. A circuit, Fig. 11, is given in which one or other of the tubes TT1 or TT2 is fired depending on the polarity induced in the output coil of the toroid CA.