Patent GB-718155-A (GB)
Title: Improvements in or relating to arrangements for the generation of voltage impulses succeeding one another in time and for testing such voltage impulse generators
IPC: G11C8/02
Filed: 1952-08-13
Abstract: 718,155. Automatic exchange equipment. SIEMENS & HALSKE AKT.-GES. Aug. 13, 1952, [Aug. 13, 1951; Aug. 18, 1951], No. 20361/52. Class 40 (4). [Also in Group XL (c)] An arrangement for producing a large number of interleaved spaced trains of pulses, for use in automatic exchange systems, comprises a coordinate array of leads, each set of co-ordinates being supplied with pulses, and gating circuits at the intersection of the co-ordinate leads, each arranged to emit a pulse when coincident pulses are applied to the co-ordinate leads defining the intersection. As shown, Fig. 3, cam contacts NPz1 ... 13 are cyclically closed and during the closure of each of these contacts a complete cycle of operation of contacts NP1 ...23 occurs. The potential at an output point, e.g. PI1, remains at -60 V unless both the associated contacts NP1, NPzl are operated when it rises to -50 V. Pulses are thus emitted in succession over terminals P(i) ...P(xiii)23. Arrangements are provided for testing the operation of the various components as follows:-The cam shaft operating the contacts NP, NPz is provided with a contact NPf operated at the beginning of each cycle and contacts NPs operated every time an NP contact is operated. Operation of the test start button T1 brings up B and HI, the latter applying firing potentials to all of the tubes Rol ... 3 which if in order operate relays P1 ... 3. If any of these fail, AL operates and lights a corresponding lamp LRol ... 3. Otherwise E operates when cam contact NPf makes and W follows momentarily to step switches DW and DW2 each to position 1. In this position Ro3 is not struck by voltage received over wiper adwl from cam contact NP1. Tube Rol however strikes to voltage from NPz1 if the latter operates' correctly. Moreover, if rectifier G1277 is properly conducting and cam contact NP1 makes properly, Ro2 strikes. These valves bring up P1 and P2 and switch DW1 is stepped to position 2 where a similar test is carried out for contacts NP2, Npz1 and rectifier Gl278; and so on. When switch DW1 reaches position O again, W operates to step DW2 to position 2, whereupon the tests are repeated with cam contact NPz2 operated, and so on. When all the tests are completed and DW2 reaches position 14, it is stepped home by the interaction of relay Y and the P relays, whereupon Z operates to effect release of the test circuit. On any fault being discovered the P relays stop the switch stepping and bring up an alarm relay L which causes the illumination of appropriate lamps. Thus if an NP contact fails, P1 and P2 do not operate and lamp Stl1 lights to indicate the type of fault and one of lamps LP1 ...LP23 lights to indicate which NP contact is faulty. Likewise if an NPz contact fails P2, but not P1, operates. Lamp Stl1 again lights, but the faulty contact is indicated by one of lamps LP(i) ... LP(xiii). If a Gl rectifier goes short circuited P1, P2 and P3 operate, Stl2 lights, and also one lamp in each of groups LP1 ... 23, LP(i) ... (xiii) to indicate the identity of the rectifier. If a rectifier goes open circuit P1 operates, but not P2, and again one lamp out of each of the groups LP1 ... 23, LP(i) ... (xiii) lights together with lamp Stl3. In a further embodiment, Fig. 2, the output pulse is dependent on the coincidence of three sets of pulses. The first set is provided by electronic switches Rol ... 23, one cycle of which occurs during the closure time of each of the cyclically operated cam contacts Pz1 ... 13, which provide the second set of pulses. Each cycle of the second set then occurs during the closure time of each of a further set of cyclicallyoperated cam contacts Pwl ... 10 which provide the third set of pulses.