Patent GB-699696-A (GB)
Title: Improvements in or relating to multi-electrode gaseous discharge tube circuits
Inventor: THOMAS DAVID GURNEY ARNOLD
IPC: H03K29/00
Filed: 1950-12-16
Abstract: 699,696. Digital electric calculating-apparatus. NATIONAL RESEARCH DEVELOPMENT CORPORATION. Dec. 28, 1951 Dec. 16, 1950], No. 30715/50. Class 106 (i). In a circuit for operating a " receiving " multi-electrode gas discharge tube according to a number stored on a " sending " tube, each tube comprising a ring of main electrodes, including an output electrode, around which a discharge may be cyclically stepped by applying pulses to guide electrodes, pulses are applied to the sending tube and when the discharge reaches the output electrode a switch is operated in a pulse input connection to the receiving tube. As described, a known kind of decimal counting gas-discharge tube is used comprising a central anode 3, Fig. 1, and the cathodes 1, 2, a discharge being stepped around the tube from one cathode to the next by successive negative " A " and " B " pulses applied from leads 11, 12 to guide electrodes 5, 6 respectively. Every time the discharge reaches cathode 2 an output pulse is produced. In the circuit of Fig. 4, the counting tubes 33, 36 are represented diagrammatically with the output cathodes connected to a bias potential through a resistance such as 45 and the other cathodes connected to earth. A pulse generator 37 supplies ten " A " and " B " pulses, Fig. 5 (a) and (b), over leads 38, 40 to the guide electrodes of sending tube 33 and, at a time depending on the number, e.g. three, stored in the tube, an output pulse, Fig. 5 (c) will be sent from cathode 32 through coupling condenser 47 to the trigger electrode 46 of a neon tube 31 which will then fire, thus raising the potential of cathode 48, Fig. 5 (d), and of a control grid 49 so that conduction in double triode 43 switches from anode 50 to anode 51. Thus, pulses, Fig. 5 (g), supplied to triode 43 via lead 42, are divided between output leads 58, 59, Fig. 5 (e) and (f), either of which may be connected by switch 57 to the " B " pulse input lead 60 of receiving tube 36 so as to add into this tube either the number stored in tube 33 or its nines complement, the pulses on lead 60 coacting with nine " A " pulses, Fig. 5 (h), supplied to lead 44. Switch 57 is shown in the " add " position in which the three pulses on lead 59, Fig. 5 (f), coact with the last three pulses on lead 44, Fig. 5 (h), to add " three " into tube 36; in the " subtract " or " complement" position, the last six of the seven pulses on lead 58, Fig. 5 (e), coact with the first six pulses on lead 44 to add in the complementary number " six." If a double switch comprising contacts 66, 67 is operated, the " B " pulses for tube 33 will be supplied from lead 58 in place of 40, thus zeroizing the tube. An electronic resetting switch, shown by 63, is provided in the anode circuit of tube 31. The generator 37 may comprise a continuously running oscillator, cold-cathode trigger tubes, double-triode switches, a " start " relay, and a decimal counting tube as described above. According to the Provisional Specification, the double triode 43 may be replaced by two cold-cathode tubes.