GB771053A - Improvements in or relating to electronic counters - Google Patents

Abstract

771,053. Electronic counting - apparatus. IMPERIAL CHEMICAL INDUSTRIES Ltd April 1, 1955 [April 7, 1954; Nov. 3, 1954], Nos. 10175/54 and 31781/54. Class 106 (1). An electronic counter using one multicathode gas-filled discharge tube for each denomination-each tube being of the kind in which each cathode has associated with it two guide electrodes, a first on its left-hand side and a second on its right-hand side, all the first guide electrodes being connected together and all the second guide electrodes being connected together, and in which the discharge can be stepped either clockwise or anti-clockwise around the tube by applying in succession negative pulses either to the first and second guide electrodes or to the second and first guide electrodes-is provided with a carry circuit between each denomination which permits the counter to count either " forwards," positively, or " backwards " negatively. Each carry circuit, which can only be used when the " transfer time " for each multi-cathode tube is constantthe " transfer time " being defined as the time taken by the discharge to pass from one cathode to an adjacent cathode via the two intermediate guide electrodes, and depending upon the rate at which the negative stepping pulses are applied-comprises the circuit of Fig. 1, where connections are taken from the " nine " and " ten " cathodes of a lower order ten-cathode tube to the guide electrodes, G1 and G2 of the next higher order tube via delays VI and V2 (mono-stable flip-flops) and coincident gates V3 and V4 (hard pentodes). The guide electrodes Gland G2 of the next higher order tube are connected by a delay, not shown, so that if either one of them receives a negative pulse from one of the gates V3 or V4 the other receives a delayed negative pulse. The delays VI and V2 are preferably one and a half times the time taken for the discharge to pass from one of the nine and ten cathodes to the other and thus if the counter is counting " forwards " coincident signals reach gate V3 when the glow reaches cathode 10, causing the guide electrodes Gland G2 of the next higher order tube to be pulsed in the order G1-G2, resulting in a positive transfer, and if the counter is counting " backwards " coincident signals reach gate V4 resulting in a negative transfer. In a second embodiment, in which the counter is used to count pulses produced by the apparatus des. cribed in Specification 757,105, [Group XXXVIII], for indicating the position of a rotating shaft, the carry between the first two denominations is effected by the circuit described in Specification 766,311 which circuit differs in principle from that shown in Fig. 1 only in that the " pick-up " points from the lower order tube are the " ten cathode and a guide electrode adjacent to the ten " cathode instead of the " ten " and " nine " cathodes, and which has the property that the transfer time for the lower order tube need not be constant, and the carry between other denominations is effected by the circuit shown in Fig. 1. Specification 757,922, [Group XXXVIII], is also referred to and Specification 771,052, [Group XXXVIII], is referred to in the first Provisional Specification.