GB877761A - Improvements relating to electronic counters - Google Patents

Abstract

877,761. Electronic counting-apparatus. FERRANTI Ltd. Sept. 24, 1958 [Oct. 1, 1957], No. 30671/57. Class 106 (1). In a multi-denominational counter with a number of multi-cathode glow-discharge counter tubes each with a pair of transfer electrodes between each pair of digit-representing cathodes, the pairs of overlapping voltage pulses which effect count-up or count-down according to their relative timing are applied to the transfer electrodes of each tube via means operative whenever the discharge in one tube represents a digit other than zero to inhibit counting action in the tube of next higher order. As shown, a and b pulses (ab representing a count-up and ba a count-down) are applied to transfer electrode connections G a and G b of decimal counting tubes 12, 32, 52 ... through amplifiers 15, 34, 53 ... and 20, the amplifiers 34, 53 ... having inputs also from the 1-9 cathode circuits of the previous denominations and acting in effect as " and " gates. Assuming the counter to be set at zero (as by pressing button 26 which brings all " 0 " cathodes down to - 150 v.) then an a pulse transfers the discharge in each tube to the a electrode " above " 0, and the associated b pulse to the b electrode. At the end of the b pulse the discharge commences to move to the "1" cathodes, the rise in potential at 24 acting through 34, 53 ... to lower the potential of the a electrodes of tubes 32, 52 ... sufficiently to attract the discharge of those tubes back to "a above 0" rather than to "1," and these tubes are read as recording "0." Similar action takes place until tube 12 has been counted up to cathode 9, when the next pair will transfer the discharge in 12 to " 0 " and 34 will receive no input from 24 after the b pulse so that 32 moves to " 1 "; tubes of higher denomination being inhibited by the positive signal from 41. Considering a count-down, tube 12 will always be counted down 1 digit by a ba pair of pulses, but any other stage will only be counted down if its discharge is at a cathode, i.e. if all the lower stages register "0." The counter may include tubes with other than ten cathodes for counting in a radix other than 10, or for counting in degrees and minutes of arc (by use of a sixcathode tube in the second denomination).