Patent GB-785021-A (GB)
Title: Improvements in or relating to electronic counting and selecting arrangements
IPC: H01J17/48
Filed: 1953-09-03
Abstract: 785,021. Electronic counting apparatus. ERICSSON TELEPHONES, Ltd., and ACTON, J. R. Nov. 29, 1954 [Sept. 3, 1953], No. 24351/53. Class 106 (1). [Also in Groups XXXIX and XL (a)] A counting or selecting circuit, Fig. 3, comprises a multi-gap cold cathode gaseous discharge tube DTA (see Group XL (a)) having ten First cathodes F0 to. F9, ten Second cathodes S0 to S9, ten commoned First guides FG1 to FG10 and ten commoned Second guides SG to SG10 arranged around a common anode in such a way that an applied impulse can cause a glow discharge to move from one pair of First and Second cathodes to another pair by way of a First and Second guide. The First guides FG and Second guides SG are connected through a resistor network to a positive bias battery BB and by way of a capacitor C1 and lead DP to a source of negative-going pulses. Each First cathode F0 to F9 is connected through a resistor R10 to R19 to earth and through a switch SW0 to SW9 to a positive battery BC. Each Second cathode S0 to S9 is connected to an outgoing pulse lead SP0 to SP9 and through a resistor R20 to R29 to earth. A glow discharge is caused to invest any selected First and Second cathode pair by operating the switches SW of the remairing First cathodes, and remains on the selected pair when the switches are returned to normal. The discharge can then be stepped to any other pair of First and Second cathodes by applying an appropriate number of pulses to the First and Second guides. During the period that the discharge remains on a particular pair of First and Second cathodes a positive potential is developed at the associated outgoing pulse lead SP due to the voltage developed across the associated resistor R20 to R29. If then the switch SW of the First cathode is operated, the increased positive potential due to the battery BC produces an increased positive potential at the Second cathode which is superimposed on the existing positive potential due to the discharge. With each lead SP connected to a separate device adapted to respond to positive potential of a particular value and not to respond to a lower value of such potential, and each device arranged on operation to provide a visual signal indicative of a particular number, the arrangement may be used to select and signal any desired digit from 0 to 9. For example, with the discharge on First cathode F0, the application of eight impulses at DP will step the discharge to First cathode F8, and operation of SW8 will then cause the signalling device associated with lead SP8 to respond and provide the desired visual signal. In another application the signalling devices associated with the leads SP are arranged to operate to a brief pulse of the voltage derived from the operation of a switch SW and to remain operated in a display position until a release signal is given. One or more switches SW0 to SW9 are operated prior to the application of a train of impulses to lead DP and cause a signal to be applied in ordered sequence to the selected output leads SP0 to SP9. The transmission of such signals may be adapted to select and signal a number in code form. For example, the " lit " and " unit " conditions of the signalling device may represent the two digits of a binary code. In a modified arrangement, similar to Fig. 3, the First cathodes are connected to output leads instead of to the switches SWO to SW9 and battery BC. During the period that the discharge remains on a particular pair of First and Second cathodes a signal can then be passed in either direction between circuits connected to these cathodes, thus providing a basic circuit arrangement which can be used in a variety of counting, selecting and computing arrangements. In one form of counting arrangement, two or more cathodes of a like kind may be connected together to form one or more groups, and each cyclic movement of the discharge in the tube be arranged to extend positive-going pulses derived from ungrouped cathodes of the other kind to one or more output leads each common to a group of cathodes. The circuit shown in Fig. 5 comprises an alternative form of discharge tube DTC having nine First cathodes F0 to F8, nine commoned Second cathodes S0 to S8, nine commoned First guides FG, and nine commoned Second guides SG. The First cathodes FO to F8 are connected through resistors R40 to R48 to earth and through switches SX0 to SX8 to a positive battery BC. The commoned Second cathodes are connected to an output lead OPC and through a resistor R8 to earth. Each switch SX0 to SX8 may be formed by a relay contact of a selector switch in a telephone exchange which is operated throughout the period the selector is in use. If then the discharge in the tube DTC is stepped around the array of cathodes, the number of signal pulses applied to the lead OPC at each cycle indicates the number of engaged selectors. The circuit may be used in other counting arrangements in which the random operation of a switch SX extends a pulse to a First cathode, which is conveyed periodically to the output lead OPC on the cyclic movement of the discharge. In a selecting arrangement similar to Fig. 5, the commoned Second cathodes S0 to S8 are connected through a resistor to earth and through a switch to a positive battery, and the First cathodes FO to F8 are connected to individual lines. With such an arrangement a discharge in the tube DTC is caused to move to the First and Second cathode pair particular to a selected line by applying a suitable number of impulses to lead DP, and a pulse of positive potential is applied to the selected line on operation of the switch. In this way a signal sending lead in the form of the discharge in the tube may be extended to a plurality of lines in cyclic order, and at least one signal pulse of one order and any number or no signal pulses of another order be passed to each line in turn. Specifications 712,171, 712,177 and 712,215, [Group XL (a)], are referred to.