Patent GB-712177-A (GB)
Title: Improvements in or relating to electronic counting and/or selecting arrangements
IPC: H01J17/48
Filed: 1950-06-22
Abstract: 712,177. Electronic counting-apparatus. ERICSSON TELEPHONES, Ltd., and ACTON, J. R. June 20, 1951 [June 22, 1950], No. 15584/50. Class 106 (1). [Also in Group XL(a)] A circuit adapted to count or divide in the scale of ten comprises a cold cathode gas-filled discharge tube CTA (see Group XL(a')) having a common anode A and forty cathode electrodes comprising a first-guide cathode with ten electrodes GA1-GA10, a second-guide cathode with ten electrodes GB1-GB10, a third group of ten electrodes consisting of nine third-guide electrodes GC1-GC9 and a signal-guide electrode GD, and a fourth group of ten electrodes consisting of nine transit electrodes TC1-TC9 and a signal electrode SC. The actual arrangement is circular so that electrode SC adjoins electrode GA1. On connecting leads PA and ZA to a D.C. source a glow discharge invests cathode SC. Operation of a start key closes contacts KS1 and KS2 to extend the negative potential at ZA to the other cathode electrodes. Leads L1 and L2 are connected to a source of alternating current, and when the potential at the end Y of the secondary winding S of the transformer TRA becomes more negative than the potential at signal-cathode SC, the discharge transfers to firstguide electrode GA1. The discharge current in passing through resistor R2 raises the potential of electrode GA1 and the discharge transfers to second-guide electrode GB1. When the potential at the point Y passes to a more positive value, the potential at cathodes GA and GB becomes less negative than the potential at cathode GC, and the discharge transfers to electrode GC1. The discharge current in passing through resistor R5 raises the potential of electrode GC1 and the discharge transfers to electrode TC1. Each subsequent impulse causes the discharge to transfer to the next electrode of the transit cathode TC until the tenth impulse causes the discharge to move to signal cathode SC and the voltage developed across resistor R6 passes an output pulse by way of lead OP to a further counting stage or to a recording device. In a modified arrangement signal-guide cathode GD is connected by an external connection directly to the third-guide cathode GC, resistor R4 and contacts KS2 being omitted. In a further arrangement, transformer TRA is omitted and small condensers are associated with the resistors connected to the various cathodes so that the potentials on the cathode electrodes are controlled by reactive means. Such an arrangement permits less tolerance as regards the wave shape and speed of the incoming pulses than with arrangements employing resistive means for guiding the glow discharge. A battery may be connected to apply a positive 'bias to cathodes GA and GB so that the glow discharge will complete a cycle of movements in response to an incomplete pulse having part or all of the positive half-cycle missing. A bias battery may also be used to enable any of the arrangements to work on D.C. pulses. Further circuits are described which employ tubes having forty or thirty-six cathode electrodes of which the transit cathode electrodes are led individually out of the tube. The individual connections may be connected together outside the tube to provide an arrangement for counting or dividing in the scale of ten or nine, or may be led to individual outlets to provide an arrangement for selecting any one of ten or nine outlets. The direction of movement of the discharge may be reversed by reversing the connections to the first and third-guide cathodes and the polarity of the electrodes may be transposed so that the common electrode forms a cathode and the other electrodes are anodes. In a counting arrangement the output lead and associated resistor may be dispensed with and the visible position of the glow discharge used to determine the number of impulses which have been received. Specification 712,171 and U.S.A. Specification 2,443,407 are referred to.