GB688039A - Improvements in or relating to gas-filled discharge tube circuits - Google Patents

Abstract

688,039. Pulse circuits. STANDARD TELEPHONES & CABLES, Ltd. Feb. 16, 1951 [Feb. 17, 1950], No. 4141/50. Class 40 (vi). In a gas-filled sequence tube having an array of anode / cathode gaps in which applied pulses cause a single discharge to travel in succession along the gaps, the cathode potential of a discharging gap is maintained substantially constant until the next gap in the array commences to conduct. In this way a higher speed of operation is obtained. The Figure shows a portion of a counting or frequency divider multistable-state circuit comprising a sequence tube having an anode A, cathode arrays of which only cathodes K1, K3 are shown and a transfer electrode array of which only electrode K2 is shown. The train of negativegoing pulses to be counted is applied at terminal P to the transfer electrode K2 and after phasereversal in transformer T1 to block the rectifiers M1 and M2. If initially the gap A/K1 is discharging then an input pulse causes gap A/K2 to break down, which extinguishes gap A/K1 by reason of the common anode resistor R3 but capacitor C1 is unable to discharge through resistor R1 whilst rectifier M1 is blocked during the incidence of a pulse at P. When the first pulse of the train ceases the discharge across gap A/K2 is extinguished and passes to gap A/K3, the time constant R2, C2 being made short so that the potential across the gap rises very rapidly and reaches its maximum value before the arrival of the next incoming pulse at P. Thus due to the blocking of rectifiers M1 M2, &c., the cathode networks R1, Cl; R2, C2, &c., may be given very short time constants, thus enabling a high input pulse repetition frequency to be handled whilst maintaining the cathode potential of any cathode, say K1, constant until the next gap A/K2 commences to conduct. Outputs may be derived at terminals O1 and 02. In a modification transformer T1 is omitted and a train of positive-going pulses coincident in time with those at the input P are applied to block rectifiers M1, M2, &c.