GB781585A - Vacuum tube gating circuits - Google Patents

Abstract

781,585. Gating circuits. SOC. D'ELECTRONIQUE ET D'AUTOMATISME. July 7, 1954 [July 9, 1953], No. 19956/54. Class 40 (6). A gating circuit comprises a triode discharge tube having the signal to be gated applied to its control-grid and the gating signal applied across a cathode resistor the output being derived from the anode load and in which a uni-directionally conducting device is connected to the cathode load resistor so as to apply to the cathode either a D.C. bias which renders the gate open or a gating voltage which closes the gate. Fig. 1 shows a gating circuit in which the signal to be gated is applied to the control grid of tube 1 at terminal 6 and in which diode 9 is normally conducting to apply a voltage +v to the cathode so that tube 1 conducts and an output signal is produced at lead 3. When a gating signal having a voltage exceeding +v is applied at terminal 11 diode 9 and tube 1 are cut-off and the output at 3 ceases. In a modification, Fig. 2 (not shown), the gating signal is applied to the cathode via a further rectifier. In a further modification, Fig. 3 (not shown), two gating signals are applied to the cathode of the triode via individual rectifiers. In a modification shown in Fig. 4 two gating signals are applied at 11<SP>1</SP>, 11<SP>2</SP> via a diode coincidence gate 131, 132 so that the triode gate 1 is closed only when two gating signals are applied at 11<SP>1</SP>, 11<SP>2</SP> simultaneously. Fig. 5 shows a modification in which a single gating signal is applied at 18 via a cathode follower stage 16 to effect the simultaneous gating of tubes 1<SP>1</SP>, 1<SP>2</SP> ... 1<SP>n</SP> which are isolated by rectifiers 12<SP>1</SP>, 12<SP>2</SP> ... 12<SP>n</SP>. In a further modification, Fig. 6 (not shown), the isolating rectifiers of Fig. 5 are dispensed with and the cathode follower and gating stage share a common cathode load resistor.