GB768535A - Improvements in and relating to glow discharge tubes - Google Patents

Abstract

768,535. Control systems for space-discharge tubes. SOC. TRIFLUX. April 27, 1955 [Jan. 11, 1955], No. 12138/55. Class 38 (4). One or more glow discharge tubes 5 are supplied by a H.F. oscillation generator with variable amplitude voltage to cause the discharge to move progressively along the tube, and is fed over an energy transmission line 4 which is coupled to the output of the generator and includes a high-impedance inductance 6 in series with and a capacitor 7 in parallel with the tube. The values of the inductance and capacitor are equal for the frequency at which the tube is fully illuminated. The generator may comprise an oscillator stage formed by a triode 10, a resonant circuit consisting of an inductance 12 and a condenser 11a in parallel between the grid and anode of the triode, and a frequency adjusting variable condenser 11 connected between the anode and earth. The inductance 12 is inductively coupled with a winding 13 connected to the grid of an output amplifier tube 14 to the anode of which is connected a resonant circuit which includes an inductance 2 which serves as the primary winding of the transformer by which the line 4 is coupled to the generator. In Fig. 6 a number of tubes 5, 51, 5<SP>11</SP>, e.g. shop signs, are supplied sequentially from the H.F. source over switches 23, 231, 23<SP>11</SP>, switch 23 opening when the first tube 5 is fully illuminated whereupon switch 231 closes to start the glow in tube 5<SP>1</SP> and tube 5 continues to be supplied from a normal A.C. supply through a transformer 25 and H.F. blocking choke 26.