GB293681A - Improvements in starting and operating luminous electric discharge tubes - Google Patents

Abstract

293,681. Rainbow Light, Inc., (Assignees of Machlett, R. R.). July 9, 1927, [Convention date]. Vacuum tubes.-Luminous electric discharge tubes applicable to flashing neon beacons and of the type with internal electrodes and rarefied gas filling and operating with high current consumption of 0.1 to 10 amps. or more, are supplied from a secondary of a main transformer connected to the main electrodes and of insufficient voltage to start the tubes, the discharge being started by applying to the main electrodes high voltages equal in phase and magnitude with respect to a central auxiliary electrode or other point of the circuit. The starting means may comprise two auxiliary transformers 9, 10 with secondaries 13, 14 connected in opposition in series across the leads 4 from the main transformer 6 to end electrodes 2 of the tube 1, a common connection 15 being made to a central electrode 3 symmetrically arranged with respect to the electrodes 2. The secondaries 13, 14 give low currents, say 10 milliamps, of high voltage sufficient to start the tube 1 and are evenly balanced to avoid their discharge through the secondary 5 of the transformer 6, this secondary 5 being of sufficient reactance to prevent discharge of one of the secondaries 13, 14 through it should the branch of the tube 1 connected to the other start first. Steady operation of the transformer 6 is ensued by designing it with sufficient reactance or by a separate reactance coil 8. The single tube 1 may be replaced by two two-electrode tubes in series, the lead 15 being connected to one end electrode of each tube, or by a series of tubes of any length with the lead 15 connected to the approximate midpoint of the series. The coils 13 and 14 or 13, 14 and 5 may be secondaries of a single transformer.