GB389536A - Improvements relating to electric discharge tubes particularly gas-filled luminous tubes - Google Patents

Abstract

389,536. Discharge apparatus. SCHALLREUTER, W. L. W., 73, Cambridge Terrace, Hyde Park, London. April 11, 1932, No. 19767/31. [Class 39 (i).] A gas-filled discharge tube, such as a lamp, is started by forming an ionizing discharge between a main electrode and an auxiliary electrode within the envelope by means of a separate condenser, which is in a circuit connecting the two electrodes and is charged through a series resistance or impedance ; or two auxiliary' electrodes may be used for the ionizing discharge, the main electrodes being used only for the main discharge. As shown in Fig. 1, one of the electrodes is formed in two parts m, a, between which a condenser c and an inductance Tp are connected. A high resistance R is inserted between the condenser and the supply S. A winding Ts, coupled with the inductance Tp, supplies a striking voltage between the main electrodes m, h, and a choke coil I protects the supply from the striking voltage. The oscillatory glow or arc discharge across the parts m, a may be arranged to cease when the main discharge has started, or it may be maintained independently of the main discharge. Several modifications are described. Each electrode may be provided with an auxiliary electrode and starting condenser. A small auxiliary electrode may be connected to earth through a condenser. The running voltage for the lamp may be produced by the oscillatory starting circuit by coupling the two circuits through a transformer. The distance between the parts m, a may be varied automatically by mounting them on bimetallic supports. In the arrangement shown in Fig. 6, the supply to the condenser c is taken from a tapping K on the secondary of the supply transformer E.