GB365471A - Improvements in or relating to luminous electric discharge tubes - Google Patents

Abstract

365,471. Discharge lamps. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London.-(Assignees of Patent-Treuhand Ges. fur Elektrische Gl³hlampen ; 11, Ehrenbergstrasse, Berlin.) June 4, 1931, No. 16272. Convention date, July 5, 1930. [Class 39 (i).] A lamp 7, Fig. 2, with electrodes 5, 6 connected through a ballast choke or resistance 8 to the supply terminals 1, 2, directly or through a transformer, has a highfrequency apparatus 10 connected in parallel across the discharge gap, the output leads 11, 12 being connected either to the electrodes or to loops 11<1>, 121 forming auxiliary electrodes, and the high-frequency apparatus being non- responsive to a voltage of one-half of the supply voltage. A stray-field transformer may be used, the choke or resistance being omitted, and a low-voltage high-frequency apparatus shunted across a portion of the secondary. In a modification, Fig. 4, the lead 9 to the high frequency apparatus contains a small glowlamp 20 with a starting voltage less than the supply voltage but an extinction voltage exceeding the running voltage of the tube 7. A transformer has its primary 21 connected through a glow-lamp 27 or a resistance having a high negative-temperature coefficient to the line, the secondaries 22, 23 supplying heating current for the electrodes. The glow-lamp 27 is similar to the lamp 20. In another modification, the glow-lamp 20 is replaced by a resistance, and the high-frequency apparatus 10 consists of a glow-lamp in parallel with a condenser and the primary of a transformer, the secondary of which is connected to the leads 11<1>, 12.