GB410581A - Improvements relating to electric cathode glow devices - Google Patents

Abstract

410,581. Discharge lamps. SIEMENS ELECTRIC LAMPS & SUPPLIES, Ltd., Caxton House, Tothill Street, London, OAKLEY, P. D., and ALDINGTON, J. N., c/o Siemens Electric Lamps & Supplies, Ltd., Dock Road, Preston. Feb. 25, 1933, No. 5801. [Class 39 (i).] A cathode-glow lamp for operation on alternating - current has two sets of electrodes in the shape of characters, the sets being connected to opposing bus-bars. In one form, Fig. 1, wires 4, 4A, 4B, 4C are sealed into the pinches 3 of the tube, and carry bus-bars 5, 5A, the wires 4, 4C serving also as current leads. The characters 7 are of thin sheet metal and are provided with tongues 8 spot welded to the bus-bars 5, 5A. The wires 4 ... 4C and their joints with the bus-bars are coated with insulation such as a ceramic, cement, or enamel. The bus-bars, except at the welds 8, are similarly insulated or glass tubing 6, 6A may be used. An annulus 9 of mica supports the bus-bars centrally. Series resistances may be inserted in one or both caps 2. The electrodes may be coated with insulation on their backs. The total surface areas of the characters of like polarity should be approximately equal. The filling may consist of neon with another gas or a metallic vapour, e.g. of neon at 5 mms. and hydrogen at 0.05 mm. or neon saturated with metallic vapour to a pressure of from 10 mm. to 25 mm. or helium or argon, alone or with hydrogen or with a metallic vapour, may be used. According to the Provisional Specification, the filling may also comprise nitrogen.