ELECTRIC DISCHARGE FLICKER LAMP

1,222,089. Glow discharge lamps. SYLVAMA ELECTRIC PRODUCTS Inc. 10 July, 1969 [10 July, 1968], No. 34880/69. Heading HID. A gas discharge flicker lamp has two electrodes bearing a coating comprising a mixture of a metal halide and a partially decomposed alkaline earth azide. The addition of the halide to the usual azide coating enables the lamp to operate with quantities of nitrogen up to 0.1% in the filling. The coating mixture may comprise barium azide and cesium azide together with from 0.5 to 50% by wt. of a halide of barium, strontium, calcium or cesium, e.g. 2% of barium iodide. This is applied in the form of an aqueous solution to the electrodes which are made from thin perforated iron sheet. The lamp envelope is repeatedly heated with gas flames and repeatedly flushed, first with nitrogen, then with neon. The coating partly decomposes with evolution of nitrogen. The filling may comprise neon at a pressure of 110 mm. The external surface of the lamp may be covered with glass beads.