GB599510A - Improvements in or relating to devices comprising an electric gaseous discharge tube - Google Patents

Abstract

599,510. Discharge apparatus. PHILIPS LAMPS, Ltd. Sept. 25, 1945, No. 24901. Convention date, Aug. 14, 1940. [Class 39 (i)] Gaseous electric discharge tubes 3 are cooled in a body of liquid, e.g. water, contained in a closed vessel 1 which also contains a small quantity of gas, the ratio of the volume of gas to that of liquid being so small as to prevent boiling of the liquid due to the rise in temperature and pressure in the vessel. The envelope of the discharge tube is preferably provided with projections 8, formed, for example, by sealing sharp edged pieces of glass or quartz thereto, to prevent the sudden formation of vapour bubbles at the discharge tube. The gas in the vessel 1 may be air, in the proportion of 1 : 9 of the volume of water, at 20‹ C. and 1 atmosphere pressure. The dissipation of heat may be increased by cooling fins. Alternatively, the vessel 1 may be cooled by water, which may circulate in a closed circuit, or by a second closed vessel containing cooling liquid and a gas. A thermostat may be provided to operate an indicator or render the discharge tube inoperative. The vessel may be formed of a material to transmit light, such as glass or quartz, and may be in parts mechanically connected. The cooling liquid may also be chosen to act as a light filter. The discharge tube is mounted on the stem 2 of the vessel 1, by means of insulators 7 carrying the leads 5, and may have a filling of rare gas and mercury at about 80 atmospheres with an output of 500 watts. The subjectmatter is identical with that of Specification 552,597.