GB364088A - Improvements in electric rare gas illuminating lamps - Google Patents

Abstract

364,088. Discharge lamps. LEDERER, A., Hermesvilla, Vienna. July 25, 1930, No. 22497. Convention date, July 30, 1929. [Class 39 (i).] - In an electric discharge lamp containing a filling of a rare gas and co-operating electrodes, one or each of which is adapted to be heated indirectly to electron-emission temperature, the size of the bulb, the pressure of the contained gas, and the size, shape, arrangement and spacing of the electrodes are such that at the voltage at which the lamp is adapted to be used the cathodic light is caused to develop and expand a considerable distance around the hot electrode, or each hot electrode, as a bright aureole, and to predominate, in the total illumination given by the lamp, over the positive column light. For use on direct current the lamp has a single hot electrode and a small anode, while for alternating current both electrodes are hot and of the same size. In an example, using a globe or similar shaped bulb, the diameter of the bulb is about three times the distance between the electrodes which are about 50 mm. apart, the filling consisting of neon at a pressure preferably between 1 and 5 mm. of mercury, and the applied voltage being less than 20 volts. The electrodes are tubular, from 2 to 3 mm. in diameter, and between 1 and 2 cm. long. The shape and dimensions of the bulb may be such that the bulb wall corresponds substantially to the outer limit of the luminescence which is developed within the bulb. A cylindrical bulb may be used, and the gaseous filling may consist of one or more of the gases helium, neon, argon, krypton, and xenon.