GB390395A - Improvements in or relating to luminous electric discharge tubes - Google Patents

Abstract

390,395. Discharge apparatus. NAAMLOOZE VENNOOTSCHAP PHILIPS' GLOEILAMPENFABRIEKEN, 13D, Emmasingel, Eindhoven, Holland. Aug. 11, 1932, No. 22501. Convention date, Aug. 19, 1931. [Class 39 (i).] In a luminous electric discharge tube containing auxiliary electrodes 7 in the form of wires or rods arranged longitudinally of the tube 1, each auxiliary electrode being connected through an impedance to a main electrode, the resistance of a unit length of the auxiliary electrodes is lower than that of an equal length of the surrounding gas column. The discharge tube is perferably provided with one or more incandescent electrodes 3 which, in the example are coated with electron - emitting material such as barium oxide and connected to the auxiliary electrodes 7 through resistances 9. Alternatively an inductance or a capacity may be connected between the electrons 3, 7. The auxiliary electrodes may consist of aluminium wires of 1 mm. diameter, with their inner ends extending to the middle of the tube, where they may be interconnected by a small insulating-tube 10, one wire 7 being wound round the tube and the other passed through the tube. The upper auxiliary electrode may be connected through an impedance to the lower main electrode, and the lower auxiliary electrode connected similarly to the upper main electrode. To prevent the superficial disintegration of the auxiliary electrodes they may be coated with' an insulating layer, for example a small porcelain tube or an oxide coating such as is described in Specification 388,302. To prevent the deposition of disintegrated matter upon the wall of the tube a part of the auxiliary electrodes may be surrounded by a grid-like screen. The filling of the tube consists of one or more rare gases, such as neon, to which a vapour, such as mercury vapour, may be added. An anode, which may be of cylindrical shape, may be mounted adjacent to the incandescent cathodes and connected thereto.