GB402586A - Improvements in or relating to electric discharge tubes employing heated electrodes - Google Patents

Abstract

402,586. Discharge apparatus. COMPAGNIE DES LAMPES, 29, Rue de Lisbonne, Paris. Oct. 26, 1932, No. 30026. Convention date, Oct. 29, 1931. [Class 39 (i).] In thermionic apparatus such as lamps and ultra-violet radiators, two electrodes each heated by means other than the discharge, for example, by an internal resistance heater, are arranged at a single pole of the discharge so that one electrode provided for the maintenance of the discharge after starting, is brought to the operating temperature by the current feeding the discharge from another electrode which initiates the discharge and which alone is exposed to disintegration during starting. An alternating-current lamp has equipotential electrodes C<1> ... C<4>, two connected together at each pole of the discharge. The heaters F<1>, F<3> of the starting electrodes C<1>, C<3> are supplied by closing the switch S, and the discharge between the electrodes C<1>, C<3> is supplied through resistances R<1> R<2>and through the heaters F<2>, F<4> of the electrodes C<2>, C<4>. When the electrodes C<2>, C<4> become hot and the discharge starts between them, the switch S is opened. The resistances R<1>, R<2> may be omitted. In a modification, the four electrodes are mounted on a single pinch in a bulb to form a low voltage lamp operated in series or parallel with similar lamps. In another modification, the electrodes C<2>, C' are farther apart than the electrodes C', C<3> and the interconnections X between the electrodes at each pole may include a resistance and a switch, the latter being opened to isolate the electrodes C <1>, C<3> during normal operation. These switches and the switch S may be operated by the discharge current.