GB748890A - Improvements in or relating to electric stabilizer circuits - Google Patents

Abstract

748,890. Cold-cathode tubes. TELEFONAKTIEBOLAGET L. M. ERICSSON. March 13, 1953 [March 14, 1952], No. 7028/53. Drawings to Specification. Class 39 (1). An electric stabilizer circuit comprises a coldcathode glow discharge tube which works at an abnormal cathode drop, i.e. so that the whole discharge surface of the cathode is covered by the glow discharge. The internal resistance of the tube is kept at a low positive value by special selection of the gas filling and cathode material. The discharge surface of the cathode must be constituted by a homogeneous material, molybdenum, zirconium, tungsten or tantalum being suitable. A suitable gas filling consists of neon with between 0.02 and 0.5 per cent of argon. Other rare gases may be added to this neon-argon mixture. Helium may be added up to a pressure corresponding to a third of the partial pressure of the neon, and krypton and/or xenon may be added up to a pressure corresponding to two thirds of the partial pressure of the argon. The total partial pressures of the argon krypton and xenon must then amount to between 0.02 and 0.5 per cent of the total partial pressures of the neon and helium. A current-voltage characteristic is shown, together with curves showing the effect of the filling mixture on the internal resistance of the tube.