GB671414A - Improvements in gaseous electric discharge devices - Google Patents

Abstract

671,414. Discharge apparatus. BRITISH THOMSON-HOUSTON CO., Ltd., and SCOTT, W. J. June 7, 1950 [July 22, 1949], No. 19354/49. Class. 39 (i). In a T.R. switch, having a filling of 10 mm. of argon and 4¢ mm. of water vapour, generation of excess hydrogen due to the dissociation of the water vapour by the electric discharge is prevented by a catalyst which is active in the presence of water vapour to catalyse hydrogen and oxygen into water. The catalyst may be coated over the whole interior surface of the device or preferably over a portion of the surface in the neighbourhood of the discharge. Alternatively, the catalyst may be applied to a glass and/or ceramic or other support mounted in the device, or a " keep-alive " electrode tipped with the catalyst may be used, in which case adjacent surfaces of the device may be coated with the catalyst by sputtering from the electrode. The metallic inside surfaces of the device are preferably coated with a noble metal of high electrical conductivity such as gold or silver. A preferred catalyst is palladium, which is active down to room temperature and may be prepared by introducing palladium chloride into the device during manufacture and reducing it by hydrogen.