GB824762A - Improvements relating to controllable gas-filled electric discharge devices of the thyratron type - Google Patents

Abstract

824,762. Thermionic valves. BRITISH THOMSON-HOUSTON CO. Ltd. Jan. 18, 1956 [Jan. 27, 1955], No. 2555/55. Class 39(1). In a gas-filled discharge tube of the thyratron type, the control electrode is a hollow cylinder whose ends extend beyond both anode and cathode, and which has attached within it an annular baffle having an aperture in the neighbourhood of the anode; an auxiliary electrode in the form of a disc-like baffle is disposed on the cathode side of said aperture, and coaxial with it. A potential different from both the cylinder potential and the anode potential may be applied to the disc, so that disc and cylinder jointly control the passage of the arc through the annular gap. In Fig. 4, the disc-baffle has a two-part construction, one part 8 being a disc lying in the same plane as the annular baffle 7, and an attached part 10 of larger diameter than the aperture in baffle 7. A priming pulse is applied to the baffle 7 in advance of the firing pulse which is applied to electrode 10. In a simpler form, Fig. 3 (not shown), only the part 10 is used, without the part 8. The electrode 10 may be shielded from the cathode, except for its edge, by a further baffle 11, which can be mounted by supports attached to the control cylinder 5, and is insulated from electrode 10, Fig. 5. To prevent the priming discharge from passing directly to baffle 11, this latter may be shielded by a further baffle 12 which may be connected to the cathode 1. A conical guide 16 assists in directing the discharge. Fig. 6 shows a practical realisation of the diagrammatic arrangement of Fig. 5. Specifications 573,232 [Group XL], and 820,885 are referred to.