GB517411A - Improvements in or relating to x-ray apparatus - Google Patents

Abstract

517,411. Supply systems for X-ray tubes; r÷ntgen - ray apparatus. NAAMLOOZE VENNOOTSCHAP PHILIPS" GLOEILAMPENFABRIEKEN. Feb. 22, 1939, No. 5922. Convention date, Feb. 25, 1938. [Class 38 (iv)] [Also in Group XX] In an X-ray apparatus in which the source of high tension is constructionally united with the tube and the whole enclosed in a metal envelope. which can be fitted in a movable manner to a stand arm of adjustable height, the total weight is kept low by associating a Greinacher circuit with the transformer for the high tension supply. This reduces the weight of the stand arm in two ways, first the Greinacher circuit is itself lighter than its equivalent step up transformer and secondly as its output is D.C. the X-ray tube can be made smaller than for an equivalent A.C. supply. The filaments 11 and 18 of the rectifier 10 and the X-ray tube 1 are heated by the high frequency supply 21, external to the apparatus, while the filament 14 of the rectifier 13 is heated from 'transformer 23, which is small because of the high frequency of the'supply. The condenser units 2 and 3 and one end of the high tension winding 9 together with the core of the high tension transformer, are connected to 'the earthed envelope 16 which embraces the source of high tension. On the high tension side the unit 2 is connected to the anode 17 and the unit 3 to the incandescent cathode 18 of the X-ray tube 1, thus the tube 1 has the sum of the voltages of the units 2 and 3 applied to'it so that the voltage of the high tension winding 9 is doubled. The high frequency supply 21 may be a thermionic oscillator. The condensers 4-5 and 6-7 respectively are connected in series in relation to the high frequency heating current and' the voltage drop produced at them is negligably smaller because of the high frequency of the current passing through them. Fig. 2, shows the arrangement of the components of the apparatus. The metal envelopes 28 and 29 are jointed together to form..the metal cover 27 of the high tension system which is attached to the metal tube 50, holding the X-ray tube 51, by the knee joints 48 and 49 and the flanges 46 and 47. The envelope 27 is suspended so as to be rotated about its axis from a carrier 59 by means of rings 60 and 61 surrounding the envelope. The carrier may be secured to a stand arm 69 which is adjustable in height and if desired, pivoted. Specification 460,739 is referred to.