GB478616A - Improved circuit-arrangement for x-ray apparatus - Google Patents

Abstract

478,616. Supply systems for discharge lamps &c. COMPAGNIE GENERALE DE RADIOLOGIE. Dec. 11, 1936, Nos. 34094 and 34095. Convention dates, Dec. 12, 1935 and Feb. 15, 1936. [Class 38 (iv)] In X-ray apparatus in which the voltage applied to the primary of the H.T. transformer is variable the voltage applied to an auxiliary transformer 8 is simultaneously varied and its secondary winding is connected in the cathode heating circuit so as to reduce the heating current when the H.T. voltage is increased and vice versa. An X-ray tube 7 is supplied from a H.T. transformer 4 whose primary is connected through a tap changing switch 3 to a tapped auto-transformer 1 which is connected to mains 2. The cathode 7b is supplied from a transformer 6 whose primary is connected to tappings on the auto-transformer 1 through a boosting transformer 8 the primary of which is connected to the tap changing switch 3 on the one hand and to a tapping on the auto-transformer 1 on the other hand so that the cathode heating current is varied when the H.T. voltage is varied. The winding 8& of the transformer, is arranged to buck the voltage applied to the heating circuit. The transformers 8 and 6 may be tapped for adjustment purposes and resistances 9 and 10 in the primary circuit of the transformer 6 may also be tapped so as to adjust the relation between anode voltage and cathode heating. Resistance 10 may be inserted if operation is desired below the optimum value of cathode heating. If strict proportionality is not required the lower end of the winding 8a may be connected to a tapping on the transformer 1 other than that to which the left-hand end of the winding 4a is connected.