GB929296A - Improvements in x-ray apparatus - Google Patents

Abstract

929,296. Supply systems for X-ray apparatus. GENERAL ELECTRIC CO. Ltd. April 17, 1962 [April 28, 1961], No. 15465/61. Class 38 (4). An X-ray system for operating two X-ray tubes simultaneously for taking radiographs in two directions comprises means whereby the two tubes can be operated from a single hightension source at different anode voltages and different anode currents. Two X-ray tubes 1, 2 are connected to a high-tension supply 5, 6 the tube 1 being connected directly to the supply whilst the tube 2 is connected in series with two thermionic valves 7, 8 ; one on either side of the tube 2 ; to the supply. The filament currents, and hence the anode currents, of the tubes 1, 2 are independently adjustable by means of variable resistors 17, 18 respectively. An autotransformer 21 is connected to an alternating current supply 3, 4, the autotransformer being provided with tappings to which are connected, by way of switches 22, 23, transformers 24, 25 which are connected over rectifiers 26, 27 to the grids of the valves 7, 8. Thus the difference in the anode voltages of the tubes 1, 2 is selected by the switch 23 and the anode current of the tube 2 is modified by the switch 22 which is ganged to a switch 20 on the variable resistor 18. In other embodiments the autotransformer 21 may be replaced by a pair of transformers connected across the supply 3, 4 and in which the potentials applied to the grids of the valves 7, 8 may be positive with respect to the cathodes.