GB931720A - Improvements in or relating to diagnostic x-ray apparatus - Google Patents

Abstract

931,720. Control circuits for X-ray apparatus. SIEMENS-REINIGER-WERKE A.G. July 15, 1960 [July 17, 1959], No. 24770/60. Class 38 (4). X-ray diagnostic apparatus is arranged to be controlled so that the exposure is terminated either by an exposure device or by means which are responsive to the product of the current taken by the X-ray tube and the time for which this current flows. An X-ray tube 1 is supplied by way of a tapped transformer 6 and a high-tension transformer 2a, 2b together with a filament heating transformer 3. A control knob 4 moves a tapping 5 to adjust the H.T. voltage and at the same time causes a control device 9 to adjust the X-ray tube current to ensure that the tube loading does not exceed a permissible limit. The device 9 is also operative to reduce the X-ray tube current in stepwise manner from the set value during the subsequent exposure. A second control knob 13 controls a variable resistor 27 whereby the time quantity of a product of time and X-ray tube current is varied and also controls a change-over switch 16 which assumes the position shown when the knob 13 is moved to place the pointer 14 at the end of a scale 15. Exposure is initiated by a control device 10 which energizes a relay 12 to close contact 11. With the change-over switch 16 in the position shown the exposure is ascertained by an exposure device 19, after a sufficient exposure, closes contact 22 whereby relay 23 is energized to open contact 24 to remove the supply. Movement of the control knob 13 to alter the position of the pointer 14 causes switch 16 to change over and moves the setting of the variable resistor 27 to give a desired time-tube current product. The exposure is initiated as before by closing contact 11 which simultaneously begins charging of a capacitor 26, until it acquires a certain charge when gas-filled valve 28 ignites thus energizing relay 29 to close contact 30 whereby relay 23 is energized to remove the supply as before. An indicator lamp 17 indicates whether the apparatus is set up to be controlled by the exposure device 19 or the time-tube current product device 26, 27.