Abstract: The invention relates to an X-ray generator including a controller for the dose rate. In order to enable universal use of this controller for different types of examination, use is made of a sampling controller in the form of a microprocessor system. There are provided memories in which the sampling frequency and the adjustment functions are stored for the various types of examination as well as the programs on the basis of which the sampling controller calculates the adjustment values for the various types of examination.

Abstract: In X-ray generators comprising a converter for generating the high-voltage for an X-ray tube, substantial dose fluctuations are liable to occur from one exposure to another of series involving a fixed exposure time due to supply voltage fluctuations or fluctuations in the object absorption. These dose fluctuations are more pronounced as the exposure time is shorter and as the converter frequency is lower. These fluctuations are reduced by terminating a series of exposures each time after the same number of converter alternations when the deviation between the actual value and the reference value of the dose or the dose rate is smaller than a predetermined value.