Abstract: Current switching point determination devices use two comparators with fixed threshold values. According to an exemplary embodiment of the present invention, a power inverter control device for switching point determination is provided which comprises a filter circuit and a subsequent single comparator. By this arrangement, the time event is independent of the amplitude and for sufficiently small frequencies also of the frequency.

Abstract: Generating an output pulse signal (Y), which has an output signal period (Ty), which is divided by a magnitude transition into a leading part (LP) and a trailing part (TP). During each output signal period (Ty) altering means (27 to 36) determine in a coarse and fine way a duration (TLP, TTP) of one or both of said output signal period parts (LP, TP) by using a clock signal (Cx) of different clock cycle durations (TCx0, TCx1, TCX2), dependent on a value of a first digital number (D1) and a value of second, less significant digital number (D3, D5), respectively.

Abstract: A description is given of a power supply unit, an X-ray device having a power supply unit, and a method of controlling a power supply unit. In order also to control non-linear control paths, such as of a power supply unit operated with mixed-mode modulation, it is proposed that the control device be designed as a digital control device which calculates at least one correcting variable. The control device processes at least a first actual value Uout, which depends on the output voltage. A time difference value is calculated from two sample values of the first actual value Uout and is multiplied by a first controller coefficient Kout. The value of the first controller coefficient can in this case change as a function of the operating point of the power supply unit.

Abstract: A description is given of a power supply unit, an X-ray device having a power supply unit, and a method of controlling a power supply unit. In order also to control non-linear control paths, such as of a power supply unit operated with mixed-mode modulation, it is proposed that the control device be designed as a digital control device which calculates at least one correcting variable. The control device processes at least a first actual value Uout, which depends on the output voltage. A time difference value is calculated from two sample values of the first actual value Uout and is multiplied by a first controller coefficient Kout. The value of the first controller coefficient can in this case change as a function of the operating point of the power supply unit.

Abstract: Two proposals are made for power supply systems comprising at least one resonant inverter and one control unit. According to the first proposal the power supply system comprises two inverters and produces two output voltages, the control circuit processing as an actual value on the one hand the sum of and on the other hand the difference between the two output voltages. According to the second proposal a control circuit does not directly process the controlled variables for a power supply system comprising at least one inverter, but difference units for controlled variables determine the deviations from a preceding sampling instant and these difference values are processed. Also the correcting variable calculated in this way is a difference value which is converted into a correcting variable value by a correcting variable summing unit. The two proposals can be advantageously combined.

Abstract: Two proposals are made for power supply systems comprising at least one resonant inverter and one control unit. According to the first proposal the power supply system comprises two inverters and produces two output voltages, the control circuit processing as an actual value on the one hand the sum of and on the other hand the difference between the two output voltages. According to the second proposal a control circuit does not directly process the controlled variables for a power supply system comprising at least one inverter, but difference units for controlled variables determine the deviations from a preceding sampling instant and these difference values are processed. Also the correcting variable calculated in this way is a difference value which is converted into a correcting variable value by a correcting variable summing unit. The two proposals can be advantageously combined.

Abstract: The invention relates to a method of determining the output capacitance of a voltage supply device, as well as a voltage supply device and an X-ray apparatus. To determine the output capacitance of a voltage supply device in a simple manner, a measuring method is proposed in which an output voltage of a predefined first measuring voltage value is generated and, subsequently, the voltage supply is turned off, so that the output capacitance is discharged through at least one precision resistor provided in the voltage supply device, the output capacitance being calculated from the discharge curve.

Abstract: In order to determine the necessary operating parameters of a power supply system with a converter for supplying a resonant arrangement having a transformer, a system having a measuring device is proposed, which activates the converter so that with components of the power supply system initially unenergized a predetermined output voltage is generated, one or more parameters characteristic of the resonant arrangement being determined from the measurement of the resonant current appearing on the primary side of the transformer. In this, after a preferably brief excitation interval, the resonant frequency, the impedance of the resonant arrangement, the capacitance value of the resonant capacitance and the leakage inductance are determined on the basis of the current path.

Abstract: In order to determine the necessary operating parameters of a power supply system with a converter for supplying a resonant arrangement having a transformer, a system having a measuring device is proposed, which activates the converter so that with components of the power supply system initially unenergized a predetermined output voltage is generated, one or more parameters characteristic of the resonant arrangement being determined from the measurement of the resonant current appearing on the primary side of the transformer. In this, after a preferably brief excitation interval, the resonant frequency, the impedance of the resonant arrangement, the capacitance value of the resonant capacitance and the leakage inductance are determined on the basis of the current path.

Abstract: The invention relates to a series resonant converter (1) comprising a control circuit (8) for controlling the output voltage of the converter. To improve the behavior of the converter, it is proposed that the control circuit (8) is provided for processing a first actual value (Uout), which depends on the respective converter output voltage (uout(t)) and for processing a second actual value (UC), which depends on the respective current (ires(t)) flowing through the series resonant circuit elements (C, L, R) of the converter (1), and that the control circuit (8) is provided for delivering a correcting variable (u) determining the scanning ratio of a pulse-width modulated voltage (upwm(t)) delivered to the series resonant circuit of the converter.