Abstract: In the case of known switched-mode power supplies with integrated preconditioner, the control curves are largely congruent, but deviate from one another in low-load operation, whereby the unregulated intermediate circuit voltage increases. To improve efficiency in low-load operation, closed-loop control of the burst cycle is effected on the primary side of the voltage transformer. The intermediate circuit voltage is limited to a permissible limit value. The closed-loop control device in the switching stage taps the intermediate circuit voltage at a voltage divider which is arranged between the preconditioner functional unit and the switching stage. An assembly additionally monitors the output voltage, for example by means of an optocoupler. Burst mode comprises one or more burst cycles. A burst cycle is started when the intermediate circuit voltage reaches its limit value. At this time, the voltage transformer is switched off. A burst cycle ends when the output voltage reaches a minimum value.

Abstract: In the case of known switched-mode power supplies with integrated preconditioner, the control curves are largely U congroent, but deviate from one another in low-load operation, whereby the unregulated intermediate circuit voltage increases. To improve efficiency in low-load operation, closed-loop control of the burst cycle is effected on the primary side of the voltage rns- former. The intermediate circuit voltage is limited to a permissible limit value. The closed-loop control device in the switching stage taps the intermediate circuit voltage at a voltage divider which is arranged between the preconditioner functional unit and the switching stage. An assembly additionally monitors the output voltage, for example by means of an optocoupler. Burst mode corn- pnses one or more burst cycles. A burst cycle is started when the intermediate circuit voltage reaches its limit value. At this time, the voltage transformer is switched off. A burst cycle ends when the output voltage reaches a minimum value.

Abstract: A power supply for X-ray generators which includes at least one inverter (11, 12, 13), at least one transformer (111, 121, 131) and at least one voltage cascade (112, 122, 132) for generating a supply voltage for an X-ray tube (15). In order to increase the output power that can be achieved with a comparatively small weight and a low ripple or output capacitance, the voltage cascade is conceived in respect of its capacitances and the stray inductance of the transformers (111, 121, 131) in such a manner that it can be made to operate in the resonance mode by appropriate control of the inverter. In respect of the properties mentioned it is notably advantageous to integrate a two-phase embodiment or three-phase embodiment with an X-ray system so as to form a compact tank generator.

Abstract: An AC/DC converter includes a resonance converter (A3) which is suitable, for example, for operation with different AC line voltages from different AC power grids. The AC/DC converter further includes a bridge circuit (A4) drivable as a full-bridge circuit and as a half-bridge circuit, an arrangement (A2) working as an up-converter coupled, at least via a capacitor, (C2) to the resonance converter (A3), and a transformer (T) in the resonance converter (A3) and realizing a point (7) at which the arrangement (A2) is capacitively (C2) coupled to the resonance converter (A3). The primary winding of the transformer (T) is divided and this dividing point is arranged as the point (7).

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: The invention relates to a power supply unit for supplying power to a plasma display panel, wherein an active network filter without electrical isolation is provided for the generation of an essentially constant DC voltage from an AC supply voltage, a DC-DC voltage converter being connected to the output of the active network filter with at least one first and one second output and with electrical isolation between the constant DC voltage and the outputs, a regulator being assigned to the DC-DC voltage converter to regulate the voltage at the first output, and a voltage actuator being connected in series at least to the second output.

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 standby circuit, an electrical device with a standby circuit, a method for the control of the electrical device and a power supply assembly. Whereas the power supply unit and the control electronics are in permanent operation when conventional devices are in the standby mode and consequently have a high power consumption, the invention proposes a solution for saving energy while retaining convenience of operation by which the power supply unit is switched off in the standby mode. A standby circuit, preferably fed by an energy buffer element, remains active in the standby mode and monitors signal inputs for activation events. When an activation event occurs, the standby circuit switches on the power supply unit.

Abstract: The invention relates to an AC/DC converter comprising a resonance converter (A3), which is suitable, for example, for operation with different AC mains voltages from different AC power grids.

Abstract: The invention relates to a voltage converter for two independent loads (L1, L2) with a bridge circuit (S1, S2, Sa, Sb and S3, S4, Sa, Sb) for a first (L1) and a second (L2) load, respectively, for converting a DC voltage (U45) jointly applied to the bridge circuits (S1, S2, Sa, Sb and S3, S4, Sa, Sb) into an AC voltage (U68, U98) assigned to the respective load (L1, L2),

Abstract: A circuit arrangement is provided for controlling an electric motor (2), in particular a three-phase, three-strand motor, which is coupled to an intermediate circuit voltage (4) via a DC/AC converter (3) having three DC/AC converter branches (7,8,9). A measuring signal (i.sub.b1,i.sub.b2,i.sub.b3) which is proportional to the branch current is derived from each of the DC/AC converter branches (7,8,9), and a control signal (I.sub.pn), which is substantially proportional to the total value of the strand currents (i.sub.1,i.sub.2,i.sub.3) of the motor, is derived from these measuring signals (i.sub.b1,i.sub.b2,i.sub.b3).

Abstract: An X-ray apparatus, includes a power supply section for powering an X-ray tube (4) with a high-voltage transformer (3) which has two groups of primary and secondary windings provided on the same transformer core, the coupling between the primary windings (16, 26) belonging to different groups being weaker than the coupling between primary and secondary windings (for example, 16, 31) belonging to the same group, the primary windings of the two groups being connected to two inverters (1, 2) which operate at the same frequency. Control of the power at the secondary side is improved in that the inverters are operated at a fixed frequency and with a duty cycle which can be independently controlled.