Abstract: A circuit in which a load connected to the output of an amplifier, and in particular for the gradient coil arrangement in a nuclear magnetic resonance tomography unit. To reduce the power loss in the amplifier, especially where, as in NMR tomography, high currents must be switched in relatively short time intervals, the supply voltage for the amplifier is delivered by a d.c. voltage generator the output voltage of which follows the input voltage in steps, but always remains a certain amount larger than the output voltage of the amplifier assigned to the respective input voltage.

Abstract: The invention relates to a high-voltage generator for supplying two different output voltages or output currents, particularly for X-ray tubes whose anode current deviates from the cathode current. Symmetrical output voltages can be obtained during operation of this device, despite asymmetrical loads to the anode and cathode, by using a resonant direct current/alternating current converter with a capacitor circuit which is discharged through two different primary windings. The discharge through one primary winding takes place with a preferably adjustable delay with respect to discharge through the other primary winding.

Abstract: A device comprising a transformer for step-wise varying voltages in which, in order to prevent undesired oscillations in the transformer, a circuit is included in the connection lead thereof, said circuit comprising at least one inductive element and at least one rectifying element. The inductance of the inductive element is a number of times higher than the leakage inductance of the transformer. The circuit has the property that the current through the inductive element (elements) does not change its direction when the sign of the voltage between its connection terminals is reversed.