Rotary anode x-ray tube comprising a circuit arrangement for accelerating and braking of the rotary anode

The stator coils (2,3) of the rotary anode drive motor is supplied with phase-offset AC voltages in the acceleration mode. In a brake mode at least one stator coil (2) is supplied with a DC voltage (10-12, 20-22). Both modes are controlled. At least one stator coil is coupled to a voltage source. In the first operational mode the source delivers a periodical AC voltage, while in a second operational mode it delivers a pulsed DC voltage. To the stator coil is parallel connected a switchable diode assembly (30) of such polarity that the pulsed DC voltage operates it in blocking direction. The control (14-16; 34-36) holds the AC voltage source in first state in the acceleration mode and switches-off the diode assembly. In the brake mode the source is held in the second state and the diode assembly is switched-on.