Abstract: The arrangement or apparatus for operating a magnetically suspended, electromotoric drive apparatus in the event of a mains disturbance comprises a drive converter feeding the drive apparatus, a driver feeding a magnetic bearing and a voltage converter, which are connected to a common intermediate circuit. The voltage converter feeds a stopping control apparatus and the drive converter can be switched to a regeneratively acting mode of operation by the stopping control apparatus in the event of a mains disturbance in order to provide at least the driver feeding the magnetic bearing and the stopping control apparatus with electrical energy via the intermediate circuit.

Abstract: A method and a device for driving a series circuit of power semicondutor switches (2) are specified. In this case, the voltage loading of the individual switches of the series circuit is balanced by providing that the voltage (Uce1 . . . Ucen) across each switch of the series circuit is measured as the controlled variable, and that this measured voltage is used to vary the switching instants in such a way that the voltage loading during switching is essentially equal for all the switches. In addition, the level of the control voltage (Ugeoff1 . . . Ugeoffn) in the blocking state can be influenced with the aid of the measured voltage in such a way that the blocking voltages of the switches are essentially equal. The advantage of the invention is to be seen in that the voltage loading of the individual semiconductors can be balanced not only during switching, but also in the blocking state.