Abstract: In the device, an electric motor is designed as a brushless, electronically commutated pancake motor (201) with permanent magnets arranged on the rotor and coreless windings arranged on the stator. Each winding is provided with a pair of terminals which can be connected in each case via a controllable switch at least to each phase conductor of the alternating power supply and to each other via a further controllable switch.In a device with pick-ups, the instantaneous voltage between one phase conductor each and a neutral conductor or another phase conductor of the alternating power supply, the instantaneous voltage between the two terminals of at least one pair of terminals, and also the instantaneous current in one winding each are repeatedly sampled. The sampled instantaneous voltages or currents are compared with one another and with corresponding threshold values in order to control the switches in dependence on the instantaneous result of the comparisons.