sources 14 and 15 with this structure the energy at the output of each terminal stage can be controlled and therefore a symmetrical adjustment of the field can be achieved the above described method and the rotary magnetic field generator offered as an exemplary embodiment for the implementation of this method make the creation of a high frequency rotating magnetic field possible by providing output signals at the two terminal stages which are accurately phase shifted by 90 u00b0 across a wide frequency range by means of the control of the terminal stages by steep edge switching pulses instead of high frequency currents all requirements for the provision of a high frequency rotating magnetic field can be achieved without difficulty in particular in respect of the adjustability across a broad frequency range and in the balancing of the separate magnetic fields which combine to cause the rotating magnetic field of circular character the digital control of the terminal stages makes it possible not only to control the terminal stages in an improved manner but also considerably facilitates the requirements in view of the variability of the frequency in case of a rigid 90 u00b0 phase difference of the sinusoidal signals at both outputs of the terminal stages due to the resonant circuits required for reasons of energization of the crossed coils 6 and 7 they only sift.