Abstract: In a method for fabricating a permanent magnet rotor for an electrical machine, a rotor support having an axis of rotation is provided. At least two poles are provided on the rotor support, each pole having at least one permanent magnet. A screen made essentially from a highly conducting material is provided on the surface of the permanent magnets facing a stator of the electrical machine. The screen is applied galvanically. On the screen an annular fiber reinforced support is fitted. The rotor support comprises two partially conical parts interacting with each other to prestress the rotor radially.

Abstract: Control circuit for semiconductor components of a converter circuit which can be switched on and off to convert direct current into three-phase current. The converter circuit is connected between a direct-current source and the stator of a synchronous machine having a cylindrical rotor. The control circuit measures rotor position and the direct current and determines from the obtained signals the value of the commutation angle .mu. of the phase current i in the converter at any value of the direct current I.sub.d on the basis of a model of the synchronous machine which solely takes account of the fundamental harmonic of the phase current i, the firing angle .alpha. of the semiconductor components being set between limits determined for any value of the direct current I.sub.d by the associated commutation angle .mu..