Abstract: An electric synchronous motor comprising a rotor with a cage winding consisting of a solid shaft and rotor laminar packets holding the cage rods, sequential poles being located in axially spaced planes, a stator with a field winding and a direct-current energizing winding located between said planes on the rotor having as characterizing feature that the lamination packets form closed rings and the shaft of the rotor has local recesses to form holes. In this way a higher starting torque can be developed than in a motor of the same size, since the cage rods are embedded in iron also in the interpolar space.

Abstract: This invention relates to a synchronous electric motor comprising a housing accommodating a stator having a.c. windings and a winding for producing a coaxial direct field and a rotor provided with a cage winding, the poles of which being arranged in axial, relatively spaced transverse planes, wherein radially extending connecting elements are arranged in the interpolar space between the cage windings and the rotor, said connecting rings being formed by rings arranged on the rotor shaft and made from non-magnetic material.

Abstract: A brushless three-phase current generator having a fed-back, controllable device for self-excitation and automatic control of the energizing current, said device comprising controllable means for deriving from the generator output part of the output voltage and the load current of the generator and the vectorial combination and supply thereof to a multi-phase rectifier whose output is connected to a stationary d.c. energizing winding of an excitor, the rotating multi-phase winding of which enables the rotating field winding of the generator through a commonly rotating rectifier, wherein the synchronous reactance of the multi-phase winding of the excitor at the frequency corresponding to the nominal speed is achieved, which is greater than the equivalent impedance of the generator field winding.