Abstract: The invention relates to a self-starting electric motor assembly of the type having a permanent magnet rotor, a stator with two windings and electronic switching elements for the windings controlled by switching signals occurring in push-pull and derived from control signals of a sensor detecting the angular position of the rotor. At standstill and for normal running operation the magnetic field distributions between the stator and rotor are selected in a known manner, so that the rotor assumes an angular position which is displaced in relation to the neutral position as an aid to starting and so that the switchover occurs at an angular position ahead of the neutral position to provide greater efficiency for the running operation.

Abstract: The invention relates to a control circuit for a brushless self-starting D.C. motor of the type having a permanent magnet rotor and stator coils, a magnetic field-dependent component or sensing coil for sensing the position of the rotor, and controllable electronic switches in respective series with the stator coils and the D.C. source. The switches control current through the stator coils in dependence on the rotary position of the rotor pursuant to magnetic field dependent parameter changes in the sensing coil. The control circuit is characterized by including an oscillator with an LC resonance circuit of which the inductance is formed by the sensing coil. The circuit includes a modulator for modulating the oscillation of the oscillator in response to the induction changes brought about in the sensing coil. The control signals for the switches are derived from the modulated oscillator oscillation because the oscillator frequency is considerably higher than the rotor speed.