Patent ID: 8450954

Claim:
An electric motor apparatus configured as a universal motor, said electric motor apparatus comprising: a rotor component and a stator component, said rotor component arranged to rotate with respect to said stator component; a rotor winding arrangement mounted on said rotor component; a stator winding arrangement mounted on said stator component; a rotational position indicator configured to generate rotational position information indicative of a relative orientation of said rotor component and said stator component; a rotor winding control unit fixedly mounted on said rotor component, said rotor winding control unit coupled to a rotor supply voltage supplied to said rotor component and configured to perform a rotor waveform generation operation to generate a rotor waveform from said rotor supply voltage in dependence on said rotational position information and to apply said rotor waveform to said rotor winding arrangement; and a stator winding waveform generator configured to receive a stator supply voltage, to generate therefrom a stator waveform in dependence on said rotational position information and to apply said stator waveform to said stator winding arrangement, wherein said rotor waveform and said stator waveform are generated in synchronization with said relative orientation of said rotor component and said stator component in order to synchronize mutual interactions of said rotor winding arrangement and said stator winding arrangement with said relative orientation.