Electronically controlled universal motor

A method of operating an electric motor apparatus, said electric motor apparatus comprising:

• a stator component and a rotor component rotationally mounted coaxially with and within said stator component;
• said stator component and said rotor component each comprising windings for generating an electromagnetic field;
• said electric motor further comprising an intermediate screening component rotationally mounted between said stator component and said rotor component and configured to provide at least some magnetic screening between said rotor component and said stator component;
• said intermediate screening component comprising at least some magnetically active sections configured such that changing magnetic fields generated by changing electric currents in said windings on either said rotor component or said stator component generate a force on said magnetically active sections causing said intermediate screening component to rotate;
• said method comprising
• controlling an output rotational speed of said motor by providing power to either said rotor or said stator or said rotor and said stator, control circuitry for independently controlling power supplied to said windings on said rotor component and said stator component in dependence upon a desired output rotational speed.

An electric motor apparatus comprising:

• a stator component and a rotor component rotationally mounted coaxially with and within said stator component;
• said stator component and said rotor component each comprising windings means for generating an electromagnetic field;
• said electric motor further comprising an intermediate screening means for providing at least some magnetic screening between said rotor component and said stator component, said intermediate screening means being rotationally mounted between said stator component and said rotor component;
• said intermediate screening means comprising at least some magnetically active means for responding to changing magnetic fields generated by changing electric currents in said windings on either said rotor component or said stator component by generating a force such that said intermediate screening component is caused to rotate;
• and
• control means for independently controlling power supplied to said winding means on said rotor component and said stator component in dependence upon a desired output rotational speed.