A pair of stators produce a magnetic field within a space between them. a ferromagnetic toroidal rotor is rotationally mounted within the magnetic field. A plurality of windings are wound radially on the rotor and each winding provides a plurality of coils. Each of coils is interconnected through a switch, the switch configured for placing each of the coils within each winding alternatively in one of an electrical series connection, an electrical parallel connection, and an electrically isolated connection, so that when operated as a generator, a selected output voltage and current are produced by rotor rotation and when operated as a motor a selected output speed and torque are produced.