Patent ID: 8550196

Claim:
A method for turning a shaft comprising: receiving a first direct current power input; receiving a second direct current power input; producing a first variable frequency alternating current control signal from the first direct current power input; separately producing a second variable frequency alternating current control signal from the second direct current power input, synchronized to the first variable frequency alternating current control signal; producing a first rotating magnetic field responsive to the first variable frequency alternating current control signal; producing a second rotating magnetic field, responsive to the second variable frequency alternating current control signal and synchronized to the first rotating magnetic field; inducing a first induced magnetic field around a conductor in a first inductive rotor, responsive to the first rotating magnetic field; inducing a second induced magnetic field around a conductor in a second inductive rotor, responsive to the second rotating magnetic field; applying a first rotational force between the first rotating magnetic field and the first induced magnetic field to the shaft; and applying a second rotational force between the second rotating magnetic field and the second induced magnetic field to the shaft.