Speed control in self-powered eddy current drive

A variable speed drive for use with a motor, said motor having a motor shaft, comprising:

• a) an electromagnet having a drive coil;
• b) an armature located close to the electromagnet, with one of the electromagnet or the armature being structured and arranged so as to be coupled with the motor shaft so as to rotate in unison with the motor shaft and the other of the electromagnet or the armature being structured and arranged so as to rotate independently of the motor shaft and being directly coupled to a load portion;
• c) a generator having a rotor and a stator, with the rotor being structured and arranged so as to be coupled with the motor shaft and the stator being structured and arranged so as to be coupled to a nonrotating point relative to the motor shaft, with one of the rotor or the stator producing a magnetic field and the other of the rotor or the stator having a winding that is located within the magnetic field, the other of the rotor or the stator that has the winding having an electrical output;
• d) a regulator for regulating the amount of electrical energy that is provided by the generator to the drive coil, the regulator being connected to the drive coil so as to rotate therewith, the regulator having an input for receiving a speed control signal;
• e) a rotary signal coupler for providing said speed control signal from a stationary position relative to the regulator, the rotary signal coupler having a rotating member that is coupled with the electromagnet and a stationary member that is held stationary with respect to the rotating member.