Patent ID: 7274280

Claim:
An autotransformer for converting three-phase AC power to nine-phase AC power comprising: a. three coils each containing serial windings and a plurality of non-serial windings; b. said serial windings and plurality of non-serial windings being magnetically coupled; c. said windings on said coils containing a start end and a finish end such that current entering the start end produces a magnetic flux in one direction whereas a current entering the finish end produces a magnetic flux in the opposite direction; d. said windings being possible of at least two methods of interconnection; e. with a first method of interconnection obtained by joining the finish end of a non-serial winding on a third coil with the start end of a serial winding on a first coil; with the finish end of said serial winding being connected to the finish end of a non-serial winding on the third coil; with the start end of said non-serial winding being connected to the start end of a non-serial winding on the first coil; f. said interconnections of the first method of interconnection being repeated sequentially for all three coils until all windings are interconnected to form a nonagon; g. with a second method of interconnection obtained by joining the start end of a non-serial winding on a second coil with the start end of a non-serial-winding on a first coil; with the finish end of said non-serial winding being connected to the start end of a non-serial winding on a third coil; with the finish end of said non-serial winding being connected to the start end of a serial winding on the first coil; with the finish end of said serial winding being connected to the finish end of a non-serial winding on a third coil; h. with said interconnections of the second method of interconnection being repeated sequentially for all three coils until all windings are interconnected to form a dodecagon; i. said nonagon and dodecagon topologies including symmetrically disposed nodes; j. said symmetrically disposed nodes providing points for applying three-phase AC input voltage and extracting AC output voltages of predetermined amplitude and phase.