In accordance with one embodiment, a contactless power transfer system is
provided that comprises a stationary member including a power input
configured to receive power at first voltage from a power supply. The
system further includes a rotating member rotatably coupled to the
stationary member and a rotary transformer. The rotary transformer has
primary and secondary sides, with the primary side being disposed on the
stationary member. The primary side has a primary winding that receives
power at the first voltage from the power input. The secondary side is
disposed on the rotating member and produces power at a second voltage.
The secondary side has a rotating core and separate secondary
sub-windings, each of which has forward and return paths that are
circumferentially disposed about the rotating core. The forward and
return paths of each of the sub-windings rotate proximate to, and are
disposed a substantially equal distance from, the primary winding
disposed on the stationary member.