Brushless electric exciter for dynamoelectric machines

DETAILED DESCRIPTION OF INVENTION The invention will next be illustrated with reference to the figures wherein similar numbers indicate the same elements in all figures.
Such figures are intended to be illustrative rather than limiting and are included herewith to facilitate the explanation of the apparatus of the present invention.
Referring now to FIG.
2, there is shown a brushless electric transformer system 30.
The system comprises first transformer winding 32 adapted to rotate about axis Z and comprising circumferentially wound first conductor 34 mounted on outer surface 36 of ferrite core 38.
Second transformer winding 40 is spaced apart from and concentric with first transformer winding 32 and comprises second conductor 42 mounted on inner cylindrical surface 44 of ferrite casing 46 that surrounds ferrite core 38.
First conductor 34 has a first diameter d.
sub.
1 and second conductor 42 has a second diameter d2 where d2 is just sufficiently larger than d.
sub.
1 such that the two conductors are spaced apart by air gap 48 that allows the first conductor to rotate without contacting the second conductor.
As shown in FIG.
2, ferrite core 38 and ferrite casing 46 form a substantially complete enclosure for stationary coil 40 and rotating coil 32 wherein the ferrite core and the ferrite casing each comprise a toroid having a C-shaped cross section.
Ferrite core 38 comprises a toroid created by rotating the C-shape axially about its closed side 50 whereas the ferrite casing 46 comprises a toroid created by rotating the C-shape axially about the open side 52 of the C-shape.
Toroidal ferrite core 38 may also be described as a cylinder with an axial bore hole 39 adapted for mounting on a shaft (not shown).
Bore hole 39 may be sufficiently sized to fit on the shaft directly or to be mounted to the shaft using a bolt (not shown) that extends through the bore hole and into the shaft.
Because the shaft or bolt used to secure the core to the shaft are typically metal, an insulating layer 37 comprising any dielectric material known in the art, may be provided between ferrite core 38 and the shaft or bolt