Abstract: A core for a multi-phase transformer includes a body made of two or more rings having a common central axis. Each ring consists of a strip of magnetic permeable material wound about the central axis. The body is provided with a plurality of radially disposed windows, each window being bound by opposed axially extending legs and opposed circumferentially extending branches. The branches of each window are provided in respective axially adjacent rings, so that the branches and legs of each window define a closed magnetic circuit of substantially uniform magnetic permeability through which magnetic flux can circulate about the windows.

Abstract: An electric motor includes a Cockcroft ring for producing a magnetic field having lines of flux extending in a first direction through an air gap. A disc capable of at least two-dimensional motion in a plane relative to the Cockcroft ring provides a plurality of conductive paths, each path having a segment that extends through the magnetic field in a second direction so that interaction with an electric current passing through a particular segment produces a thrust force acting on the disc via that segment. A multiphase toroid shaped transformer induces electric currents to flow in the conductive paths and thus through the corresponding segments. The direction and magnitude of the respective thrust forces and thus the motion of the disc relative to the Cockcroft ring can be controlled by varying the magnitude and/or phase relationship of the electric currents flowing through the segments.

Abstract: A core for a multi-phase transformer includes a body made of two or more rings having a common central axis. Each ring consists of a strip of magnetic permeable material wound about the central axis. The body is provided with a plurality of radially disposed windows, each window being bound by opposed axially extending legs and opposed circumferentially extending branches. The branches of each window are provided in respective axially adjacent rings, so that the branches and legs of each window define a closed magnetic circuit of substantially uniform magnetic permeability through which magnetic flux can circulate about the windows.

Abstract: An electric motor 10.sub.vi includes a Cockcroft ring 12 for producing a magnetic field having lines of flux extending in the first direction through an air gap 18. A disc 14 capable of at least two dimensional motion in a plane relative to the Cockcroft ring 12 provides a plurality of conductive paths C.sub.A -C.sub.E. Each path C.sub.A -C.sub.E has a segment 16.sub.A -16.sub.E respectively that extends through the magnetic field in a second direction so that interaction with an electric current passing through a particular segment 16.sub.A -16.sub.E, produces a thrust force acting on the disc 14 via that segment 16.sub.A -16.sub.E. A multi phase toroid shaped transformer 40 induces electric currents to flow in the paths C.sub.A -C.sub.E and thus through the corresponding segments 16.sub.A -16.sub.E. One of the segments, for example 16.sub.A is located relative to a second segment for example 16.sub.E, so that their respective thrust forces do not lie in the same axis.

Abstract: A primary member for a linear induction machine comprises a magnetic core having four parallel limbs with a respective pole face on each limb. Thus the core is similar to an E-core with an additional limb. Windings are preferably disposed only on the inner two limbs so that there are effectively no end windings, all windings coupling with the core.

Abstract: A layer of metal is cast on a surface of a metal backing and while the cast metal is still molten, a varying electromagnetic force is generated along an edge of the strip which induces electric currents in the molten metal. The resulting mechanical force exerted in the molten metal is such that the metal is restrained from flowing to the edge of the strip.

Abstract: A linear induction motor primary has the winding conductors on at least part of its working face arranged in two nonparallel groups of mutually parallel conductors. All the windings on the working face, including end windings and cross over windings, are closely coupled to the magnetic material of the core of the primary.