A rotary electromagnetic machine is described which comprises first and second substantially cylindrical parts arranged to move relative to each other about a common axis. The first cylindrical part produces a spatially periodic radial magnetic field across an air gap, the magnetic field having a regular alternating polarity around the circumference of the first cylindrical part. The second cylindrical part comprises at least one laminar electrical conductor wrapped into cylindrical form and placed in the air gap to intercept the magnetic field, the laminar electrical conductor comprising a regular pattern of electrically conductive paths within the air gap. In more general terms, rotary motors in which the wire coils are replaced by laminations of material in which patterned conducting paths are created are described. The conducting laminations are placed in the air gap between an armature and backing iron that is constructed so as to reduce eddy current losses.
