While the whole weight of magnetic shields provided in a tank of a transformer is reduced, eddy current loss by magnetic flux leaked from a winding is reduced. A transformer is configured using an iron core having an iron core leg and an iron core yoke, windings wound around the iron core leg, a tank having the iron core and the windings therein, and a first magnetic shield and second magnetic shields formed by laminating silicon steel sheets inside the tank. The first magnetic shield is arranged opposite to the windings, the second magnetic shields are arranged between the first magnetic shield and the tank, and the first magnetic shield and the second magnetic shields are fixed to the tank by different support members.

An electronic device which is inductively powered or charged has a receiver coil on which a metal object can be placed without causing deterioration of the coil's magnetic field and without generating heat in the metal object. An ultra-thin, flexible, high magnetic permeability metal foil having a thickness of 50 μm or less is provided as a shielding layer between the coil and the object. Radial slits are provided in the shielding layer, which suppress unwanted eddy currents in the layer to reduce power transfer losses and heat generation.

A magnetic circuit component includes a magnetic core and a coil formed by winding a conductor around the magnetic core. The magnetic circuit component includes a magnetic material section that is formed from a soft magnetic material, and that covers a part of a surface of the coil or the entire surface of the coil and is disposed away from the magnetic core.

A contactless power supply device includes a power-transmitting-side pad and a power-receiving-side pad. Each of the power-transmitting-side pad and the power-receiving-side pad has a core and a coil. The core has a plate-shaped yoke portion. The coil has a first coil portion and a second coil portion. The first coil portion is arranged on a top surface of the yoke portion. The second coil portion is arranged along an outer periphery of the yoke portion.

A magnetic shield for shielding adjacent coils of an ICPT system. One or more conductors are configured to distribute induced eddy currents from the surface of the shield to below the surface and thus reduce heating due to eddy currents. The magnetic shield may be employed to transfer power over rotary couplings, such as the shaft of a wind turbine.

A non-eddy current electro-magnetic interference (EMI) shield to prevent or inhibit generation of eddy currents in the shield. The shield may include a non-conductive enclosure, one or more conductive traces interlaced on the non-conductive enclosure, wherein the one or more conductive traces do not form any conductive loops, and one or more ground connections on the one or more conductive traces, wherein the one or more ground connections do not form a ground loop. The EMI shielded electronic device may at least partially encompass an electronic device, such as a magnetic tracker, wherein the EMI shield comprises a non-conductive housing, with conductive traces interlaced on the housing, in a pattern or arrangement such that the conductive traces do not form any conductive loops. One or more ground connections may be provided for the one or more conductive traces.

A resonant induction wireless power transfer coil assembly designed for low loss includes a wireless power transfer coil, a non-saturated backing core layer adjacent the wireless power transfer coil, an eddy current shield, a gap layer between the backing core layer and the eddy current shield, and an enclosure that encloses the wireless power transfer coil, backing core layer, gap layer and eddy current shield. The gap layer has a thickness in a thickness range for a given thickness of the backing core layer where eddy current loss in the eddy current shield is substantially flat over the thickness range. A thickness of the backing core layer and a thickness of the gap layer are selected where a total power loss comprising power loss in the backing core layer plus eddy current loss over the gap layer is substantially minimized.

In some examples, a magnetic shield for a plasma source is provided. An example magnetic shield comprises a back-shell. The back-shell includes a cage defined, at least in part, by an arrangement of bars of ferro-magnetic material. The cage is sized and configured to at least extend over a top side of an RF source coil for the plasma source.

A shield sheet comprises a collar magnetic sheet and a center magnetic sheet. The collar magnetic sheet is provided with a hole adapted to the center magnetic sheet. The center magnetic sheet has one end fixed in the hole and the other end protruding out of the collar magnetic sheet. The collar magnetic sheet comprises at least one first magnetic permeable layer, which is a nanocrystal strip, an amorphous strip or a metallic soft magnetic strip. The center magnetic sheet comprises at least two second magnetic permeable layers stacked one on another, which are fragmented nanocrystal strips, fragmented amorphous strips or fragmented metallic soft magnetic strips. Fewer nanocrystal strips are stacked for the collar magnetic sheet in the shield sheet of the invention, facilitating the miniaturization of the shield sheet and increasing charging efficiency.

In some examples, a patterned magnetic core includes a first sub-score and at least one second sub-core. The first and second sub-cores are spaced apart by a gap, optionally filled with material of sufficiently low electrical conductivity. Each of the first and second sub-scores includes a number of magnetic layers and a number of interlamination layers disposed between the magnetic layers in an alternating fashion.