A heat dissipation structure for the reactor includes a housing, a reactor body, and one or more heat dissipation pipes. Each of the one or more heat dissipation pipes is disposed in a cavity of the housing and is connected to the housing in a leak-tight manner, a closed cavity is formed between the one or more heat dissipation pipes and the housing, and the reactor body is disposed in the closed cavity. The above heat dissipation structure for the reactor allows to improve the heat dissipation effect of the reactor under the premise that protection requirements are met. The current carrying density of the coil of the reactor body can be increased and the diameter of copper wires can be reduced under the same conditions, thereby reducing the usage of copper and effectively reducing the cost and weight.

A microelectromechanical system (MEMS) coil assembly is presented herein. In some embodiments, the MEMS coil assembly includes a foldable substrate and a plurality of coil segments. Each coil segment includes a portion of the substrate, two conductors arranged on the portion of the substrate. The substrate can be folded to stack the coil segments on top of each other and to electrically connect first and second conductors of adjacent coil segments. In some other embodiments, the MEMS coil assembly includes a plurality of coil layers stacked onto each other. Each coil layer includes a substrate and a conductor to form a coil. The conductors of adjacent coil layers are connected through a via. The MEMS coil assembly can be arranged between a pair of magnets. An input signal can be applied to the MEMS coil assembly to cause the MEMS coil assembly to move orthogonally relative to the magnets.

A reactor includes a coil having gaps between adjacent turns of a winding, a core inserted through the coil, and a heat-dissipating material that is in contact with a side face of the coil. The heat-dissipating material is inserted between the adjacent turns of the winding of the coil, and the thickness of the heat-dissipating material outside the coil in a direction of an axis of the coil is smaller than the thickness of the heat-dissipating material between the adjacent turns of the winding. By reducing the thickness of the heat-dissipating material outside the coil where contribution to coil cooling is small, the amount of the heat-dissipating material can be reduced without lowering the cooling performance to the coil.

An electromagnetic device is provided with improved thermal management. The electromagnetic device includes a core assembly and one or more sets of windings wrapped around the core assembly. The core assembly is constructed from a plurality of U-shaped cores, or from a plurality of U-shaped cores and I-shaped cores in combination. Various arrangements of thermally conductive plates disposed within the core assembly are provided. The thermally conductive plates transfer heat away from the core assembly to improve the thermal characteristics of the electromagnetic device.

An electromagnetic device is provided with improved thermal management. The electromagnetic device includes a core assembly and one or more sets of windings wrapped around the core assembly. The core assembly is constructed from a plurality of U-shaped cores, or from a plurality of U-shaped cores and I-shaped cores in combination. Various arrangements of thermally conductive plates disposed within the core assembly are provided. The thermally conductive plates transfer heat away from the core assembly to improve the thermal characteristics of the electromagnetic device.

A three-phase AC reactor according to an embodiment of the present invention includes three-phase coils that are not arranged in parallel, an input and output terminal block having an input and output unit having a parallel arrangement, and an external connection position change unit disposed between a coil end of each of the three-phase coils and the input and output terminal block to connect the coil end to the input and output terminal block.

A three-phase AC reactor according to an embodiment of the present invention includes three-phase coils that are not arranged in parallel, an input and output terminal block having an input and output unit having a parallel arrangement, and an external connection position change unit disposed between a coil end of each of the three-phase coils and the input and output terminal block to connect the coil end to the input and output terminal block.

An apparatus has a laminate substrate that has a first surface and an opposite second surface. A laminate transformer is located within the laminate substrate between the first surface and the second surface. The transformer has a first coil adjacent the first surface and a second coil adjacent the second surface. A magnetic core element on the first surface overlaps a portion of the first coil. A lead frame on the first surface is spaced apart from the magnetic core element. A portion of the lead frame overlaps a portion of the first coil to provide a thermal conductive path.

A wireless charging device according to an embodiment, can effectively discharge heat by including an insulating heat dissipation part in the inner part of a magnetic part or between the magnetic part and a coil part. Therefore, the wireless charging device can be effectively used for a transportation means such as an electric vehicle that requires high-capacity power transmission between a transmitter and a receiver.

A reactor includes a coil including a wire that is covered with an insulating film and is wound, the coil including a first lateral surface and a second lateral surface different from the first lateral surface; a cooler that faces the first lateral surface; and an insulating heat radiation layer that is sandwiched between the first lateral surface and the cooler. In the first lateral surface, the wire is not covered with the insulating film. In the second lateral surface, the wire is covered with the insulating film. A degree of flatness of the first lateral surface is lower than a degree of flatness of the second lateral surface.