A magnetic core for an electromagnetic induction device, comprising: a limb made of a grain-oriented material, a yoke made of an amorphous material, and an auxiliary joint member made of grain-oriented material, wherein the auxiliary joint member joints the limb with the yoke, wherein the grain orientation of the limb is perpendicular to the grain orientation of the auxiliary joint member.

A coil electronic component includes a body including ferrite, a coil portion embedded in the body, external electrodes electrically connected to the coil portion, and a magnetic permeability adjusting layer disposed in the body and including ferrite having a Curie temperature lower than that of the ferrite included in the body.

An inductor element includes a wire-winding portion and a core portion. In the wire-winding portion, a conductor is wound in a coil shape. The core portion surrounds the wire-winding portion and contains a magnetic powder and a resin. The wire-winding portion includes an inner circumferential surface. A winding-wire inner circumferential neighboring region is a region of the core portion within a distance from the inner circumferential surface toward a winding axis of the wire-winding portion. An inner-core central region is a region of the core portion within a distance from the winding axis center toward an existing region of the wire-winding portion in an outward direction perpendicular to the winding axis center. SS15.0% is satisfied, where S(%) and S1(%) are respectively an area ratio of a magnetic powder in the inner-core central region and the winding-wire inner circumferential neighboring region.

An integrated magnetic element is provided, including a first magnetic-core frame, three second magnetic-core frames, and three coil windings. The first magnetic-core frame has a first side pillar and a second side pillar opposite to the first side pillar. The three second magnetic-core frames are arranged on the side corresponding to the first side pillar of the first magnetic-core frame, and are arranged in parallel with the axis of the first side pillar of the first magnetic-core frame. Each of the second magnetic-core frames has a first side pillar adjacent to the first side pillar of the first magnetic-core frame, and a second side pillar opposite to the first side pillar of itself. The three coil windings connect to a three-phase grid, and wind around the first side pillar of the first magnetic-core frame and the corresponding first side pillar of the second magnetic-core frame respectively.

A voltage converter is designed to convert an alternating input voltage into a direct output voltage. The voltage converter includes a first sub-converter having a first switch half-bridge, which is coupled to a first pole of the input voltage by a first main coil, and a second sub-converter having a second switch half-bridge, which is coupled to the first pole of the input voltage by a second main coil. In addition, the voltage converter includes a diode half-bridge, which is jointly used by the first sub-converter and the second sub-converter. The voltage converter has a first return coil and a second return coil, which couple a center point of the diode half-bridge to a second pole of the input voltage. The first and second main coils and the first and second return coils form a coupled choke, the coupled choke having a choke core. The choke core has at least one outer leg, which is surrounded by windings of the first and/or second main coil and/or of the first and/or second return coil, and at least one center leg, which is not surrounded by windings of the main coils or of the return coils. The outer leg and the center leg have materials with different permeabilities.

A radio-frequency (RF) transformer includes a ferrite core defining a bore therethrough. The RF transformer also includes a first wire and a second wire. The first and second wires are twisted and form a first exterior half loop at least partially around an exterior of the ferrite core. The first wire, but not the second wire, forms a second exterior half loop at least partially around the exterior of the ferrite core. The ferrite core is configured to provide a primarily magnetic coupling for signals having a frequency that is less than a predetermined threshold. The first and second wires are configured to provide a primarily capacitive coupling for signals having the frequency that is greater than the predetermined threshold.

A coil electronic component includes a body and external terminals. The body includes a winding coil part and a pillar-shaped core part inserted inside of the winding coil part and formed of a magnetic metal. The external terminals are connected to the winding coil part and disposed on an external surface of the body. The body contains the magnetic metal and a resin, and the pillar-shaped core part has magnetic permeability higher than that of a portion of the body disposed outside of the winding coil part.

A reactor including: a coil having a winding portion; a magnetic core that is disposed extending inside and outside the winding portion, and is configured to form a closed magnetic circuit; and a resin mold that includes an inner resin disposed between the winding portion and the magnetic core, and does not cover an outer peripheral face of the winding portion.

Current sensors and associated measurement systems. A current sensor includes: an insulating substrate provided with a central opening; a Rogowski winding surrounding the central opening and including a first coil and a second coil which are superposed and electrically connected in series, the first coil and the second coil being wound around the substrate along a first contour line and a second contour line, respectively, each contour line defining, in the plane of the substrate, a contour in the shape of a quadrilateral centred on the central opening;
wherein a length of the contour in the shape of a quadrilateral defined by the first contour line is greater than a length of the quadrilateral defined by the second contour line and a width thereof is smaller than a width of the quadrilateral defined by the second contour line.

An inductor includes a body having a first magnetic portion above and below a coil, and a second magnetic portion above and below the first magnetic portion. The magnetic flux density of the magnetic substance in the first magnetic portion is higher than that of the magnetic substance in the second magnetic portion.