Disclosed herein is a common mode filter that includes first and second terminal electrodes provided on the first flange part, third and fourth terminal electrodes provided on the second flange part, a first wire wound around the winding core part and having one end connected to the first terminal electrode and other end connected to the third terminal electrode, and a second wire wound around the winding core part and having one end connected to the second terminal electrode and other end connected to the fourth terminal electrode. The winding core part includes a first winding region, a second winding region, and a third winding region positioned between the first and second winding regions in the axial direction. The first and second wires are bifilar-wound in the first and second winding regions and layer-wound in the third winding region.

A noise filter (10) is equipped with a plurality of conductors (20) having respective winding portions (21) and a ring-shaped core (30) which is inserted through the winding portions of the a plurality of conductors and made of a magnetic material. The ring-shaped core is composed of a pair of divisional cores (41) and (42) which are combined together by joining each pair of joining surfaces (43) and (44), located at each end, of the pair of divisional cores and. The one divisional core is straight and is inserted through the winding portions of the a plurality of conductors. The other divisional core has partition walls (45) each of which is located between adjacent ones of the a plurality of conductors, projects toward the one divisional core, and serves to form a magnetic path between the partition wall and the one divisional core.

An inductor element includes a resin substrate which is an insulating substrate including conductor patterns, and coils defined by the conductor patterns. Two coils are arranged on the same plane, and connected in series. Adjacent coils define a closed magnetic circuit. That is, the winding direction and the connection of the coils are determined such that magnetic flux that interlinks coils that are adjacent in the planar direction define a loop. There are also provided an inductor bridge and a high-frequency filter that include the inductor element.

The present disclosure provides a wrapping method for the common inductor. The common mode inductor includes a first coil winding and a second coil winding. The wrapping method for a common mode inductor includes steps of: disposing two isolation blocking sheets at different positions of a magnetic core; wrapping the first coil winding around the magnetic core, wherein the first coil winding is divided into two wrapping areas by one of the isolation blocking sheets; wrapping the second coil winding around the magnetic core, wherein the second coil winding is divided into two wrapping areas by the other one of the isolation blocking sheets, wherein the first coil winding and the second coil winding are symmetrically wrapped.

A common mode noise filter includes a first coil and a second coil. The first coil is formed in a plurality of insulating layers and includes a spiral first coil conductor and a spiral second coil conductor. The second coil is formed in the plurality of insulating layers and includes a spiral third coil conductor and a spiral fourth coil conductor. The first and third coil conductors are magnetically coupled to form a first common mode filter unit, and the second and fourth coil conductors are magnetically coupled to form a second common mode filter unit. As viewed from above, a first direction in which currents flow through the first and third coil conductors in the first common mode filter unit is opposite to a second direction in which currents flow through the second and fourth coil conductors in the second common mode filter unit.

A holder holds a first magnetic member through which a first signal cable is passed and a second magnetic member through which a second signal cable is passed. The holder holds the first magnetic member with a first holding portion including an elastic engagement portion. The holder is also provided with a second holding portion to hold the second magnetic member at a position where the second magnetic member overlaps with the first magnetic member. A restrict portion is arranged on the elastic engagement portion and configured to restrict movement of the second magnetic member held by the second holding portion.

The present disclosure provides a switching power supply, an EMI filter, a common mode inductor and a wrapping method for the common mode inductor. The common mode inductor includes a first coil winding and a second coil winding. The wrapping method for a common mode inductor includes steps of: disposing two isolation blocking sheets at different positions of a magnetic core; wrapping the first coil winding around the magnetic core, wherein the first coil winding is divided into two wrapping areas by one of the isolation blocking sheets; wrapping the second coil winding around the magnetic core, wherein the second coil winding is divided into two wrapping areas by the other one of the isolation blocking sheets, wherein the first coil winding and the second coil winding are symmetrically wrapped.

Inductor designs and methods are provided. An inductor can include a first core and a second core. The first core can be larger than the second core and the second core can be seated within the inner diameter of the first core. A first and a second wire can be provided that each wrap around the first core and the second core. The first core can have less windings than the second core.

An inductor is provided, comprising: a first ferrite core piece and a second ferrite core piece, each of which are made of substantially similar materials, exhibit desired electromagnetic properties, and which are fashioned in a substantially similar manner and shape, and wherein each of the first and second ferrite core pieces comprises a substantially planar mating surface, a center post, and a wire core assembly channel, and wherein a first substantially planar mating surface of the first ferrite core piece is adapted to planarly mate with a second substantially planar mating surface of the second ferrite core piece; and a wire core assembly adapted to be substantially self-locating and self-centering about a first or second center post when located in a respective first or second wire core assembly channel.

A common-mode choke coil comprises a ferrite core including a winding core portion and first and second flange portions. The common-mode choke coil also comprises first and second wires, each of which is helically wound around the winding core portion. The common-mode choke coil further comprises first and second terminal electrodes to which a first end of the first wire and a second end of the first wire, that is opposite the first end, are electrically connected, respectively. In addition, the common-mode choke coil comprises third and fourth terminal electrodes to which a first end of the second wire and a second end of the second wire, that is opposite the first end, are electrically connected, respectively. A common-mode inductance value at 150 C. and 100 kHz is 160 H or more, and a return loss at 20 C. and 10 MHz is 27.1 dB or less.