Unique systems, methods, techniques and apparatuses of a power transformer are disclosed. One exemplary embodiment is a transformer comprising a core; a first winding wound around the core; a second winding coaxially wound around the first winding so as to surround the first winding and forming an air gap between the first winding and second winding; and a plate having a relative permeability greater than 1 and less than 25 structured to be inserted into the air gap.

In order to provide a transformer and an electric power converter which are less likely to become deteriorated with time and which have stable insulation performance, the transformer according to the present invention is provided with: a core; a bobbin in which a low-voltage-side primary winding and a high-voltage-side secondary winding are disposed along the central magnetic leg of the core; and a bobbin support part that supports the bobbin at an end of the bobbin on the primary winding side, such that an air gap is provided between the central magnetic leg of the core and a surface of the bobbin corresponding to the secondary winding.

A magnetic component has a primary coil 10; a secondary coil 20 disposed to face the primary coil 10; a core 500 which passes through the primary coil 10 and the secondary coil 20; and a coil sealing part 50 which seals at least the primary coil 10 and the secondary coil 20, and a part or whole of region between the primary coil 10 and the secondary coil 20 and the core 500.

A magnetic component has a primary coil 10; a secondary coil 20 disposed to face the primary coil 10; a core 500 which passes through the primary coil 10 and the secondary coil 20; and a coil sealing part 50 which seals at least the primary coil 10 and the secondary coil 20, and a part or whole of region between the primary coil 10 and the secondary coil 20 and the core 500.

A power converter includes a magnetic core, a plurality of windings, a plurality of metal sidewalls, a first insulating member, and a second insulating member. The plurality of windings are each wound around the magnetic core and bent to have a portion extending in a direction in which the magnetic core extends. The plurality of metal sidewalls are disposed outside the plurality of windings and extend in the direction in which the magnetic core extends. The first insulating member is disposed between the plurality of windings and between the windings and the magnetic core. The second insulating member is disposed on an outside of the plurality of windings and in contact with each of the plurality of sidewalls and each of the plurality of windings. The second insulating member has a thermal conductivity higher than a thermal conductivity of the first insulating member.

A power converter includes a magnetic core, a plurality of windings, a plurality of metal sidewalls, a first insulating member, and a second insulating member. The plurality of windings are each wound around the magnetic core and bent to have a portion extending in a direction in which the magnetic core extends. The plurality of metal sidewalls are disposed outside the plurality of windings and extend in the direction in which the magnetic core extends. The first insulating member is disposed between the plurality of windings and between the windings and the magnetic core. The second insulating member is disposed on an outside of the plurality of windings and in contact with each of the plurality of sidewalls and each of the plurality of windings. The second insulating member has a thermal conductivity higher than a thermal conductivity of the first insulating member.

Provided is a power conversion device, including: a casing having a recessed portion; a magnetic component accommodated in the recessed portion of the casing; a heat radiation plate, which covers an opening of the recessed portion of the casing, and is thermally coupled to the magnetic component; and a fixing band wound around the magnetic component and the heat radiation plate to fix the magnetic component to the heat radiation plate, wherein at least a part of the fixing band is accommodated in a band accommodating groove formed in the recessed portion of the casing. With this configuration, assembly dimensional tolerance caused between the magnetic component and the heat radiation plate can be eliminated and it is therefore possible to maintain high output and achieve downsizing.

Provided is a power conversion device, including: a casing having a recessed portion; a magnetic component accommodated in the recessed portion of the casing; a heat radiation plate, which covers an opening of the recessed portion of the casing, and is thermally coupled to the magnetic component; and a fixing band wound around the magnetic component and the heat radiation plate to fix the magnetic component to the heat radiation plate, wherein at least a part of the fixing band is accommodated in a band accommodating groove formed in the recessed portion of the casing. With this configuration, assembly dimensional tolerance caused between the magnetic component and the heat radiation plate can be eliminated and it is therefore possible to maintain high output and achieve downsizing.

An electronic device has a primary coil 10; a secondary coil 20 disposed to face the primary coil 10; a primary-side electronic element 110 electrically connected to the primary coil 10; and a secondary-side electronic element 210 electrically connected to the secondary coil 20. The primary coil 10 has a primary-side first coil 10a that is provided on another side of the secondary coil 20, and a primary-side second coil 10b that is provided on one side of the primary-side first coil 10a. A connecting part 19 connecting the primary-side first coil 10a and the primary-side second coil 10b is provided and passes through a space of the secondary coil 20.

A switch-mode DC-DC power converter includes one or more input terminals and output terminals, and a transformer coupled between the input and output terminals. The transformer includes a plurality of winding sets. Each winding set includes a primary winding and a secondary winding magnetically coupled with one another. The primary winding and the secondary winding include the same number of turns. The primary windings of the plurality of winding sets are connected in series and the secondary windings of the plurality of winding sets are connected in parallel. The power converter also includes at least one spacer positioned to separate an adjacent pair of the plurality of winding sets. A magnetic coupling between the adjacent pair of the plurality of winding sets is less than the magnetic coupling between the primary winding and the secondary winding within each winding set.