A magnetic component for an electronic circuit includes a core having a core body and a core leg extending from the core body. The core body defines a core body height, and the core leg defines a core leg height less than the core body height. A conductive winding is positioned about the core leg. The winding defines a winding height. A winding height offset ratio is defined as the winding height divided by the core body height. In some embodiments the winding height offset ratio is less than about 1.1. The winding can be positioned on a bobbin structure disposed about the core leg. The magnetic component can be positioned in an enclosure to form an electronic device such as a power control or a power supply, and a thermally conductive gap-filler can be positioned between the magnetic component and the enclosure wall to dissipate heat from the magnetic component. The reduced height of the core leg provides a reduced gap distance between the core body and the enclosure wall for improving heat transfer, reducing thermal gap-filler material volume and reducing enclosure size. A method of forming an electronic device is also provided.

A chip resistor includes a substrate, and a plurality of resistor elements each having a resistive film provided on the substrate and an interconnection film provided on the resistive film in contact with the resistive film. An electrode is provided on the substrate. Fuses disconnectably connect the resistor elements to the electrode. The resistive film is made of at least one material selected from the group of NiCr, NiCrAl, NiCrSi, NiCrSiAl, TaN, TaSiO.sub.2, TiN, TiNO and TiSiON.

A chip resistor includes a substrate, and a plurality of resistor elements each having a resistive film provided on the substrate and an interconnection film provided on the resistive film in contact with the resistive film. An electrode is provided on the substrate. Fuses disconnectably connect the resistor elements to the electrode. The resistive film is made of at least one material selected from the group of NiCr, NiCrAl, NiCrSi, NiCrSiAl, TaN, TaSiO.sub.2, TiN, TiNO and TiSiON.

A detachable transformer includes a first bobbin, a primary winding, a second bobbin, a secondary winding and a magnetic core set. The magnetic core set peripherally surrounds the first bobbin and the second bobbin and is inserted into them. A top and a bottom of the first bobbin respectively have a first winding recess and an installation recess. The primary winding is arranged in the first winding recess. A side of the installation recess has a first opening connecting with an external space. A top of the second bobbin has a second winding recess. The secondary winding is arranged in the second winding recess. The second bobbin is arranged in the installation recess through the first opening, whereby the first bobbin and the second bobbin form a detachable connection.

A detachable transformer includes a first bobbin, a primary winding, a second bobbin, a secondary winding and a magnetic core set. The magnetic core set peripherally surrounds the first bobbin and the second bobbin and is inserted into them. A top and a bottom of the first bobbin respectively have a first winding recess and an installation recess. The primary winding is arranged in the first winding recess. A side of the installation recess has a first opening connecting with an external space. A top of the second bobbin has a second winding recess. The secondary winding is arranged in the second winding recess. The second bobbin is arranged in the installation recess through the first opening, whereby the first bobbin and the second bobbin form a detachable connection.

Embodiments of the invention disclose methods of assembling and using an adjustable inductor to vary inductance. An adjustable inductor, according to embodiments of the invention, includes a wire coil configured to mount on a first side of a conductive plate. The wire coil is conductive and is a plurality of windings. A core has a first portion and a second portion. The first and second portions are configured with a plurality of grooves for threading engagement with the plurality of windings of the wire coil. The threading engagement attaches the core to the plurality of windings of the wire coil. Rotating the core results in varied inductance.

An adjustable inductor, according to embodiments of the invention, includes a wire coil configured to mount on a first side of a conductive plate. The wire coil is conductive and is a plurality of windings. A core has a first portion and a second portion. The first and second portions are configured with a plurality of grooves for threading engagement with the plurality of windings of the wire coil. The threading engagement attaches the core to the plurality of windings of the wire coil, which results in varied inductance.

An adjustable inductor, according to embodiments of the invention, includes a wire coil configured to mount on a first side of a conductive plate. The wire coil is conductive and is a plurality of windings. A core has a first portion and a second portion. The first and second portions are configured with a plurality of grooves for threading engagement with the plurality of windings of the wire coil. The threading engagement attaches the core to the plurality of windings of the wire coil, which results in varied inductance.

A rolled iron core traction transformer, comprising an iron core (1); the iron core (1) is formed by splicing two symmetrical annealed iron-core closed single frames (1-1); each iron-core closed single frame (1-1) is formed by sequentially coiling continuous silicon steel sheets; the iron-core closed single frame (1-1) has two iron core column single bodies (1-1-1) having approximately semicircular cross sections; the iron core (1) has two iron core columns (1-2) thereon spliced by the iron core column single bodies (1-1-1) and having approximately circular cross sections; each iron core column (1-2) is sequentially provided with a low-voltage T winding (6), a low-voltage F winding (5) and a high-voltage winding (4) thereon from inside to outside; two sides of each high-voltage winding (4) are respectively provided with a first tapping area and a second tapping area; the first tapping area is provided with low-voltage side high-voltage tapping outgoing lines (16); the second lapping area is provided with high-voltage side high-voltage tapping outgoing lines (18); two low-voltage side high-voltage tapping outgoing lines (16) are connected together via a no-load voltage regulation switch (9); and two high-voltage side high-voltage tapping outgoing lines (18) are connected together via another no-load voltage regulation switch (9). The transformer reduces no-load loss, has a small no-load current, low noise and strong anti-short circuit capability, reduces the electrodynamic force generated by a sudden short circuit, and improves the short circuit tolerance capability of the transformer.

A rolled iron core traction transformer, comprising an iron core (1); the iron core (1) is formed by splicing two symmetrical annealed iron-core closed single frames (1-1); each iron-core closed single frame (1-1) is formed by sequentially coiling continuous silicon steel sheets; the iron-core closed single frame (1-1) has two iron core column single bodies (1-1-1) having approximately semicircular cross sections; the iron core (1) has two iron core columns (1-2) thereon spliced by the iron core column single bodies (1-1-1) and having approximately circular cross sections; each iron core column (1-2) is sequentially provided with a low-voltage T winding (6), a low-voltage F winding (5) and a high-voltage winding (4) thereon from inside to outside; two sides of each high-voltage winding (4) are respectively provided with a first tapping area and a second tapping area; the first tapping area is provided with low-voltage side high-voltage tapping outgoing lines (16); the second lapping area is provided with high-voltage side high-voltage tapping outgoing lines (18); two low-voltage side high-voltage tapping outgoing lines (16) are connected together via a no-load voltage regulation switch (9); and two high-voltage side high-voltage tapping outgoing lines (18) are connected together via another no-load voltage regulation switch (9). The transformer reduces no-load loss, has a small no-load current, low noise and strong anti-short circuit capability, reduces the electrodynamic force generated by a sudden short circuit, and improves the short circuit tolerance capability of the transformer.