Provided is an inductor winding method and an inductor winding device. The inductor winding method comprises steps of: A. dividing turns of coil of each winding of the inductor into a first winding and a second winding based on a preset ratio; B. winding the first winding on one of multiple magnetic columns, and winding the second winding on another one of the multiple magnetic columns which is different from the magnetic column on which the first winding is wound; and C. performing step A and step B cyclically until all the windings of the inductor are wound. With a coupling inductor having interleaving-wound structure, power frequency magnetic fluxes generated by magnetic lines in magnetic columns counteract one another, thereby solving the problem of high magnetic flux density in a magnetic core while achieving certain leakage inductance.

High-frequency transformers using solid wire for welding-type power supplies are disclosed. An example welding-type power supply transformer includes: a first coil assembly comprising a first plurality of turns of a first solid wire wrapped around a first bobbin to form a first single-layer primary winding, and a second plurality of turns of a second conductor over the first plurality of turns to form a first single-layer secondary winding; a second coil assembly comprising a third plurality of turns of a second solid wire wrapped around a second bobbin to form a second single-layer primary winding, and a fourth plurality of turns of the second conductor over the third plurality of turns to form a second single-layer secondary winding; and first and second cores disposed at least partially within the first and second bobbins.

A method and apparatus for providing welding type power supply includes a power circuit and a control circuit. The power circuit receives input power and provides welding type power to a welding output. The power circuit includes a transformer having a primary winding and a secondary winding. The secondary winding is in electrical communication with the welding output. The control circuit is connected to control the power circuit. The transformer includes a bobbin with the primary winding and the secondary winding wound thereon. The bobbin can includes vents to allow air flow into the bobbin. A winding separator can be disposed between the primary and secondary windings.

A transformer includes a magnetic core assembly including a cylindrical bobbin around which transformer windings are wrapped. Primary transformer windings are wrapped around the cylindrical bobbin of the magnetic core assembly with additional primary transformer windings that are extended to come in contact with one or more external surfaces of the magnetic core assembly. Secondary transformer windings are wrapped around the cylindrical bobbin of the magnetic core assembly with additional secondary transformer windings that are extended to come in contact with the one or more external surfaces of the magnetic core assembly.

A transformer includes a magnetic core assembly including a cylindrical bobbin around which transformer windings are wrapped. Primary transformer windings are wrapped around the cylindrical bobbin of the magnetic core assembly with additional primary transformer windings that are extended to come in contact with one or more external surfaces of the magnetic core assembly. Secondary transformer windings are wrapped around the cylindrical bobbin of the magnetic core assembly with additional secondary transformer windings that are extended to come in contact with the one or more external surfaces of the magnetic core assembly.

A switching power converter includes an integrated transformer and coupled inductor, first and second primary switching circuits, and a master controller. The integrated transformer and coupled inductor includes (a) first and second primary windings electrically coupled in series and (b) first and second secondary windings. The first and second primary switching circuits are electrically coupled to an end of the first primary winding and an end of the second primary winding, respectively. The master controller is configured to determine a magnitude of magnetizing current of the integrated transformer and coupled inductor from a difference between magnitude of current flowing through the first secondary winding and magnitude of current flowing through the second secondary winding, when the first and second primary switching circuits are in their respective off-states.

A leakage transformer includes a core and a printed wiring board. The core includes a first magnetic leg and a second magnetic leg. The second magnetic leg is spaced from the first magnetic leg. The printed wiring board includes an insulating portion and conductor wiring. The conductor wiring includes a first coil and a second coil. The first coil is formed of a first winding and is wound around only the first magnetic leg, not around the second magnetic leg. The second coil is formed of a second winding and includes a first part and a second part. The first part is wound around only the first magnetic leg, not around the second magnetic leg. The second part is wound around both the first and second magnetic legs.

A leakage transformer includes a core and a printed wiring board. The core includes a first magnetic leg and a second magnetic leg. The second magnetic leg is spaced from the first magnetic leg. The printed wiring board includes an insulating portion and conductor wiring. The conductor wiring includes a first coil and a second coil. The first coil is formed of a first winding and is wound around only the first magnetic leg, not around the second magnetic leg. The second coil is formed of a second winding and includes a first part and a second part. The first part is wound around only the first magnetic leg, not around the second magnetic leg. The second part is wound around both the first and second magnetic legs.

Embodiments of the present application provide a transformer and a bidirectional isolated resonant converter, where the transformer includes a first side winding, a second side winding, and a magnetic core. The magnetic core includes a winding column, at least one side column and two connecting portions. The first side winding includes: a first side first winding and a first side second winding that are electrically connected, and the second side winding is located between the first side first winding and the first side second winding. An air gap is provided on the winding column, and the air gap is provided between the second side winding and a first end surface of the winding column, and a first side equivalent leakage inductance and a second side equivalent leakage inductance are obtained through the air gap.

A leakage transformer includes a secondary coil wound around a leg member of a core, and a primary coil wound around the leg member outside of the secondary coil. Between the primary coil and the secondary coil, (i) spacers of non-magnetic members and (ii) bypass cores that are magnetic members to induce therein a portion of magnetic flux generated in the core are arranged. The bypass cores are arranged with gaps therebetween in a direction of the internally induced magnetic flux. A total value of the gaps between the bypass cores is determined in accordance with a target value of leakage inductance. A maximum value of the gaps between the bypass cores is less than or equal to a value obtained by multiplying a minimum value of gaps between the bypass cores and each of the primary coil and the secondary coil by a positive coefficient less than one.