Patent Application
20240047128
The present invention relates to a matrix transformer including a body, made of a soft magnetic material, and a plurality of electrical current-conductive windings, the body forming a closed magnetic circuit through openings in at least one printed circuit board (PCB), the body having a plurality of magnetic legs that are surrounded by the windings, the body further having two parallel magnetic plates that are on respective sides of the PCB and that are connected to one another by the magnetic legs, and the windings, due to a suitably selected winding direction, each forming at least one magnetic field-free zone in the magnetic plates.
Transformers that are integrated into printed circuit boards (PCBs) are used to achieve flat designs and predictable heat dissipation. These transformers are made of a flat soft magnetic material core structure, preferably ferrite, and windings. The magnetic core structure forms a closed magnetic circuit through openings in a PCB. The windings (i.e., turns), which are formed by strip conductors or conductor tracks on the PCB, surround magnetic legs of the magnetic core structure.
The windings may be established using multiple PCBs instead of just one PCB. Additional winding parts formed by electrical conductors may also be mounted on the PCB. The winding parts may be formed from wound wires or cut sheet metal, for example.
To minimize the number of conductor layers required in the PCB, the windings formed by the strip conductor structures are distributed over multiple magnetic legs. The magnetic legs are arranged in a row and column shaped structure. Through a suitably selected winding direction of the windings respectively around the magnetic legs, this arrangement forms a so-called matrix transformer.
This type of matrix transformer is described in U.S. Pat. No. 4,665,357.
A matrix transformer has the advantage that magnetic fluxes therein partially cancel one another out, and magnetic losses caused by alternating magnetic fields are likewise reduced. The formation of at least one magnetic field-free zone can be achieved by a suitable arrangement of magnetic legs and winding directions.
An object is to achieve improved cooling and/or higher electrical power for a matrix transformer.
In embodiments of the present invention, a matrix transformer includes a body, a plurality of windings, and a heat sink having a cooling pin connected thereto. The body is made of a soft magnetic material and forms a closed magnetic circuit through openings in at least one printed circuit board (PCB). The body includes a plurality of magnetic legs and two parallel magnetic plates. The magnetic legs extend through the openings in the PCB and are surrounded by respective ones of the windings. The magnetic plates are positioned over respective sides of the PCB (i.e., top and bottom magnetic plates are positioned over top and bottom sides of the PCB). The magnetic legs connect the magnetic plates to one another. The windings (or turns) are electrical current conductive windings. The windings, owing to a suitably selected winding direction, each form at least one magnetic field-free zone in the magnetic plates. A recess is provided in one of the magnetic plates within the magnetic field-free zone of the one of the magnetic plates (e.g., a recess is provided in the bottom magnetic plate within the magnetic field-free zone of the bottom magnetic plate). The cooling pin is guided through the recess as far as a surface of the PCB.
Embodiments of the present invention achieve the above object and/or other objects in that a recess is introduced into at least one magnetic plate within the magnetic field-free zone, through which recess a cooling pin which is connected to a heat sink is guided up to a surface of the PCB.
A matrix transformer in accordance with embodiments of the present invention is based on the finding that the magnetic field-free zone is not necessary for the functioning of the transformer, so that the magnet material may be saved there, thus providing the option for coupling a heat sink to the transformer.
A matrix transformer in accordance with embodiments of the present invention are illustrated and explained in greater detail below with reference to the drawings, which include the following:
Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the present invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
Referring now to
The matrix transformer further includes a plurality of electrical current-conductive windings (or turns) 4. Windings 4 surround or wrap around the portions of magnetic legs 2 extending through respective openings in PCB 3. Windings 4, owing to a suitably selected winding direction, each form at least one magnetic field-free zone in magnetic plates 5, 6.
A recess 10 is provided in bottom magnetic plate 5 within the magnetic field-free zone of the bottom magnetic plate.
The matrix transformer further includes a heat sink 11 having a cooling pin 12 connected thereto. Cooling pin 12 is guided through recess 10 as far as a surface of PCB 3.
In further detail,
In particular,
Multiple windings 4 of an electrical conductor are symbolically illustrated around each of magnetic legs 2. Windings 4 may be formed by strip conductors of a multilayer PCB. The PCB itself is not depicted in
In a middle region 9 (i.e., the center) of each of bottom and top magnetic plates 5, 6, magnetic fluxes 8 largely cancel one another out. Consequently, middle region 9 of each magnetic plate 5, 6 is essentially free of magnetic fields. Because middle region 9 of each magnetic plates 5, 6 thus does not contribute to the functioning of the matrix transformer, middle region 9 of either or both magnetic plates 5, 6 may be omitted (i.e., removed) without impairing the functioning of the matrix transformer.
It is thus possible to introduce a recess 10 that is circular, for example, in the center or middle region 9 of bottom magnetic plate 5, as schematically illustrated in
As shown in
Very efficient cooling of a matrix transformer may be achieved in this way, via which it is also possible in particular to increase the power of the matrix transformer.
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the present invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the present invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2021 003 119.9 | Jun 2021 | DE | national |
This application is a continuation of International Application No. PCT/EP2022/065333, published in German, with an International filing date of Jun. 7, 2022, which claims priority to DE 10 2021 003 119.9, filed Jun. 17, 2021, the disclosures of which are incorporated in their entirety by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2022/065333 | Jun 2022 | US |
| Child | 18489914 | US |
