Transformers and power supplies

Abstract

The application discloses a transformer and a power supply. The transformer is a step-down transformer, and the transformer comprises a magnetic core, a primary winding and a secondary winding. The magnetic core comprises a magnetic window column. The primary winding is horizontally wound along the cross-section direction of the magnetic window column. The secondary winding is vertically wound along the height direction of the magnetic window column. The application can balance the small size and low cost, and improve the performance of the transformer.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and more particularly to a transformer and a power supply. Background Technology

[0002] Transformers are crucial components in power supplies, and their performance directly impacts the overall performance of the power supply. Currently, there are two main types of transformer structures: a vertical structure and a planar structure. The vertical structure transformer is the traditional type, where all windings on both the primary and secondary sides are wound vertically along the magnetic window from bottom to top and from the inside out. The planar structure transformer, on the other hand, has all windings wound horizontally along the magnetic window from the outside in. Vertical structure transformers have the advantage of lower cost, but their larger size hinders the trend towards miniaturization in power supplies. Conversely, while planar structure transformers are smaller, they are more expensive. Summary of the Invention

[0003] This invention provides a transformer and a power supply that balance small size and low cost while improving transformer performance.

[0004] According to one aspect of the present invention, a transformer is provided, the transformer being a step-down transformer, the transformer comprising: Magnetic core, the magnetic core including a magnetic window post; The primary winding is horizontally wound along the cross-sectional direction of the column in the magnetic window; The secondary winding is wound perpendicularly along the height direction of the column in the magnetic window.

[0005] Optionally, the primary winding includes: N sets of primary windings are connected in series; the secondary winding is wound between the N sets of primary windings; wherein, N≥2.

[0006] Optionally, the number of secondary windings is M groups, and the M groups of secondary windings are connected in parallel; the primary winding and the secondary winding are wound in a one-to-one correspondence; wherein, M≥2.

[0007] Optionally, the secondary winding includes: The secondary sub-windings of group P are connected in series; the primary sub-windings and the secondary sub-windings are alternately arranged; wherein, P≥2.

[0008] Optionally, the primary winding includes a first primary sub-winding and a second primary sub-winding, and the number of secondary windings is M groups, which are connected in parallel; the M groups of secondary windings are located between the first primary sub-winding and the second primary sub-winding; wherein, M≥2.

[0009] Optionally, the number of columns in the magnetic window is one or at least two; If the number of columns in the magnetic window is one, then both the primary winding and the secondary winding are wound on the columns in the magnetic window; If the number of columns in the magnetic window is at least two, then the N groups of primary side sub-windings included in the primary side winding are wound on different columns in the magnetic window; or, the M groups of secondary side windings are wound on different columns in the magnetic window; or, the P groups of secondary side sub-windings included in the secondary side winding are wound on different columns in the magnetic window.

[0010] Optionally, the air gap of the magnetic core is located at the top of the column in the magnetic window, and the total height of the primary winding and the secondary winding is less than the height of the air gap.

[0011] Optionally, the secondary winding has less than or equal to 3 winding groups.

[0012] Optionally, the primary winding is wound using a printed circuit board or a coil winding. And / or, the secondary winding is wound using a printed circuit board or using flat wire.

[0013] Optionally, the transformer is applied to a flyback converter circuit, a forward converter circuit, a two-transistor forward converter circuit, a push-pull converter circuit, a half-bridge converter circuit, a full-bridge converter circuit, an LLC resonant converter circuit, an active clamp flyback converter circuit, or an asymmetric half-bridge converter circuit.

[0014] According to another aspect of the present invention, a power supply is provided, comprising a transformer as described in any embodiment of the present invention.

[0015] This invention provides a transformer with a planar vertical structure. Specifically, by adopting a combination structure of a primary side planar and a secondary side vertical, it makes full use of the voltage and current characteristics of the primary and secondary windings. It can integrate the advantages of vertical structure transformers and planar structure transformers into the transformer provided by this invention, so that this invention can achieve both small size and low cost.

[0016] Furthermore, in this embodiment of the invention, both the primary and secondary windings are wound on the columns of a magnetic window, which helps to reduce the leakage inductance and distributed capacitance of the transformer. The horizontal winding of the primary winding, compared to a vertically structured transformer, provides a higher current density. Additionally, the vertical winding of the secondary winding, compared to a planar structured transformer, allows for the placement of insulating materials such as insulating tape and insulating paper between the coils, achieving better insulation performance at a lower cost.

[0017] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of a transformer structure provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of another transformer structure provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of another transformer structure provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a magnetic core provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of a primary winding provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of another primary winding structure provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of a secondary winding provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of another secondary winding structure provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of another magnetic core structure provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of another transformer structure provided in an embodiment of the present invention; Figure 11 This is a schematic diagram of another transformer structure provided in an embodiment of the present invention; Figure 12 A schematic diagram of the primary winding connection of a transformer provided in an embodiment of the present invention; Figure 13 This is a schematic diagram of the secondary winding wiring of a transformer provided in an embodiment of the present invention. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] This invention provides a transformer, which can be a high-frequency transformer or a low-frequency transformer, covering a wide range of frequencies. Specifically, the transformer can be used in a power supply, which also includes transistors. The switching frequency of these transistors can be 50kHz, 60kHz, 100kHz, 200kHz, or higher. The frequency of the transformer refers to the switching frequency of the transistors.

[0023] Figure 1 This is a schematic diagram of a transformer provided as an embodiment of the present invention. See also... Figure 1 The transformer includes: Magnetic core 10, which includes a magnetic window post 11; Primary winding 20 is horizontally wound along the cross-sectional direction of column 11 in the magnetic window; The secondary winding 30 is wound perpendicularly along the height direction of the column 11 in the magnetic window.

[0024] The magnetic core 10 is made of soft magnetic materials such as ferrite, nanocrystalline, and amorphous materials, and is used to gather and confine magnetic lines of force, reduce magnetic leakage, and enhance electromagnetic coupling efficiency. For example, the magnetic core 10 is an ER-type ferrite core, which includes a magnetic window post 11, a side post, and a magnetic yoke 12. The primary winding 20 and the secondary winding 30 are wound on the magnetic window post 11.

[0025] Furthermore, since this transformer is a step-down transformer, compared to the primary winding 20, the primary winding 20 has a higher voltage and a lower current; while the secondary winding 30 has a lower voltage and a higher current. The beneficial effects achieved by the embodiments of the present invention will be analyzed below from the perspectives of voltage and current.

[0026] The primary winding 20 has a higher voltage and therefore more coil turns. It is wound horizontally, for example, from the outside in, which reduces the transformer's vertical height. The secondary winding 30 has a lower voltage and therefore fewer coil turns. It is wound vertically, for example, from bottom to top along the magnetic window column 11, which also does not significantly affect the transformer's vertical height.

[0027] The primary winding 20 handles a smaller current, thus requiring a thinner wire diameter. Horizontal winding can be used, and a printed circuit board (PCB) can be employed for this purpose. Since the current in the primary winding 20 is relatively small, using a PCB keeps costs manageable. The secondary winding 30 handles a larger current, requiring a thicker wire diameter. Vertical winding can be used, employing flat wire or similar cables. However, for the secondary winding 30, using a PCB would significantly increase the cost.

[0028] Therefore, the present invention provides a transformer with a planar vertical structure. Specifically, by adopting a combination structure of a primary side planar and a secondary side vertical, it makes full use of the voltage and current characteristics of the primary winding 20 and the secondary winding 30. It can integrate the advantages of vertical structure transformers and planar structure transformers into the transformer provided by the present invention, so that the present invention can take into account both small size and low cost.

[0029] Furthermore, in this embodiment of the invention, both the primary winding 20 and the secondary winding 30 are wound on the column 11 of the magnetic window, which helps to reduce the leakage inductance and distributed capacitance of the transformer. The horizontal winding of the primary winding 20, compared to a vertically structured transformer, provides a higher current density. Additionally, the vertical winding of the secondary winding 30, compared to a planar structured transformer, allows for the placement of insulating materials such as insulating tape and insulating paper between the coils, achieving better insulation performance at a lower cost.

[0030] Figure 2 A schematic diagram of another transformer structure provided in an embodiment of the present invention. See also... Figure 2Based on the above embodiments, optionally, the primary winding 20 includes N sets of primary sub-windings 21 connected in series; the secondary winding 30 is wound between the N sets of primary sub-windings 21; wherein, N≥2. This configuration helps to reduce eddy currents and leakage inductance of the transformer and improve the efficiency of the transformer.

[0031] For example, the voltage of the primary winding 20 is 600V, and its coil has 30 turns. In this embodiment of the invention, N=3, and the primary winding 20 is split into three primary sub-windings 21 connected in series, each with 10 turns. Therefore, the voltage of each primary sub-winding 21 is 1 / 3 of that of the primary winding 20. The reduction in voltage of the primary sub-windings 21 reduces the magnetomotive force of each primary sub-winding 21, thereby reducing the eddy currents and leakage inductance of the transformer and improving the efficiency of the transformer.

[0032] See also Figure 2 Based on the above embodiments, optionally, the number of secondary windings 30 is M groups, and the M groups of secondary windings 30 are connected in parallel; the primary sub-windings and secondary windings 30 are wound in a one-to-one correspondence; wherein, M≥2. This arrangement is equivalent to arranging the primary windings 20 and secondary windings 30 in a matrix. Specifically, each primary sub-winding 21 is wound horizontally along the column 11 of the magnetic window, and multiple primary sub-windings 21 are wound vertically along the column 11 of the magnetic window. For the primary winding 20, its coils form a matrix arrangement. The primary sub-windings 21 and secondary windings 30 are wound in a one-to-one correspondence, specifically, the primary sub-windings 21 and secondary windings 30 are arranged sequentially along the vertical direction of the column 11 of the magnetic window. For the entire transformer, the primary windings 20 and secondary windings 30 form a matrix arrangement. This arrangement is beneficial for further reducing eddy currents in the transformer, improving transformer efficiency, and increasing transformer output current.

[0033] For example, the voltage of the primary winding 20 is 600V, and its coil has 30 turns. In this embodiment of the invention, N=3 is set, and the primary winding 20 is split into three primary sub-windings 21 connected in series, each with 10 turns. Simultaneously, M=3 is set, and the number of secondary windings 30 is three groups, each with 2 turns. Specifically, each primary sub-winding 21 is wound horizontally, and each secondary winding 30 is wound vertically. The winding configuration along the vertical direction is: primary sub-winding 21, secondary winding 30, primary sub-winding 21, secondary winding 30, primary sub-winding 21, and secondary winding 30.

[0034] By adding two sets of secondary windings 30 to the original secondary winding 30, if one set of secondary windings 30 can carry a current of 10A, then three sets of secondary windings 30 can carry a current of 30A. Specifically, the number of primary sub-windings 21 and secondary windings 30 are equal and they are wound in a one-to-one correspondence. One primary sub-winding 21 corresponds to one secondary winding 30, and the three primary sub-windings 21 can induce current in the three sets of secondary windings 30. Therefore, in this embodiment of the invention, the number of secondary windings 30 is set to M, which can increase the output current of the transformer. Furthermore, the primary sub-windings 21 are wound in different layers, and secondary windings 30 are sandwiched between adjacent primary sub-windings 21. Therefore, the magnetomotive force generated by the primary windings 20 is further split. Furthermore, the winding arrangement provided in this embodiment of the invention avoids the windings extending beyond the magnetic field coverage area, allowing the magnetic lines of force to fully cover the windings. This results in a larger coupling coefficient between the primary winding 20 and the secondary winding 30, leading to better coupling and reduced leakage flux. Therefore, this embodiment of the invention further reduces magnetomotive force, leakage inductance, and eddy currents, improving transformer efficiency. Additionally, this arrangement results in lower common-mode voltages between the primary windings 20 and between the secondary windings 30, minimizing EMC issues for the transformer.

[0035] Based on the above embodiments, optionally, the secondary winding 30 includes P groups of secondary sub-windings connected in series; the primary sub-windings and secondary sub-windings are alternately arranged; wherein, P≥2. This arrangement helps to reduce eddy currents and leakage inductance of the transformer and improve the efficiency of the transformer. Specifically, when the voltage of the secondary winding 30 is large, for example, the voltage of the secondary winding exceeds 100V, by setting multiple groups of secondary sub-windings connected in series, the voltage of each secondary sub-winding is 1 / P of the voltage of the secondary winding 30, while the voltage of each primary sub-winding is 1 / N of the voltage of the primary winding 20.

[0036] The specific winding method is as follows: each primary sub-winding is wound horizontally, and each secondary sub-winding is wound vertically. Along the vertical direction, the winding arrangement is: primary sub-winding, secondary sub-winding, primary sub-winding, secondary sub-winding, ... The number of primary and secondary sub-windings are equal and they are wound in a one-to-one correspondence, with one primary sub-winding corresponding to one secondary sub-winding. This arrangement constitutes a transformer with a matrix layout. Unlike the aforementioned embodiments, this embodiment is more suitable for scenarios with higher secondary voltages.

[0037] Figure 3 A schematic diagram of another transformer structure provided in an embodiment of the present invention. See also... Figure 3Based on the above embodiments, optionally, the primary winding 20 includes a first primary sub-winding 22 and a second primary sub-winding 23, and the number of secondary windings 30 is M groups, with the M groups of secondary windings 30 connected in parallel; the M groups of secondary windings 30 are located between the first primary sub-winding 22 and the second primary sub-winding 23; wherein, M≥2.

[0038] For example, M=2, and the number of secondary windings 30 is 2 sets. The specific winding method of this transformer is as follows: the first primary winding 22 and the second primary winding 23 are wound horizontally, and each secondary winding 30 is wound vertically. In the vertical direction, the winding method of each winding is: first primary winding 22, secondary winding 30, secondary winding 30, and second primary winding 23. The primary winding 20 includes the first primary winding 22 and the second primary winding 23, which is more suitable for situations where the number of turns in the primary winding 20 is small. Setting the number of secondary windings 30 to M sets can increase the output current of the transformer. Furthermore, the two sets of secondary windings 30 are located between the first primary winding 22 and the second primary winding 23. The secondary winding 30 at the top is closer to the first primary winding 22, and there is only one secondary winding 30 between the top secondary winding 30 and the second primary winding 23. Similarly, the secondary winding 30 at the bottom is also closer to the second primary winding 23, and there is only one secondary winding 30 between the bottom secondary winding 30 and the first primary winding 22. Therefore, overall, the secondary windings 30 are relatively close to the primary windings, which helps reduce leakage inductance.

[0039] Based on the above embodiments, optionally, the air gap of the magnetic core 10 ( Figure 3 (Not shown in the image) Located at the top of column 11 in the magnetic window, the total height of the primary winding 20 and secondary winding 30 is less than the height of the air gap. This arrangement helps to reduce the loss of the magnetic core 10.

[0040] For example, the number of windings in the secondary winding 30 is less than or equal to 3. Since the secondary winding 30 is wound perpendicularly to the column 11 in the magnetic window, the number of windings in the secondary winding 30 has a greater impact on the total height of the primary winding 20 and the secondary winding 30. By adjusting the number of windings in the secondary winding 30, the total height of the primary winding 20 and the secondary winding 30 can be better controlled, making it less than the height of the air gap.

[0041] Figure 4 This is a schematic diagram of a magnetic core provided in an embodiment of the present invention. See also... Figure 4 This structure is half of the structure of magnetic core 10. The complete magnetic core 10 consists of two pieces. Figure 4The structures shown are arranged in a relatively opposite manner. The magnetic core 10 includes a magnetic window post 11, a magnetic yoke 12, and side posts 13. The magnetic window post 11 is the core channel of the magnetic circuit; the primary and secondary windings are wound around the magnetic window post 11, forming the main path of the magnetic flux. The side posts 13 and the magnetic window post 11 are symmetrically distributed, forming return branches for the magnetic flux, allowing the magnetic lines of force to form a loop. The magnetic yoke 12 connects the magnetic window post 11 and the side posts 13, guiding the magnetic flux from the side posts 13 back to the magnetic window post 11, completing the entire closed magnetic circuit.

[0042] Figure 5 This is a schematic diagram of a primary winding structure provided in an embodiment of the present invention. See also... Figure 5 In one embodiment, the primary winding 20 may optionally be wound using a printed circuit board. The printed circuit board can utilize its internal copper foil to form coils, which can be wound horizontally to form a planar structure.

[0043] Figure 6 This is a schematic diagram of another primary winding structure provided in an embodiment of the present invention. See also... Figure 6 In another embodiment, the primary winding 20 is optionally wound into a disc shape. Disc winding involves winding the excitation wire into a disc shape along the horizontal direction of the column 11 in the magnetic window, forming a planar structure.

[0044] Figure 7 This is a schematic diagram of a secondary winding provided in an embodiment of the present invention. See also... Figure 7 In one embodiment, the secondary winding 30 is optionally wound with flat wire. Specifically, the flat wire can be copper wire, aluminum wire, aluminum-copper alloy wire, or other alloy wires; this embodiment of the invention does not limit the material of the flat wire. The larger width and thickness of the flat wire facilitates the passage of large currents, and its winding method is simple and low-cost. Furthermore, during the winding process along the vertical direction of the column 11 in the magnetic window, insulating materials such as reinforcing insulating tape can be used to isolate the layers in the vertical direction, thereby further improving the insulation performance and withstand voltage strength of the transformer.

[0045] Figure 8 This is a schematic diagram of another secondary winding structure provided in an embodiment of the present invention. See also... Figure 8 In one embodiment, the secondary winding 30 may optionally be wound using a printed circuit board. The printed circuit board can utilize its internal copper foil to form coils, increasing the area of ​​the copper foil to meet the high current requirements of the secondary winding 30. Furthermore, by using a multi-layer printed circuit board, with each layer of copper foil forming a coil, the secondary winding 30 can be wound along the vertical direction of the column 11 in the magnetic window through series connection between the layers.

[0046] In the above embodiments, the shape of the magnetic window post 11 is shown to be circular, which is not intended to limit the invention. In other embodiments, the shape of the magnetic window post 11 may also be elliptical or other shapes. Correspondingly, the coil shapes of the primary winding 20 and the secondary winding 30 may be circular, elliptical, or other shapes.

[0047] In the above embodiments, it is exemplarily shown that the number of columns 11 in the magnetic window is one, and the primary winding 20 and the secondary winding 30 are both wound on the same column 11 in the magnetic window.

[0048] Figure 9 A schematic diagram of another magnetic core provided in an embodiment of the present invention. See also Figure 9 In another embodiment, optionally, the structure is half of the magnetic core 10, and the complete magnetic core 10 includes two pieces of... Figure 9 The structures shown are arranged relative to each other. The magnetic core 10 includes two magnetic window pillars 11, and magnetic yokes 12 and side pillars 13 corresponding to the two magnetic window pillars 11. The side pillars 13 between the two magnetic window pillars 11 are combined into a single structure. The primary winding 20 comprises N sets of primary sub-windings 21 wound on different magnetic window pillars 11; or, M sets of secondary windings 30 wound on different magnetic window pillars 11; or, the secondary winding comprises P sets of secondary sub-windings wound on different magnetic window pillars 11.

[0049] Figure 9 The illustration shows two magnetic windows with different shapes for the pillars 11, namely circular and elliptical, which is not intended to limit the invention. In other embodiments, the pillars 11 in both magnetic windows may be either circular or elliptical.

[0050] In other embodiments, the number of columns 11 in the magnetic window can be set to three or more, which can be set as needed in practical applications.

[0051] Based on the above embodiments, the transformer provided in this invention can optionally be applied to flyback converter circuits, forward converter circuits, two-transistor forward converter circuits, push-pull converter circuits, half-bridge converter circuits, full-bridge converter circuits, LLC resonant converter circuits, active clamp flyback converter circuits (ACF), or asymmetric half-bridge converter circuits (AHB), etc. The flyback converter circuit can be a quasi-resonant (QR) flyback circuit, and its feedback method can be primary-side feedback (PSR) or secondary-side feedback (SSR); the flyback converter circuit can also be a hard-switching flyback circuit; the half-bridge converter circuit can be a symmetrical resonant half-bridge circuit, etc. This invention can be applied to any switching power supply topology that includes a transformer, and will not be listed individually.

[0052] In practical applications, the primary and secondary windings are wound in specific ways according to the characteristics of the topology and power requirements. The following is a detailed description, but it is not intended to limit the scope of the invention.

[0053] In one embodiment, optionally, for low-power transformers (e.g., below 300W), the primary winding 20 is wound using a printed circuit board or wire coil along the horizontal direction of the magnetic window column 11, while the secondary winding is wound using flat wire or a printed circuit board along the vertical direction of the magnetic window column 11. Since the current in the primary winding 20 is relatively small, planar winding along the horizontal direction of the magnetic window column 11 using a printed circuit board effectively dissipates heat between the primary windings 20 in a planar direction. Compared to the secondary winding 30, the voltage applied to the primary winding 20 is higher, allowing the primary winding 20 to be divided into N different primary sub-windings 21 arranged in different printed circuit board layer matrices. For example, the primary sub-windings 21 can be distributed in two, four, six, etc., depending on the number of turns in the primary winding 20. Compared to the primary winding 20, the secondary winding 30 has a larger current; using flat wire or a printed circuit board for winding is beneficial for meeting the high current requirements. The secondary winding 30 can be a single-layer winding or a multi-layer winding; if the secondary winding 30 is a multi-layer winding, it can have a maximum of three layers. This is because the secondary winding 30 has a vertical structure, and its height would affect the coupling between the primary winding 20 and the secondary winding 30.

[0054] Furthermore, when using flat wire to configure the secondary winding 30 as a three-layer winding, the width and thickness of the flat wire should be considered. By appropriately reducing the width and thickness of the flat wire, the horizontal and vertical dimensions of the flat wire can be reduced to avoid affecting the coupling between the primary winding 20 and the secondary winding 30.

[0055] Figure 10 A schematic diagram of another transformer structure provided in an embodiment of the present invention. See also... Figure 10 In another embodiment, optionally, for the transformer in a 100W quasi-resonant flyback circuit, the primary winding 20 adopts a printed circuit board along the column of the magnetic window ( Figure 10 (Not shown in the image) The secondary winding 30 is wound horizontally, and the secondary winding 30 is wound with flat wire along the vertical direction of the column in the magnetic window. The primary winding 20 includes a first primary sub-winding 22 and a second primary sub-winding 23 connected in series, and the secondary winding 30 is located between the first primary sub-winding 22 and the second primary sub-winding 23.

[0056] The quasi-resonant flyback circuit is a commonly used topology in low-power applications. However, this topology suffers from low core utilization due to the transformer operating in one quadrant, and places high demands on the leakage inductance and distributed capacitance of the transformer windings. This embodiment of the invention employs a matrix transformer with a primary-side planar + secondary-side vertical planar structure. Specifically, the first primary-side sub-winding 22 is wound horizontally along the column 11 of the magnetic window, and the second primary-side sub-winding 23 is wound horizontally along the column 11 of the magnetic window. The first primary-side sub-winding 22 and the second primary-side sub-winding 23 are wound vertically along the column 11 of the magnetic window. For the primary-side winding 20, its coils form a matrix arrangement. Simultaneously, the secondary-side winding 30 is located between the first primary-side sub-winding 22 and the second primary-side winding 23. For the entire transformer, the primary-side winding 20 and the secondary-side winding 30 form a matrix arrangement. This configuration, where the secondary winding 30 is sandwiched between the first primary winding 22 and the second primary winding 23, results in a larger coupling coefficient and lower leakage inductance between the primary winding 20 and the secondary winding 30. Furthermore, by splitting the primary winding 20 into two primary windings and using the secondary winding 30 as a sandwich, a large area of ​​the primary winding 20 facing each other is cut off, thereby reducing the distributed capacitance. Additionally, the sandwiching of the secondary winding 30 disperses the heat source of the primary winding, thus improving transformer heat dissipation.

[0057] Figure 11 A schematic diagram of another transformer structure provided in an embodiment of the present invention. See also... Figure 11 In another embodiment, optionally, for the transformer in a 360W symmetrical resonant half-bridge circuit, the primary winding 20 adopts a coil along the column of the magnetic window ( Figure 11 (Not shown in the diagram) The secondary winding 30 is wound horizontally, and is wound along the vertical direction of the column in the magnetic window on the printed circuit board. The coil is wound horizontally on a self-adhesive insulating sheet, which further improves the insulation performance. The primary winding 20 includes four sets of primary sub-windings 21 connected in series, and the number of secondary windings 30 is four. For example, the second layer of primary sub-winding 21 has 6 turns and is wound horizontally at the top of the self-adhesive insulating sheet; the fourth layer of primary sub-winding 21 has 6 turns and is wound horizontally at the top of the self-adhesive insulating sheet; the sixth layer of primary sub-winding 21 has 2 turns and is wound horizontally at the bottom of the self-adhesive insulating sheet; and the seventh layer of primary sub-winding 21 has 5 turns and is wound horizontally at the top of the self-adhesive insulating sheet. The first, third, fifth, and eighth layers of secondary windings 30 have four layers on the printed circuit board with a copper thickness of 2 oz, increasing the current by increasing the area of ​​the copper foil.

[0058] Figure 12 This is a schematic diagram of the primary winding wiring of a transformer provided in an embodiment of the present invention. (In conjunction with...) Figure 11 and Figure 12From the perspective of the terminal 201 of the primary winding 20, the primary sub-winding 21 is connected in series through the red terminal.

[0059] Figure 13 This is a schematic diagram of the secondary winding wiring of a transformer provided in an embodiment of the present invention. (In conjunction with...) Figure 11 and Figure 13 From the perspective of the terminal 301 of the secondary winding 30, each secondary winding 30 is connected in parallel through the black wiring.

[0060] Based on the above embodiments, the present invention also compares the performance and cost of vertical structure transformers, planar structure transformers, and the planar-vertical structure matrix transformers provided in the present invention, as shown in Table 1.

[0061] Table 1 As can be seen from Table 1, the planar vertical structure matrix transformer provided in this embodiment combines the advantages of both vertical structure transformers and planar structure transformers, and has high current and high power density, high insulation, and low cost, which is conducive to achieving high operating frequency at a lower cost.

[0062] This invention also provides a power supply, which includes a transformer as provided in any embodiment of this invention. The technical principle and the effects produced are similar and will not be described again.

[0063] Optionally, the power supply also includes transistors. Classified by material type, the transistor can be a gallium nitride transistor or a silicon carbide transistor, etc.; classified by control method and carrier type, the transistor can be a metal-oxide-semiconductor field-effect transistor (MOSFE, or MOS transistor for short), an insulated gate bipolar transistor (IGBT), or a triode, etc.; for MOS transistors, classified by structure type, the transistor can be a planar MOS or a superjunction MOS, etc.

[0064] Optionally, the power supply also includes a control chip, which controls the control mode of the power supply circuit and generates PWM drive signals to turn the transistors on and off. For example, classified by the power supply circuit topology, the control chip can be a flyback control chip, a forward control chip, an LLC resonant control chip, a half-bridge control chip, or a full-bridge control chip; classified by feedback method, the control chip can be a primary-side feedback chip or a secondary-side feedback chip; classified by integration level, the control chip can be a pure control chip, a control chip with integrated transistors, or a control chip with integrated power factor correction (PFC).

[0065] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A transformer, characterized in that, The transformer is a step-down transformer, and the transformer includes: Magnetic core, the magnetic core including a magnetic window post; The primary winding is horizontally wound along the cross-sectional direction of the column in the magnetic window; The secondary winding is wound perpendicularly along the height direction of the column in the magnetic window.

2. The transformer according to claim 1, characterized in that, The primary winding includes: N sets of primary windings are connected in series; the secondary winding is wound between the N sets of primary windings; wherein, N≥2.

3. The transformer according to claim 2, characterized in that, The number of secondary windings is M groups, and the M groups of secondary windings are connected in parallel; the primary winding and the secondary winding are wound in a one-to-one correspondence; wherein, M≥2.

4. The transformer according to claim 2, characterized in that, The secondary winding includes: The secondary sub-windings of group P are connected in series; the primary sub-windings and the secondary sub-windings are alternately arranged; wherein, P≥2.

5. The transformer according to claim 1, characterized in that, The primary winding includes a first primary sub-winding and a second primary sub-winding, and the number of secondary windings is M groups, which are connected in parallel; the M groups of secondary windings are located between the first primary sub-winding and the second primary sub-winding; wherein, M≥2.

6. The transformer according to any one of claims 2 to 5, characterized in that, The number of columns in the magnetic window is one or at least two; If the number of columns in the magnetic window is one, then both the primary winding and the secondary winding are wound on the columns in the magnetic window; If the number of columns in the magnetic window is at least two, then the N groups of primary side sub-windings included in the primary side winding are wound on different columns in the magnetic window; or, the M groups of secondary side windings are wound on different columns in the magnetic window; or, the P groups of secondary side sub-windings included in the secondary side winding are wound on different columns in the magnetic window.

7. The transformer according to any one of claims 3 to 5, characterized in that, The air gap of the magnetic core is located at the top of the column in the magnetic window, and the total height of the primary winding and the secondary winding is less than the height of the air gap.

8. The transformer according to claim 7, characterized in that, The secondary winding has a winding group number of less than or equal to 3 groups.

9. The transformer according to claim 1, characterized in that, The primary winding is made by winding a printed circuit board or by winding a wire disc; And / or, the secondary winding is wound using a printed circuit board or using flat wire.

10. The transformer according to claim 1, characterized in that, It is applied to flyback converter circuits, forward converter circuits, two-transistor forward converter circuits, push-pull converter circuits, half-bridge converter circuits, full-bridge converter circuits, LLC resonant converter circuits, active clamp flyback converter circuits, or asymmetric half-bridge converter circuits.

11. A power supply, characterized in that, Including the transformer as described in any one of claims 1-10.

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