WO2023222094A1

WO2023222094A1 - Magnetic device, resonant circuit and led drive power supply

Info

Publication number: WO2023222094A1
Application number: PCT/CN2023/095108
Authority: WO
Inventors: 梅进光; 杨军
Original assignee: 英飞特电子（杭州）股份有限公司
Priority date: 2022-05-18
Filing date: 2023-05-18
Publication date: 2023-11-23
Also published as: CN114974802A

Abstract

Disclosed in the present application are a magnetic device, a resonant circuit and an LED drive power supply, relating to the field of power supplies. The magnetic device comprises a magnetic core and a plurality of layers of PCBs, wherein the magnetic core comprises two magnetic flat boards and several magnetic column pairs; the sectional area of a first magnetic column in each magnetic column pair is smaller than that of a second magnetic column; each layer of a PCB is provided with through holes allowing all magnetic columns to pass through the PCB; a primary winding on each layer of a first PCB among the plurality of layers of PCBs is wound around one magnetic column pair; and a secondary winding on each layer of a second PCB is wound around a second magnetic column in the magnetic column pair around which the primary winding is wound.

Description

A magnetic device, a resonant circuit and an LED driving power supply

This application claims priority to a Chinese patent application filed with the China Patent Office on May 18, 2022, with application number 202210539488. incorporated in this application.

Technical field

This application relates to the field of power supplies, and in particular to a magnetic device, a resonant circuit and an LED driving power supply.

Background technique

Among existing switching power supplies, resonant circuits are widely used due to their advantages of low switching loss, high frequency and small size. The magnetic components of a typical resonant circuit LLC circuit include a resonant inductor and a transformer. In the existing technology, the transformer includes a skeleton and a magnetic core. Two winding slots are provided on the skeleton to wind the primary and secondary windings respectively. Two E-type The magnetic core and the wound bobbin form a transformer. This transformer has a high leakage inductance and can be used to replace the resonant inductor. Therefore, this transformer structure actually integrates the leakage inductance and the magnetic device of the transformer, making the switching power supply smaller. Smaller, lower cost.

In order to further reduce the size and cost of magnetic devices, planar transformers, also known as matrix transformers, are used in some fields. The planar transformer removes the skeleton, sets the primary and secondary windings on the PCB, and makes holes on the PCB so that the magnetic core passes directly through the PCB. Existing planar transformers are used in fields such as server power supplies to meet the power supply needs of low voltage and high current. Specifically, in patent CN113517120A, a matrix transformer is provided with a central magnetic column and multiple secondary magnetic columns surrounding the central magnetic column. Multiple windings are provided on the PCB board. The primary winding is wound around the central magnetic column, and the multiple secondary windings are respectively It is wound around the secondary magnetic column to realize multiple transformers, and then the primary windings of multiple transformers are connected in series and the secondary windings are connected in parallel to achieve the effect of low voltage and high current.

However, this kind of matrix transformer has a large number of magnetic columns, complicated wiring of the windings on the PCB board, and high design difficulty. It cannot be directly applied to non-low voltage and high current scenarios. Using the matrix transformer in the existing technology will inevitably increase the number of winding designs. The complexity and cost of the PCB board.

Therefore, how to provide a solution to the above technical problems is currently a problem that those skilled in the art need to solve.

Contents of the invention

In view of this, the purpose of this application is to provide a magnetic device, a resonant circuit and an LED driving power supply with a simple structure and a wide range of applications. The specific plan is as follows:

A magnetic device including a magnetic core and a multi-layer PCB board, wherein:

The magnetic core includes: two parallel magnetic flat plates, and several magnetic column pairs arranged vertically between the two magnetic flat plates. Each magnetic column pair includes a first magnetic column and a second magnetic column. Each magnetic column pair is centered on a third magnetic column. The cross-sectional area of one magnetic column is smaller than the cross-sectional area of the second magnetic column;

All PCB boards are located between two magnetic plates. Each PCB board is provided with through holes, and all pairs of magnetic posts pass through the PCB board through the through holes;

The multi-layer PCB board includes several layers of first PCB boards and several layers of second PCB boards;

The first PCB board of each layer is provided with a primary winding, and the primary winding is wound around the magnetic column pair;

The second PCB board of each layer is provided with a secondary winding, and the secondary winding is wound around the second magnetic column in the pair of magnetic columns wound by the primary winding.

Optionally, the two magnetic flat plates are the first flat plate and the second flat plate respectively, and all pairs of magnetic columns and the second flat plate have an integrated structure.

Optionally, the vertical distance between each first magnetic column and the first flat plate is determined by the target resonant inductance;

The vertical distance between each second magnetic column and the first flat plate is determined by the target excitation inductance.

Optionally, the ratio of the cross-sectional area of the first magnetic column to the cross-sectional area of the second magnetic column is determined by the target resonant inductance.

Optional, the value range of the cross-sectional area ratio is [0.05, 1).

Optionally, the vertical distance between the first magnetic column and the second magnetic column in each magnetic column pair is determined by the target resonant inductance.

Optionally, the first PCB board and the second PCB board are arranged alternately.

Optionally, all primary windings are connected through blind holes, buried holes or vias to form a total primary winding;

All secondary windings are connected through blind holes, buried holes or vias to form a total secondary winding.

Correspondingly, this application also discloses a resonant circuit including any of the above magnetic devices.

Correspondingly, this application also discloses an LED driving power supply, including the above resonant circuit.

This application discloses a magnetic device, which includes a magnetic core and a multi-layer PCB board. The magnetic core includes: two parallel magnetic flat plates, and several pairs of magnetic pillars arranged vertically between the two magnetic flat plates. Each pair of magnetic pillars It includes a first magnetic column and a second magnetic column, and the cross-sectional area of the first magnetic column in each magnetic column is smaller than the cross-sectional area of the second magnetic column; all PCB boards are located between the two magnetic flat plates, and each PCB board is There are through holes through which all magnetic column pairs pass through the PCB board; the multi-layer PCB board includes several layers of first PCB boards and several layers of second PCB boards; the first PCB board of each layer is provided with a primary winding. The side winding is wound around the pair of magnetic columns; the second PCB board of each layer is provided with a secondary winding, and the secondary winding is wound around the second magnetic column in the pair of magnetic columns wound by the primary winding. By setting the cross-sectional area of the first magnetic column and the second magnetic column and the winding method of the primary winding and the secondary winding, this application achieves the function of the transformer and the function of the transformer magnetic leakage replacing the resonant inductor, and at the same time increases the magnetic field. Compared with the existing technology, the magnetic device of this application has lower cost and volume, simpler structure and wider application scenarios.

Description of the drawings

In order to explain the embodiments of the present application or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only This is an embodiment of the present application. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without exerting creative efforts.

Figure 1 is a structural distribution diagram of a magnetic device in an embodiment of the present application;

Figure 2 is a structural distribution diagram of the first magnetic core in the embodiment of the present application;

Figure 3 is a structural distribution diagram of the second magnetic core in the embodiment of the present application;

Figure 4 is a structural distribution diagram of the third magnetic core in the embodiment of the present application;

Figure 5a is a structural distribution diagram of a resonant output rectifier circuit in an embodiment of the present application;

Figure 5b is a structural distribution diagram of another resonant output rectifier circuit in the embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, those of ordinary skill in the art will not All other embodiments obtained without creative work fall within the scope of protection of this application.

The traditional matrix transformer has a large number of magnetic columns, complicated wiring of the windings on the PCB board, and high design difficulty. It cannot be directly applied to non-low voltage and high current scenarios. Using the matrix transformer in the existing technology will inevitably increase the complexity of the winding design. degree and cost of the PCB board.

By setting the cross-sectional area of the first magnetic column and the second magnetic column and the winding method of the primary winding and the secondary winding, this application achieves the function of the transformer and the function of the transformer magnetic leakage replacing the resonant inductor, and at the same time increases the magnetic field. Compared with the existing technology, the magnetic device of this application has lower cost and volume, simpler structure and wider application scenarios.

The embodiment of the present application discloses a magnetic device, as shown in Figure 1, which includes a magnetic core and a multi-layer PCB board, wherein:

The magnetic core includes: two parallel magnetic flat plates 1, and several magnetic column pairs arranged vertically between the two magnetic flat plates 1. Each magnetic column pair includes a first magnetic column 21 and a second magnetic column 22. Each magnetic column pair includes a first magnetic column 21 and a second magnetic column 22. The cross-sectional area of the first magnetic column 21 in the center of the column is smaller than the cross-sectional area of the second magnetic column 22;

All PCB boards are located between the two magnetic plates 1, each PCB board is provided with through holes, and all pairs of magnetic columns pass through the PCB boards through the through holes;

The first PCB board of each layer is provided with a primary winding 31, and the primary winding 31 is wound around the magnetic column pair;

A secondary winding 32 is provided on the second PCB of each layer. The secondary winding 32 is wound around the second magnetic column 22 centered on the magnetic column wound by the primary winding 31 .

It can be understood that in this embodiment, all PCB boards serve as carriers of the primary winding 31 or the secondary winding 32 and are arranged between the two magnetic plates 1 through the through holes. At this time, the primary windings 31 and 32 on the PCB board The secondary windings 32 respectively surround corresponding magnetic columns, and are generally wound in a figure-8 shape, as shown in Figure 1; specifically, for the primary winding 31 on any first PCB board, the primary winding 31 is aligned with the magnetic columns. It is wound as a unit, that is, the primary winding 31 simultaneously surrounds the first magnetic column 21 and the second magnetic column 22 in the pair of magnetic columns. Correspondingly, the second magnetic column 22 will be wound by any second PCB board. Surrounded by the secondary winding 22, this winding method forms a transformer, and at the same time causes the magnetic device to generate leakage inductance. This leakage inductance can replace the resonant inductor in the resonant circuit. That is, in this embodiment, the magnetic device integrates the resonant circuit needs Transformers and inductors, when this magnetic device is applied to a resonant circuit, the number of components in the resonant circuit is reduced, reducing cost and volume. Compared with the matrix transformer in which multiple magnetic columns are arranged to wind multiple secondary windings in the prior art, in this embodiment, a pair of magnetic columns in the magnetic device only includes a first magnetic column 21 and a second magnetic column. 22, right There is one primary winding 31 and one secondary winding 32, which eliminates the need for the integration of multiple transformers in the matrix transformer in the prior art, and does not require complex structures such as primary series connection and secondary parallel connection of multiple transformers.

Optionally, in order to make the wiring arrangement more concise, the first magnetic column 21 and the second magnetic column 22 on each magnetic column pair are arranged in the X direction, and all magnetic column pairs are arranged perpendicular to the X direction on the plane of the plate. direction arrangement, correspondingly, the number of primary windings 31 on the first PCB board of each layer and the number of secondary windings 32 on the second PCB board of each layer are the same as the number of magnetic column pairs. The primary windings 31 are on The arrangement on the first PCB and the distribution of the secondary windings 32 on the second PCB correspond to the positions of the magnetic column pairs or the second magnetic columns 22 .

This application discloses a magnetic device, which includes a magnetic core and a multi-layer PCB board. The magnetic core includes: two parallel magnetic flat plates, and several pairs of magnetic columns vertically arranged between the two magnetic flat plates. Each of the magnetic column pairs includes a first magnetic column and a second magnetic column, and the cross-sectional area of the first magnetic column in each of the magnetic column pairs is smaller than the cross-sectional area of the second magnetic column; all of the PCB boards Located between the two magnetic plates, each layer of the PCB is provided with a through hole, and all pairs of magnetic columns pass through the PCB through the through hole; the multi-layer PCB includes several layers A first PCB board and several layers of second PCB boards; the first PCB board of each layer is provided with a primary winding, and the primary winding is wound around the magnetic column pair; the second PCB board of each layer is A secondary winding is provided, and the secondary winding is wound around the second magnetic column in the pair of magnetic columns wound by the primary winding. By setting the cross-sectional area of the first magnetic column and the second magnetic column and the winding method of the primary winding and the secondary winding, this application achieves the function of the transformer and the function of the transformer magnetic leakage replacing the resonant inductor, and at the same time increases the magnetic field. Compared with the existing technology, the magnetic device of this application has lower cost and volume, simpler structure and wider application scenarios.

The embodiment of the present application discloses a specific magnetic device. Compared with the previous embodiment, this embodiment explains the technical solution as follows. specific:

In some specific embodiments, the two magnetic flat plates 1 are respectively a first flat plate and a second flat plate, and all pairs of magnetic columns and the second flat plate have an integrated structure. It can be understood that the arrangement of the integrated structure ensures that there is no air gap between the pair of magnetic pillars and the second flat plate, and the air gap on the magnetic device only exists between the pair of magnetic pillars and the first flat plate.

It can be understood that there is an air gap between the pair of magnetic columns and the magnetic flat plate 1, and the air gap is located outside the PCB board instead of between the two PCB boards. In this way, the positions of the air gap and the windings are misaligned, which can effectively reduce eddy current losses.

Optionally, the vertical distance between each first magnetic column 21 and the first flat plate is determined by the target resonant inductance; The vertical distance between each second magnetic column 22 and the first flat plate is determined by the target excitation inductance. The vertical distance here is the air gap distance between the magnetic cores.

It can be understood that the vertical distance between the first magnetic column 21 and the first flat plate has a correlation with the leakage inductance of the magnetic device. Since the leakage inductance is set to replace the resonant inductance, the first magnetic inductance can be determined according to the required target resonant inductance. The vertical distance between the second magnetic column 21 and the first flat plate; similarly, the vertical distance between the second magnetic column 22 and the first flat plate has a correlation with the excitation inductance of the transformer. Therefore, the distance between the second magnetic column 22 and the first flat plate can be determined according to the required target excitation inductance. The vertical distance of the first plate. The determination of the vertical distance between the first magnetic column 21 and the first flat plate and the vertical distance between the second magnetic column 22 and the first flat plate are independent of each other. Each is optimized and does not interfere with each other. Therefore, when specifically determining the vertical distance, the first flat plate and the first flat plate need to be considered. The distance between the second flat plates, the thickness of all PCB boards, the height of the first magnetic pillar 21 and the second magnetic pillar 22 and other factors.

It can be understood that the target resonant inductance in this embodiment is also related to the cross-sectional area ratio and vertical distance of the first magnetic column 21 and the second magnetic column 22, specifically:

The cross-sectional area ratio between the cross-sectional area of the first magnetic pillar 21 and the cross-sectional area of the second magnetic pillar 22 is determined by the target resonant inductance. Usually in the field of LED driving, the cross-sectional area ratio ranges from [0.05, 1). When the air gap is fixed, the smaller the cross-sectional area ratio is, the smaller the leakage inductance is. The value sets the cross-sectional area ratio.

Similarly, the vertical distance between the first magnetic column 21 and the second magnetic column 22 in each magnetic column pair is determined by the target resonant inductance, that is, the vertical distance between the first magnetic column 21 and the second magnetic column 22 in each magnetic column pair. The size of the leakage inductance can also be adjusted for distance, and the vertical distance between the first magnetic column 21 and the second magnetic column 22 of each magnetic column is determined according to the required inductance value of the target resonant inductance.

Optionally, in this embodiment, the shape of the first magnetic column 21 and the second magnetic column 22 of each magnetic column is not strictly regulated except that it is a standard cylinder. It can be in any shape, including but not limited to circles, rectangles, rounded rectangles, and beveled rectangles, and chamfers can also be added according to design requirements. As shown in Figure 2, the cross section of the first magnetic column 21 is circular, and the second magnetic column 21 has a circular cross section. The cross section of the magnetic column 22 is rectangular. As shown in Figure 3, the cross section of the first magnetic column 21 is rectangular, and the cross section of the second magnetic column 22 is a rounded rectangle. In this embodiment, the first magnetic column 21 and the second magnetic column 22 have a rectangular cross section. There are no strict requirements for the relative position of the magnetic columns 22 on the second flat plate. It can be that all pairs of magnetic columns are located within a central range of a certain distance from the side on the second flat plate as shown in Figure 2, or it can be as shown in Figure 2 The outer sides of the first magnetic column 21 and the second magnetic column 22 are flush with the two sides of the second flat plate respectively. They can also be the outer sides of the first magnetic column 21 or the second magnetic column 22 . The outside is flush with one side of the second plate, as shown in Figure 4. It can be understood that FIGS. 2 to 4 are schematic diagrams taking two magnetic column pairs as an example, and other numbers of magnetic column pairs can also be positioned or shaped according to the above description.

The embodiment of the present application discloses a specific magnetic device. Compared with the previous embodiment, this embodiment explains the technical solution as follows.

It can be understood that the first PCB board serves as the carrier of the primary winding 31, and the second PCB board serves as the carrier of the secondary winding 32. According to the basic requirements of transformer production, all primary windings 31 wound on the same magnetic column pair should have the same winding direction to ensure that the direction of the magnetic field is consistent and prevent the magnetic circuits from canceling each other. Similarly, the secondary windings 32 wound on the same second magnetic column 22 should have the same winding direction.

Optionally, the secondary windings 32 of different layers and the primary windings 31 of different layers are interspersed with each other, and at least one layer of second PCB boards is provided between the two layers of first PCB boards. The layers of PCB boards can be regarded as "original" -The "symmetrical" clamping form of "vice-original" can effectively reduce the interaction between current and magnetic fields, reduce electromagnetic interference, and at the same time reduce the copper loss of magnetic devices. Therefore, usually the first PCB board and the second PCB board are arranged alternately. Specifically, there is at least one layer of second PCB board between any two adjacent first PCB boards, and any two adjacent layers of second PCB board There is at least one layer of first PCB board between them.

Optionally, similar windings in different layers can be electrically connected through buried holes, blind holes or via holes. Specifically, all primary windings 31 are connected through blind holes, buried holes or via holes to form a total primary winding; Similarly, all secondary windings 32 are connected through blind holes, buried holes or via holes to form a total secondary winding.

It can be understood that the total secondary winding formed by all the secondary windings 32 can be a tapped winding, and its resonant output rectification circuit can be as shown in Figure 5a. The total secondary winding can also be a two-terminal winding, and its resonant output rectifier The circuit can be shown in Figure 5b.

Correspondingly, an embodiment of the present application also discloses a resonant circuit, including the magnetic device described in any of the above embodiments.

Specifically, the resonant circuit is any resonant circuit including a resonant inductor and a transformer. The resonant circuit includes but is not limited to an LCC resonant circuit and an LLCC resonant circuit. The magnetic device serves as an integrated component of the transformer and the resonant inductor in the resonant circuit.

For specific details about the magnetic device, please refer to the relevant descriptions in the above embodiments and will not be described again here.

Correspondingly, an embodiment of the present application also discloses an LED driving power supply, including a resonant circuit as described in any of the above embodiments.

Among them, the resonant circuit and LED driving power supply in this embodiment have the same technical effect as the magnetic device in the above embodiment, and will not be described again here.

Finally, it should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or any such actual relationship or sequence between operations. Furthermore, the terms "comprises," "comprises," or any other variations thereof are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also those not expressly listed other elements, or elements inherent to the process, method, article or equipment. Without further limitation, an element defined by the statement "comprises a..." does not exclude the presence of additional identical elements in a process, method, article, or apparatus that includes the stated element.

The above is a detailed introduction to a magnetic device, a resonant circuit and an LED driving power supply provided by this application. Specific examples are used in this article to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understanding. The method of this application and its core idea; at the same time, for those of ordinary skill in the field, there will be changes in the specific implementation and application scope based on the idea of this application. In summary, the contents of this specification should not understood as a limitation on this application.

Industrial applicability

The embodiments of this application provide a magnetic device, a resonant circuit and an LED driving power supply, which are used in the field of power supply. In the embodiment of the present application, by setting the cross-sectional area of the first magnetic column and the second magnetic column and the winding method of the primary winding and the secondary winding, the transformer function and the transformer magnetic leakage replacing the resonant inductor function are realized. At the same time, the utilization rate of the magnetic core is increased.

Claims

A magnetic device including a magnetic core and a multi-layer PCB board, wherein:

The magnetic core includes: two parallel magnetic flat plates, and a plurality of magnetic column pairs arranged vertically between the two magnetic flat plates. Each of the magnetic column pairs includes a first magnetic column and a second magnetic column. The cross-sectional area of the first magnetic column in the pair of magnetic columns is smaller than the cross-sectional area of the second magnetic column;

All the PCB boards are located between the two magnetic flat plates, each layer of the PCB board is provided with a through hole, and all the magnetic column pairs pass through the PCB board through the through hole;

The multi-layer PCB board includes several layers of first PCB boards and several layers of second PCB boards;

The first PCB board of each layer is provided with a primary winding, and the primary winding is wound around the pair of magnetic columns;

Each layer of the second PCB is provided with a secondary winding, and the secondary winding is wound around the second magnetic column in the pair of magnetic columns wound by the primary winding.
The magnetic device according to claim 1, wherein the two magnetic flat plates are a first flat plate and a second flat plate respectively, and all pairs of magnetic columns and the second flat plate are of an integrated structure.
The magnetic device according to claim 2, wherein,

The vertical distance between each first magnetic column and the first flat plate is determined by the target resonant inductance;

The vertical distance between each second magnetic column and the first flat plate is determined by the target excitation inductance.
The magnetic device according to claim 1, wherein a cross-sectional area ratio of the cross-sectional area of the first magnetic pillar to the cross-sectional area of the second magnetic pillar is determined by a target resonant inductance.
The magnetic device according to claim 4, wherein the cross-sectional area ratio ranges from [0.05, 1).
The magnetic device of claim 1, wherein the vertical distance between the first magnetic column and the second magnetic column in each magnetic column pair is determined by a target resonant inductance.
The magnetic device according to any one of claims 1 to 6, wherein the first PCB board and the second PCB board are arranged alternately.
The magnetic device according to claim 7, wherein all the primary windings are connected through blind holes, buried holes or via holes to form a total primary winding;

All the secondary windings are connected through blind holes, buried holes or via holes to form a total secondary winding.
A resonant circuit, which includes the magnetic device according to any one of claims 1 to 8.
An LED driving power supply, comprising a resonant circuit as claimed in claim 9.