Magnetic device, resonant circuit and LED driving power supply

Abstract

The application discloses a magnetic device, a resonant circuit and an LED driving power supply, and relates to the field of power supplies.The magnetic device comprises a magnetic core and a multilayer PCB board, the magnetic core comprises two magnetic plates and a plurality of magnetic column pairs, the cross-sectional area of the first magnetic column in each magnetic column pair is smaller than that of the second magnetic column; each layer of the PCB board is provided with a through hole for allowing all the magnetic columns to pass through the PCB board; in the multilayer PCB board, the primary winding on each first PCB board is wound around the magnetic column pair; and the secondary winding on each second PCB board is wound around the second magnetic column in the magnetic column pair wound by the primary winding. Through the setting of the cross-sectional areas of the first magnetic column and the second magnetic column and the winding mode of the primary winding and the secondary winding, the transformer function and the transformer leakage magnetic field are used to replace the resonant inductance function, the utilization rate of the magnetic core is increased, the magnetic device is lower in cost and volume, the structure is simpler, and the application scenarios are more extensive.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power supply, in particular to a magnetic device, a resonant circuit and an LED driving power supply. BACKGROUND

[0002] In existing switching power supplies, resonant circuits are widely used due to their low switching loss and small size. The magnetic device of a typical resonant LLC circuit includes a resonant inductor and a transformer. The transformer in the prior art includes a skeleton and a magnetic core. Two winding slots are provided on the skeleton for winding the primary and secondary windings. Two E-shaped magnetic cores and the wound skeleton form a transformer. This transformer has high leakage inductance and can replace the resonant inductor. Therefore, this transformer structure is actually a magnetic device that integrates leakage inductance and a transformer, making the switching power supply smaller and lower in cost.

[0003] To further reduce the size and cost of the magnetic device, planar transformers, also known as matrix transformers, are used in some fields. The planar transformer removes the skeleton and sets the primary and secondary windings on the PCB. Holes are opened on the PCB to allow the magnetic core to pass directly through the PCB. Existing planar transformers are used in server power supplies and other fields to meet the power supply requirements of low voltage and high current. For example, patent CN113517120A provides a matrix transformer with a central magnetic column and multiple secondary magnetic columns surrounding the central magnetic column. Multiple windings are provided on the PCB. The primary winding is wound around the central magnetic column, and the multiple secondary windings are wound around the secondary magnetic columns, respectively, to realize multiple transformers. The primary windings of the multiple transformers are connected in series, and the secondary windings are connected in parallel, thereby achieving the effect of low voltage and high current.

[0004] However, this matrix transformer has a large number of magnetic columns, and the wiring of the windings on the PCB is complex, making the design difficult. It cannot be directly applied to non-low-voltage and high-current scenarios. Using the existing matrix transformer will inevitably increase the complexity of winding design and the cost of the PCB.

[0005] Therefore, how to provide a solution to the above technical problems is a problem that needs to be solved by those skilled in the art. SUMMARY

[0006] Therefore, how to provide a solution to the above technical problems is a problem that needs to be solved by those skilled in the art.

[0007] A magnetic device includes a magnetic core and a multi-layer PCB, wherein:

[0008] The magnetic core comprises: two parallel magnetic plates, a plurality of magnetic column pairs vertically arranged between the two magnetic plates, each of the magnetic column pairs comprising a first magnetic column and a second magnetic column, and the cross-sectional area of the first magnetic column is smaller than that of the second magnetic column in each of the magnetic column pairs.

[0009] All the PCBs are located between the two magnetic plates, each of the PCBs is provided with a through hole, and all the magnetic column pairs pass through the PCBs through the through holes.

[0010] The multi-layer PCBs comprise a plurality of first PCBs and a plurality of second PCBs.

[0011] Each of the first PCBs is provided with a primary winding, and the primary winding is wound around the magnetic column pairs.

[0012] Each of the second PCBs is provided with a secondary winding, and the secondary winding is wound around the second magnetic column in the magnetic column pairs wound by the primary winding.

[0013] Preferably, the two magnetic plates are a first plate and a second plate, respectively, and all the magnetic column pairs are in an integral structure with the second plate.

[0014] Preferably, the vertical distance between each of the first magnetic columns and the first plate is determined by a target resonant inductance.

[0015] The vertical distance between each of the second magnetic columns and the first plate is determined by a target excitation inductance.

[0016] Preferably, the cross-sectional area ratio of the cross-sectional area of the first magnetic column to the cross-sectional area of the second magnetic column is determined by a target resonant inductance.

[0017] Preferably, the cross-sectional area ratio is in a range of [0.05, 1).

[0018] Preferably, the vertical distance between the first magnetic column and the second magnetic column in each of the magnetic column pairs is determined by a target resonant inductance.

[0019] Preferably, the first PCBs and the second PCBs are arranged alternately.

[0020] Preferably, all the primary windings are connected to form a total primary winding through blind holes, buried holes or vias.

[0021] All the secondary windings are connected to form a total secondary winding through blind holes, buried holes or vias.

[0022] Correspondingly, the application also discloses a resonant circuit comprising the magnetic device.

[0023] Correspondingly, the application also discloses an LED driving power supply comprising the resonant circuit.

[0024] The application discloses a magnetic device, comprising a magnetic core and a plurality of PCB boards, the magnetic core comprises: two parallel magnetic plates, a plurality of magnetic column pairs vertically arranged between the two magnetic plates, each magnetic column pair comprises a first magnetic column and a second magnetic column, and the cross-sectional area of the first magnetic column is smaller than that of the second magnetic column in each magnetic column pair; all the PCB boards are located between the two magnetic plates, each PCB board is provided with a through hole, and all the magnetic column pairs pass through the PCB boards through the through holes; the plurality of PCB boards comprise a plurality of first PCB boards and a plurality of second PCB boards; each first PCB board is provided with a primary winding, and the primary winding is wound around the magnetic column pair; each second PCB board is provided with a secondary winding, and the secondary winding is wound around the second magnetic column in the magnetic column pair wound by the primary winding. By setting the cross-sectional areas of the first magnetic column and the second magnetic column and the winding modes of the primary winding and the secondary winding, the utilization rate of the magnetic core is increased while the transformer function and the transformer leakage magnetic field substitute resonant inductance function are realized, compared with the prior art, the magnetic device has lower cost and volume, simpler structure and wider application scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0026] Figure 1 The structural distribution diagram of a magnetic device in the embodiment of the present application is shown in the figure.

[0027] Figure 2 The structural distribution diagram of a first magnetic core in the embodiment of the present application is shown in the figure.

[0028] Figure 3 The structural distribution diagram of a second magnetic core in the embodiment of the present application is shown in the figure.

[0029] Figure 4 The structural distribution diagram of a third magnetic core in the embodiment of the present application is shown in the figure.

[0030] Figure 5a The structural distribution diagram of a resonant output rectifier circuit in the embodiment of the present application is shown in the figure.

[0031] Figure 5b The structural distribution diagram of another resonant output rectifier circuit in the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0033] The conventional matrix transformer has a large number of magnetic columns, and the winding on the PCB board has a complex wiring and a high design difficulty, and cannot be directly applied to a non-low-voltage and large-current scene. The use of the matrix transformer in the prior art will inevitably increase the complexity of the winding design and the cost of the PCB board.

[0034] The present application sets the cross-sectional area of the first magnetic column and the second magnetic column and the winding mode of the primary winding and the secondary winding. While realizing the functions of the transformer and the function of replacing the resonant inductor by the leakage magnetic field of the transformer, the utilization rate of the magnetic core is increased. Compared with the prior art, the magnetic device of the present application has lower cost and volume, simpler structure, and wider application scenarios.

[0035] The embodiment of the present application discloses a magnetic device, as shown in Figure 1 The magnetic device comprises a magnetic core and a multi-layer PCB board, wherein:

[0036] The magnetic core comprises two parallel magnetic plates 1, a plurality of magnetic column pairs vertically arranged between the two magnetic plates 1, each magnetic column pair comprising a first magnetic column 21 and a second magnetic column 22, and the cross-sectional area of the first magnetic column 21 in each magnetic column pair being smaller than that of the second magnetic column 22.

[0037] All the PCB boards are located between the two magnetic plates 1, 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.

[0038] The multi-layer PCB board comprises a plurality of layers of first PCB boards and a plurality of layers of second PCB boards.

[0039] The primary winding 31 is arranged on each layer of the first PCB board and surrounds the magnetic column pair.

[0040] The secondary winding 32 is arranged on each layer of the second PCB board and surrounds the second magnetic column 22 in the magnetic column pair wound by the primary winding 31.

[0041] It can be understood that all the PCB boards in the embodiment are carriers of the primary winding 31 or the secondary winding 32 and are arranged between the two magnetic plates 1 through the through hole. At this time, the primary winding 31 and the secondary winding 32 on the PCB board surround the corresponding magnetic column and are generally wound in the shape of an 8, as shown inFigure 1 As shown; specifically, for any primary side winding 31 on any first PCB board, the primary side winding 31 is wound around a magnetic column pair as a unit, that is, the primary side winding 31 is wound around both the first magnetic column 21 and the second magnetic column 22 in the magnetic column pair, and correspondingly, the second magnetic column 22 is wound around by the secondary side winding 32 on any second PCB board. This winding method forms a transformer, and at the same time makes the magnetic device generate leakage inductance, which can replace the resonant inductance in the resonant circuit. That is, in this embodiment, the magnetic device integrates the transformer and inductance required by the resonant circuit. When this magnetic device is applied to the resonant circuit, the number of components of the resonant circuit is reduced, and the cost and volume are reduced. Compared with the matrix transformer form in the prior art, in which multiple magnetic columns are used to wind multiple secondary side windings, in this embodiment, only one first magnetic column 21 and one second magnetic column 22 are included in one magnetic column pair in the magnetic device, corresponding to one primary side winding 31 and one secondary side winding 32. It is not necessary to integrate multiple transformers in the matrix transformer of the prior art, nor is it necessary to have a complex structure such as series connection of primary sides and parallel connection of secondary sides of multiple transformers.

[0042] Further, in order to make the wiring arrangement more simple, the first magnetic column 21 and the second magnetic column 22 on each magnetic column pair are arranged in the X direction, and all the magnetic column pairs are arranged perpendicular to the X direction in the plane of the flat plate. Correspondingly, the number of primary side windings 31 on each layer of first PCB boards and the number of secondary side windings 32 on each layer of second PCB boards are the same as the number of magnetic column pairs. The arrangement of the primary side windings 31 on the first PCB boards and the distribution of the secondary side windings 32 on the second PCB boards correspond to the positions of the magnetic column pairs or the second magnetic columns 22.

[0043] The application discloses a magnetic device, comprising a magnetic core and multiple layers of PCB boards, the magnetic core comprises: two parallel magnetic flat plates, a plurality of magnetic column pairs vertically arranged between the two magnetic flat plates, each magnetic column pair comprising a first magnetic column and a second magnetic column, the cross-sectional area of the first magnetic column in each magnetic column pair being smaller than that of the second magnetic column; all the PCB boards are located between the two magnetic flat plates, each layer of the PCB boards is provided with a through hole, and all the magnetic column pairs pass through the PCB boards through the through holes; the multiple layers of the PCB boards comprise a plurality of layers of first PCB boards and a plurality of layers of second PCB boards; each layer of the first PCB boards is provided with a primary side winding, and the primary side winding is wound around the magnetic column pair; each layer of the second PCB boards is provided with a secondary side winding, and the secondary side winding is wound around the second magnetic column in the magnetic column pair wound by the primary side winding. By setting the cross-sectional areas of the first magnetic column and the second magnetic column and the winding method of the primary side winding and the secondary side winding, the utilization rate of the magnetic core is increased while the functions of the transformer and the transformer leakage inductance replacing the resonant inductance are realized. Compared with the prior art, the magnetic device of the application has lower cost and volume, simpler structure, and wider application scenarios.

[0044] The embodiment of the present application discloses a specific magnetic device, and relative to the previous embodiment, the technical scheme is further described and optimized. Specifically:

[0045] In some specific embodiments, the two magnetic plates 1 are respectively a first plate and a second plate, and all the magnetic column pairs are integrated with the second plate. It can be understood that the integrated structure ensures that there is no air gap between the magnetic column pairs and the second plate, and the air gap on the magnetic device only exists between the magnetic column pairs and the first plate.

[0046] It can be understood that there is an air gap between the magnetic column pairs and the magnetic plate 1, which is outside the PCB board, not between the two-layer PCB boards, so that the air gap and the position of the winding are staggered, which can effectively reduce the eddy current loss.

[0047] Further, the vertical distance of each first magnetic column 21 from the first plate is determined by the target resonant inductance; and the vertical distance of each second magnetic column 22 from the first plate is determined by the target excitation inductance. Here, the vertical distance is also the air gap distance between the magnetic cores.

[0048] It can be understood that the vertical distance of the first magnetic column 21 from the first plate has a correlation with the leakage inductance of the magnetic device, and since the leakage inductance is used to replace the resonant inductance, the vertical distance of the first magnetic column 21 from the first plate can be determined according to the target resonant inductance required; similarly, the vertical distance of the second magnetic column 22 from the first plate has a correlation with the excitation inductance of the transformer, and thus the vertical distance of the second magnetic column 22 from the first plate can be determined according to the target excitation inductance required. The determination of the vertical distance of the first magnetic column 21 from the first plate and the vertical distance of the second magnetic column 22 from the first plate is independent of each other, and is optimized respectively without interference, and thus various factors such as the distance between the first plate and the second plate, the thickness of all the PCB boards, the height of the first magnetic column 21 and the second magnetic column 22 need to be considered when the vertical distance is specifically determined.

[0049] It can be understood that in the embodiment, the target resonant inductance also has a correlation with the cross-sectional area ratio of the first magnetic column 21 and the second magnetic column 22 and the vertical distance, and specifically:

[0050] The cross-sectional area ratio of the cross-sectional area of the first magnetic column 21 to the cross-sectional area of the second magnetic column 22 is determined by the target resonant inductance, and in the field of LED driving, the value range of the cross-sectional area ratio is [0.05, 1). In the case of a fixed air gap, the smaller the value of the cross-sectional area ratio, the smaller the inductance of the leakage inductance, and the larger the value of the cross-sectional area ratio, the larger the inductance of the leakage inductance, and the cross-sectional area ratio can be set according to the inductance value of the target resonant inductance required.

[0051] 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 distance between the first magnetic column 21 and the second magnetic column 22 in each magnetic column pair can also adjust the size of the leakage inductance, and the vertical distance between the first magnetic column 21 and the second magnetic column 22 in each magnetic column pair is determined according to the required target resonant inductance.

[0052] Further, in the embodiment, the shape of the first magnetic column 21 and the second magnetic column 22 in each magnetic column pair is not strictly required to be a standard column, and the cross-sectional shape can be any shape, including but not limited to a circular shape, a rectangular shape, a rounded rectangular shape, an oblique rectangular shape, and a chamfered rectangular shape. Figure 2 As shown in FIG. 6, the cross section of the first magnetic column 21 is circular, and the cross section of the second magnetic column 22 is rectangular. Figure 3 As shown in FIG. 7, the cross section of the first magnetic column 21 is rectangular, and the cross section of the second magnetic column 22 is rounded rectangular. In the embodiment, the relative position of the first magnetic column 21 and the second magnetic column 22 on the second plate is not strictly required, and can be as shown in FIG. 8, that is, all magnetic column pairs are located in the central range of the second plate at a distance from the side edge. Figure 2 As shown in FIG. 9, the outer side of the first magnetic column 21 and the outer side of the second magnetic column 22 are flush with the two side edges of the second plate. Figure 2 As shown in FIG. 10, the outer side of the first magnetic column 21 or the outer side of the second magnetic column 22 is flush with one side edge of the second plate. Figure 4 As shown in FIG. 11, the outer side of the first magnetic column 21 or the outer side of the second magnetic column 22 is flush with one side edge of the second plate. Figures 2-4 As shown in FIG. 12, the outer side of the first magnetic column 21 or the outer side of the second magnetic column 22 is flush with one side edge of the second plate.

[0053] The embodiment of the present application discloses a specific magnetic device, and relative to the previous embodiment, the technical solution is further described and optimized.

[0054] It can be understood that the first PCB board is a carrier of the primary winding 31, and the second PCB board is a carrier of the secondary winding 32, according to the basic requirement of transformer production, all primary windings 31 wound on the same magnetic column pair should have the same winding direction to ensure that the magnetic field direction is consistent and avoid mutual cancellation of the magnetic circuit, and similarly, the secondary windings 32 wound on the same second magnetic column 22 should have the same winding direction.

[0055] Further, the different layer auxiliary winding 32 and the different layer primary winding 31 are interpenetrated, at least one second PCB is arranged between the two layers of the first PCB, and the layers of the PCB can be regarded as a "symmetrical" clamping winding form of "primary-secondary-primary", which can effectively reduce the mutual influence between the current magnetic fields, reduce electromagnetic interference, and reduce the copper loss of the magnetic device. Therefore, the first PCB and the second PCB are usually arranged alternately, specifically, there is at least one second PCB between any two adjacent first PCBs, and there is at least one first PCB between any two adjacent second PCBs.

[0056] Further, for the same type of winding in different layers, the buried hole, blind hole or via hole can be used for electrical connection, specifically, all the primary windings 31 are connected to form a total primary winding through the blind hole, buried hole or via hole; similarly, all the auxiliary windings 32 are connected to form a total auxiliary winding through the blind hole, buried hole or via hole.

[0057] It can be understood that the total auxiliary winding formed by all the auxiliary windings 32 can be a tapped winding, and the resonant output rectifier circuit thereof can be as shown in Figure 5a The total auxiliary winding can also be a two-terminal winding, and the resonant output rectifier circuit thereof can be as shown in Figure 5b

[0058] Correspondingly, the embodiment of the application also discloses a resonant circuit comprising the magnetic device in any of the above embodiments.

[0059] Specifically, the resonant circuit is any resonant circuit comprising a resonant inductor and a transformer, and the resonant circuit includes but is not limited to an LCC resonant circuit and an LLCC resonant circuit, and the magnetic device is used as an integrated element of the transformer and the resonant inductor in the resonant circuit.

[0060] Specifically, the details of the magnetic device can be referred to the related description in the above embodiments, which will not be repeated here.

[0061] Correspondingly, the embodiment of the application also discloses an LED driving power supply comprising the resonant circuit in any of the above embodiments.

[0062] Among them, the resonant circuit and the LED driving power supply in the embodiment have the same technical effects as the magnetic device in the above embodiments, which will not be repeated here.

[0063] ​Finally, it needs to be pointed out that in this document, relational terms such as first and second and the like can only be used to distinguish one entity or action from another entity or action, without necessarily requiring or implying that there is any such actual relationship or order between these entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, so that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without more limitations, an element defined by the statement "comprising a" does not exclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0064] The above describes in detail the magnetic device, resonant circuit and LED driving power supply provided by the present application. The principles and implementation manners of the present application are described by using specific examples. The above description of the embodiments is only used to help understand the method of the present application and its core idea. Meanwhile, for those skilled in the art, the specific implementation manners and application ranges can be changed according to the idea of the present application. In summary, the content of the present description should not be understood as a limitation of the present application.

Claims

1. A magnetic device, characterized by, The magnetic core and the multi-layer PCB board are included, wherein: The magnetic core includes: two parallel magnetic plates, a plurality of magnetic column pairs vertically arranged between the two magnetic plates, each magnetic column pair including only a first magnetic column and a second magnetic column, the first magnetic column and the second magnetic column in each magnetic column pair being arranged in an X direction, and all the magnetic column pairs being arranged in a direction perpendicular to the X direction in the plane of the plates; the cross-sectional area of the first magnetic column being smaller than that of the second magnetic column in each magnetic column pair; All the PCB boards are located between the two magnetic plates, each PCB board having a through hole, and all the magnetic column pairs passing through the PCB boards through the through holes; The multi-layer PCB board includes a plurality of first PCB boards and a plurality of second PCB boards; Each first PCB board has a primary winding, which is wound in an 8-shaped manner around the magnetic column pair; Each second PCB board has a secondary winding, which is wound in an 8-shaped manner around the second magnetic column in the magnetic column pair wound by the primary winding.

2. The magnetic device of claim 1, wherein, The two magnetic plates are a first plate and a second plate, and all the magnetic column pairs are in an integral structure with the second plate.

3. The magnetic device of claim 2, wherein: The vertical distance between each first magnetic column and the first plate is determined by a target resonant inductance; The vertical distance between each second magnetic column and the first plate is determined by a target magnetizing inductance.

4. The magnetic device of claim 1, wherein, The cross-sectional area ratio of the first magnetic column to the second magnetic column is determined by a target resonant inductance.

5. The magnetic device of claim 4, wherein, The cross-sectional area ratio is in the range of [0.05, 1).

6. The magnetic device of claim 1, wherein, The distance between the first magnetic column and the second magnetic column in each magnetic column pair in the X direction is determined by a target resonant inductance.

7. The magnetic device according to any one of claims 1 to 6, wherein The first PCB boards and the second PCB boards are arranged alternately.

8. The magnetic device of claim 7, wherein, All the primary windings are connected to form a total primary winding through blind holes, buried holes, or vias; All the secondary windings are connected to form a total secondary winding through blind holes, buried holes, or vias.

9. A resonant circuit, characterized by The magnetic device as claimed in any one of claims 1 to 8.

10. An LED driving power supply, characterized by, The resonant circuit as claimed in claim 9.

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