Planar transformer and charging device
By employing a closely spaced primary and secondary winding design in a planar transformer, the current loop area is reduced, solving the problems of electromagnetic interference and production costs, and achieving efficient electromagnetic interference suppression and cost reduction.
Patent Information
- Application Number
- CN202423160276.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2034-12-20
AI Technical Summary
The interlayer coupling between the primary and secondary windings of existing planar transformers results in significant electromagnetic interference, increasing production costs and electromagnetic interference capabilities. Furthermore, traditional wound-rotor transformers are relatively large in size.
The primary and secondary windings are designed to be closely spaced. By setting a central circular mounting hole on the PCB board, the primary and secondary windings are closely spaced around the central circular mounting hole. The secondary winding is set close to the inner and outer edges of the primary winding, which reduces the current loop area and reduces electromagnetic interference.
This effectively reduces the electromagnetic interference capability of planar transformers, reduces production costs, and eliminates the need for additional shielding layers. Only four PCB layers are required to ensure electromagnetic interference resistance, further reducing production costs.
Smart Images
Figure CN223757370U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to transformer field especially relates to a planar transformer and charging device. BACKGROUND
[0002] The basic principle of transformer is through electromagnetic induction principle, utilizes the varying AC voltage to produce the varying magnetic field, finally produces induced electromotive force to produce current. The existing traditional winding type transformer, winding type transformer is composed of primary winding and secondary winding and magnetic core, and primary winding and secondary winding are wound on the magnetic core respectively, through changing the number of turns of both ends winding, reach the effect that voltage is raised or reduced. And according to such implementation finished product transformer, finally will make the volume of transformer be larger, and we know that the traditional winding type transformer has poor anti-electromagnetic interference ability.
[0003] And the existing planar transformer has the improvement that is different from traditional transformer in volume, but the interlayer coupling between the primary winding and the secondary winding of the existing planar transformer, resulting in the interlayer capacitance of the planar transformer is larger, increases electromagnetic interference. The existing planar transformer mostly increases shielding layer between the primary winding and the secondary winding, or increases shielding layer between the primary winding layer and the secondary winding layer, to reduce the influence of electromagnetic interference on circuit. This results in the number of layers of planar transformer is at least 6 or more, increases the production cost. SUMMARY
[0004] To solve the problems in the prior art, the utility model provides a planar transformer and charging device.
[0005] Firstly, the utility model discloses a planar transformer, including PCB board, magnetic core, primary winding, first secondary winding and second secondary winding, the PCB board includes the bottom layer PCB, second layer PCB, third layer PCB and top layer PCB that stack in turn, the PCB board is preformed with the magnetic core mounting hole for setting up the magnetic core, the magnetic core sets up in the magnetic core mounting hole, the magnetic core mounting hole includes the middle circular mounting hole, the primary winding sets up on the top layer PCB and the bottom layer PCB, and the primary winding is closely arranged around the middle circular mounting hole, the first secondary winding and the second secondary winding set up on the second layer PCB and the third layer PCB, the first secondary winding is closely arranged around the middle circular mounting hole, and the second secondary winding is arranged around the middle circular mounting hole, and is closely arranged to the inner and outer side edges of the first secondary winding.
[0006] In some embodiments, the PCB board comprises a primary side circuit region and a secondary side circuit region arranged oppositely; the primary side circuit region and the secondary side circuit region are respectively located on two sides of the middle circular mounting hole; the primary winding is routed from the primary side circuit region of the top layer PCB, spirally arranged from outside to inside around the middle circular mounting hole, passes through the first through hole on the top layer PCB, is led out from the second through hole on the bottom layer PCB, and is then spirally arranged from inside to outside around the middle circular mounting hole and led out to the primary side circuit region of the bottom layer PCB.
[0007] In some embodiments, the primary winding is spirally arranged clockwise around the middle circular mounting hole on the top layer PCB; the primary winding is spirally arranged clockwise around the middle circular mounting hole on the bottom layer PCB.
[0008] In some embodiments, the first secondary winding is routed from the secondary side circuit region of the third layer PCB, passes through the third through hole on the third layer PCB after winding around the middle circular mounting hole once, is led out from the fourth through hole on the second layer PCB, and is then led out to the secondary side circuit region of the second layer PCB after winding around the middle circular mounting hole once.
[0009] In some embodiments, the first secondary winding is routed counterclockwise around the middle circular mounting hole on the third layer PCB; the first secondary winding is routed counterclockwise around the middle circular mounting hole on the second layer PCB.
[0010] In some embodiments, the second secondary winding is routed from the secondary side circuit region of the third layer PCB, sequentially along the outer edge and the inner edge of the first secondary winding, passes through the fifth through hole on the third layer PCB after winding around the middle circular mounting hole twice, is led out from the sixth through hole on the second layer PCB, and is then led out to the secondary side circuit region of the second layer PCB after winding around the middle circular mounting hole once along the inner edge of the first secondary winding.
[0011] In some embodiments, the second secondary winding is routed counterclockwise around the middle circular mounting hole on the third layer PCB, sequentially along the outer edge and the inner edge of the first secondary winding; the second secondary winding is routed counterclockwise around the middle circular mounting hole on the second layer PCB, along the inner edge of the first secondary winding.
[0012] In some embodiments, the shape of the magnetic core comprises one of an EC type, an ETD type, and an EER type.
[0013] In some embodiments, the primary winding, the first secondary winding, and the second secondary winding are copper foil windings etched on the PCB board.
[0014] The utility model discloses a kind of charging devices, including the planar transformer of the first aspect.
[0015] The utility model discloses a kind of planar transformer and charging device, planar transformer includes PCB board, magnetic core, primary winding, first secondary winding and second secondary winding;PCB board includes bottom layer PCB, second layer PCB, third layer PCB and top layer PCB in turn, PCB board is pre-configured with the magnetic core mounting hole for setting magnetic core, magnetic core is arranged in magnetic core mounting hole, magnetic core mounting hole includes middle circular mounting hole, primary winding is arranged on top layer PCB and bottom layer PCB, primary winding is closely arranged around middle circular mounting hole;First secondary winding and second secondary winding are arranged on second layer PCB and third layer PCB, first secondary winding is closely arranged around middle circular mounting hole, while second secondary winding is arranged around middle circular mounting hole, and the inner and outer side edges of first secondary winding are closely arranged;By primary winding being closely arranged around middle circular mounting hole;First secondary winding is closely arranged around middle circular mounting hole, while second secondary winding is arranged around middle circular mounting hole 90, and the inner and outer side edges of first secondary winding are closely arranged;Current loop area of primary winding and first secondary winding, second secondary winding can be maximized to reduce, and the smaller current loop area, the stronger anti-electromagnetic interference ability, so that the electromagnetic interference of the planar transformer is greatly reduced, without increasing shielding layer, i.e. planar transformer only needs to set four layers of PCB, in guaranteeing the anti-electromagnetic interference ability of planar transformer, the purpose of reducing production cost is achieved. BRIEF DESCRIPTION OF DRAWINGS
[0016] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the drawings needed to be used in the embodiment description will be briefly introduced, and obviously, the drawings in the following description are some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained without creative labor.
[0017] Figure 1 The utility model provides the planar transformer's plan view for embodiment of the utility model;
[0018] Figure 2 The utility model provides the bottom view of planar transformer for embodiment of the utility model;
[0019] Figure 3 The utility model provides the top layer plan of planar transformer for embodiment of the utility model;
[0020] Figure 4 The utility model provides the bottom layer plan of planar transformer for embodiment of the utility model;
[0021] Figure 5 A third layer plan view of the planar transformer is provided for the embodiment of the present application.
[0022] Figure 6 A second layer plan view of the planar transformer is provided for the embodiment of the present application.
[0023] Figure 7 A planar size schematic view of the planar transformer is provided for the embodiment of the present application.
[0024] Figure 8 A side size schematic view of the planar transformer is provided for the embodiment of the present application.
[0025] Reference signs: 10, bottom layer PCB; 20, second layer PCB; 30, third layer PCB; 40, top layer PCB; 50, magnetic core; 60, primary winding; 70, first secondary winding; 80, second secondary winding; 90, middle circular mounting hole; 41, first through hole; 11, second through hole; 31, third through hole; 21, fourth through hole; 32, fifth through hole; 22, sixth through hole. DETAILED DESCRIPTION
[0026] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are 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 the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0027] It should be understood that, when used in the present specification and the appended claims, the terms "comprise" and "include" indicate the presence of the described features, integers, steps, operations, elements, and / or components, but do not exclude one or more other features, integers, steps, operations, elements, components, and / or groups thereof.
[0028] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.
[0029] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.
[0030] It should also be further understood that the terms "and" and "or" as used in this specification and the appended claims refer to any combination of one or more of the associated listed items and all possible combinations, and include such combinations.
[0031] like Figure 1 and Figure 2 As shown, this utility model discloses a planar transformer, including a PCB board, a magnetic core 50, a primary winding 60, a first-stage winding 70, and a second-stage winding 80; see also... Figure 3 , Figure 4 , Figure 5 and Figure 6, the PCB board includes bottom layer PCB 10, second layer PCB 20, third layer PCB 30 and top layer PCB 40 which are stacked in sequence, the PCB board is provided with a magnetic core mounting hole for setting the magnetic core 50, the magnetic core 50 is arranged in the magnetic core mounting hole, the magnetic core mounting hole includes a middle circular mounting hole 90, the primary winding 60 is arranged on the top layer PCB 40 and the bottom layer PCB 10, and the primary winding 60 is closely arranged around the middle circular mounting hole 90; the first secondary winding 70 and the second secondary winding 80 are arranged on the second layer PCB 20 and the third layer PCB 30, the first secondary winding 70 is closely arranged around the middle circular mounting hole 90, and the second secondary winding 80 is arranged around the middle circular mounting hole 90 while being closely arranged adjacent to the inner and outer side edges of the first secondary winding 70.
[0032] Specifically, the planar transformer can be used in a charging device. The PCB board includes four layers, from bottom to top, the bottom layer PCB 10, the second layer PCB 20, the third layer PCB 30 and the top layer PCB 40 which are insulated from each other. The magnetic core mounting hole further includes profiled mounting holes located on the opposite sides of the middle circular mounting hole 90, the magnetic core mounting hole penetrates through the bottom layer PCB 10, the second layer PCB 20, the third layer PCB 30 and the top layer PCB 40, and the magnetic core 50 is buckled in the magnetic core mounting hole from the direction of the bottom layer PCB 10 and the top layer PCB 40, so that the magnetic core 50 is mounted on the PCB board to form a complete planar transformer. The primary winding 60 is closely arranged around the middle circular mounting hole 90; the first secondary winding 70 is closely arranged around the middle circular mounting hole 90, and the second secondary winding 80 is arranged around the middle circular mounting hole 90 while being closely arranged adjacent to the inner and outer side edges of the first secondary winding 70, which can minimize the current loop area of the primary winding 60 and the first secondary winding 70 and the second secondary winding 80. According to the electromagnetic field theory, the smaller the current loop area is, the stronger the anti-electromagnetic interference ability is, thereby greatly reducing the electromagnetic interference of the planar transformer, and there is no need to increase a shielding layer. That is, the planar transformer disclosed in the embodiment only needs to be provided with four layers of PCB, i.e. the bottom layer PCB 10, the second layer PCB 20, the third layer PCB 30 and the top layer PCB 40, which can ensure the anti-electromagnetic interference ability of the planar transformer and achieve the purpose of reducing production cost.
[0033] In some embodiments, in order to ensure that the planar transformer has excellent heat dissipation, high conductivity, compact structure and light weight, the primary winding 60, the first secondary winding 70 and the second secondary winding 80 are copper foil windings etched on the PCB board, and the copper foils of the primary winding 60 are closely arranged, and the copper foils of the first secondary winding 70 are closely arranged along the inner and outer side edges of the copper foils of the second secondary winding 80.
[0034] For a better understanding of the present application, reference will be made to the following drawings, in whichFigure 3 and Figure 4 In some embodiments, the PCB board includes a primary side circuit area and a secondary side circuit area disposed opposite to each other; the primary side circuit area and the secondary side circuit area are respectively located on both sides of the intermediate circular mounting hole 90. The primary winding 60 starts from the primary side circuit area of the top layer PCB 40, spirally arranged around the intermediate circular mounting hole 90 from the outside to the inside, passes through the first through hole 41 on the top layer PCB 40, is led out from the second through hole 11 on the bottom layer PCB 10, and then spirally arranged around the intermediate circular mounting hole 90 from the inside to the outside, leading out to the primary side circuit area of the bottom layer PCB 10.
[0035] The primary circuit area is used to assemble electronic components and circuits related to voltage input, while the secondary circuit area is used to assemble electronic components and circuits related to voltage output. The magnetic core mounting hole, magnetic core 50, primary winding 60, first-stage winding 70, and second-stage winding 80 are all located between the primary and secondary circuit areas. The primary winding is connected to the primary circuit area, and the secondary winding is connected to the secondary circuit area. The planar transformer converts the input voltage to the required output voltage, ensuring that the electrical equipment electrically connected to the charging device receives the correct power support.
[0036] Specifically, the primary winding 60 is spirally arranged clockwise around the intermediate circular mounting hole 90 on the top layer PCB 40; the primary winding 60 is spirally arranged clockwise around the intermediate circular mounting hole 90 on the bottom layer PCB 10.
[0037] Specifically, the first through-hole 41 on the top PCB 40 is located at the end of the innermost primary winding 60 on the top PCB 40, while the second through-hole 11 on the bottom PCB 10 is located at the beginning of the innermost primary winding 60 on the top PCB 40. The primary winding 60 is connected to the primary circuit area of the top PCB 40 by spiraling clockwise around the central circular mounting hole 90 from the outside to the inside, passing through the first through-hole 41 on the top PCB 40, and exiting from the second through-hole 11 on the bottom PCB 10. Then, it spirals clockwise from the inside to the outside around the central circular mounting hole 90, leading out to the primary circuit area of the bottom PCB 10, where it is connected to the primary circuit area of the bottom PCB 10.
[0038] See also Figure 5 and Figure 6In some embodiments, the first secondary winding 70 is routed from the secondary circuit area of the third layer PCB 30, passes through the third via 31 on the third layer PCB 30, and is led out from the fourth via 21 on the second layer PCB 20 after winding around the middle circular mounting hole 90 once.
[0039] That is, the first secondary winding 70 is not spirally wound around the middle circular mounting hole 90 like the primary winding 60, so as to leave a space for the second secondary winding 80 inside and outside.
[0040] Specifically, the first secondary winding 70 is counterclockwise annularly routed around the middle circular mounting hole 90 on the third layer PCB 30; and the first secondary winding 70 is counterclockwise annularly routed around the middle circular mounting hole 90 on the second layer PCB 20.
[0041] Specifically, the first secondary winding 70 is connected with the circuit of the secondary circuit area of the third layer PCB 30, passes through the third via 31 on the third layer PCB 30, and is led out from the fourth via 21 on the second layer PCB 20 after winding around the middle circular mounting hole 90 once, and is led to the secondary circuit area of the second layer PCB 20 after winding around the middle circular mounting hole 90 once, and is connected with the circuit of the secondary circuit area of the second layer PCB 20.
[0042] In some embodiments, the second secondary winding 80 is routed from the secondary circuit area of the third layer PCB 30, sequentially along the outer edge and the inner edge of the first secondary winding 70, passes through the fifth via 32 on the third layer PCB 30, and is led out from the sixth via 22 on the second layer PCB 20 after winding around the middle circular mounting hole 90 twice, and is led to the secondary circuit area of the second layer PCB 20 after winding around the middle circular mounting hole 90 once along the inner edge of the first secondary winding 70.
[0043] Specifically, the second secondary winding 80 is counterclockwise routed around the middle circular mounting hole 90 on the third layer PCB 30, sequentially along the outer edge and the inner edge of the first secondary winding 70; and the second secondary winding 80 is counterclockwise routed around the middle circular mounting hole 90 on the second layer PCB 20, along the inner edge of the first secondary winding 70.
[0044] Specifically, the copper foil width of the second secondary winding 80 is smaller than the copper foil width of the first secondary winding 70, the fifth through hole 32 is adjacent to the third through hole 31, the sixth through hole 22 is adjacent to the fourth through hole 21, and the second secondary winding 80 is sequentially wired along the outer edge and the inner edge of the first secondary winding 70 on the third layer PCB 30, so that the loop area of the first secondary winding 70 and the second secondary winding 80 can be effectively reduced. The second secondary winding 80 is connected with the circuit in the auxiliary circuit area of the third layer PCB 30, sequentially wired along the outer edge and the inner edge of the first secondary winding 70, passes through the fifth through hole 32 on the third layer PCB 30 after winding around the intermediate circular mounting hole 90 twice counterclockwise, is led out from the sixth through hole 22 on the second layer PCB 20 along the inner edge of the first secondary winding 70, is led out to the auxiliary circuit area of the second layer PCB 20 after winding around the intermediate circular mounting hole 90 once counterclockwise, and is connected with the circuit in the auxiliary circuit area of the second layer PCB 20.
[0045] In some embodiments, in order to cooperate with the intermediate circular mounting hole 90, the shape of the magnetic core 50 includes one of EC type, ETD type and EER type, and compared with other shapes of mounting holes, the circumference of the circular shape is the smallest, so that the loop area of the winding around the intermediate circular mounting hole 90 can be reduced as much as possible.
[0046] The utility model discloses still a kind of charging device, including the planar transformer disclosed in above embodiment.
[0047] The planar transformer disclosed by the utility model can reduce the loop area of the winding as much as possible by the above compact wiring mode, ensure the anti-electromagnetic interference capability of the planar transformer, without shielding layer, only need to set four layers of PCB, achieve the purpose of reducing production cost, and can reduce the volume of the planar transformer as much as possible. Figure 7 And Figure 8 As shown in the drawings, the length L1 of the planar transformer disclosed by the utility model can reach 20.48 mm, the width L2 can reach 18 mm, and the height H can reach 4.9 mm.
[0048] The above is only a specific embodiment of the utility model, but the protection scope of the utility model is not limited to this, any skilled person in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the utility model, and these modifications or replacements should be covered in the protection scope of the utility model. Therefore, the protection scope of the utility model should be subject to the protection scope of claims.
Claims
1. A planar transformer, characterized by The application relates to a PCB board, a magnetic core, a primary winding, a first secondary winding and a second secondary winding; the PCB board comprises a bottom layer PCB, a second layer PCB, a third layer PCB and a top layer PCB which are stacked in sequence, a magnetic core mounting hole for mounting the magnetic core is preformed in the PCB board, the magnetic core is arranged in the magnetic core mounting hole, the magnetic core mounting hole comprises a middle circular mounting hole, the primary winding is arranged on the top layer PCB and the bottom layer PCB, and the primary winding is closely arranged around the middle circular mounting hole; the first secondary winding and the second secondary winding are arranged on the second layer PCB and the third layer PCB, the first secondary winding is closely arranged around the middle circular mounting hole, and the second secondary winding is arranged around the middle circular mounting hole and is closely arranged on the inner and outer side edges of the first secondary winding.
2. The planar transformer according to claim 1, characterized in that The PCB board comprises a primary circuit area and a secondary circuit area which are oppositely arranged; the primary circuit area and the secondary circuit area are respectively arranged on the two sides of the middle circular mounting hole, the primary winding is arranged on the primary circuit area of the top layer PCB, spirally arranged around the middle circular mounting hole from outside to inside, passes through a first through hole on the top layer PCB, is led out from a second through hole on the bottom layer PCB, and is spirally arranged around the middle circular mounting hole from inside to outside and is led out to the primary circuit area of the bottom layer PCB.
3. The planar transformer according to claim 2, characterized in that The primary winding is spirally arranged around the middle circular mounting hole clockwise on the top layer PCB; the primary winding is spirally arranged around the middle circular mounting hole clockwise on the bottom layer PCB.
4. The planar transformer according to claim 2, characterized in that, The first secondary winding is arranged on the secondary circuit area of the third layer PCB, passes through a third through hole on the third layer PCB after being arranged around the middle circular mounting hole once, is led out from a fourth through hole on the second layer PCB, and is led out to the secondary circuit area of the second layer PCB after being arranged around the middle circular mounting hole once.
5. The planar transformer of claim 2, wherein, The first secondary winding is spirally arranged around the middle circular mounting hole counterclockwise on the third layer PCB; the first secondary winding is spirally arranged around the middle circular mounting hole counterclockwise on the second layer PCB.
6. The planar transformer according to claim 5, characterized in that The second secondary winding is arranged on the secondary circuit area of the third layer PCB, sequentially arranged along the outer edge and the inner edge of the first secondary winding, passes through a fifth through hole on the third layer PCB after being arranged around the middle circular mounting hole twice, is led out from a sixth through hole on the second layer PCB, and is led out to the secondary circuit area of the second layer PCB after being arranged around the middle circular mounting hole once along the inner edge of the first secondary winding.
7. The planar transformer according to claim 6, characterized in that The second secondary winding is spirally arranged around the middle circular mounting hole counterclockwise on the third layer PCB along the outer edge and the inner edge of the first secondary winding; the second secondary winding is spirally arranged around the middle circular mounting hole counterclockwise on the second layer PCB along the inner edge of the first secondary winding.
8. The planar transformer of claim 1, wherein, The shape of the magnetic core comprises one of an EC type, an ETD type and an EER type.
9. The planar transformer of claim 1, wherein, The primary winding, the first secondary winding and the second secondary winding are copper foil windings etched on the PCB board.
10. A charging device, characterized by A planar transformer comprising the planar transformer of any one of claims 1 to 9.