Planar transformer
By improving the structural design of the planar transformer and using a combination of quality tube core and insulated shell, the problems of long production cycle, high cost and low adjustability of traditional planar transformers are solved, and a compact structure and EMI-optimized planar transformer is realized.
Patent Information
- Application Number
- CN202421678596.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-16
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2034-07-16
AI Technical Summary
Traditional planar transformers have long production cycles, high cost, low adjustability, and are difficult to meet miniaturization and EMI requirements.
The combined structure of the quality tube core, winding coil and insulated shell is adopted. The primary and secondary winding coils are symmetrically arranged. The lead-out terminals are fixed on the insulated shell by injection molding. The core is designed with notches to increase the distance between the winding and the core, achieving compact structure and automated production.
It realizes a planar transformer with compact structure, high reliability, meets safety rules and has the advantages of EMI.
Smart Images
Figure CN223140524U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of transformers, and particularly relates to a planar transformer. Background Art
[0002] Compared with a conventional transformer, the core size of a planar transformer is greatly reduced, especially the height is reduced a lot. This application feature has obvious advantages in occasions where the space in power equipment (such as a charger) is strictly limited, so it can become the preferred magnetic component in many power equipment.
[0003] At present, the traditional planar transformer is a combined structure of a single circuit board and a core. The single circuit board is a multi-layer structure. When the input voltage is very high, for example, when the input is an AC power supply, there are more primary windings in the transformer, and more circuit board layers are required. Then the process of the circuit board is complicated, resulting in an overly long production cycle of the traditional planar transformer. Moreover, the more layers the circuit board has, the higher the process and the lower the error tolerance, so the production cost of the traditional planar transformer is increased. When the traditional planar transformer needs to change the interlayer capacitance size or the number of winding turns of the circuit board, the design of the circuit board must be adjusted, but the time for re-design is long and time-consuming. In other words, a new circuit board needs to be used. However, due to the overly long production cycle of the multi-layer circuit board used in the traditional planar transformer, the traditional planar transformer must spend too much time waiting for the new circuit board in production, which also results in very low adjustability of the traditional planar transformer.
[0004] Moreover, for the traditional planar transformer, when there are safety rule standards and EMI requirements, to meet the creepage distance requirement, the distance between the winding pins and the core must be lengthened, resulting in an increase in the overall length of the transformer, which is not conducive to the miniaturization of the transformer; to meet the EMI requirement of the transformer, the coils of the transformer should not be exposed as much as possible. Summary of the Utility Model
[0005] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a planar transformer.
[0006] The purpose of the utility model is achieved by the following technical solutions:
[0007] The present utility model provides a planar transformer, comprising: a quality control magnetic core, a winding coil, and an insulating housing. The winding coil includes a primary winding coil and a secondary winding coil. Two secondary winding coils are symmetrically arranged on both sides of the primary winding coil, and positioning holes are provided on the secondary winding coil. Primary lead terminals and secondary lead terminals are provided on the insulating housing. The primary lead terminals are connected to the primary winding coil, and the secondary lead terminals are connected to the positioning holes of the secondary winding coil. The winding coil is sleeved between two symmetrically arranged quality control magnetic cores to form a transformer body, and then the transformer body is encapsulated with the insulating housing.
[0008] Further, oval through-holes are provided on both the primary winding coil and the secondary winding coil.
[0009] Preferably, the quality control magnetic core includes a magnetic core side post and a magnetic core oval middle post. A notch is further provided on the edge of the quality control magnetic core, and the magnetic core oval middle post passes through the oval through-hole.
[0010] Further, the primary lead terminals include a first connection end, a first fixing end, and a first welding end. The secondary lead terminals include a second connection end, a second fixing end, and a second welding end. The primary lead terminals are injection molded on the insulating housing through the first fixing end, and the secondary lead terminals are injection molded on the insulating housing through the second fixing end. The primary lead terminals are connected to the insulating housing through the first connection end, and the secondary lead terminals are connected to the insulating housing through the second connection end. The primary lead terminals are welded to the primary winding coil through the first welding end, and the secondary lead terminals are welded to the positioning holes of the secondary winding coil through the second welding end.
[0011] Preferably, the first connection end and the second connection end are solder pads, and the primary lead terminals and the secondary lead terminals are surface-mounted on the surface of the insulating housing through the solder pads.
[0012] Preferably, the primary lead terminals are inserted and welded on the insulating housing through the first connection end, and the secondary lead terminals are inserted and welded on the insulating housing through the second connection end.
[0013] The beneficial effects of the present utility model are as follows:
[0014] 1) The structure of the planar transformer of the present utility model is compact. The small external dimensions can achieve automated production, with high reliability, meeting the requirements of safety regulations, and having advantages in EMI. Description of the Drawings
[0015] Figure 1 It is a schematic structural diagram of a surface-mounted planar transformer of an embodiment of the present utility model;
[0016] Figure 2 Explosion diagram of the surface-mounted planar transformer structure of a planar transformer according to an embodiment of the present invention;
[0017] Figure 3 Schematic diagram of the structure of the quality control magnetic core of a planar transformer according to an embodiment of the present invention;
[0018] Figure 4 Schematic diagram of the insulating housing with surface-mounted lead terminals of a planar transformer according to an embodiment of the present invention;
[0019] Figure 5 Schematic diagram of the insulating housing with inserted lead terminals of a planar transformer according to an embodiment of the present invention;
[0020] In the figure, 1 - quality control magnetic core, 2 - winding coil, 3 - insulating housing, 21 - primary winding coil, 22 - secondary winding coil, 31 - primary lead terminal, 32 - secondary lead terminal, 311 - first connection end, 312 - first fixed end, 313 - first welding end, 321 - second connection end, 322 - second fixed end, 323 - second welding end. Specific embodiments
[0021] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.
[0022] Exemplarily, the schematic diagram of the structure of a planar transformer with surface-mounted lead terminals on the insulating housing is as Figure 1 shown. The present invention provides a planar transformer, including a quality control magnetic core 1, a winding coil 2, and an insulating housing 3.
[0023] Exemplarily, the explosion diagram of the structure of a planar transformer with surface-mounted lead terminals on the insulating housing is as Figure 2As shown, it includes a magnetic core 1, a primary winding coil 21, a secondary winding coil 22, an insulating housing 3, a primary lead terminal 31, and a secondary lead terminal 32. Among them, the primary lead terminal 31 and the secondary lead terminal 32 can be surface-mounted or inserted and welded. To improve the automation of welding, a surface-mounted structure is preferred. The insulating housing is generally a plastic part with strong insulation performance, and the lead terminals are injection-molded into the insulating housing to form an integral structure. The primary winding coil 21 is placed between the secondary winding coils 22, which can increase the coupling between the primary and secondary windings of the transformer and reduce the leakage inductance. Through holes are provided on both the primary winding coil 21 and the secondary winding coil 22, and a positioning hole is provided on the secondary winding coil 22. The primary lead terminal 31 is connected to the primary winding coil 21, and the secondary lead terminal 32 is connected to the positioning hole of the secondary winding coil 22.
[0024] Exemplarily, a schematic diagram of the magnetic core of a planar transformer is as Figure 3 As shown, the magnetic core structure of a planar transformer includes a magnetic core side post 31, an elliptical middle post 32 of the magnetic core, and a notch 33 provided on the edge of the magnetic core. With a special structure, under the same size conditions, the magnetic core has a larger effective cross-sectional area, which can reduce the number of turns of the transformer winding. On the one hand, the side post magnetic core 31 has a larger cross-sectional area of the magnetic core side post and can enclose the coil inside to reduce electromagnetic interference. The elliptical middle post 32 can have a larger middle post area, and the elliptical middle post 32 passes through the through holes of the primary winding coil 21 and the secondary winding coil 22. The magnetic core has a notch 33, and the position of the notch 33 is the lead-out position of the transformer winding coil. After the winding coil is led out from the notch 33, it is connected to the primary lead terminal 31 and the secondary lead terminal 32 on the insulating housing. Setting the notch 33 can also increase the distance between the winding and the magnetic core. Two magnetic cores 1 are symmetrically arranged through the elliptical middle post 32 of the magnetic core, and a winding coil 2 is sleeved on the elliptical middle post 32 of the magnetic core to form a transformer body. Then, the transformer body is encapsulated with the insulating housing 3.
[0025] Exemplarily, a schematic diagram of the surface mounting of the primary lead terminal 31 and the secondary lead terminal 32 on the insulating housing is as Figure 4As shown, the primary lead terminal 31 includes a first connection end 311, a first fixed end 312, and a first welding end 313. The secondary lead terminal 32 includes a second connection end 321, a second fixed end 322, and a second welding end 323. The primary lead terminal 31 is fixed on the insulating housing 3 by injection molding through the first fixed end 312. The secondary lead terminal 32 is fixed on the insulating housing 3 by injection molding through the second fixed end 322. The first connection end 311 and the second connection end 321 are pads. The primary lead terminal 31 and the secondary lead terminal 32 are mounted on the surface of the insulating housing 3 through the pads. The primary lead terminal 31 is welded to the primary winding coil 21 through the first welding end 313. The secondary lead terminal 32 is welded in the positioning hole of the secondary winding coil 22 through the second welding end 323.
[0026] Exemplarily, a schematic diagram of the primary lead terminal 31 and the secondary lead terminal 32 inserted into the insulating housing is as Figure 5 shown; wherein the primary lead terminal 31 includes a first connection end 311, a first fixed end 312, and a first welding end 313. The secondary lead terminal 32 includes a second connection end 321, a second fixed end 322, and a second welding end 323. The primary lead terminal 31 is fixed on the insulating housing 3 by injection molding through the first fixed end 312. The secondary lead terminal 32 is fixed on the insulating housing 3 by injection molding through the second fixed end 322. The primary lead terminal 31 is welded to the primary winding coil 21 through the first welding end 313. The secondary lead terminal 32 is welded in the positioning hole of the secondary winding coil 22 through the second welding end 323. The primary lead terminal 31 is inserted and welded to the insulating housing 3 through the first connection end 311. The secondary lead terminal 32 is inserted and welded to the insulating housing 3 through the second connection end 321.
[0027] The above is only the preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments. Instead, it can be used in various other combinations, modifications, and environments, and can be changed within the scope of the concept described herein through the above teachings or the techniques or knowledge in related fields. Any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall fall within the protection scope of the appended claims of the present invention.
Claims
1. A planar transformer, characterized in that, Including: A quality control magnetic core (1), a winding coil (2), and an insulating housing (3). The winding coil (2) includes a primary winding coil (21) and a secondary winding coil (22). Two secondary winding coils (22) are symmetrically arranged on both sides of the primary winding coil (21). A positioning hole is provided on the secondary winding coil (22). The insulating housing (3) is provided with a primary lead-out terminal (31) and a secondary lead-out terminal (32). The primary lead-out terminal (31) is connected to the primary winding coil (21), and the secondary lead-out terminal (32) is connected to the positioning hole of the secondary winding coil (22). The winding coil (2) is sleeved between two symmetrically arranged quality control magnetic cores (1) to form a transformer body, and then the transformer body is encapsulated with the insulating housing (3).
2. The planar transformer according to claim 1, characterized in that: Elliptical through holes are provided on both the primary winding coil (21) and the secondary winding coil (22).
3. The planar transformer according to claim 2, wherein: The quality control magnetic core (1) includes a magnetic core side post (31) and a magnetic core elliptical middle post (32). A notch (33) is further provided on the edge of the quality control magnetic core (1). The magnetic core elliptical middle post (32) passes through the elliptical through hole.
4. A planar transformer according to claim 1, wherein: The primary lead-out terminal (31) includes a first connection end (311), a first fixed end (312), and a first welding end (313). The secondary lead-out terminal (32) includes a second connection end (321), a second fixed end (322), and a second welding end (323). The primary lead-out terminal (31) is injection-molded on the insulating housing (3) through the first fixed end (312), and the secondary lead-out terminal (32) is injection-molded on the insulating housing (3) through the second fixed end (322). The primary lead-out terminal (31) is connected to the insulating housing (3) through the first connection end (311), and the secondary lead-out terminal (32) is connected to the insulating housing (3) through the second connection end (321). The primary lead-out terminal (31) is welded to the primary winding coil (21) through the first welding end (313), and the secondary lead-out terminal (32) is welded to the positioning hole of the secondary winding coil (22) through the second welding end (323).
5. The planar transformer according to claim 4, wherein: The first connection end (311) and the second connection end (321) are pads. The primary lead-out terminal (31) and the secondary lead-out terminal (32) are surface-mounted on the surface of the insulating housing (3) through the pads.
6. A planar transformer according to claim 4, wherein: The primary lead-out terminal (31) is inserted and welded on the insulating housing (3) through the first connection end (311), and the secondary lead-out terminal (32) is inserted and welded on the insulating housing (3) through the second connection end (321).