LLC transformer
By adopting a cake-like wire winding process and a multi-layer magnetic core structure in the LLC transformer, combined with a ferrite magnetic rod, the problem of decreasing volume and magnetic coupling ability in the prior art is solved, and a compact structure, small volume and high leakage inductance are achieved.
Patent Information
- Application Number
- CN202421840675.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-31
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-07-31
AI Technical Summary
While improving the leakage inductance, existing LLC transformers often lead to volume increase and poor magnetic coupling capabilities, making it difficult to enhance leakage inductance while maintaining a compact structure and small volume.
The cake-like winding process of the upper and lower cake-wire coils is adopted, combining multi-layer magnetic cores and ferrite rods to increase the magnetic flux and effective cross-sectional area, thereby reducing the number of coil turns and optimizing the winding space.
It realizes that while maintaining the compact structure and small volume, it significantly enhances the leakage inductance, meets the needs of the resonant circuit, and improves the voltage withstandability of the transformer.
Smart Images
Figure CN222995212U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to an LLC transformer, in particular to an LLC transformer with a compact structure, small volume and enhanced leakage inductance. Background Art
[0002] In the application of LLC power supplies, in order to facilitate the resonance debugging and stability of the entire power supply, a general resonance circuit externally adds a resonance inductor and a capacitor to adjust the resonance circuit. However, this will make the power supply structure complex, the volume increase, the electromagnetic interference large, and the product efficiency low. To solve the above problems, in the prior art, increasing the leakage inductance in the transformer is adopted to replace the resonance inductor. However, since the resonance inductor required for resonance is relatively large, the leakage inductance of the transformer is often very small. Usually, the distance between the primary coil and the secondary coil is increased, so that the coupling coefficient between the primary coil and the secondary coil becomes smaller to achieve the purpose of increasing the leakage inductance. However, this often makes the transformer volume larger and the magnetic coupling ability poor. Therefore, how to ensure the leakage inductance while reducing the volume is an urgent problem to be solved by the present utility model. Summary of the Utility Model
[0003] The problem to be solved by the present utility model is to provide an LLC transformer with the characteristics of a compact structure, small volume and enhanced leakage inductance.
[0004] To solve the above technical problems, the technical solution of the present utility model is: an LLC transformer, and its innovation lies in: the LLC transformer includes an upper magnetic core, an upper pancake coil disposed below the upper magnetic core, a ferrite magnetic rod disposed below the upper pancake coil, a lower pancake coil disposed below the ferrite magnetic rod, a lower magnetic core disposed below the lower pancake coil, and a bottom bracket disposed below the lower magnetic core. A thermistor for detecting the heating temperature is disposed between the upper magnetic core and the lower magnetic core; the upper pancake coil and the lower pancake coil are located in a chamber formed by the upper magnetic core and the lower magnetic core.
[0005] Preferably, the longitudinal section of the upper magnetic core is in a shape of "3", including an upper magnetic core body, a first channel and a second channel which are disposed on the upper magnetic core body and are parallel to each other. Two parallel side edges of the upper pancake coil are respectively located in the first channel and the second channel; the first channel and the second channel constitute the upper half of the chamber, and the ferrite magnetic rod is located in the chamber; a first protrusion which separates the first channel and the second channel and is parallel to the first channel is disposed on the upper magnetic core, and the first protrusion is embedded in the middle of two parallel side edges of the upper pancake coil.
[0006] Preferably, a first backing plate and a second backing plate are disposed on the upper magnetic core and are respectively located in the first channel and the second channel. Both the first backing plate and the second backing plate are located between the upper magnetic core and the upper pancake coil.
[0007] Preferably, the height of the first backing plate and the second backing plate is greater than or equal to the thickness of the upper pancake coil.
[0008] Preferably, the longitudinal section of the lower magnetic core is in a "3" shape, including a lower magnetic core body, a third channel and a fourth channel which are arranged on the lower magnetic core body and are parallel to each other. Two parallel side edges of the lower pancake coil are respectively located in the third channel and the fourth channel; the third channel and the fourth channel form the lower half of the chamber, and the ferrite magnetic rod is located in the chamber; a second protrusion which separates the third channel and the fourth channel and is parallel to the third channel is disposed on the lower magnetic core, and the second protrusion is embedded in the middle of the two parallel side edges of the lower pancake coil.
[0009] Preferably, a third backing plate and a fourth backing plate are disposed on the lower magnetic core and are respectively located in the third channel and the fourth channel. Both the third backing plate and the fourth backing plate are located between the lower magnetic core and the lower pancake coil.
[0010] Preferably, the height of the third backing plate and the fourth backing plate is greater than or equal to the thickness of the lower pancake coil.
[0011] Preferably, both the upper magnetic core and the lower magnetic core are respectively composed of a plurality of upper magnetic core units and lower magnetic core units arranged side by side. The upper magnetic core units and the lower magnetic core units correspond to each other one by one. The upper pancake coil is wound around the upper magnetic core in a pancake shape, and the lower pancake coil is wound around the lower magnetic core.
[0012] Preferably, the ferrite magnetic rod is composed of two parallel columnar structures, including a first ferrite magnetic rod unit and a second ferrite magnetic rod unit. Both the first ferrite magnetic rod unit and the second ferrite magnetic rod unit are magnetic strips.
[0013] Preferably, a first pin end and a second pin end for accessing the pins of the upper pancake coil, and a third pin end and a fourth pin end for accessing the pins of the lower pancake coil are disposed on the bottom bracket.
[0014] The advantages of the present utility model are as follows: By adopting the above structure, in order to save the winding space and limit the product height within a controllable range, the pancake wire winding process is used for winding the upper pancake wire coil and the lower pancake wire coil, which can reduce the wire package thickness. The wire materials of the upper pancake wire coil and the lower pancake wire coil use coated wires, and the film coating rate of the coating reaches 50% or above, so that the primary and secondary withstand voltages of the transformer can reach 4.2 KV. The upper magnetic core and the lower magnetic core are used to increase the effective cross-sectional area, and two ferrite magnetic rods are added to increase the magnetic flux, thereby reducing the number of turns in the upper pancake wire coil and the lower pancake wire coil and optimizing the winding space. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The present utility model will be further described in detail below with reference to the drawings and specific embodiments.
[0016] Figure 1 is a perspective view of an LLC transformer of the present utility model.
[0017] Figure 2 is an exploded perspective view of an LLC transformer of the present utility model.
[0018] Figure 3 is a perspective view of an LLC transformer of the present utility model with the upper magnetic core omitted.
[0019] Figure 4 is a structural schematic diagram of an LLC transformer of the present utility model.
[0020] Figure 5 is a left view of an LLC transformer of the present utility model.
[0021] Figure 6 is a sectional view of an LLC transformer of the present utility model.
[0022] Figure 7 is a top view of an LLC transformer of the present utility model.
[0023] Figure 8 is a structural schematic diagram of an LLC transformer of the present utility model including an upper pancake wire coil, an upper magnetic core and a ferrite magnetic rod.
[0024] Figure 9 is a structural schematic diagram of an LLC transformer of the present utility model including a lower pancake wire coil, a lower magnetic core and a bottom bracket.
[0025] In the figure: 1 - upper magnetic core, 11 - first channel, 12 - second channel, 13 - first protrusion, 14 - first backing plate, 15 - second backing plate, 2 - upper pancake coil, 3 - ferrite rod, 31 - first ferrite rod unit, 32 - second ferrite rod unit, 4 - lower pancake coil, 5 - lower magnetic core, 51 - third channel, 52 - fourth channel, 53 - second protrusion, 54 - third backing plate, 55 - fourth backing plate, 6 - base, 61 - first pin end, 62 - second pin end, 63 - third pin end, 64 - fourth pin end, 7 - thermistor. Detailed implementation
[0026] The LLC transformer of the present utility model includes an upper magnetic core 1, an upper pancake coil 2 disposed below the upper magnetic core 1, a ferrite rod 3 disposed below the upper pancake coil 2, a lower pancake coil 4 disposed below the ferrite rod 3, a lower magnetic core 5 disposed below the lower pancake coil 4, and a base 6 disposed below the lower magnetic core 5. A thermistor 7 for detecting the heating temperature is disposed between the upper magnetic core 1 and the lower magnetic core 5. The upper pancake coil 2 and the lower pancake coil 4 are located in the chamber formed by the upper magnetic core 1 and the lower magnetic core 5.
[0027] By adopting the above structure, in order to save the winding space and limit the product height within a controllable range, the pancake wire winding process is adopted for the winding of the upper pancake coil 2 and the lower pancake coil 4, so that the thickness of the wire package can be reduced. The wire of the upper pancake coil 2 and the lower pancake coil 4 uses coated wire, and the coating rate of the coating reaches 50% or more, so that the primary and secondary withstand voltage of the transformer can reach 4.2 KV. The upper magnetic core 1 and the lower magnetic core 5 are used to increase the effective cross-sectional area, and two ferrite rods 3 are added to increase the magnetic flux and the effective cross-sectional area, thereby reducing the number of turns of the coils in the upper pancake coil 2 and the lower pancake coil 4 and optimizing the winding space.
[0028] The longitudinal section of the upper magnetic core 1 of the present utility model is in the shape of a "3", including an upper magnetic core body, a first channel 11 and a second channel 12 which are disposed on the upper magnetic core body and are parallel to each other. The two parallel side edges of the upper pancake coil 2 are respectively located in the first channel 11 and the second channel 12. The first channel 11 and the second channel 12 form the upper half of the chamber, and the ferrite rod 3 is located in the chamber. A first protrusion 13 which separates the first channel 11 and the second channel 12 and is parallel to the first channel 11 is disposed on the upper magnetic core 1, and the first protrusion 13 is embedded in the middle of the two parallel side edges of the upper pancake coil 2. First backing plates 14 and second backing plates 15 which are respectively located in the first channel 11 and the second channel 12 are disposed on the upper magnetic core 1, and both the first backing plates 14 and the second backing plates 15 are located between the upper magnetic core 1 and the upper pancake coil 2. The height of the first backing plates 14 and the second backing plates 15 is greater than or equal to the thickness of the upper pancake coil 2.
[0029] The longitudinal section of the lower magnetic core 5 is in a shape of "3", including a lower magnetic core body, a third channel 51 and a fourth channel 52 which are arranged on the lower magnetic core body and are parallel to each other. Two parallel side edges of the lower pancake wire coil 4 are respectively located in the third channel 51 and the fourth channel 52. The third channel 51 and the fourth channel 52 form the lower half of the chamber, and the ferrite magnetic rod 3 is located in the chamber. A second protrusion 53 which separates the third channel 51 and the fourth channel 52 and is parallel to the third channel 51 is arranged on the lower magnetic core 5, and the second protrusion 53 is embedded in the middle of the two parallel side edges of the lower pancake wire coil 4. Third pads 54 and fourth pads 55 which are respectively located in the third channel 51 and the fourth channel 52 are arranged on the lower magnetic core 5, and both the third pads 54 and the fourth pads 55 are located between the lower magnetic core 5 and the lower pancake wire coil 4. The heights of the third pads 54 and the fourth pads 55 are greater than or equal to the thickness of the lower pancake wire coil 4.
[0030] Both the upper magnetic core 1 and the lower magnetic core 5 are EE80 series magnetic cores. For the convenience of assembly, the upper magnetic core 1 and the lower magnetic core 5 are respectively composed of a plurality of upper magnetic core 1 units and lower magnetic core 5 units which are arranged side by side. The upper magnetic core 1 units and the lower magnetic core 5 units correspond to each other one by one. The upper pancake wire coil 2 is wound around the upper magnetic core 1 in a pancake shape, and the lower pancake wire coil 4 is wound around the lower magnetic core 5.
[0031] The above-mentioned ferrite magnetic rod 3 is composed of two parallel columnar structures, including a first ferrite magnetic rod unit 31 and a second ferrite magnetic rod unit 32. Both the first ferrite magnetic rod unit 31 and the second ferrite magnetic rod unit 32 are magnetic strips. The first ferrite magnetic rod unit 31 and the second ferrite magnetic rod unit 32 are used to increase the effective cross-sectional area of the magnetic core, thereby reducing the number of turns of the coil and optimizing the winding space. When two first ferrite magnetic rod units 31 and second ferrite magnetic rod units 32 with a length of 90 * width of 10 * height of 11.8 mm are used to strengthen the magnetic flux, the leakage magnetic flux can be enhanced to increase the leakage inductance to 21 uH ± 7% to meet the matching resonant leakage inductance and make the matching resonant circuit reach the best working state.
[0032] For the convenience of pin control and structure optimization, a first pin end 61 and a second pin end 62 for the pins of the upper pancake wire coil 2 to access, and a third pin end 63 and a fourth pin end 64 for the pins of the lower pancake wire coil 4 to access are arranged on the bottom bracket 6.
[0033] It should be understood that the above description is for illustrative purposes and not for limitation. Upon reading the above description, many embodiments and many applications other than the provided examples will be apparent to those skilled in the art. Accordingly, the scope of this teaching should not be determined with reference to the above description, but should be determined with reference to the appended claims and the full scope of equivalents to which those claims are entitled. For the sake of completeness, all articles and references, including patent applications and published patents, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein from the foregoing claims is not intended to abandon such subject matter, nor should it be considered that the inventor has not considered such subject matter to be part of the disclosed utility model subject matter.
Claims
1. An LLC transformer, characterized in that: The LLC transformer includes an upper magnetic core, an upper pancake wire coil arranged below the upper magnetic core, a ferrite rod arranged below the upper pancake wire coil, a lower pancake wire coil arranged below the ferrite rod, a lower magnetic core arranged below the lower pancake wire coil, and a bottom support arranged below the lower magnetic core. A thermistor for detecting heating temperature is arranged between the upper magnetic core and the lower magnetic core; the upper pancake wire coil and the lower pancake wire coil are located in a cavity formed by the upper magnetic core and the lower magnetic core.
2. An LLC transformer as claimed in claim 1, characterized in that: The longitudinal section of the upper magnetic core is in the shape of a 3, and includes an upper magnetic core body, a first channel and a second channel arranged on the upper magnetic core body and parallel to each other, and the two parallel sides of the upper pie-in-the-wire coil are respectively located in the first channel and the second channel; the first channel and the second channel constitute the upper half of the chamber, and the ferrite magnetic rod is located in the chamber; a first protrusion is provided on the upper magnetic core, which separates the first channel and the second channel and is arranged parallel to the first channel, and the first protrusion is embedded in the middle of the two parallel sides of the upper pie-in-the-wire coil.
3. An LLC transformer as claimed in claim 2, characterized in that: The upper magnetic core is provided with a first pad and a second pad located in the first channel and the second channel respectively, and the first pad and the second pad are both located between the upper magnetic core and the upper pancake wire coil.
4. An LLC transformer as claimed in claim 3, characterized in that: The height of the first pad and the second pad is greater than or equal to the thickness of the upper pie wire coil.
5. An LLC transformer as claimed in claim 1, characterized in that: The longitudinal section of the lower magnetic core is in the shape of a "3", and includes a lower magnetic core body, a third channel and a fourth channel arranged on the lower magnetic core body and parallel to each other, and the two parallel sides of the lower pancake wire coil are respectively located in the third channel and the fourth channel; the third channel and the fourth channel constitute the lower half of the chamber, and the ferrite magnetic rod is located in the chamber; the lower magnetic core is provided with a second protrusion separating the third channel and the fourth channel and arranged parallel to the third channel, and the second protrusion is embedded in the middle of the two parallel sides of the lower pancake wire coil.
6. An LLC transformer as claimed in claim 5, characterized in that: The lower magnetic core is provided with a third pad and a fourth pad located in the third channel and the fourth channel respectively, and the third pad and the fourth pad are both located between the lower magnetic core and the lower pancake wire coil.
7. An LLC transformer as claimed in claim 6, characterized in that: The height of the third pad and the fourth pad is greater than or equal to the thickness of the lower pancake wire coil.
8. An LLC transformer as claimed in claim 1, characterized in that: The upper magnetic core and the lower magnetic core are respectively composed of a plurality of upper magnetic core units and lower magnetic core units arranged side by side, the upper magnetic core units correspond to the lower magnetic core units one by one, the upper pancake wire coil is wound on the upper magnetic core in a pancake shape, and the lower pancake wire coil is wound on the lower magnetic core.
9. An LLC transformer as claimed in claim 1, characterized in that: The ferrite rod is composed of two parallel columnar structures, including a first ferrite rod unit and a second ferrite rod unit, and the first ferrite rod unit and the second ferrite rod unit are both magnetic strips.
10. An LLC transformer as claimed in claim 1, characterized in that: The base is provided with a first pin end and a second pin end for connecting the pins of the upper pie-wire coil, and a third pin end and a fourth pin end for connecting the pins of the lower pie-wire coil.