Circuit boards, transformers, microwave generators, and home appliances

Abstract

A circuit board (100), a transformer (20), a microwave generator (1000), and a home appliance, wherein the circuit board (100) is used in the microwave generator (1000), and the circuit board (100) includes a substrate (10), a transformer (20), and a voltage doubler rectifier capacitor (30), the transformer (20) is provided on the substrate (10), and the voltage doubler rectifier capacitor (30) is provided between the substrate (10) and the transformer (20).

Description

Technical Field

[0001] This application claims the priority and rights of the patent application with patent application number 202321190303.5 filed with the China National Intellectual Property Administration on May 16, 2023, the priority and rights of the patent application with patent application number 202310555916.2 filed with the China National Intellectual Property Administration on May 16, 2023, and the priority and rights of the patent application with patent application number 202321190233.3 filed with the China National Intellectual Property Administration on May 16, 2023, and incorporates the full text thereof herein by reference.

[0002] This application relates to the technical field of circuit boards, and particularly to circuit boards, transformers, microwave generators and household appliances.

Background Art

[0003] In related technologies, a microwave oven includes an electric control panel, and the electric control panel includes a substrate, a transformer and a voltage doubler rectifier capacitor. Since the voltage doubler rectifier capacitor and the transformer are provided side by side on the substrate, the volume of the electric control panel becomes too large.

Summary of the Invention

Means for Solving the Problems

[0004] Embodiments of this application provide a circuit board, a transformer, a microwave generator, and a household appliance.

[0005] The circuit board of the embodiments of this application is used in a microwave generator, and the circuit board includes a substrate, a transformer and a voltage doubler rectifier capacitor, the transformer is provided on the substrate, the voltage doubler rectifier capacitor is provided between the substrate and the transformer.

[0006] The above circuit board reduces the volume of the circuit board by placing the voltage-doubler rectifier capacitor below the transformer, thereby reducing the space occupied by the voltage-doubler rectifier capacitor on the circuit board, which is advantageous for miniaturizing the circuit board. The voltage-doubler rectifier capacitor is placed below the transformer, and the transformer is used to restrict the movement of the voltage-doubler rectifier capacitor, thereby preventing solder leakage caused by the voltage-doubler rectifier capacitor lifting up when welding it.

[0007] In some embodiments, the transformer is The circuit includes a skeletal component, and the voltage-doubler rectifier capacitor is provided between the skeletal component and the substrate.

[0008] In some embodiments, the transformer is The circuit board includes a first baffle, the first baffle being provided at one end of the skeletal piece, and the first baffle being used to limit the movable space of a portion of the voltage doubler rectifier capacitor in the horizontal direction of the circuit board.

[0009] In some embodiments, the transformer comprises a lead frame, the circuit board further includes a discharge resistor, the discharge resistor is provided between the lead frames, and the lead frames are used to restrict the position of the discharge resistor.

[0010] In some embodiments, the circuit board is Includes bus capacitors and differential mode inductors, The bus capacitor is provided between the differential mode inductor and the transformer, and the differential mode inductor and the bus capacitor are arranged sequentially on the substrate.

[0011] In some embodiments, the circuit board is The circuit board includes a heat sink and a resonant capacitor, wherein the heat sink is provided at a position away from the center of the circuit board. The resonant capacitor is provided between a part of the heat sink and the substrate, and the heat sink is used to lower the temperature of the resonant capacitor.

[0012] In some embodiments, the circuit board includes a power device, the power device is removably connected to the side of the heatsink.

[0013] In some embodiments, the heat sink includes a plurality of heat dissipation fins, which are used to increase the contact area with air.

[0014] In some embodiments, the circuit board is The circuit board includes at least two voltage-doubler rectifier capacitors, the at least two of which are arranged symmetrically along the length of the circuit board.

[0015] In some embodiments, the transformer is The structure includes a magnetic core structure, a skeleton, a first coil, and a second coil, the magnetic core structure includes two magnetic cores, the magnetic core comprises a first magnetic column, the first magnetic column is flattened, and the longitudinal direction of the first magnetic column is aligned with the longitudinal direction of the magnetic core. An insertion hole is provided in the frame, the insertion hole conforms to the shape of the first magnetic column, a first groove and a second groove are provided on the outside of the wall of the insertion hole at spaced apart, at least a portion of the first magnetic column is located inside the insertion hole, and the two first magnetic columns are provided facing each other at spaced apart. The first coil is wound around the outside of the hole wall of the insertion hole and is located in the first groove. The second coil is wound around the outside of the hole wall of the insertion hole and is located within the second groove.

[0016] In some embodiments, the first magnetic pole satisfies the condition that L / d is 2 to 40, where L is the length of the first magnetic pole and d is the width of the first magnetic pole. In some embodiments, d is 5 mm to 12 mm.

[0017] In some embodiments, the transformer is It includes a magnetic core structure, a skeleton, a first coil, and a second coil, the magnetic core structure includes two magnetic cores, and the magnetic cores are provided with a first magnetic column. An insertion hole is provided in the frame, the insertion hole conforms to the shape of the first magnetic column, a first groove and a second groove are provided on the outside of the hole wall of the insertion hole at spaced apart, at least a portion of the first magnetic column is located inside the insertion hole, the two first magnetic columns are provided facing each other at spaced apart, the bottom surface of the first groove is the surface of the first winding, the bottom surface of the second groove is the surface of the second winding, and the first winding surface and the second winding surface have a difference in height in the radial direction of the insertion hole. The first coil is wound around the surface of the first winding and is located in the first groove. The second coil is wound around the second winding surface and is located within the second groove.

[0018] In some embodiments, the height difference is 0.5 mm to 4 mm. The transformer in the embodiment of the present application is The structure includes a magnetic core structure, a skeleton, a first coil, and a second coil, the magnetic core structure includes two magnetic cores, the magnetic core comprises a first magnetic column, the first magnetic column is flattened, and the longitudinal direction of the first magnetic column is aligned with the longitudinal direction of the magnetic core. An insertion hole is provided in the frame, the insertion hole conforms to the shape of the first magnetic column, a first groove and a second groove are provided on the outside of the wall of the insertion hole at spaced apart, at least a portion of the first magnetic column is located inside the insertion hole, and the two first magnetic columns are provided facing each other at spaced apart. The first coil is wound around the outside of the hole wall of the insertion hole and is located in the first groove. The second coil is wound around the outside of the hole wall of the insertion hole and is located within the second groove.

[0019] In the above transformer, the first magnetic column has a flat shape, the insertion hole conforms to the shape of the first magnetic column, and without increasing the volume of the transformer and the magnetic core and the cost of the transformer, the saturation resistance of the transformer can be enhanced, and the height of the transformer and the volume of the transformer can be further reduced, thereby realizing miniaturization of household appliances.

[0020] In some embodiments, the first coil is a primary coil, the second coil is a secondary coil, the two first magnetic columns are provided opposite to each other at an interval, an air gap is formed, and the air gap is provided close to the first coil.

[0021] In some embodiments, the width of the air gap is 1.5 mm to 3.2 mm.

[0022] In some embodiments, the bottom surface of the first groove is the first winding surface, the bottom surface of the second groove is the second winding surface, and there is a height difference between the first winding surface and the second winding surface along the radial direction of the insertion hole.

[0023] The transformer in the embodiment of the present application includes a magnetic core structure, a skeleton, a first coil, and a second coil, the magnetic core structure includes two magnetic cores, the magnetic core includes a first magnetic column, an insertion hole is provided in the skeleton, the insertion hole conforms to the shape of the first magnetic column, a first groove and a second groove are provided at intervals outside the hole wall of the insertion hole, at least a part of the first magnetic column is located in the insertion hole, the two first magnetic columns are provided opposite to each other at an interval, the bottom surface of the first groove is the first winding surface, the bottom surface of the second groove is the second winding surface, and there is a height difference between the first winding surface and the second winding surface in the radial direction of the insertion hole, the first coil is wound around the first winding surface and is located in the first groove, the second coil is wound around the second winding surface and is located in the second groove.

[0024] In the above transformer, the first coil is wound on the surface of the first winding, and the second coil is wound on the surface of the second winding. Since there is a difference in height between the surface of the first winding and the surface of the second winding in the radial direction of the insertion hole, the first and second coils employ a misaligned winding method, which reduces the coupling coefficient and reduces the hard switching characteristics of the IGBT at low power, thereby enabling it to be used in low power applications.

[0025] In some embodiments, the height difference is 0.5 mm to 4 mm.

[0026] In some embodiments, the height difference exists over a 360-degree circumferential direction of the insertion hole.

[0027] In some embodiments, the insertion hole is flattened, the longitudinal direction of the radial cross-section of the insertion hole is perpendicular to the height direction of the transformer, and the height difference includes a first height difference along the longitudinal direction of the radial cross-section of the insertion hole and a second height difference along the width direction of the radial cross-section of the insertion hole, wherein the first height difference is equal to the second height difference.

[0028] In some embodiments, the first magnetic column has a flattened shape that conforms to the shape of the insertion hole, and the longitudinal direction of the first magnetic column is aligned with the longitudinal direction of the magnetic core.

[0029] In some embodiments, the magnetic core includes a connecting portion and a second magnetic column, the connecting portion connecting the first magnetic column and the second magnetic column, the second magnetic column being located outside the insertion hole, and the two second magnetic columns being spaced apart and facing each other outside the first groove.

[0030] In some embodiments, the distance between the upper edge of the first magnetic pole and the upper edge of the connection portion along the height direction of the transformer is m, where m = (L / k-1)*d, where k is 5 to 20, L is the length of the first magnetic pole, and d is the width of the first magnetic pole.

[0031] In some embodiments, the first magnetic column satisfies the condition that the ratio of L / d is 2 to 40, where L is the length of the first magnetic column and d is the width of the first magnetic column.

[0032] In some embodiments, d is 5 mm to 12 mm.

[0033] In some embodiments, the frame includes a second baffle, the second baffle separating the first groove and the second groove, and the thickness of the second baffle is g, where g is 3.5 mm to 5 mm.

[0034] The microwave generator in the embodiment of the present invention includes a circuit board described in any of the above embodiments, or a transformer described in any of the above embodiments.

[0035] The above microwave generator reduces the volume of the circuit board by placing the voltage-doubler rectifier capacitor below the transformer, thereby reducing the space occupied by the voltage-doubler rectifier capacitor on the circuit board, which is advantageous for miniaturizing the circuit board. The voltage-doubler rectifier capacitor is placed below the transformer, and the transformer is used to restrict the movement of the voltage-doubler rectifier capacitor, thereby preventing solder leakage caused by the voltage-doubler rectifier capacitor lifting up when welding it.

[0036] The home appliance in the embodiment of the present invention includes a circuit board described in any of the above embodiments, or a transformer described in any of the above embodiments.

[0037] In the above-mentioned home appliance, the first magnetic column is flattened, and the insertion hole conforms to the shape of the first magnetic column. This increases the saturation resistance of the transformer without increasing the volume of the transformer and magnetic core, or the cost of the transformer. Furthermore, it allows for a reduction in the height and volume of the transformer, thereby enabling miniaturization of the home appliance. The first coil is wound around the first winding surface, and the second coil is wound around the second winding surface. The first and second winding surfaces have a difference in height in the radial direction of the insertion hole. This allows for a misaligned winding method for the first and second coils, reducing the coupling coefficient and the hard switching characteristics of the IGBT at low power, thus enabling it to be used in low-power applications.

[0038] Additional aspects and advantages of this application are partially shown in the following description, partially become apparent from the following description, or are understood through the implementation of this application.

[0039] The above and / or additional aspects and advantages of this application will become apparent and readily apparent from the description of embodiments in combination with the following drawings. [Brief explanation of the drawing]

[0040] [Figure 1] This is a schematic diagram of the first structure of a circuit board according to an embodiment of the present invention. [Figure 2] This is a schematic diagram of the second structure of the circuit board according to the embodiment of the present invention. [Figure 3] This is a schematic diagram of the third structure of the circuit board according to the embodiment of the present invention. [Figure 4] This is a schematic diagram of the fourth structure of the circuit board according to the embodiment of the present invention. [Figure 5] This is a schematic diagram of the fifth structure of the circuit board according to the embodiment of the present invention. [Figure 6] This is a schematic diagram of the sixth structure of the circuit board according to the embodiment of the present invention. [Figure 7] This is a schematic diagram of the module of a microwave generator according to an embodiment of the present invention. [Figure 8] This is a schematic diagram of the structure of the transformer according to the embodiment of the present invention. [Figure 9] This is a schematic diagram of another structure of the transformer according to the embodiment of the present invention. [Figure 10] This is a schematic diagram of the structure of the magnetic core of the present embodiment. [Figure 11] This is a schematic diagram of another structure of the magnetic core of the embodiment of the present invention. [Figure 12] This is a schematic diagram of the magnetic core structure of the embodiment of the present invention. [Figure 13] This is a schematic diagram of the skeletal structure of the embodiment of the present invention. [Figure 14a] This is a schematic diagram of the structure of a different magnetic core according to the embodiment of the present invention. [Figure 14b] This is a schematic diagram of the structure of a different magnetic core according to the embodiment of the present invention. [Figure 14c] This is a schematic diagram of the structure of a different magnetic core according to the embodiment of the present invention. [Figure 14d] This is a schematic diagram of the structure of a different magnetic core according to the embodiment of the present invention. [Figure 14e] This is a schematic diagram of the structure of a different magnetic core according to the embodiment of the present invention. [Figure 14f] This is a schematic diagram of the structure of a different magnetic core according to the embodiment of the present invention. [Figure 14g] This is a schematic diagram of the structure of a different magnetic core according to the embodiment of the present invention. [Figure 14h] This is a schematic diagram of the structure of a different magnetic core according to the embodiment of the present invention. [Figure 14i] This is a schematic diagram of the structure of a different magnetic core according to the embodiment of the present invention. [Figure 14j] This is a schematic diagram of the structure of a different magnetic core according to the embodiment of the present invention. [Figure 14k] This is a schematic diagram of the structure of a different magnetic core according to the embodiment of the present invention. [Figure 14l] This is a schematic diagram of the structure of a different magnetic core according to the embodiment of the present invention. [Figure 14m] This is a schematic diagram of the structure of a different magnetic core according to the embodiment of the present invention. [Figure 14n] This is a schematic diagram of the structure of a different magnetic core according to the embodiment of the present invention. [Figure 14o] This is a schematic diagram of the structure of a different magnetic core according to the embodiment of the present invention. [Figure 15]This is a cross-sectional view of the transformer according to the present embodiment. [Figure 16] This is a schematic diagram of the structure of a transformer magnetic core, a related technology. [Figure 17] This is a schematic diagram of the structure of a transformer, a related technology. [Modes for carrying out the invention]

[0041] The embodiments described below will be explained in detail, with examples of such embodiments shown in the drawings, where throughout, the same or similar designations indicate the same or similar elements, or elements having the same or similar functions. The embodiments described below with reference to the drawings are illustrative and are used solely for illustrative purposes of the present application and should not be understood as limiting the present application.

[0042] In this description, the terms “first” and “second” are used solely for descriptive purposes and should not be understood as indicating or suggesting relative importance or specifying the number of technical features being referred to. Therefore, features designated as “first” or “second” may be explicitly or implicitly defined as including one or more of the aforementioned features. In this description, “multiple” means two or more unless otherwise clearly and specifically defined.

[0043] In this description, unless otherwise explicitly stated or limited, the terms “attachment,” “connection,” and “connection” shall be interpreted broadly, and may include, for example, a fixed connection, a detachable connection, or an integral connection. It may be a mechanical connection or an electrical connection. It may be a direct connection, an indirect connection via an intermediate medium, or an internal communication between two elements or an interaction between two elements. A person skilled in the art will understand the specific meaning of these terms in this application depending on the specific circumstances.

[0044] In the description of this application, the statement that the first feature is "above" or "below" the second feature may include cases where the first and second features are in direct contact, or cases where the first and second features are not in direct contact but are in contact through other features between them. Furthermore, the statement that the first feature is "above," "above," or "upper side" of the second feature includes cases where the first feature is directly above or diagonally above the second feature, or simply indicates that the horizontal altitude of the first feature is higher than that of the second feature. The statement that the first feature is "below," "below," or "below side" of the second feature includes cases where the first feature is directly below or diagonally below the second feature, or simply indicates that the horizontal altitude of the first feature is lower than that of the second feature.

[0045] The disclosure of this application provides many different embodiments or examples to realize different structures of the application. For the sake of brevity of the disclosure, the parts and configurations of specific examples are described below. Of course, these are merely illustrative and are not intended to limit the application. The application may also repeat reference numerals and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity and does not in itself indicate relationships between the various embodiments and / or configurations considered. The application also provides examples of various specific processes and materials, but those skilled in the art will be able to recognize the application of other processes and / or the use of other materials.

[0046] Referring to Figure 1, the circuit board 100 of this embodiment is used in a microwave generator 1000. The circuit board 100 includes a substrate 10, a transformer 20, and a voltage doubler rectifier capacitor 30. The transformer 20 is mounted on the substrate 10. The voltage doubler rectifier capacitor 30 is mounted between the substrate 10 and the transformer 20.

[0047] The above-mentioned circuit board 100 is advantageous for miniaturization because, by placing the voltage-doubler rectifier capacitor 30 below the transformer 20, the space occupied by the voltage-doubler rectifier capacitor 30 on the circuit board 100 can be reduced, thereby reducing the volume of the circuit board 100. The voltage-doubler rectifier capacitor 30 is placed below the transformer 20, and the transformer 20 is used to restrict the movement of the voltage-doubler rectifier capacitor 30, thereby preventing solder leakage caused by the voltage-doubler rectifier capacitor 30 lifting up when welding it.

[0048] Specifically, current inverter microwave control mainly employs single-ended resonant converters and high-voltage amplification circuits. The single-ended resonant converter employs an inverter topology structure, enabling inverter operation with a single switching element while simultaneously achieving soft-switching control. To reduce the voltage value that the secondary side of the inverter transformer 20 must withstand, while increasing the voltage value obtainable on the load side and improving the operational stability of the magnetron, a voltage doubler rectifier circuit is mainly used in inverter microwaves. The voltage doubler rectifier circuit has a simple circuit structure and is easy to control. Voltage doubler rectifier circuits are divided into half-wave voltage doubler rectifier circuits and full-wave voltage doubler rectifier circuits, with full-wave voltage doubler rectifier circuits being the most commonly used today. A full-wave voltage doubler rectifier circuit can be composed of two high-voltage diodes (not shown) and a high-voltage film capacitor (not shown).

[0049] In the embodiment shown in Figure 1, the substrate 10 can be rectangular. The substrate 10 can support the transformer 20, thereby allowing the transformer 20 to be connected to the substrate 10. The transformer 20, as the main element of the circuit board 100, is positioned close to the center of the substrate 10. A voltage doubler rectifier capacitor 30 is provided on the circuit board 100. The voltage doubler rectifier capacitor 30 can be provided at one end close to the transformer 20. The voltage doubler rectifier capacitor 30 can be provided between the substrate 10 and the transformer 20, and by providing the voltage doubler rectifier capacitor 30 below the transformer 20, the space occupied by the voltage doubler rectifier capacitor 30 on the circuit board 100 can be reduced, thereby reducing the volume of the circuit board 100, which is advantageous for miniaturizing the circuit board 100. Furthermore, the voltage doubler rectifier capacitor 30 is located below the transformer 20, and the transformer 20 is used to restrict the movement of the voltage doubler rectifier capacitor 30, thereby preventing solder leakage caused by the voltage doubler rectifier capacitor 30 lifting up when welding it.

[0050] Referring to Figures 1 and 2, in some embodiments, the transformer 20 includes a skeletal frame 21. The voltage doubler rectifier capacitor 30 is provided between the skeletal frame 21 and the substrate 10.

[0051] This solves the problem of solder leakage caused by the lifting of the voltage doubler rectifier capacitor 30 when welding the voltage doubler rectifier capacitor 30.

[0052] Specifically, in Figure 1, the frame piece 21 can be placed on top of the voltage doubler rectifier capacitor 30. The voltage doubler rectifier capacitor 30 can be inserted into the substrate 10 and placed between the frame piece 21 and the substrate 10. The height direction of the circuit board 100 can be represented by H. By placing the voltage doubler rectifier capacitor 30 between the frame piece 21 and the substrate 10, the movable space of the voltage doubler rectifier capacitor 30 can be limited in the H direction of the circuit board 100, thereby solving the problem of solder leakage caused by the lifting of the voltage doubler rectifier capacitor 30 when welding it.

[0053] In one embodiment, the lifting of the voltage doubler rectifier capacitor 30 refers to the fact that the component is not fully inserted when the voltage doubler rectifier capacitor 30 is inserted, causing it to tilt and lift up when the component is welded. Solder leakage refers to poor contact caused by insufficient solder at the weld.

[0054] In the embodiment shown in Figure 3, the transformer 20 further includes a primary winding 22 and a secondary winding 23. The secondary winding 23 can be wound around one end of the skeletal piece 21 that is closer to the voltage doubler rectifier capacitor 30. The primary winding 22 can be wound around the other end of the skeletal piece 21. The voltage doubler rectifier capacitor 30 can be provided between the secondary winding 23 and the substrate 10, thereby further limiting the movable space of the voltage doubler rectifier capacitor 30.

[0055] Referring to Figures 1 and 2, in some embodiments, the transformer 20 includes a first baffle 24. The first baffle 24 is provided at one end of the skeletal piece 21. The first baffle 24 is used to limit the movable space of a portion of the voltage doubler rectifier capacitor 30 in the horizontal direction of the circuit board 100.

[0056] In this way, the voltage doubler rectifier capacitor 30 can be fixed in place by limiting the movable space of a portion of the voltage doubler rectifier capacitor 30 in the horizontal direction of the circuit board 100 using the first baffle 24.

[0057] Specifically, in Figure 1, the first baffle 24 can be provided at one end of the frame piece 21 that is close to the voltage doubler rectifier capacitor 30. The first baffle 24 can be connected to the frame piece 21, and a portion of the first baffle 24 can be provided below the frame piece 21 and positioned on one side of the voltage doubler rectifier capacitor 30. The outer surface of the first baffle 24 is substantially parallel to one side of the substrate 10 that is close to the outer surface of the first baffle 24, thereby limiting the movable space of a portion of the voltage doubler rectifier capacitor 30 in the horizontal direction of the circuit board 100, and thereby fixing the voltage doubler rectifier capacitor 30. The horizontal direction of the circuit board 100 is parallel to the top surface of the substrate 10.

[0058] Referring to Figures 4 and 5, in some embodiments, the transformer 20 includes a lead frame 25. The circuit board 100 further includes a discharge resistor 40. The discharge resistor 40 is located between the lead frames 25. The lead frames 25 are used to restrict the position of the discharge resistor 40.

[0059] In this way, the volume of the circuit board 100 can be reduced and the vibration resistance of the discharge resistor 40 can be improved.

[0060] Specifically, the lead frame 25 is connected to the skeletal piece 21 and can be located beneath the skeletal piece 21. The lead frame 25 can be inserted into the substrate 10. The discharge resistor 40 is provided on the substrate 10 and is located beneath the skeletal piece 21. In the embodiment shown in Figure 5, a recess 26 is provided in the lead frame 25. The discharge resistor 40 can be located within the recess 26. The lead frame 25 can be positioned closer to the center of the discharge resistor 40. In one embodiment, the discharge resistor 40 can be inserted into the substrate first, and then the transformer 20 can be attached, so that the lead frame 25 engages with the discharge resistor 40 by the recess 26, thereby limiting the movable space of the discharge resistor 40 in the H direction of the circuit board 100, improving the vibration resistance of the discharge resistor 40, and by providing the discharge resistor 40 beneath the skeletal piece 21, the volume of the circuit board 100 can be reduced. Furthermore, in the embodiment shown in Figure 4, by fixing the discharge resistor 40 under the skeletal piece 21 via the lead frame 25, the discharge resistor 40 is in contact with the substrate 10, and the discharge resistor 40 can be stably fixed, thereby preventing the leads of the discharge resistor 40 from breaking during welding.

[0061] Referring to Figure 3, in some embodiments, the circuit board 100 includes a bus capacitor 50 and a differential mode inductor 60. The bus capacitor 50 is located between the differential mode inductor 60 and the transformer 20. The differential mode inductor 60 and the bus capacitor 50 are arranged sequentially on the board.

[0062] In this way, by reducing the width of the circuit board 100, the volume of the circuit board 100 can be reduced.

[0063] Specifically, in the embodiment shown in Figure 3, the width direction of the circuit board 100 can be represented by D. The differential mode inductor 60 is provided closer to one side of the circuit board 100 in the D direction. The bus capacitor 50 can be provided between the differential mode inductor 60 and the frame piece 21. The differential mode inductor 60 and the bus capacitor 50 can be provided sequentially on the board 10 in directions mutually orthogonal to the D direction, thereby reducing the width of the circuit board 100 and thus reducing the volume of the circuit board 100.

[0064] Referring to Figures 1 and 3, in some embodiments, the circuit board 100 includes a heat sink 70 and a resonant capacitor 91. The heat sink 70 is located away from the center of the circuit board 100. The resonant capacitor 91 is located between a portion of the heat sink 70 and the board 10. The heat sink 70 is used to lower the temperature of the resonant capacitor 91.

[0065] In this way, the resonant capacitor 91 can be made to dissipate heat, and the volume of the circuit board 100 can be further reduced.

[0066] Specifically, in the embodiment shown in Figure 3, the heat sink 70 can be provided at a position away from the center of the circuit board 100. In Figure 1, the heat sink 70 can have a T-shaped structure and can form a housing space 92 together with the substrate 10. The resonant capacitor 91 can be inserted into the substrate 10 and located within the housing space 92. Because the resonant capacitor 91 is provided within the housing space 92, the top and sides of the resonant capacitor 91 can dissipate heat, improving heat dissipation efficiency and further reducing the volume of the circuit board 100.

[0067] Referring to Figure 6, in some embodiments, the circuit board 100 includes a power device 90. The power device 90 is detachably connected to the side of the heatsink 70.

[0068] In this way, the heat dissipation efficiency of the power device 90 can be improved, and maintenance and replacement are easier.

[0069] Specifically, in the embodiment shown in Figure 6, the circuit board 100 further includes screws 80. The power device 90 is inserted into the board 10 and can be fixedly attached to the side of the heat sink 70 by screws 80. The power device 90 is fixedly connected to the side of the heat sink 70, which can improve the heat dissipation efficiency of the power device 90. In one embodiment, if the power device 90 fails, it can be easily replaced by loosening the screws 80. Note that there may be two screws 80, which can be provided at both ends of the power device 90. In other embodiments, the number of screws 80 may be four or other numbers, and is not specifically limited thereto.

[0070] In the embodiment shown in Figure 6, the power device 90 can be provided in the housing space 92, which is advantageous for miniaturizing the circuit board 100.

[0071] Referring to Figure 6, in some embodiments, the heat sink 70 includes a plurality of heat dissipation fins 71. The plurality of heat dissipation fins 71 are used to increase the contact area with the air.

[0072] In this way, the heat dissipation efficiency of the heatsink 70 can be improved.

[0073] Specifically, in Figure 6, a plurality of heat dissipation fins 71 are provided on the top and side surfaces of the heat sink 70. The plurality of heat dissipation fins 71 can be provided on the heat sink 70 at intervals. By providing the plurality of heat dissipation fins 71 at intervals on the heat sink 70, the contact area between the heat dissipation fins 71 and the air can be increased, thereby increasing the heat exchange rate and improving the heat dissipation efficiency of the heat sink 70.

[0074] In other embodiments, the heat dissipation fins 71 provided on the top surface of the heat sink 70 can be provided perpendicular to the width direction of the circuit board 100 in the projection direction, or parallel to the width direction of the circuit board 100. The heat dissipation fins 71 provided on the side surface of the heat sink 70 can be provided parallel to the substrate 10 in the projection direction, or perpendicular to the substrate 10.

[0075] Referring to Figure 2, in some embodiments, the circuit board 100 includes at least two voltage doubler rectifier capacitors 30. The at least two voltage doubler rectifier capacitors 30 are arranged symmetrically along the length of the circuit board 100.

[0076] In this way, the volume of the circuit board 100 can be reduced, which is advantageous for miniaturizing the circuit board 100.

[0077] Specifically, in the embodiment shown in Figure 2, the length of the circuit board 100 can be represented by L. Two voltage doubler rectifier capacitors 30 are provided on the circuit board 100. The two voltage doubler rectifier capacitors 30 can be provided symmetrically on the substrate 10 along the L direction of the circuit board 100 and are located below the skeletal piece 21, thereby reducing the dimensions of the circuit board 100 in the width direction to a certain extent, which reduces the volume of the circuit board 100 and is advantageous for miniaturizing the circuit board 100.

[0078] Referring to Figure 7, the microwave generator 1000 in the embodiment of the present application includes the circuit board 100 described in any of the above embodiments.

[0079] The microwave generator 1000 described above reduces the volume of the circuit board 100 by placing the voltage doubler rectifier capacitor 30 below the transformer 20, thereby reducing the space occupied by the voltage doubler rectifier capacitor 30 on the circuit board 100, which is advantageous for miniaturizing the circuit board 100. The voltage doubler rectifier capacitor 30 is placed below the transformer 20, and the transformer 20 is used to restrict the movement of the voltage doubler rectifier capacitor 30, thereby preventing solder leakage caused by the voltage doubler rectifier capacitor 30 lifting up when welding it.

[0080] Specifically, the microwave generator 1000 includes an inverter microwave oven. A heat dissipation air passage (not shown) is provided inside the microwave generator 1000, and the circuit board 100 can be placed in the heat dissipation air passage. By rationally designing the layout of elements on the circuit board 100 using the heat dissipation air passage, the volume of the circuit board 100 can be reduced, achieving miniaturization, which is advantageous for the overall design of the microwave generator 1000.

[0081] In related technologies, home appliances (e.g., inverter microwave ovens) are equipped with transformers, and the transformers include a magnetic core structure, which consists of two magnetic cores, each having a single cylindrical magnetic column, and the two cylindrical magnetic columns of the two magnetic cores are provided within an insulating frame, with primary and secondary coils wound around the positions corresponding to the two cylindrical magnetic columns in the insulating frame, respectively. The two cylindrical magnetic columns are separated by an air gap and are used to improve the saturation resistance when the transformer carries a resonant current. However, because the outer diameter of the cylindrical magnetic cores of the transformer is relatively large, the volume of the transformer increases, and it is difficult to improve saturation resistance unless the cross-sectional area of ​​the magnetic cores is changed, i.e., the size of the magnetic cores is not increased.

[0082] Specifically, referring to Figure 16 in the related technology, the magnetic core 160 in the transformer 200 includes a cylindrical magnetic column 161, which is in contact with both sides of the magnetic core 160, and the cylindrical magnetic column 161 is located on the outermost side of the magnetic core 160. Because the diameter of the cylindrical magnetic core 161 in the related technology is relatively large, the diameter range of the cylindrical magnetic core 161 is approximately 15 cm to 20 cm. This increases the volume of the transformer 200, and if the cross-sectional area of ​​the magnetic core 160 is not changed, i.e., the magnetic core 160 is not enlarged, it is difficult to improve the saturation resistance of the transformer 200.

[0083] Referring to Figures 8 to 13, an embodiment of the present invention provides a transformer 20. The transformer 20 includes a magnetic core structure 210, a frame 220, a first coil 230, and a second coil 240. The magnetic core structure 210 includes two magnetic cores 211, each having a first magnetic column 2111, the first magnetic column 2111 being flattened, and the longitudinal direction of the first magnetic column 2111 aligns with the longitudinal direction of the magnetic core 211. The frame 220 is provided with an insertion hole 221, the insertion hole 221 conforming to the shape of the first magnetic column 2111, and spaced-apart first grooves 222 and second grooves 223 are provided on the outside of the hole wall of the insertion hole 221, at least a portion of the first magnetic column 2111 is located inside the insertion hole 221, and the two first magnetic columns 2111 are spaced apart and facing each other. The first coil 230 is wound around the outside of the hole wall of the insertion hole 221 and is located in the first groove 222. The second coil 240 is wound around the outside of the hole wall of the insertion hole 221 and is located in the second groove 223.

[0084] In the above-described transformer 20, the first magnetic column 2111 is flattened, and the insertion hole 221 conforms to the shape of the first magnetic column 2111. This makes it possible to increase the saturation resistance of the transformer 20 without increasing the volume of the transformer 20 and the magnetic core 211, or the cost of the transformer 20. Furthermore, it is possible to further reduce the height and volume of the transformer 20, thereby enabling the miniaturization of home appliances.

[0085] Specifically, in one embodiment, the core structure 210 combines two cores 211 attached to a framework 220 into a structure shaped like the Chinese character "kou" (square with a hole in the middle). Specifically, the two cores 211 are arranged opposite to each other, and the two first magnetic columns 2111 of the two cores 211 are inserted into the insertion holes 221 of the framework 220 in an opposite manner to enhance the electromagnetic induction effect, thereby increasing the magnetic induction intensity of the first coil 230 and the second coil 240 and realizing the voltage conversion between the first coil 230 and the second coil 240 of the transformer 20. The transformer 20 is applicable to an inverter, and miniaturization of the inverter can also be realized.

[0086] [[ID=**4**]]The material of the core 211 may be ferrite or other materials, and is not specifically limited here. Specifically, the core 211 of the transformer 20 can be manufactured by pressure molding ferrite powder, thereby enhancing the anti-interference ability.

[0087] The direction in which the two first magnetic columns 2111 are arranged opposite to each other is perpendicular to the height direction of the transformer 20. Thereby, while reducing the height of the core 211 and the volume of the transformer 20, miniaturization of the household electrical appliance product is realized. Also, due to the limitation of the physical structure of the core 211, the amount of magnetic flux passing through the core 211 cannot be increased infinitely, and saturation of the core 211 is caused in a certain state. Saturation of the core 211 may cause overheating of the coil, and there is a risk of damage and burnout of the coil or device. Therefore, the embodiment of the present application can enhance the saturation resistance of the transformer 20 by providing an air gap 250.

[0088] By making the first magnetic column 2111 present a flat shape to reduce the height of the core 211, the effective cross-sectional area of the core 211 is decreased, thereby effectively reducing the maximum saturation magnetic flux density and improving the saturation resistance of the transformer 20 to realize miniaturization of the household electrical appliance product. That the first magnetic column 2111 presents a flat shape means that in the height direction of the transformer 20 (as shown in FIG. 10), the width d of the first magnetic column 2111 is smaller than the length L of the first magnetic column 2111, and the width d of the first magnetic column 2111 is along the height direction of the transformer 20.

[0089] The frame 220 can be used to support the first coil 230 and the second coil 240 of the transformer 20. More specifically, the frame 220 can provide winding space for the first coil 230 and the second coil 240 of the transformer 20. The frame 220 can also be used to provide a safe and stable voltage conversion environment by fixing the magnetic core 211 of the transformer 20. In one embodiment, the frame 220 may be an insulating frame, thereby improving the flame retardancy of the transformer 20.

[0090] In one embodiment, the insertion hole 211 may be a flattened hole to conform to the shape of the first magnetic pole 2111, thereby fixing the magnetic core 211 of the transformer 20.

[0091] The first coil 230 may be a primary coil and the second coil 240 may be a secondary coil, or the first coil 230 may be a secondary coil and the second coil 240 may be a primary coil. The first groove 222 of the frame 220 is used to wind the first coil 230, and the second groove 223 of the frame 220 is used to wind the second coil 240. In one embodiment, the wire diameter of the second coil 240 can be smaller than that of the first coil 230, and the number of turns of the second coil 240 can be greater than that of the first coil 230. That is, the transformer 20 may be a step-up transformer. In the transformer 20, it is possible to achieve a voltage in the second coil 240 that is greater than the voltage in the first coil 230, thereby satisfying the voltage conversion requirement of the transformer 20.

[0092] Referring to Figures 11 and 13, in some embodiments, the magnetic core 211 includes a connecting portion 2112 and a second magnetic column 2113, the connecting portion 2112 connecting the first magnetic column 2111 and the second magnetic column 2113, the second magnetic column 2113 is located outside the insertion hole 221, and the two second magnetic columns 2113 are spaced apart and facing each other outside the first groove 222. In this way, the first magnetic columns 2111 of the two magnetic cores 211 are drilled into the insertion holes 221, and together with the connecting portions 2112 and the second magnetic columns 2113, they form a structure shaped like the Chinese character 'kou' (square), and by surrounding the framework 220 together, the structural joining of the magnetic core 211 and the framework 220 becomes more firm.

[0093] Specifically, in one embodiment, the first magnetic column 2111 may be perpendicular to the connecting portion 2112, the second magnetic column 2113 may be perpendicular to the connecting portion 2112, and the first magnetic column 2111 and the second magnetic column 2113 are provided at intervals, so that the magnetic core 211 is inserted through and surrounds the framework 220 from the insertion hole 221 in the shape of the Chinese character 'kou' (square), thereby ensuring that the structural joining of the magnetic core 211 and the framework 220 becomes more firm.

[0094] The connecting portion 2112 connects the first magnetic column 2111 and the second magnetic column 2113, and the connecting portion 2112 can be used to support and stabilize the first magnetic column 2111 and the second magnetic column 2113. In one embodiment, the connecting portion 2112 can be in interference fit with the side wall of the framework 220, further enhancing the stability of the joining between the magnetic core 211 and the framework 220.

[0095] In one embodiment, both the first magnetic column 2111 and the insertion hole 221 can be of a flat structure, making the fitting between the first magnetic column 2111 and the insertion hole 221 tight and difficult to rattle.

[0096] That is, the first magnetic columns 2111 of the two magnetic cores 211 are drilled into the insertion holes 221, and together with the connecting portions 2112 and the second magnetic columns 2113, they form a structure shaped like the Chinese character 'kou' (square), and by surrounding the framework 220 together, the structural joining of the magnetic core 211 and the framework 220 becomes more firm.

[0097] Referring to FIGS. 9 and 10, in some embodiments, along the height direction of the transformer 20, the distance between the upper edge of the first magnetic column 2111 and the upper edge of the connecting portion 2112 is m, and m = (L / k - 1) * d, where k is 5 to 20, L is the length of the first magnetic column 2111, and d is the width of the first magnetic column 2111.

[0098] Thus, the formula m=(L / k-1)*d is used to restrict the possible ranges of the length L, width d, and distance m of the first magnetic column 2111 in the magnetic core, thereby ensuring that miniaturization of home appliances can be achieved without increasing the volume and cost of the transformer 20.

[0099] Specifically, the first magnetic pole 2111 is connected perpendicularly to the connection part 2112, and the height of the transformer 20 changes according to the possible values ​​of the width d of the first magnetic pole 2111. More specifically, increasing the possible values ​​of the width d of the first magnetic pole 2111 increases the height of the skeleton 220 of the transformer 20, which increases the space occupied in terms of height and volume of the transformer 20, thereby increasing production costs. Decreasing the possible values ​​of the width d of the first magnetic pole 2111 decreases the height of the skeleton 220 of the transformer 20, which reduces the space occupied in terms of height and volume of the transformer 20, thereby enabling miniaturization of home appliances.

[0100] The formula m=(L / k-1)*d is used to restrict the possible ranges of the length L, width d, and distance m of the first magnetic column 2111 in the magnetic core, thereby ensuring miniaturization of home appliances without increasing the volume and cost of the transformer 20.

[0101] In one embodiment, the length L of the first magnetic column 2111 of the magnetic core 211 may be 20 mm, the width d of the first magnetic column 2111 may be 8 mm, and the distance m between the upper edge of the first magnetic column 2111 and the upper edge of the connecting portion 2112 may be 10 mm. Based on the formula m = (L / k-1)*d, the value of k is 8.9. In one embodiment, the possible range of k may be [5, 20].

[0102] In other words, the formula m=(L / k-1)*d is used to limit the possible ranges of the length L, width d, and distance m of the first magnetic column 2111 in the magnetic core, thereby ensuring that miniaturization of home appliances can be achieved without increasing the volume and cost of the transformer 20.

[0103] In some embodiments, the first magnetic column 2111 satisfies the condition that L / d is 2 to 40, where L is the length of the first magnetic column 2111 and d is the width of the first magnetic column 2111.

[0104] In this way, the ratio L / d of the length L of the first magnetic pole 2111 to the width d of the first magnetic pole 2111 ensures that the possible values ​​of the width d of the first magnetic pole 2111 are kept within a small range, thereby effectively reducing the maximum saturation magnetic flux density and improving the safety performance of the transformer 20.

[0105] Specifically, the ratio L / d of the length L of the first magnetic column 2111 to the width d of the first magnetic column 2111 is selected from the range [2, 40], and by ensuring that the possible values ​​of the width d of the first magnetic column 2111 are within a small range, the maximum saturation magnetic flux density is effectively reduced.

[0106] More specifically, theoretical alternating magnetic flux can induce an induced current in the conductor cross-section of the magnetic core 211. According to Lenz's law, the magnetic field that generates the induced current always opposes the change in the amount of magnetic flux that causes the induced current. As a result, the magnetic flux concentrates on the surface of the magnetic core 211, reducing the effective cross-sectional area of ​​the magnetic core 211. This phenomenon is also known as the skin effect of the magnetic core.

[0107] Furthermore, the power core 211 has hysteresis characteristics, and in areas of high magnetic flux density in the cross-section of the core 211, the corresponding permeability decreases. That is, when the core 211 is subjected to constant current excitation, the autowinding inductance value decreases, and the saturation resistance of the core 211 decreases.

[0108] In one embodiment, the skin effect of the magnetic core 211 can be reduced by decreasing the width d of the flattened cross-section of the magnetic core 211 while keeping the cross-sectional area of ​​the magnetic core 211 constant, and consequently, the maximum saturation magnetic flux density can be effectively reduced.

[0109] In one embodiment, the ratio L / d of the length L of the first magnetic column 2111 to the width d of the first magnetic column 2111 is selected from the range [2, 40], i.e., 2 ≤ L / d ≤ 40. In one example, the ratio of L / d may be 2, 7, 16, 23, 27, 34, 40, or other values ​​between 2 and 40.

[0110] In other words, the ratio L / d of the length L of the first magnetic pole 2111 to the width d of the first magnetic pole 2111 ensures that the possible values ​​of the width d of the first magnetic pole 2111 are kept within a small range, thereby effectively reducing the maximum saturation magnetic flux density and improving the safety performance of the transformer 20.

[0111] In one embodiment, the cross-sectional view of the magnetic core 211 includes the structural shape shown in Figure 10, but is not limited thereto. As shown in Figures 14a to 14o, the connection portion 2112 of the magnetic core 211 can have a rectangular, polygonal, or irregularly shaped cross-sectional view, and is not specifically limited thereto.

[0112] Referring to Figure 10, in some embodiments, d is 5 mm to 12 mm.

[0113] This effectively reduces the maximum saturation magnetic flux density by selecting the width d of the first magnetic column 2111 from a range of 5 mm to 12 mm, thereby reducing the height of the magnetic core and the height of the transformer 20.

[0114] Specifically, the width d of the first magnetic pole 2111 should be selected from an appropriate range so as to reduce the height of the transformer 20 while effectively reducing the maximum saturation magnetic flux density.

[0115] If the width d of the first magnetic pole 2111 is selected to be too small, the effect of reducing the maximum saturation magnetic flux density will be insufficient. If the width d of the first magnetic pole 2111 is selected to be too large, the occupied volume of the transformer 20 will increase, thereby increasing costs.

[0116] In one embodiment, the width d of the first magnetic column 2111 can be selected from the range of [5 mm, 12 mm].

[0117] The width d of the first magnetic column 2111 is selected from the range of 5 mm to 12 mm, i.e., 5 mm ≤ d ≤ 12 mm. In one example, the width d may be 5 mm, 6 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, or any other value between 5 mm and 12 mm.

[0118] In other words, the width d of the first magnetic pole 2111 is selected from a range of 5 mm to 12 mm in order to reduce the height of the transformer 20 while effectively reducing the maximum saturation magnetic flux density.

[0119] Referring to Figures 8 and 9, in some embodiments, the first coil 230 is a primary coil, the second coil 240 is a secondary coil, the two first magnetic poles 2111 are spaced apart and facing each other, forming an air gap 250, which is positioned close to the first coil 230.

[0120] In this way, by providing an air gap of 250, the saturation resistance of the transformer 20 when it flows a resonant current is increased, reducing damage to the device and ultimately providing a stable operating environment for the transformer 20.

[0121] Specifically, in one embodiment, the air gap 250 can be the gap between two opposing first magnetic poles 2111 and the gap between two opposing second magnetic poles 2113, and can be formed in other ways, and is not specifically limited thereto.

[0122] The air gap 250 can be located on the side of the first coil 230 and is used to increase the saturation resistance of the transformer 20 when it carries a resonant current, reduce device damage, and ultimately provide the transformer 20 with a stable operating environment.

[0123] In other words, by providing an air gap 250 in the transformer 20, saturation occurs when the transformer 20 is operating, reducing damage to the device and ultimately providing a stable operating environment for the transformer 20.

[0124] Referring to Figure 8, in some embodiments, the width s of the air gap 250 is 1.5 mm to 3.2 mm.

[0125] This allows the width s of the air gap 250 to be set in the range of 1.5 mm to 3.2 mm, thereby increasing the saturation resistance of the transformer 20, reducing device losses in the transformer 20, and ensuring a safe operating environment for the transformer 20.

[0126] Specifically, the width s of the air gap 250 should be selected from an appropriate range so that the transformer 20 operates properly.

[0127] If the width s of the air gap 250 is selected to be too small, the saturation tolerance of the transformer 20 will be insufficient. If the width s of the air gap 250 is selected to be too large, the copper loss of the transformer 20 will increase.

[0128] In one embodiment, the width s of the air gap 250 can be selected from a range of 1.5 mm to 3.2 mm.

[0129] The width s of the air gap 250 is selected from the range of 1.5 mm to 3.2 mm, i.e., 1.5 mm ≤ s ≤ 3.2 mm. In one example, the width s may be 1.5 mm, 1.7 mm, 1.8 mm, 2.0 mm, 2.3 mm, 2.6 mm, 3.2 mm, or other values ​​between 1.5 mm and 3.2 mm.

[0130] In other words, by setting the width s of the air gap 250 to a range of 1.5 mm to 3.2 mm, the saturation resistance of the transformer 20 is increased, the device loss of the transformer 20 is reduced, and a safe operating environment for the transformer 20 is ensured.

[0131] Referring to Figures 8 and 9, in some embodiments, the frame 220 includes a second baffle 224, the second baffle 224 separating the first groove 222 and the second groove 223, and the thickness of the second baffle 224 is g, where g is 3.5 mm to 5 mm.

[0132] Thus, on the one hand, the second baffle 224 separates the first coil 230 and the second coil 240, reducing potential safety hazards, while on the other hand, the frame 220 can adjust the leakage inductance and coupling coefficient of the transformer 20 by adjusting the thickness g of the second baffle 224.

[0133] Specifically, the second baffle 224 is provided between the first groove 222 and the second groove on the outside of the hole wall of the insertion hole 221. By separating the first coil 230 and the second coil 240, the second baffle 224 prevents the first coil 230 and the second coil 240 from becoming entangled with each other, thereby reducing potential safety hazards.

[0134] In one embodiment, the second baffle 224 may be made of an insulating material, thereby improving the flame retardancy of the frame 220.

[0135] In one embodiment, the thickness g of the second baffle 224 is selected from the range of 3.5 mm to 5 mm. The frame 220 can adjust the leakage inductance and coupling coefficient of the transformer 20 by adjusting the thickness g of the second baffle 224. Specifically, the thickness g of the second baffle 224 is selected from the range of [3.5 mm, 5 mm], and as the thickness g of the second baffle 224 increases, the leakage inductance of the transformer 20 increases and the coupling coefficient between the first coil 230 and the second coil 240 decreases, and as the thickness g of the second baffle 224 decreases, the leakage inductance of the transformer 20 decreases and the coupling coefficient between the first coil 230 and the second coil 240 increases.

[0136] The thickness g is selected from the range of 3.5 mm to 5 mm, i.e., 3.5 mm ≤ g ≤ 5 mm. In one example, the thickness g may be 3.5 mm, 3.7 mm, 3.8 mm, 4.0 mm, 4.3 mm, 4.6 mm, 5 mm, or any other value between 3.5 mm and 5 mm.

[0137] Referring to Figures 9 and 15, in some embodiments, the bottom surface of the first groove 222 is the first winding surface 2221, the bottom surface of the second groove 223 is the second winding surface 2231, and the first winding surface 2221 and the second winding surface 2231 have a difference in elevation along the radial direction of the insertion hole 221.

[0138] In this way, by setting the height of the first winding surface 2221 to be greater than the height of the second winding surface 2231, the amount of magnetic flux from the first coil 230 to the second coil 240 is reduced, thereby lowering the coupling coefficient between the first coil 230 and the second coil 240.

[0139] Specifically, in one embodiment, the first winding surface 2221 is used for winding the primary coil, and the second winding surface 2231 is used for winding the secondary coil. Furthermore, the first winding surface 2221 and the second winding surface 2231 are separated by a second baffle 224, thereby improving the safety of the windings of the transformer 20.

[0140] As shown in Figure 8, the radial direction of the insertion hole 221 may be such that it radiates outward in a 360° range from the center of the first magnetic column 2111. Furthermore, by making the height of the first winding surface 2221 along the radial direction of the insertion hole 221 greater than the height of the second winding surface 2231 along the radial direction of the insertion hole 221, the amount of magnetic flux from the first coil 230 to the second coil 240 is reduced, thereby lowering the coupling coefficient between the first coil 230 and the second coil 240.

[0141] In one embodiment, referring to Figure 15, in the vertical direction, the first winding surface 2221 and the second winding surface 2231 have a height difference of k2. In the horizontal direction, the first winding surface 2221 and the second winding surface 2231 have a height difference of k1.

[0142] In other embodiments, the surface areas of the four different planes of the first winding surface 2221 can each be larger than the surface areas of the four corresponding planes of the second winding surface 2231. In other embodiments, the surface areas of two of the planes of the first winding surface 2221 can each be larger than the surface areas of the two corresponding planes of the second winding surface 2231, and are not specifically limited herein.

[0143] In other words, by making the height of the first winding surface 2221 greater than the height of the second winding surface 2231 along the radial direction of the insertion hole 221, the amount of magnetic flux from the first coil 230 to the second coil 240 is reduced, thereby lowering the coupling coefficient between the first coil 230 and the second coil 240.

[0144] In one embodiment, the length L of the first magnetic column 2111 of the magnetic core 211 may be 20 mm, the width d of the first magnetic column 2111 may be 8 mm, the distance m between the upper edge of the first magnetic column 2111 and the upper edge of the connecting portion 2112 may be 10 mm, the thickness g of the first baffle may be 5 mm, the number of turns of the primary coil may be 30 turns, the number of turns of the secondary coil may be 250 turns, and the width s of the air gap may be 2.2 mm.

[0145] Embodiments of the present invention further provide a home appliance. The home appliance includes a transformer 20 according to any of the embodiments described above.

[0146] In the above-mentioned home appliance, the first magnetic column 2111 is flattened, and the insertion hole 221 conforms to the shape of the first magnetic column 2111. This makes it possible to increase the saturation resistance of the transformer 20 without increasing the volume of the transformer 20 and the magnetic core 211, or the cost of the transformer 20. Furthermore, it is possible to further reduce the height and volume of the transformer 20, thereby enabling miniaturization of the home appliance.

[0147] The above description of the embodiment of the transformer 20 and its beneficial effects also applies to the home appliance of the embodiment of this application, and to avoid duplication, a detailed explanation is omitted here.

[0148] Home appliances include, but are not limited to, microwave ovens, oven ranges, air conditioners, and dishwashers. Home appliances are widely used for food preparation, dishwashing, and other related applications.

[0149] Current transformers for inverter microwave ovens include a magnetic core structure, which consists of two magnetic cores, each with a single circular magnetic column. The two circular magnetic columns of the two cores are fitted into an insulating framework, and a primary coil and a secondary coil are wound around the positions corresponding to the two circular magnetic columns in the insulating framework. The leakage inductance and its coupling coefficient are adjusted by adjusting the thickness of the gap wall between the primary and secondary coils.

[0150] The leakage inductance of the above transformer directly affects the hard-switching characteristics of the IGBT, and especially during low-power operation of microwave ovens, a low coupling coefficient (large leakage inductance energy) is required to provide reverse current in the resonant cavity and achieve zero-voltage conduction of the IGBT. However, the above solution cannot be adapted to low-power applications by further reducing the coupling coefficient unless the thickness of the partition walls and the number of windings are changed, thereby increasing the volume and cost of the transformer.

[0151] Specifically, referring to Figure 17 in the related technology, since the height of the first plane 171 around which the primary coil 170 is wound and the height of the second plane 181 around which the secondary coil 180 is wound are the same, in the related technology, if the thickness of the partition wall 190 and the number of coil turns are not changed, the coupling coefficient of the transformer 200 cannot be further reduced to make it suitable for low-power applications.

[0152] Referring to FIGS. 8 to 13, an embodiment of the present application provides a transformer 20. The transformer 20 includes a core structure 210, a skeleton 220, a first coil 230, and a second coil 240. The core structure 210 includes two cores 211, and the core 211 includes a first magnetic column 2111. An insertion hole 221 is provided in the skeleton 220. The insertion hole 221 is adapted to the shape of the first magnetic column 2111. A first groove 222 and a second groove 223 are provided at intervals outside the hole wall of the insertion hole 221. At least a part of the first magnetic column 2111 is located in the insertion hole 221. The two first magnetic columns 2111 are provided opposite to each other at intervals. The bottom surface of the first groove 222 is the first winding surface 2221, and the bottom surface of the second groove 223 is the second winding surface 2231. The first winding surface 2221 and the second winding surface 2231 have a height difference in the radial direction of the insertion hole 221. The first coil 230 is wound around the first winding surface 2221 and is located in the first groove 222. The second coil 240 is wound around the second winding surface 2231 and is located in the second groove 223.

[0153] In the above transformer 20, the first coil 230 is wound around the first winding surface 2221, and the second coil 240 is wound around the second winding surface 2231. Since the first winding surface 2221 and the second winding surface 2231 have a height difference in the radial direction of the insertion hole 221, the first coil 230 and the second coil 240 adopt a misaligned winding method, which can reduce the coupling coefficient and reduce the hard switching characteristics of the IGBT at low output, and thus can be applied to low output applications.

[0154] Specifically, in one embodiment, the core structure 210 is combined in a Chinese character "kou" shape structure with two cores 211 arranged opposite to the skeleton 220.

[0155] The core 211 may be ferrite or other materials, and is not specifically limited here. Specifically, the core 211 can be manufactured by pressure molding ferrite powder, which is applied to the high-frequency transformer 20 to increase the magnetic permeability, and thus improve the quality factor of the inductor and reduce the loss of the coil.

[0156] The first magnetic column 2111 may be flattened or have other shapes, and is not specifically limited herein. The insertion hole 221 conforms to the shape of the first magnetic column 2111, and the electromagnetic induction effect is enhanced by ensuring that the two first magnetic columns 2111 of the two magnetic cores 211 are inserted facing each other into the insertion hole 221 of the framework 220.

[0157] The frame 220 can be used to support and separate the first coil 230 and the second coil 240 of the transformer 20. More specifically, the frame 220 can provide winding space for the first coil 230 and the second coil 240 of the transformer 20. The frame 220 can also be used to provide a safe and stable voltage conversion environment by fixing the magnetic core 211 of the transformer 20. In one embodiment, the frame 220 may be an insulating frame, thereby improving the flame retardancy of the transformer 20.

[0158] The first winding surface 2221 of the first groove 222 of the frame 220 is used for winding the first coil 230, and the second winding surface 2231 of the second groove 223 is used for winding the second coil 240. This ensures that the first coil 230 and the second coil 240 are located in different winding spaces, reducing potential safety hazards caused by entanglement between the coils and improving the safety performance of the transformer 20.

[0159] The wire diameter of the second coil 240 can be smaller than that of the first coil 230, and the number of turns of the second coil 240 can be greater than that of the first coil 230. In other words, the transformer 20 may be a step-up transformer. In the transformer 20, it is possible to achieve a voltage in the second coil 240 that is greater than the voltage in the first coil 230, thereby satisfying the voltage conversion requirement of the transformer 20. In one embodiment, the first coil 230 may be a primary coil and the second coil 240 may be a secondary coil, or the first coil 230 may be a secondary coil and the second coil 240 may be a primary coil.

[0160] In one embodiment, as shown in Figure 8, the radial height of the insertion hole 221 of the first winding surface 2221 can be greater than the radial height of the insertion hole 221 of the second winding surface 2231, so that there is a height difference k1 between the first winding surface 2221 and the second winding surface 2231 in the radial direction of the insertion hole 221, and as a result there exists an additional leakage flux space of a spacing distance k1 between the first coil 230 and the first magnetic pole 2111. That is, the larger the spacing distance k1, the greater the leakage flux energy of the first coil 230, the less the amount of magnetic flux from the first coil 230 to the second coil 240, and consequently the lower the coupling coefficient between the first coil 230 and the second coil 240 in the transformer 20, which reduces the temperature rise of the power devices in the transformer 20, thereby reducing the hard switching characteristics of the IGBT during low-power operation of the transformer 20 and improving the reliability of the transformer 20.

[0161] In another embodiment, the radial height of the insertion hole 221 of the second winding surface 2231 can be greater than the radial height of the insertion hole 221 of the first winding surface 2221 (not shown), and the first winding surface 2221 and the second winding surface 2231 have a height difference k1 in the radial direction of the insertion hole 221, thereby creating an additional leakage flux space of a spacing distance k1 between the second coil 240 and the first magnetic pole 2111. That is, the larger the spacing distance k1, the greater the leakage flux energy of the second coil 240, which reduces the amount of magnetic flux from the second coil 240 to the second coil 230, and consequently the coupling coefficient between the first coil 230 and the second coil 240 in the transformer 20, thereby reducing the temperature rise of the power devices in the transformer 20, reducing the hard switching characteristics of the IGBT during low-power operation of the transformer 20, and improving the reliability of the transformer 20.

[0162] In one embodiment, the embodiment of the present invention can improve the saturation resistance of the transformer 20 by providing an air gap 250. Specifically, due to limitations in the physical structure of the magnetic core 211, the amount of magnetic flux passing through the magnetic core 211 cannot be increased indefinitely, causing saturation of the magnetic core 211 under certain conditions. Saturation of the magnetic core 211 can cause coil overheating, and there is a risk of damage and burnout of the coil or device. Therefore, the saturation resistance of the transformer 20 can be improved by providing an air gap 250.

[0163] If the width s of the air gap 250 is selected to be too small, the saturation tolerance of the transformer 20 will be insufficient. If the width s of the air gap 250 is selected to be too large, the copper loss of the transformer 20 will increase. Therefore, the width s of the air gap 250 can be selected from the range [1.5 mm, 3.2 mm], i.e., 1.5 mm ≤ s ≤ 3.2 mm. In one example, the width s may be 1.5 mm, 1.7 mm, 1.8 mm, 2.0 mm, 2.3 mm, 2.6 mm, 3.2 mm, or other values ​​between 1.5 mm and 3.2 mm.

[0164] Referring to Figure 15, in some embodiments, the height difference is 0.5 mm to 4 mm. In this way, by providing an appropriate height difference between the first winding surface 2221 and the second winding surface 2231, the height of the transformer 20 is reduced, the coupling coefficient of the transformer 20 is reduced, and thereby the hard switching characteristics of the IGBT when the transformer 20 is operating at low power are reduced.

[0165] Specifically, the height difference includes a first height difference k1 along the length direction of the radial cross-section of the insertion hole 221 and a second height difference k2 along the width direction of the radial cross-section of the insertion hole 221, and the first height difference k1 or the second height difference k2 may be present individually, and is not specifically limited thereto. That is, by setting the height of the first winding surface 2221 along the radial cross-section of the insertion hole 221 to be greater than the height of the second winding surface 2231 along the radial cross-section of the insertion hole 221, the amount of magnetic flux from the first coil 230 to the second coil 240 is reduced, thereby lowering the coupling coefficient between the first coil 230 and the second coil 240.

[0166] The height difference should be selected from an appropriate range in order to reduce the height of the transformer 20 while simultaneously decreasing the coupling coefficient of the transformer 20.

[0167] If the height difference is selected too small, the coupling coefficient of the transformer 20 cannot be effectively reduced. If the height difference is selected too large, the height of the transformer 20 increases, and the volume and space occupied by the transformer 20 increase.

[0168] In one embodiment, the first height difference k1 can be selected from the range [0.5 mm, 4 mm], i.e., 0.5 mm ≤ k1 ≤ 4 mm. In one example, the first height difference k1 may be 0.5 mm, 0.8 mm, 1.3 mm, 2.7 mm, 3.2 mm, 3.6 mm, 4 mm, or other values ​​between 0.5 mm and 4 mm.

[0169] The second altitude difference k2 is selected from the range [0.5 mm, 4 mm], i.e., 0.5 mm ≤ k2 ≤ 4 mm. In one example, the second altitude difference k2 may be 0.5 mm, 0.7 mm, 1.4 mm, 2.3 mm, 3.5 mm, 3.9 mm, 4 mm, or other values ​​between 0.5 mm and 4 mm.

[0170] Referring to Figure 13, the radial direction of the insertion hole 221 is parallel to the drawing. The axial direction of the insertion hole 221 is perpendicular to the drawing, and the circumferential direction of the insertion hole 221 is a rotational direction around the axial direction of the insertion hole 221 in a plane parallel to the drawing.

[0171] Referring to Figures 13 and 15, in some embodiments, the height difference exists over a 360-degree circumferential direction of the insertion hole 221.

[0172] Thus, the difference in height between the first winding surface 2221 and the second winding surface 2231 extends 360 degrees around the insertion hole 221, causing a difference in the winding heights of the first coil 230 and the second coil 240. This reduces the coupling coefficient between the first coil 230 and the second coil 240, thereby reducing the hard switching characteristics of the IGBT when the transformer 20 is operating at low power.

[0173] Specifically, referring to Figure 15, in one embodiment, the height of any point within a 360-degree circumferential direction of the insertion hole 221 of the first winding surface 2221 can be made greater than the height of any point within a 360-degree circumferential direction of the insertion hole 221 of the second winding surface 2231.

[0174] More specifically, the height of the first groove 222 where the first winding surface 2221 is located can be greater than the height of the second groove 223 where the second winding surface 2231 is located. That is, the first winding surface 2221 and the second winding surface 2231 have a height difference k1 in the radial direction of the insertion hole 221, and the first winding surface 2221 and the second winding surface 2231 have a height difference k2 in the axial direction of the insertion hole 221. As a result, there exists a leakage flux space between the first coil 230 and the first magnetic pole 2111 with additional spacing distances k1 and k2. In other words, the larger the spacing distances k1 and k2, the greater the leakage flux energy of the first coil 230, which reduces the amount of magnetic flux from the first coil 230 to the second coil 240. Consequently, the coupling coefficient between the first coil 230 and the second coil 240 in the transformer 20 decreases, thereby reducing the temperature rise of the power devices in the transformer 20. This reduces the hard switching characteristics of the IGBTs during low-power operation of the transformer 20 and improves the reliability of the transformer 20.

[0175] In another embodiment, the height of any point within a 360-degree circumferential direction of the insertion hole 221 of the first winding surface 2221 can be made smaller than the height of any point within a 360-degree circumferential direction of the insertion hole 221 of the second winding surface 2231.

[0176] More specifically, the height of the first groove 222 where the first winding surface 2221 is located can be smaller than the height of the second groove 223 where the second winding surface 2231 is located. That is, the first winding surface 2221 and the second winding surface 2231 have a height difference k1 in the radial direction of the insertion hole 221, and the first winding surface 2221 and the second winding surface 2231 have a height difference k2 in the axial direction of the insertion hole 221. As a result, there are leakage flux spaces of additional spacing distances k1 and k2 between the second coil 240 and the first magnetic pole 2111. In other words, the larger the spacing distances k1 and k2, the greater the leakage flux energy of the second coil 240, and the less magnetic flux is transmitted from the second coil 240 to the first coil 230. This reduces the coupling coefficient between the first coil 230 and the second coil 240 in the transformer 20, thereby reducing the temperature rise of the power devices in the transformer 20, which in turn reduces the hard switching characteristics of the IGBTs during low-power operation of the transformer 20 and improves the reliability of the transformer 20.

[0177] Referring to Figure 15, in some embodiments, the insertion hole 221 is flattened, the longitudinal direction of the radial cross-section of the insertion hole 221 is perpendicular to the height direction of the transformer 20, and the height difference includes a first height difference k1 along the longitudinal direction of the radial cross-section of the insertion hole 221 and a second height difference k2 along the width direction of the radial cross-section of the insertion hole 221, where the first height difference k1 is equal to the second height difference k2.

[0178] In this way, by providing a first height difference k1 and a second height difference k2, the height difference between the winding positions of the first coil 230 and the second coil 240 is increased, reducing the coupling coefficient between the first coil 230 and the second coil 240, thereby reducing the hard switching characteristics of the IGBT when the transformer 20 is operating at low power.

[0179] Specifically, the insertion hole 221 has a flattened shape, which reduces the height of the frame 220, and further reduces the height and volume of the transformer 20, thereby reducing the space occupied by the transformer 20.

[0180] In one embodiment, the height difference includes a first height difference k1 along the length direction of the radial cross-section of the insertion hole 221 and a second height difference k2 along the width direction of the radial cross-section of the insertion hole 221, increasing the height difference in the winding positions of the first coil 230 and the second coil 240, reducing the coupling coefficient between the first coil 230 and the second coil 240, and reducing the hard switching characteristics of the IGBT when the transformer 20 is operating at low power.

[0181] Furthermore, there is at least one type of altitude difference: either a first altitude difference k1 or a second altitude difference k2. That is, there may be only the first altitude difference k1, or only the second altitude difference k2, or both the first and second altitude differences k2 may exist simultaneously, and this is not specifically limited.

[0182] When a first altitude difference k1 and a second altitude difference k2 exist simultaneously, the possible values ​​of the first altitude difference k1 and the possible values ​​of the second altitude difference k2 may or may not be equal, and are not specifically limited to these values.

[0183] Referring to Figures 10 and 13, in some embodiments, the first magnetic column 2111 has a flattened shape that conforms to the shape of the insertion hole 221, and the longitudinal direction of the first magnetic column 2111 is aligned with the longitudinal direction of the magnetic core 211.

[0184] In this way, the first magnetic pole 2111 and the insertion hole 221 are fixed together by a flattened structure that fits together with each other, which reduces the height and volume of the transformer 20, and on the other hand, ensures a tight fit between the first magnetic pole 2111 and the insertion hole 221, providing the transformer 20 with a stable voltage conversion environment.

[0185] Specifically, referring to Figure 16, in the related technology, the magnetic core 60 in the transformer 200 includes a cylindrical magnetic column 61, which is in contact with both sides of the cylindrical magnetic column 61 and the magnetic core 60, and the cylindrical magnetic column 61 is located on the outermost side of the magnetic core 60. In the related technology, the diameter of the cylindrical magnetic column 61 of the magnetic core 60 is large, resulting in a large volume for the transformer 200. In the embodiment of the present application, the first magnetic column 2111 is flattened to reduce the height of the frame 220, and further reduces the height and volume of the transformer 20. In addition, the first magnetic column 2111 is flattened to ensure a tight fit with the flattened insertion hole 221, making it less prone to rattling.

[0186] In more detail, the first magnetic column 2111 has a flattened shape, which reduces the height of the magnetic core 211 and consequently reduces the effective cross-sectional area of ​​the magnetic core 211. This effectively reduces the maximum saturation magnetic flux density, improves the saturation resistance of the transformer 20, and enables the miniaturization of home appliances.

[0187] The flattening of the first magnetic column 2111 means that, in the height direction of the transformer 20 (as shown in Figure 10), the width d of the first magnetic column 2111 is smaller than the length L of the first magnetic column 2111, and the width d of the first magnetic column 2111 is aligned with the height direction of the transformer 20.

[0188] In one embodiment, the cross-sectional view of the magnetic core 211 includes the structural shape shown in Figure 10, but is not limited thereto. As shown in Figures 14a to 14o, the connection portion 2112 of the magnetic core 211 can have a rectangular, polygonal, or irregularly shaped cross-sectional view, and is not specifically limited thereto.

[0189] Referring to Figures 11 and 13, in some embodiments, the magnetic core 211 includes a connecting portion 2112 and a second magnetic column 2113, the connecting portion 2112 connecting the first magnetic column 2111 and the second magnetic column 2113, the second magnetic column 2113 is located outside the insertion hole 221, and the two second magnetic columns 2113 are spaced apart and facing each other outside the first groove 222.

[0190] In this way, the first magnetic columns 2111 of the two magnetic cores 211 are inserted into the insertion holes 221, and the connection part 2112 and the second magnetic columns 2113 form a Chinese character "kou" (mouth) shaped structure, and by surrounding the framework 220 together, the structural connection between the magnetic core 211 and the framework 220 becomes stronger.

[0191] Specifically, in one embodiment, the first magnetic column 2111 may be perpendicular to the connection part 2112, the second magnetic column 2113 may be perpendicular to the connection part 2112, and the first magnetic column 2111 and the second magnetic column 2113 are provided at an interval, so that the magnetic core 211 is inserted into and surrounds the framework 220 from the insertion hole 221 in the shape of a Chinese character "kou" (mouth), thereby ensuring that the structural connection between the magnetic core 211 and the framework 220 becomes stronger.

[0192] The connection part 2112 connects the first magnetic column 2111 and the second magnetic column 2113. The connection part 2112 may be a magnetic block, and the connection part 2112 can be used to support and stabilize the first magnetic column 2111 and the second magnetic column 2113. In one embodiment, the connection part 2112 can be in interference fit with the side wall of the framework 220 to further enhance the stability of the connection between the magnetic core 211 and the framework 220.

[0193] In one embodiment, both the first magnetic column 2111 and the insertion hole 221 can be in a flat structure, making the fitting between the first magnetic column 2111 and the insertion hole 221 tight and difficult to rattle.

[0194] Referring to FIGS. 9 and 10, in some embodiments, along the height direction of the transformer 20, the distance between the upper edge of the first magnetic column 2111 and the upper edge of the connection part 2112 is m, and m = (L / k - 1)*d, where k is between 5 and 20, L is the length of the first magnetic column 2111, and d is the width of the first magnetic column 2111.

[0195] Thus, by using the formula m=(L / k-1)*d to restrict the possible ranges of the length L, width d, and distance m of the first magnetic column 2111 in the magnetic core, it is possible to effectively reduce the saturation magnetic flux density without increasing the volume and cost of the transformer 20, and to achieve miniaturization of home appliances.

[0196] Specifically, the first magnetic pole 2111 is connected perpendicularly to the connection part 2112, and the height of the transformer 20 changes according to the possible values ​​of the width d of the first magnetic pole 2111.

[0197] If the width d of the first magnetic pole 2111 is selected to be too small, the effect of reducing the maximum saturation magnetic flux density will be insufficient. If the width d of the first magnetic pole 2111 is selected to be too large, the occupied volume of the transformer 20 will increase, thereby increasing costs.

[0198] In one embodiment, the width d of the first magnetic pole 2111 is selected from a range of 5 mm to 12 mm, i.e., 5 mm ≤ d ≤ 12 mm, in order to reduce the height of the transformer 20 while effectively reducing the maximum saturation magnetic flux density. In one example, the width d may be 5 mm, 6 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, or other values ​​between 5 mm and 12 mm.

[0199] The formula m=(L / k-1)*d is used to restrict the possible ranges of the length L, width d, and distance m of the first magnetic column 2111 in the magnetic core, thereby ensuring miniaturization of home appliances without increasing the volume and cost of the transformer 20.

[0200] In one embodiment, the length L of the first magnetic column 2111 of the magnetic core 211 may be 20 mm, the width d of the first magnetic column 2111 may be 8 mm, and the distance m between the upper edge of the first magnetic column 2111 and the upper edge of the connecting portion 2112 may be 10 mm. Based on the formula m = (L / k-1)*d, the value of k is 8.9. In one embodiment, the possible range of k may be [5, 20].

[0201] In some embodiments, the first magnetic column 2111 satisfies the condition that the ratio value of L / d is 2 to 40, where L is the length of the first magnetic column 2111 and d is the width of the first magnetic column 2111.

[0202] In this way, the ratio L / d of the length L of the first magnetic pole 2111 to the width d of the first magnetic pole 2111 ensures that the value of the width d of the first magnetic pole 2111 is kept within a small range, thereby effectively reducing the maximum saturation magnetic flux density and improving the safety performance of the transformer 20.

[0203] Specifically, the ratio L / d of the length L of the first magnetic column 2111 to the width d of the first magnetic column 2111 is selected from the range [2, 40], and by ensuring that the value of the width d of the first magnetic column 2111 is within a small range, the maximum saturation magnetic flux density is effectively reduced.

[0204] More specifically, theoretical alternating magnetic flux can induce an induced current in the conductor cross-section of the magnetic core 211. According to Lenz's law, the magnetic field that generates the induced current always opposes the change in the amount of magnetic flux that causes the induced current. As a result, the magnetic flux concentrates on the surface of the magnetic core 211, reducing the effective cross-sectional area of ​​the magnetic core 211. This phenomenon is also known as the skin effect of the magnetic core.

[0205] Furthermore, the power core 211 has hysteresis characteristics, and in areas of high magnetic flux density in the cross-section of the core 211, the corresponding permeability decreases. That is, when the core 211 is subjected to constant current excitation, the autowinding inductance value decreases, and the saturation resistance of the core 211 decreases.

[0206] In one embodiment, the skin effect of the magnetic core 211 can be reduced by decreasing the width d of the flattened cross-section of the magnetic core 211 while keeping the cross-sectional area of ​​the magnetic core 211 constant, and consequently, the maximum saturation magnetic flux density can be effectively reduced.

[0207] In one embodiment, the ratio L / d of the length L of the first magnetic column 2111 to the width d of the first magnetic column 2111 is selected from the range [2, 40], i.e., 2 ≤ L / d ≤ 40. In one example, the ratio of L / d may be 2, 7, 16, 23, 27, 34, 40, or other values ​​between 2 and 40.

[0208] Referring to Figures 8 and 9, in some embodiments, the frame 220 includes a second baffle 224, the second baffle 224 separating the first groove 222 and the second groove 223, and the thickness of the second baffle 224 is g, where g is 3.5 mm to 5 mm.

[0209] Thus, on the one hand, the second baffle 224 separates the first coil 230 and the second coil 240, reducing potential safety hazards, while on the other hand, the frame 220 can adjust the leakage inductance and coupling coefficient of the transformer 20 by adjusting the thickness g of the second baffle 224.

[0210] Specifically, the second baffle 224 is provided between the first groove 222 and the second groove 223 on the outside of the hole wall of the insertion hole 221. By separating the first coil 230 and the second coil 240, the second baffle 224 prevents the first coil 230 and the second coil 240 from becoming entangled with each other, thereby reducing potential safety hazards.

[0211] In one embodiment, the second baffle 224 may be made of an insulating material, thereby improving the flame retardancy of the frame 220.

[0212] In one embodiment, the thickness g of the second baffle 224 is selected from the range of 3.5 mm to 5 mm. The frame 220 can adjust the leakage inductance and coupling coefficient of the transformer 20 by adjusting the thickness g of the second baffle 224. Specifically, the thickness g of the second baffle 224 is selected from the range of [3.5 mm, 5 mm], and as the thickness g of the second baffle 224 increases, the leakage inductance of the transformer 20 increases and the coupling coefficient between the first coil 230 and the second coil 240 decreases, and as the thickness g of the second baffle 224 decreases, the leakage inductance of the transformer 20 decreases and the coupling coefficient between the first coil 230 and the second coil 240 increases.

[0213] The thickness g is selected from the range of 3.5 mm to 5 mm, i.e., 3.5 mm ≤ g ≤ 5 mm. In one example, the thickness g may be 3.5 mm, 3.7 mm, 3.8 mm, 4.0 mm, 4.3 mm, 4.6 mm, 5 mm, or any other value between 3.5 mm and 5 mm.

[0214] Embodiments of the present invention further provide a home appliance. The home appliance includes a transformer 20 according to any of the embodiments described above.

[0215] In the above-mentioned home appliance, the first coil 230 is wound around the first winding surface 2221, and the second coil 240 is wound around the second winding surface 2231. Since the first winding surface 2221 and the second winding surface 2231 have a difference in height in the radial direction of the insertion hole 221, the first coil 230 and the second coil 240 employ a misaligned winding method, which reduces the coupling coefficient and reduces the hard switching characteristics of the IGBT at low power, thereby enabling it to be used in low-power applications.

[0216] The above description of the embodiment of the transformer 20 and its beneficial effects also applies to the home appliance of the embodiment of this application, and to avoid duplication, a detailed explanation is omitted here.

[0217] Home appliances include, but are not limited to, microwave ovens, oven ranges, air conditioners, and dishwashers. Home appliances are widely used for food preparation, dishwashing, and other related applications.

[0218] In this specification, any reference to the terms “one embodiment,” “several embodiments,” “some embodiments,” “exemplary embodiment,” “example,” “specific example,” or “several examples” means that the specific features, structures, materials, or properties described in the embodiments or examples are included in at least one embodiment or example of this disclosure. The exemplary expressions of the above terms in this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or properties described may be combined in an appropriate manner in any one or more embodiments or examples.

[0219] Although embodiments of this application have been shown and described, these embodiments are illustrative and should not be understood as limiting the application. Those skilled in the art will understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of this application, and the scope of this application is limited by the claims and their equivalents. [Explanation of Symbols]

[0220] Microwave generator-1000, circuit board-100, board-10, transformer-20, voltage doubler rectifier capacitor-30, discharge resistor-40, bus capacitor-50, differential mode inductor-60, heat sink-70, screw-80, power device-90, frame piece-21, primary winding-22, secondary winding-23, first baffle-24, lead frame-25, recess-26, heat sink fin-71, Resonant capacitor - 91, housing space - 92, magnetic core structure - 210, skeleton - 220, first coil - 230, second coil - 240, air gap - 250, magnetic core - 211, insertion hole - 221, first groove - 222, second groove - 223, second baffle - 224, first magnetic column - 2111, connection part - 2112, second magnetic column - 2113, first winding surface - 2221, second winding surface - 2231.

Claims

1. A circuit board used in a microwave generator, wherein the circuit board is Includes a circuit board, transformer, and voltage doubler rectifier capacitor, The transformer is provided on the circuit board. The circuit board is characterized in that the voltage-doubler rectifier capacitor is provided between the substrate and the transformer.

2. The transformer includes a skeletal structure, The circuit board according to claim 1, characterized in that the voltage doubler rectifier capacitor is provided between the skeletal piece and the substrate.

3. The transformer includes a first baffle, The circuit board according to claim 2, wherein the first baffle is provided at one end of the skeletal piece, and the first baffle is used to limit the movable space of a portion of the voltage doubler rectifier capacitor in the horizontal direction of the circuit board.

4. The circuit board according to claim 1, wherein the transformer comprises a lead frame, the circuit board further includes a discharge resistor, the discharge resistor is provided between the lead frames, and the lead frames are used to restrict the position of the discharge resistor.

5. The circuit board includes a bus capacitor and a differential mode inductor. The circuit board according to claim 1, characterized in that the bus capacitor is provided between the differential mode inductor and the transformer, and the differential mode inductor and the bus capacitor are arranged sequentially on the substrate.

6. The circuit board includes a heat sink and a resonant capacitor. The heat sink is provided at a position away from the center of the circuit board. The circuit board according to claim 1, wherein the resonant capacitor is provided between a part of the heat sink and the substrate, and the heat sink is used to lower the temperature of the resonant capacitor.

7. The circuit board according to claim 6, wherein the circuit board includes a power device, and the power device is detachably connected to the side of the heat sink.

8. The circuit board according to claim 6, characterized in that the heat sink includes a plurality of heat dissipation fins, and the plurality of heat dissipation fins are used to increase the contact area with air.

9. The circuit board includes at least two voltage doubler rectifier capacitors, The circuit board according to claim 1, characterized in that at least two of the voltage doubler rectifier capacitors are provided symmetrically along the length of the circuit board.

10. The transformer includes a magnetic core structure, a frame, a first coil, and a second coil. The aforementioned magnetic core structure includes two magnetic cores, each of which comprises a first magnetic column, the first magnetic column being flattened, and the longitudinal direction of the first magnetic column being aligned with the longitudinal direction of the magnetic core. An insertion hole is provided in the frame, the insertion hole conforms to the shape of the first magnetic column, a first groove and a second groove are provided on the outside of the hole wall of the insertion hole at spaced intervals, at least a portion of the first magnetic column is located inside the insertion hole, and the two first magnetic columns are provided facing each other at a distance apart. The first coil is wound around the outside of the hole wall of the insertion hole and is located in the first groove. The circuit board according to claim 1, characterized in that the second coil is wound around the outside of the hole wall of the insertion hole and is located in the second groove.

11. The circuit board according to claim 10, characterized in that the first magnetic column satisfies the condition that L / d is 2 to 40, where L is the length of the first magnetic column and d is the width of the first magnetic column.

12. The circuit board according to claim 11, characterized in that d is 5 mm to 12 mm.

13. The transformer includes a magnetic core structure, a frame, a first coil, and a second coil. The aforementioned magnetic core structure includes two magnetic cores, each of which comprises a first magnetic column. An insertion hole is provided in the frame, the insertion hole conforms to the shape of the first magnetic column, a first groove and a second groove are provided on the outside of the hole wall of the insertion hole at spaced apart, at least a portion of the first magnetic column is located inside the insertion hole, the two first magnetic columns are provided facing each other at spaced apart, the bottom surface of the first groove is the surface of the first winding, the bottom surface of the second groove is the surface of the second winding, and the first winding surface and the second winding surface have a difference in height in the radial direction of the insertion hole. The first coil is wound around the surface of the first winding and is located in the first groove. The circuit board according to any one of claims 1 to 12, characterized in that the second coil is wound around the surface of the second winding and located in the second groove.

14. The circuit board according to claim 13, characterized in that the height difference is 0.5 mm to 4 mm.

15. It includes a magnetic core structure, a frame, a first coil and a second coil, The aforementioned magnetic core structure includes two magnetic cores, each of which comprises a first magnetic column, the first magnetic column being flattened, and the longitudinal direction of the first magnetic column being aligned with the longitudinal direction of the magnetic core. An insertion hole is provided in the frame, the insertion hole conforms to the shape of the first magnetic column, a first groove and a second groove are provided on the outside of the hole wall of the insertion hole at spaced intervals, at least a portion of the first magnetic column is located inside the insertion hole, and the two first magnetic columns are provided facing each other at a distance apart. The first coil is wound around the outside of the hole wall of the insertion hole and is located in the first groove. A transformer characterized in that the second coil is wound around the outside of the hole wall of the insertion hole and is located within the second groove.

16. The transformer according to claim 15, characterized in that the first coil is a primary coil, the second coil is a secondary coil, the two first magnetic poles are spaced apart and facing each other, an air gap is formed, and the air gap is provided close to the first coil.

17. The transformer according to claim 16, characterized in that the width of the air gap is 1.5 mm to 3.2 mm.

18. The transformer according to any one of claims 15 to 17, characterized in that the bottom surface of the first groove is the surface of the first winding, the bottom surface of the second groove is the surface of the second winding, and the first winding surface and the second winding surface have a difference in height along the radial direction of the insertion hole.

19. It includes a magnetic core structure, a frame, a first coil and a second coil, The aforementioned magnetic core structure includes two magnetic cores, each of which comprises a first magnetic column. An insertion hole is provided in the frame, the insertion hole conforms to the shape of the first magnetic column, a first groove and a second groove are provided on the outside of the hole wall of the insertion hole at spaced apart, at least a portion of the first magnetic column is located inside the insertion hole, the two first magnetic columns are provided facing each other at spaced apart, the bottom surface of the first groove is the surface of the first winding, the bottom surface of the second groove is the surface of the second winding, and the first winding surface and the second winding surface have a difference in height in the radial direction of the insertion hole. The first coil is wound around the surface of the first winding and is located in the first groove. A transformer characterized in that the second coil is wound around the surface of the second winding and is located within the second groove.

20. The transformer according to claim 19, characterized in that the aforementioned height difference is 0.5 mm to 4 mm.

21. The transformer according to claim 19, characterized in that the height difference exists over 360 degrees in the circumferential direction of the insertion hole.

22. The transformer according to claim 19, characterized in that the insertion hole is flattened, the length direction of the radial cross-section of the insertion hole is perpendicular to the height direction of the transformer, the height difference includes a first height difference along the length direction of the radial cross-section of the insertion hole and a second height difference along the width direction of the radial cross-section of the insertion hole, and the first height difference is equal to the second height difference.

23. The transformer according to claim 15 or 19, characterized in that the first magnetic column has a flattened shape that conforms to the shape of the insertion hole, and the length direction of the first magnetic column is along the length direction of the magnetic core.

24. The transformer according to claim 15 or 19, characterized in that the magnetic core includes a connecting portion and a second magnetic column, the connecting portion connects the first magnetic column and the second magnetic column, the second magnetic column is located outside the insertion hole, and the two second magnetic columns are provided on the outside of the first groove, spaced apart and facing each other.

25. The transformer according to 24, characterized in that, along the height direction of the transformer, the distance between the upper edge of the first magnetic pole and the upper edge of the connection part is m, where m = (L / k-1) * d, where k is 5 to 20, L is the length of the first magnetic pole, and d is the width of the first magnetic pole.

26. The transformer according to claim 15 or 19, characterized in that the first magnetic pole satisfies the condition that the ratio value of L / d is 2 to 40, where L is the length of the first magnetic pole and d is the width of the first magnetic pole.

27. The transformer according to claim 25, characterized in that d is 5 mm to 12 mm.

28. The transformer according to claim 15 or 19, characterized in that the frame includes a second baffle, the second baffle separates the first groove and the second groove, and the thickness of the second baffle is g, where g is 3.5 mm to 5 mm.

29. A microwave generator characterized by including a circuit board according to claim 1, or a transformer according to claim 15 or 19.

30. A home appliance characterized by including a circuit board according to claim 1, or a transformer according to claim 15 or 19.

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