Electromagnetic cooking utensil

Abstract

The electromagnetic cooking utensil comprises a base, an electromagnetic wire coil arranged in the base and a circuit board located below the electromagnetic wire coil, and the projection of the electromagnetic wire coil on the horizontal plane and the projection of the circuit board on the horizontal plane are at least partially overlapped. The electromagnetic wire coil comprises a wire coil frame, a coil wound on the wire coil frame and a plurality of magnetic conductive strips located below the coil, a first filter capacitor is arranged on the circuit board, and part of the magnetic conductive strips are located above the first filter capacitor so as to cover at least part of the area of the first filter capacitor. Part of the magnetic conductive strip is located above the first filter capacitor and covers at least part of the area of the first filter capacitor, so that a high-frequency electromagnetic field generated by the electromagnetic wire coil can be effectively shielded, the probability that electromagnetic interference directly acts on the first filter capacitor and related circuits thereof is reduced, the working environment of the first filter capacitor is more stable, and the filtering effect is improved. Therefore, the overall electromagnetic compatibility of the electromagnetic cooking utensil is improved.

Description

Technical Field

[0001] This application belongs to the field of kitchen utensil technology, specifically relating to an electromagnetic cooking appliance. Background Technology

[0002] Electromagnetic cooking appliances, such as induction cookers, induction rice cookers, and induction pressure cookers, work by using high-frequency alternating current to induce eddy currents in the cookware through an electromagnetic coil, thereby heating the cookware. During operation, these appliances generate electromagnetic interference. This interference can affect the normal operation of other electronic components inside the induction cooker through electromagnetic field coupling, and can also interfere with other appliances by entering the external power grid. The negative impact of this electromagnetic interference is particularly pronounced during the operation of high-power electromagnetic cooking appliances.

[0003] To ensure that electromagnetic cooking appliances meet electromagnetic compatibility requirements and improve their electromagnetic interference immunity, existing technologies generally employ measures such as changing the number of turns of the electromagnetic coil, changing the differential mode inductance, or changing the size of the resonant capacitor. However, these measures have minimal improvement effects and can lead to an increase in the overall cost of the electromagnetic cooking appliance.

[0004] Existing technology discloses an induction cooker, including a base, a circuit board mounted on the base, and a coil plate mounted on the base. A choke coil and at least two capacitors are mounted on the circuit board, with at least one of the choke coil and capacitors located on the edge of the circuit board away from the coil plate. This induction cooker achieves electromagnetic compatibility requirements by adjusting the placement of the choke coil and capacitors on the circuit board; however, it has the disadvantage of increasing the footprint of the circuit board on the base, increasing the size of the induction cooker, and hindering the miniaturization of the entire unit. Utility Model Content

[0005] This application provides an electromagnetic cooking appliance to solve the technical problems of high cost and poor effectiveness of existing electromagnetic cooking appliances for improving electromagnetic compatibility.

[0006] The technical solution adopted in this application is as follows:

[0007] An electromagnetic cooking appliance includes a base, an electromagnetic coil disposed within the base, and a circuit board located below the electromagnetic coil. The projection of the electromagnetic coil on a horizontal plane at least partially overlaps with the projection of the circuit board on a horizontal plane. The electromagnetic coil includes a coil frame, a coil wound around the coil frame, and a plurality of magnetic strips located below the coil. The circuit board is provided with a first filter capacitor, and some of the magnetic strips are located above the first filter capacitor to cover at least a portion of the first filter capacitor.

[0008] The magnetic strips in this application can more effectively gather and guide magnetic lines of force, allowing them to pass more concentratedly through the bottom of the cookware, reducing magnetic field leakage and minimizing interference to other electronic components in the base during the operation of the electromagnetic coil. The fact that part of the magnetic strip is located above the first filter capacitor and covers at least a portion of it effectively shields the high-frequency electromagnetic field generated by the electromagnetic coil, reducing the probability of electromagnetic interference directly affecting the first filter capacitor and its related circuitry. This makes the working environment of the first filter capacitor more stable, improves the filtering effect, and thus enhances the overall electromagnetic compatibility of the electromagnetic cooking appliance.

[0009] Furthermore, during the operation of the electromagnetic coil, the magnetic strip can absorb some heat. The relative positional relationship between the magnetic strip and the first filter capacitor in this application can provide a certain degree of heat insulation protection for the first filter capacitor, thereby helping to reduce the operating temperature of the first filter capacitor, extend its service life, and improve the stability and reliability of the electromagnetic cooking appliance.

[0010] Furthermore, by rationally arranging the magnetic strip and the first filter capacitor in space, this application can make full use of the limited space inside the base, which helps to achieve the miniaturization of the entire electromagnetic cooking appliance.

[0011] The circuit board is provided with a second filter capacitor, and part of the magnetic strip is located above the second filter capacitor to cover at least a portion of the second filter capacitor.

[0012] The magnetic strip effectively shields the high-frequency electromagnetic field generated by the electromagnetic coil. This technical solution, by covering the magnetic strip, reduces the impact of electromagnetic interference on the second filter capacitor, ensuring its stable operation and thus improving the electromagnetic compatibility of the electromagnetic cooking appliance. Electromagnetic cooking appliances generate a large amount of heat during operation, especially in the area near the coil and magnetic strip. This technical solution, by covering the second filter capacitor with the magnetic strip, provides a certain degree of heat insulation, preventing the second filter capacitor from aging or degrading due to high temperatures. This helps extend the lifespan of the second filter capacitor and improves the stability and reliability of the electromagnetic cooking appliance.

[0013] The first filter capacitor and the second filter capacitor are arranged at intervals on the circuit board.

[0014] This technical solution arranges the first and second filter capacitors alternately on the circuit board, which effectively reduces electromagnetic interference between the first and second filter capacitors and to other surrounding electronic components, thus improving the electromagnetic compatibility of the entire electromagnetic cooking appliance. Furthermore, in high-frequency circuits, signals are prone to crosstalk between different components through electromagnetic field coupling. This technical solution, by arranging the first and second filter capacitors alternately, increases the distance between them, reducing the mutual influence of electromagnetic fields, thereby reducing the possibility of signal crosstalk, ensuring signal purity and accuracy, and guaranteeing the stable operation of the electromagnetic cooking appliance.

[0015] Furthermore, during the operation of electromagnetic cooking appliances, both the first and second filter capacitors generate heat due to the current passing through them. If the two are arranged too closely, the heat is prone to accumulate, leading to excessively high local temperatures, which affects their respective performance and lifespan, and may even cause malfunctions. Arranging them alternately can make the heat dissipate more evenly, avoid local overheating, help maintain the first and second filter capacitors working within a suitable temperature range, and improve the stability and reliability of electromagnetic cooking appliances.

[0016] Furthermore, arranging the first and second filter capacitors alternately provides more flexibility in the arrangement of heat dissipation measures. For example, heat dissipation components such as heat sinks can be added between the first and second filter capacitors, or the heat dissipation wiring design of the circuit board can be optimized to further improve heat dissipation efficiency and ensure that the temperature of key electronic components can be effectively controlled when the electromagnetic cooking appliance operates at high power for a long time.

[0017] The magnetic strip capable of covering at least a portion of the first filter capacitor is elongated, fan-shaped, or trapezoidal.

[0018] This technical solution, through the rational design of the magnetic strip shape, can further reduce the impact of electromagnetic interference on the first filter capacitor. Furthermore, different shaped magnetic strips can be optimally arranged according to the internal structure of the electromagnetic cooking appliance. For example, fan-shaped or trapezoidal magnetic strips can better fit the shape of the coil holder, making full use of limited space and achieving a compact design. Moreover, different magnetic strip shapes can improve heat dissipation performance; for example, elongated or trapezoidal magnetic strips facilitate heat dissipation, thereby reducing the operating temperature of the first filter capacitor and extending its service life.

[0019] There are multiple first filter capacitors arranged side by side; the magnetic strip extends to the outer periphery of the coil frame so that one magnetic strip covers at least a portion of the area of ​​two first filter capacitors.

[0020] In this technical solution, arranging multiple first filter capacitors side by side can achieve a wider frequency band filtering effect. Covering multiple first filter capacitors with a single magnetic strip can further reduce electromagnetic interference and ensure more stable filtering performance of the first filter capacitors. Moreover, covering multiple first filter capacitors with a single magnetic strip can make full use of the internal space of the electromagnetic cooking appliance, avoiding additional shielding measures or complex heat dissipation designs. This compact design contributes to the miniaturization of electromagnetic cooking appliances.

[0021] The circuit board is also equipped with a rectifier bridge, with one end of the first filter capacitor electrically connected to the power grid and the other end electrically connected to the input terminal of the rectifier bridge.

[0022] The mains input for electromagnetic cooking appliances is typically 220V AC. One end of the first filter capacitor is connected to the mains power grid. This first filter capacitor filters out high-frequency noise and interference from the mains, preventing these interference signals from affecting the normal operation of the internal circuitry of the electromagnetic cooking appliance. It also prevents high-frequency signals generated during the operation of the electromagnetic cooking appliance from entering the mains and interfering with other appliances. The rectifier bridge efficiently converts AC to DC. Using full-wave rectification, the rectifier bridge fully utilizes both the positive and negative half-cycles of the AC power, resulting in higher efficiency and lower power loss compared to half-wave rectification. The combination of the first filter capacitor and the rectifier bridge effectively reduces high-frequency noise and ripple in the mains power grid, lowers electromagnetic interference, and improves the electromagnetic compatibility of the electromagnetic cooking appliance. Furthermore, by adjusting the capacitance of the first filter capacitor and the parameters of the rectifier bridge, the output voltage and current can be flexibly adjusted to adapt to the operating requirements of the electromagnetic cooking appliance at different power levels.

[0023] The circuit board is also provided with a second filter capacitor, a third filter capacitor, an inductor, an IGBT, and a resonant capacitor. The third filter capacitor is electrically connected to the output terminal of the rectifier bridge. One end of the second filter capacitor is electrically connected to the inductor and the other end is grounded. The resonant capacitor and the coil form a resonant circuit. One end of the resonant circuit is electrically connected to the second filter capacitor and the other end is electrically connected to the collector of the IGBT.

[0024] This technical solution connects the third filter capacitor to the output of the rectifier bridge, effectively smoothing the pulsating DC voltage after rectification, reducing ripple, and providing a more stable DC power supply for subsequent circuits. The second filter capacitor, in conjunction with an inductor, forms an LC filter circuit, further reducing ripple and high-frequency noise in the power grid, ensuring a cleaner input voltage for the IGBT and coil. The resonant capacitor and coil form a resonant circuit, generating high-frequency current, effectively improving the heating efficiency of the electromagnetic cooking appliance and reducing power loss. The resonant circuit, in conjunction with the IGBT, enables stable switching control and power regulation through IGBT switching control, while reducing the risk of overvoltage and overcurrent.

[0025] The circuit board also includes a second filter capacitor, a third filter capacitor, an IGBT, a heat sink, and a resonant capacitor. The circuit board has a first mounting area for the first filter capacitor, the second filter capacitor, the third filter capacitor, and the resonant capacitor, and a second mounting area for the IGBT and the heat sink. The base has a first heat dissipation area opposite to the first mounting area and a second heat dissipation area opposite to the second mounting area. Both the first and second heat dissipation areas have a plurality of heat dissipation holes. The base includes a first perimeter and a second perimeter that are perpendicular to each other. The first heat dissipation area is located on the first perimeter, and the second heat dissipation area is located on the second perimeter.

[0026] This technical solution centrally arranges the first, second, and third filter capacitors in the first mounting area, facilitating circuit design and maintenance while reducing electromagnetic interference. The IGBT and heatsink are placed in the second mounting area; the heatsink quickly absorbs the heat generated during IGBT operation and dissipates it through ventilation holes, ensuring stable IGBT temperature during high-power operation. Separating the first and second mounting areas and designating corresponding heat dissipation zones allows for targeted optimization of heat dissipation. Ventilation holes on the mutually perpendicular first and second perimeter edges better guide airflow, further improving heat dissipation efficiency.

[0027] The base is equipped with a first fan and a second fan. The air outlet of the first fan is directly facing the first heat dissipation area, and the air outlet of the second fan is directly facing the second heat dissipation area. The air outlet direction of the first fan is perpendicular to the air outlet direction of the second fan.

[0028] In this technical solution, the air outlet of the first fan faces the first heat dissipation area, and the air outlet of the second fan faces the second heat dissipation area, thereby achieving zoned heat dissipation and targeted cooling of key electronic components to avoid heat concentration. The air outlet directions of the first and second fans are perpendicular, which reduces airflow interference between the two fans, ensuring uniform airflow distribution, preventing localized overheating, reducing airflow resistance, improving airflow utilization, and avoiding noise escalation caused by airflow conflict.

[0029] The electromagnetic cooking appliance also includes a panel with a recessed area for placing cookware, and the electromagnetic coil is a concave electromagnetic coil.

[0030] In this technical solution, the concave electromagnetic coil matches the shape of the bottom of the cookware, allowing for a closer fit, reducing heat loss, and improving thermal efficiency. Furthermore, the concave electromagnetic coil design creates a three-dimensional heating space, resulting in a more uniform distribution of the electromagnetic field, making it particularly suitable for high-power cooking. For high-power cooking, electromagnetic compatibility (EMC) issues during coil operation require special attention. This technical solution effectively addresses EMC problems through the design of the relative positional relationship between the magnetic strip and the first filter capacitor. Moreover, the three-dimensional design of the concave electromagnetic coil increases the distance between the first filter capacitor and the coil, further improving electromagnetic interference and enhancing the stability and reliability of the electromagnetic cooking appliance. Attached Figure Description

[0031] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0032] Figure 1 This is an exploded view of an electromagnetic cooking appliance according to one embodiment of this application;

[0033] Figure 2 This is a cross-sectional view of an electromagnetic cooking appliance according to one embodiment of this application;

[0034] Figure 3 This is a top view of the base according to one embodiment of this application;

[0035] Figure 4 This is a schematic diagram showing the relative positional relationship between the magnetic strip and the components inside the base in one embodiment of this application;

[0036] Figure 5 This is a perspective view of a circuit board according to one embodiment of this application;

[0037] Figure 6 This is a circuit diagram of an electromagnetic cooking appliance according to one embodiment of this application.

[0038] in,

[0039] 1. Panel;

[0040] 2. Electromagnetic coil; 21. Coil frame; 22. Coil; 23. Magnetic strip;

[0041] 3. Base; 31. First perimeter; 32. Second perimeter; 33. Ventilation holes;

[0042] 4. First fan;

[0043] 5. Second fan;

[0044] 6. Circuit board; 61. First filter capacitor; 62. Second filter capacitor; 63. Third filter capacitor; 64. Resonant capacitor; 65. Inductor; 66. Heat sink. Detailed Implementation

[0045] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.

[0046] Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below. It should be noted that, unless otherwise specified, the embodiments of this application and the features thereof can be combined with each other.

[0047] Furthermore, it should be understood in the description of this application that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0048] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0049] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0050] like Figure 2 , Figure 3 , Figure 4 As shown, an electromagnetic cooking appliance includes a base 3, an electromagnetic coil 2 disposed within the base 3, and a circuit board 6 located below the electromagnetic coil 2. The projection of the electromagnetic coil 2 on a horizontal plane at least partially overlaps with the projection of the circuit board 6 on a horizontal plane. The electromagnetic coil 2 includes a coil frame 21, a coil 22 wound around the coil frame 21, and a plurality of magnetic strips 23 located below the coil 22. A first filter capacitor 61 is provided on the circuit board 6, and some of the magnetic strips 23 are located above the first filter capacitor 61 to cover at least a portion of the first filter capacitor 61.

[0051] This application does not limit the type of electromagnetic cooking appliance, which may include induction cookers, induction rice cookers, induction pressure cookers, grills that use electromagnetic heating, etc.

[0052] In this application, the projection of the electromagnetic coil 2 on the horizontal plane overlaps at least partially with the projection of the circuit board 6 on the horizontal plane, which can make full use of the internal space of the base 3 and help to miniaturize the entire electromagnetic cooking appliance.

[0053] The magnetic strip 23 in this application can more effectively gather and guide magnetic lines of force, allowing them to pass more concentratedly through the bottom of the cookware, reducing magnetic field leakage and minimizing interference to other electronic components in the base 3 during the operation of the electromagnetic coil 2. Part of the magnetic strip 23 is located above the first filter capacitor 61 and covers at least a portion of it, effectively shielding the high-frequency electromagnetic field generated by the electromagnetic coil 2. This reduces the probability of electromagnetic interference directly affecting the first filter capacitor 61 and its related circuits, making the working environment of the first filter capacitor 61 more stable, improving the filtering effect, and thus enhancing the overall electromagnetic compatibility of the electromagnetic cooking appliance.

[0054] Moreover, during the operation of the electromagnetic coil 2, the magnetic strip 23 can absorb some heat. The relative positional relationship between the magnetic strip 23 and the first filter capacitor 61 in this application can play a certain role in heat insulation protection for the first filter capacitor 61, thereby helping to reduce the working temperature of the first filter capacitor 61, extend the service life of the first filter capacitor 61, and improve the stability and reliability of the electromagnetic cooking appliance.

[0055] Furthermore, by rationally arranging the magnetic strip 23 and the first filter capacitor 61 in space, this application can make full use of the limited space within the base 3, which helps to achieve the miniaturization of the entire electromagnetic cooking appliance.

[0056] As a preferred embodiment of this application, such as Figure 4 and Figure 5 As shown, a second filter capacitor 62 is provided on the circuit board 6, and a portion of the magnetic strip 23 is located above the second filter capacitor 62 to cover at least a portion of the second filter capacitor 62.

[0057] The magnetic strip 23 effectively shields the high-frequency electromagnetic field generated by the electromagnetic coil 2. This technical solution, through the shielding of the magnetic strip 23, reduces the impact of electromagnetic interference on the second filter capacitor 62, ensuring its stable operation and thus improving the electromagnetic compatibility of the electromagnetic cooking appliance. The electromagnetic cooking appliance generates a large amount of heat during operation, especially in the area near the coil 22 and the magnetic strip 23. This technical solution, by using the magnetic strip 23 to shield the second filter capacitor 62, provides a certain degree of heat insulation, preventing the second filter capacitor 62 from aging or degrading due to high temperatures. This helps extend the service life of the second filter capacitor 62 and improves the stability and reliability of the electromagnetic cooking appliance.

[0058] In order to uniformly guide the magnetic field lines generated by the energized coil 22 to the outer ring of the electromagnetic coil 22 disk, so that the magnetic field strength in the middle and outer ring of the electromagnetic coil 22 disk is basically the same, preferably, the multiple magnetic strips 23 are radially distributed on the coil frame 21.

[0059] In one embodiment, by designing the relative positions of the first filter capacitor 61 and the second filter capacitor 62, and by designing the shape of the magnetic strip 23 to increase the cross-sectional area of ​​the magnetic strip 23, the first filter capacitor 61 and the second filter capacitor 62 can be covered by the same magnetic strip 23.

[0060] In another embodiment, the projection of a single magnetic strip 23 in the horizontal plane is insufficient to simultaneously cover the first filter capacitor 61 and the second filter capacitor 62, that is, the first filter capacitor 61 and the second filter capacitor 62 are covered by different magnetic strips 23.

[0061] As a preferred embodiment of this application, such as Figure 3 and Figure 5 As shown, the first filter capacitor 61 and the second filter capacitor 62 are arranged at intervals on the circuit board 6. The term "interval arrangement" refers to the fact that there is a certain distance between the first filter capacitor 61 and the second filter capacitor 62. Arranging the first filter capacitor 61 and the second filter capacitor 62 at intervals on the circuit board 6 can effectively reduce electromagnetic interference between the first filter capacitor 61 and the second filter capacitor 62 and to other surrounding electronic components, thus improving the electromagnetic compatibility of the entire electromagnetic cooking appliance. Furthermore, in high-frequency circuits, signals are prone to crosstalk between different components through electromagnetic field coupling. This technical solution, by arranging the first filter capacitor 61 and the second filter capacitor 62 at intervals, increases the distance between them, reduces the mutual influence of electromagnetic fields, thereby reducing the possibility of signal crosstalk, ensuring signal purity and accuracy, and ensuring the stable operation of the electromagnetic cooking appliance.

[0062] Furthermore, during the operation of the electromagnetic cooking appliance, both the first filter capacitor 61 and the second filter capacitor 62 will generate heat due to the current passing through them. If the two are arranged too closely, the heat will easily accumulate, leading to excessively high local temperatures, which will affect their respective performance and lifespan, and may even cause malfunctions. Arranging them alternately can make the heat dissipate more evenly, avoid local overheating, and help maintain the first filter capacitor 61 and the second filter capacitor 62 working within a suitable temperature range, thereby improving the stability and reliability of the electromagnetic cooking appliance.

[0063] Furthermore, arranging the first filter capacitor 61 and the second filter capacitor 62 at intervals provides more flexibility in the arrangement of heat dissipation measures. For example, heat dissipation components such as heat sinks 66 can be added between the first filter capacitor 61 and the second filter capacitor 62, or the heat dissipation wiring design of the circuit board 6 can be optimized to further improve heat dissipation efficiency and ensure that the temperature of key electronic components can be effectively controlled when the electromagnetic cooking appliance operates at high power for a long time.

[0064] Preferably, the first filter capacitor 61 mainly functions as a filter in the circuit, used to filter out the noise impact of the power grid on the circuit, and to filter out the noise impact of the electromagnetic cooking appliance circuit on the power grid. The second filter capacitor 62 is a freewheeling capacitor. The function of the second filter capacitor 62 is to absorb the reverse electromotive force in the coil 22 to protect the power devices and maintain the continuity of the current. Part of the magnetic strip 23 can cover the freewheeling capacitor, which can further optimize the distribution of the electromagnetic field, make the working environment of the freewheeling capacitor more stable, thereby improving the freewheeling effect and ensuring that the electromagnetic cooking appliance can maintain a stable fire output even when the power supply is unstable.

[0065] The distance between electronic components on circuit board 6 affects the size of parasitic inductance 65 and parasitic capacitance. This embodiment arranges the filter capacitor and freewheeling capacitor alternately, reducing parasitic parameters between the first filter capacitor 61 and the freewheeling capacitor, thereby reducing the impact of these parasitic parameters on circuit performance. For example, smaller parasitic inductance 65 and capacitance help improve filtering effect, allowing the filter capacitor to more effectively filter out high-frequency noise. It also ensures more stable current and voltage changes during the freewheeling process, reducing voltage spikes and current fluctuations caused by parasitic parameters, and improving the overall performance of the electromagnetic cooking appliance. The first filter capacitor 61 filters out ripples and noise from the power grid, providing a more stable power supply to the power circuit of the electromagnetic cooking appliance. The freewheeling capacitor acts as a buffer and freewheeling element during the switching process of the power transistor switch (i.e., IGBT), reducing sudden current changes. The alternate arrangement of the first filter capacitor 61 and the freewheeling capacitor allows them to function better in the circuit with less mutual interference. Their combined effect further improves power quality, providing a better power guarantee for the normal operation of the electromagnetic cooking appliance.

[0066] Furthermore, such as Figure 3 , Figure 4 and Figure 5 As shown, the spaced arrangement of the first filter capacitor 61 and the freewheeling capacitor provides space for the arrangement of the inductor 65. That is, the inductor 65 is located between the first filter capacitor 61 and the freewheeling capacitor, which not only improves the space utilization of the circuit board 6, but also facilitates the wiring design of the electrical connection between the freewheeling capacitor and the inductor 65.

[0067] This application does not limit the shape design of the magnetic strip 23. The magnetic strip 23 that can cover at least a portion of the first filter capacitor 61 can be elongated, fan-shaped, or trapezoidal. By rationally designing the shape of the magnetic strip 23, the impact of electromagnetic interference on the first filter capacitor 61 can be further reduced. Moreover, different shapes of magnetic strips 23 can be optimized according to the internal structure of the electromagnetic cooking appliance. For example, fan-shaped or trapezoidal magnetic strips 23 can better fit the shape of the coil holder 21, making full use of limited space and achieving a compact design. Furthermore, different shapes of magnetic strips 23 can improve their heat dissipation performance. For example, elongated or trapezoidal magnetic strips 23 are conducive to heat dissipation, thereby reducing the operating temperature of the first filter capacitor 61 and extending its service life. Of course, the magnetic strip 23 used to cover the first filter capacitor 61 can also be designed in other shapes.

[0068] This application does not limit the number of the first filter capacitor 61, which can be any of the following embodiments:

[0069] Implementation Method 1: This implementation method is not illustrated. In this implementation method, there is one first filter capacitor.

[0070] Implementation Method Two: (e.g.) Figure 3 , Figure 4 and Figure 5 As shown, there are multiple first filter capacitors 61 arranged side by side. A magnetic strip 23 extends to the outer periphery of the coil frame 21, so that one magnetic strip 23 covers at least a portion of the area of ​​two first filter capacitors 61. The side-by-side arrangement of multiple first filter capacitors 61 achieves a wider frequency band filtering effect. Covering multiple first filter capacitors 61 with a single magnetic strip 23 further reduces electromagnetic interference and ensures more stable filtering performance. Furthermore, covering multiple first filter capacitors 61 with a single magnetic strip 23 fully utilizes the internal space of the electromagnetic cooking appliance, avoiding additional shielding measures or complex heat dissipation designs. This compact design contributes to the miniaturization of electromagnetic cooking appliances. Figure 6 As shown, it provides a specific example of two first filter capacitors 61, namely C1 and C2.

[0071] like Figure 6As shown, the circuit board 6 is also equipped with a rectifier bridge DB1. One end of the first filter capacitor 61 is electrically connected to the power grid, and the other end is electrically connected to the input terminal of the rectifier bridge DB1.

[0072] The mains input of electromagnetic cooking appliances is typically 220V AC. One end of the first filter capacitor 61 is electrically connected to the mains. This first filter capacitor 61 filters out high-frequency noise and interference from the mains, preventing these interference signals from affecting the normal operation of the internal circuitry of the electromagnetic cooking appliance. It also prevents high-frequency signals generated during the operation of the electromagnetic cooking appliance from entering the mains and interfering with other appliances. The rectifier bridge DB1 efficiently converts AC to DC. Utilizing full-wave rectification, the rectifier bridge DB1 fully utilizes both the positive and negative half-cycles of the AC power, resulting in higher efficiency and lower power loss compared to half-wave rectification. The combination of the first filter capacitor 61 and the rectifier bridge effectively reduces high-frequency noise and ripple in the mains, lowers electromagnetic interference, and improves the electromagnetic compatibility of the electromagnetic cooking appliance. Furthermore, by adjusting the capacitance of the first filter capacitor 61 and the parameters of the rectifier bridge DB1, the output voltage and current can be flexibly adjusted to meet the operating requirements of the electromagnetic cooking appliance at different power levels.

[0073] like Figure 6 As shown, a second filter capacitor 62 is also provided on circuit board 6 (i.e., Figure 6 In the circuit structure, C9), the third filter capacitor 63 (i.e. Figure 6 In the circuit structure, C8), inductor 65 (i.e. Figure 6 The circuit structure includes L1, IGBT, and resonant capacitor 64 (i.e., L1). Figure 6 In the circuit structure, C11), the third filter capacitor 63 and the rectifier bridge (i.e. Figure 6 The output terminal of DB1 in the circuit structure is electrically connected, and one end of the second filter capacitor 62 is connected to the inductor 65 (i.e. Figure 6 In the circuit structure, L1 is electrically connected at one end and grounded at the other. The resonant capacitor 64 is connected to the coil 22 (i.e., Figure 6 In the circuit structure, L2 forms a resonant circuit. One end of the resonant circuit is electrically connected to the second filter capacitor 62, and the other end is electrically connected to the collector of the IGBT. Connecting the third filter capacitor 63 to the output of the rectifier bridge DB1 can effectively smooth the pulsating DC voltage after rectification, reduce ripple, and provide a more stable DC power supply for subsequent circuits. The second filter capacitor 62 and inductor 65 form an LC filter circuit, which can further reduce ripple and high-frequency noise in the power grid, ensuring a cleaner input voltage for the IGBT and coil 22. The resonant capacitor 64 and coil 22 form a resonant circuit, thereby generating high-frequency current, effectively improving the heating efficiency of the electromagnetic cooking appliance, and reducing power loss. The resonant circuit, in conjunction with the IGBT, enables stable switching control and power regulation through IGBT switching control, while reducing the risk of overvoltage and overcurrent.

[0074] Preferably, the first filter capacitor 61 is filter capacitors C1 and C2. The first filter capacitor 61 mainly plays a filtering role in the circuit, used to filter out the noise impact of the power grid on the circuit, and to filter out the noise impact of the electromagnetic cooking appliance circuit on the power grid. The second filter capacitor 62 is a freewheeling capacitor C9, mainly used to absorb the reverse electromotive force in the coil 22 to protect the power devices and maintain the continuity of the current, and also has the function of filtering out noise in the circuit. The third filter capacitor 63 is a safety capacitor C8. The safety capacitor can effectively filter out high-frequency noise and ripple in the power grid, and through the filtering effect of the safety capacitor, the impact of electromagnetic interference on other electronic devices can be reduced, while improving the anti-interference capability of the electromagnetic cooking appliance itself.

[0075] The arrangement of the electronic components on the circuit board 6 in this application can adopt any of the following embodiments:

[0076] Implementation Method 3: This implementation method is not illustrated. In this implementation method, the first filter capacitor, the second filter capacitor, the third filter capacitor, the resonant capacitor, and the IGBT are located on the same side of the circuit board. A cooling fan for heat dissipation of the circuit board is provided inside the base, and heat dissipation holes are provided on the base near the IGBT.

[0077] Implementation Method Four: (e.g.) Figure 3 and Figure 4 As shown, the circuit board 6 is also provided with a second filter capacitor 62, a third filter capacitor 63, an IGBT, a heat sink 66, and a resonant capacitor 64; the circuit board 6 has a first mounting area for setting the first filter capacitor 61, the second filter capacitor 62, the third filter capacitor 63, and the resonant capacitor 64, and a second mounting area for setting the IGBT and the heat sink 66; the base 3 is provided with a first heat dissipation area opposite to the first mounting area and a second heat dissipation area opposite to the second mounting area, and both the first heat dissipation area and the second heat dissipation area are provided with a plurality of heat dissipation holes 33; the base 3 includes a first perimeter 31 and a second perimeter 32 that are perpendicular to each other, the first heat dissipation area is located on the first perimeter 31, and the second heat dissipation area is located on the second perimeter 32.

[0078] The shape of the heat dissipation hole 33 can be circular, elongated, triangular and / or other irregular structure.

[0079] In this fourth embodiment, the first filter capacitor 61, the second filter capacitor 62, and the third filter capacitor 63 are centrally arranged in the first mounting area, which facilitates circuit design and maintenance and reduces electromagnetic interference. The IGBT and heat sink 66 are arranged in the second mounting area. The heat sink 66 can quickly absorb the heat generated during IGBT operation and dissipate it through the heat dissipation holes 33, ensuring temperature stability of the IGBT during high-power operation. Dividing the first and second mounting areas into separate zones with corresponding heat dissipation areas allows for targeted optimization of heat dissipation. Heat dissipation holes 33 are provided on the mutually perpendicular first and second perimeter edges 31 and 32 to better guide airflow and further improve heat dissipation efficiency.

[0080] This fourth embodiment can employ any of the following embodiments to dissipate heat from the first mounting area and the second mounting area.

[0081] Example 1: This example 1 is not shown in the figure. In this example 1, a cooling fan is provided in the base. Part of the air outlet of the cooling fan faces the first mounting area and another part faces the second mounting area, so that the cooling fan can simultaneously cool the first mounting area and the second mounting area.

[0082] Example 2: As Figure 3 and Figure 4 As shown, the base 3 is equipped with a first fan 4 and a second fan 5. The air outlet of the first fan 4 faces the first heat dissipation area, and the air outlet of the second fan 5 faces the second heat dissipation area. The air outlet direction of the first fan 4 is perpendicular to that of the second fan 5. In this embodiment 2, the air outlet of the first fan 4 faces the first heat dissipation area, and the air outlet of the second fan 5 faces the second heat dissipation area, thereby achieving zoned heat dissipation and targeted cooling of key electronic components, avoiding heat concentration. The perpendicular air outlet directions of the first fan 4 and the second fan 5 reduce airflow interference between them, ensuring uniform airflow distribution, preventing localized overheating, reducing airflow resistance, improving airflow utilization, and avoiding noise escalation caused by airflow conflict.

[0083] The electromagnetic cooking appliance also includes a control panel 1. This application does not limit the shape of the control panel 1 and the electromagnetic coil 2, and any of the following embodiments can be adopted:

[0084] Implementation Method 5: This implementation method 5 is not illustrated. In this implementation method 5, the panel is a flat plate structure, and correspondingly, the electromagnetic coil is a flat electromagnetic coil.

[0085] Implementation method six: such as Figure 1 and Figure 2As shown, panel 1 has a recessed area for placing cookware, and the electromagnetic coil 2 is a concave electromagnetic coil 2. In this sixth embodiment, the concave electromagnetic coil 2 matches the shape of the bottom of the cookware, allowing it to fit more closely to the cookware, reducing heat loss and improving heat utilization efficiency. Moreover, the design of the concave electromagnetic coil 2 can form a three-dimensional heating space, making the electromagnetic field distribution more uniform, which is especially suitable for high-power cooking. For high-power cooking, the electromagnetic compatibility issue during the operation of the electromagnetic coil 2 needs special attention. This technical solution can effectively solve the electromagnetic compatibility problem through the design of the relative positional relationship between the magnetic strip 23 and the first filter capacitor 61. Furthermore, the three-dimensional design of the concave electromagnetic coil 2 can increase the distance between the first filter capacitor 61 and the coil 22, thereby further improving the electromagnetic interference effect and enhancing the stability and reliability of the electromagnetic cooking appliance.

[0086] For any parts not mentioned in this application, existing technologies may be used or referenced.

[0087] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0088] The above descriptions are merely embodiments of this application and are not intended to limit this application. The technical features or structures in the foregoing different embodiments can be arbitrarily combined to form other specific technical solutions as needed. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. An electromagnetic cooking appliance comprising a base, an electromagnetic coil disposed within the base, and a circuit board positioned below the electromagnetic coil, a projection of the electromagnetic coil onto a horizontal plane at least partially overlapping a projection of the circuit board onto the horizontal plane, the electromagnetic coil comprising a coil holder, a coil wound around the coil holder, and a plurality of magnetic flux guide strips positioned below the coil, characterized in that, The circuit board is provided with a first filter capacitor, and part of the magnetic conductive strips is located above the first filter capacitor to cover at least part of the area of the first filter capacitor.

2. The electromagnetic cooking appliance according to claim 1, characterized in that, The circuit board is provided with a second filter capacitor, and part of the magnetic conductive strips is located above the second filter capacitor to cover at least part of the area of the second filter capacitor.

3. The electromagnetic cooking appliance according to claim 2, characterized in that, The first filter capacitor and the second filter capacitor are arranged at intervals on the circuit board.

4. The electromagnetic cooking appliance according to claim 1, characterized in that, The magnetic conductive strips capable of covering at least part of the area of the first filter capacitor are in the shape of a long strip, a fan or a trapezoid.

5. The electromagnetic cooking appliance according to claim 1, characterized in that, There are multiple first filter capacitors, and the multiple first filter capacitors are arranged side by side; the magnetic conductive strips extend to the outer periphery of the coil holder, so that one magnetic conductive strip covers at least part of the area of at least two first filter capacitors.

6. The electromagnetic cooking appliance according to claim 1, characterized in that, The circuit board is further provided with a rectifier bridge, one end of the first filter capacitor is electrically connected to a power grid, and the other end is electrically connected to an input end of the rectifier bridge.

7. The electromagnetic cooking appliance according to claim 6, characterized in that, The circuit board is further provided with a second filter capacitor, a third filter capacitor, an inductor, an IGBT and a resonance capacitor, the third filter capacitor is electrically connected to an output end of the rectifier bridge, one end of the second filter capacitor is electrically connected to the inductor, and the other end is grounded, the resonance capacitor and the coil constitute a resonance circuit, one end of the resonance circuit is electrically connected to the second filter capacitor, and the other end is electrically connected to a collector of the IGBT.

8. The electromagnetic cooking appliance according to claim 1, characterized in that, The circuit board is further provided with a second filter capacitor, a third filter capacitor, an IGBT, a heat sink and a resonance capacitor; the circuit board has a first mounting area in which the first filter capacitor, the second filter capacitor, the third filter capacitor and the resonance capacitor are arranged, and a second mounting area in which the IGBT and the heat sink are arranged; the base is provided with a first heat dissipation area opposite to the position of the first mounting area, and a second heat dissipation area opposite to the position of the second mounting area; the first heat dissipation area and the second heat dissipation area are both provided with a plurality of heat dissipation holes; the base comprises a first surrounding edge and a second surrounding edge which are perpendicular to each other, the first heat dissipation area is arranged on the first surrounding edge, and the second heat dissipation area is arranged on the second surrounding edge.

9. The electromagnetic cooking appliance according to claim 8, characterized in that, The base is provided with a first fan and a second fan, an air outlet of the first fan is opposite to the first heat dissipation area, an air outlet of the second fan is opposite to the second heat dissipation area, and the air outlet direction of the first fan is perpendicular to the air outlet direction of the second fan.

10. The electromagnetic cooking appliance according to claim 1, wherein the electromagnetic cooking appliance further comprises a panel provided with a recessed area for placing a pot, and the electromagnetic coil disc is a recessed electromagnetic coil disc.

11. The electromagnetic cooking appliance according to claim 1, wherein the electromagnetic cooking appliance further comprises a panel provided with a recessed area for placing a pot, and the electromagnetic coil disc is a recessed electromagnetic coil disc.

12. The electromagnetic cooking appliance according to claim 1, wherein the electromagnetic cooking appliance further comprises a panel provided with a recessed area for placing a pot, and the electromagnetic coil disc is a recessed electromagnetic coil disc.

13. The electromagnetic cooking appliance according to claim 1, wherein

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