Magnetron and microwave appliance

Abstract

The application discloses a magnetron and a microwave electric appliance. The magnetron is used in the microwave electric appliance. The magnetron comprises a filament, a wire diameter of the filament is greater than or equal to 0.6 mm and less than or equal to 0.67 mm, and the filament is configured to have a current greater than or equal to 8 A when the microwave electric appliance works at an output power greater than or equal to 50 W. By setting the wire diameter of the magnetron filament to be between 0.6 mm and 0.67 mm, the wire diameter of the filament is increased compared with the wire diameter of the filament in the prior art, the resistance of the filament is reduced according to Ohm's law without changing the length and resistivity of the filament, the current of the magnetron is increased when the voltage remains unchanged, and therefore the stability of the microwave oven in microwave output can be improved.

Description

Technical Field

[0001] This invention relates to the field of microwave electrical appliance technology, and more specifically, to a magnetron and a microwave electrical appliance. Background Technology

[0002] Currently, the lowest power setting of a microwave oven is still too high for heating foods with shells, defrosting foods, and fermenting foods, requiring the oven to use even lower power. However, the power of a microwave oven is controlled by the current in the magnetron. Further reducing the power would result in insufficient current in the magnetron, thus reducing the stability of the microwave output. Summary of the Invention

[0003] The present invention provides a magnetron and microwave appliance that can solve or improve the technical problem of unstable microwave output in microwave ovens when operating at low power due to insufficient current in the magnetron.

[0004] An embodiment of the present invention provides a magnetron for use in a microwave appliance. The magnetron includes a filament with a wire diameter greater than or equal to 0.6 mm and less than or equal to 0.67 mm, and the filament is configured such that when the microwave appliance operates at an output power greater than or equal to 50 watts, the current of the filament is greater than or equal to 8 amps.

[0005] Thus, by setting the diameter of the magnetron filament to between 0.6 mm and 0.67 mm, the filament diameter is increased compared to that of existing technologies. Without changing the filament length and resistivity, Ohm's law reduces the filament resistance, thereby increasing the magnetron current while keeping the voltage constant, and thus improving the stability of microwave output in the microwave oven.

[0006] In some embodiments, the filament has a length of 10.5 mm to 13.8 mm.

[0007] In some embodiments, the outer diameter of the filament is 3.8 mm to 4.2 mm.

[0008] In some embodiments, the filament pitch is 1 mm to 1.32 mm.

[0009] In some embodiments, the magnetron includes an anode, a cathode, a first magnet, and a second magnet, the anode and the cathode being spaced apart and opposite each other, the cathode including a filament, and the anode, the filament, and the cathode being located between the first magnet and the second magnet.

[0010] In some embodiments, the anode is annular, and the cathode passes through a through-hole formed by the anode.

[0011] In some embodiments, the anode includes an anode cylinder and anode blades, the anode blades and the cathode are located in the anode cylinder, the anode blades are connected to the inner side of the anode cylinder, and a heat sink is connected to the outer side of the anode cylinder.

[0012] In some embodiments, the radiator includes a plurality of heat dissipation components arranged axially, each heat dissipation component including a cylindrical portion and a heat dissipation portion, the cylindrical portion being sleeved and connected to the anode cylinder, the heat dissipation portion being connected to the side of the cylindrical portion opposite to the anode cylinder, and the heat dissipation portion being bent.

[0013] In some embodiments, the magnetron includes a duct component with an air duct inside, and the anode, the cathode, the first magnet, the second magnet, and the heat sink are located in the air duct. One end of the heat sink is connected to the anode cylinder, and the other end of the heat sink is connected to the side wall of the duct component facing the air duct.

[0014] The microwave electrical appliance of the present invention includes the magnetron described in any of the above embodiments, and the frequency converter is electrically connected to the magnetron.

[0015] In some embodiments, the frequency converter includes a transformer, the transformer including a primary winding, a secondary winding and a filament winding, the secondary winding and the filament winding being magnetically coupled to the primary winding, the magnetron including an anode, the secondary winding being electrically connected to the anode, and the filament winding being electrically connected to the filament.

[0016] In some embodiments, the frequency converter includes a first insulated-gate bipolar transistor (IGBT), a second IGBT, a controller, a filter circuit, and a rectifier bridge. The first IGBT and the second IGBT are connected to the primary winding. The controller is configured to control the switching on and off of the first IGBT and the second IGBT to regulate the output power of the frequency converter. The filter circuit is used to maintain voltage stability in the frequency converter, and the rectifier bridge is used to convert the type of current input to the frequency converter.

[0017] The above embodiments provide a magnetron and microwave appliance in which the diameter of the magnetron filament is set to between 0.6 mm and 0.67 mm, which is larger than the filament diameter of the prior art. Without changing the filament length and resistivity, the resistance of the filament is reduced according to Ohm's law, thereby increasing the current of the magnetron while keeping the voltage constant, and thus improving the stability of microwave output in the microwave oven.

[0018] Additional aspects and advantages of embodiments of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of the invention. Attached Figure Description

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0020] Figure 1 This is a schematic diagram of the structure of a microwave appliance according to certain embodiments of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of a magnetron according to certain embodiments of the present invention;

[0022] Figure 3 This is a schematic diagram of the filament structure according to certain embodiments of the present invention;

[0023] Figure 4 This is a schematic diagram of the anode structure in some embodiments of the present invention;

[0024] Figure 5 This is a schematic diagram of the structure of a transformer according to certain embodiments of the present invention;

[0025] Figure 6 This is a circuit diagram of the inverter connecting to the magnetron in some embodiments of the present invention.

[0026] Explanation of icon numbers:

[0027] 100. Microwave electrical appliance; 10. Magnetron; 12. Anode; 121. Through hole; 122. Anode cylinder; 123. Anode blade; 13. Cathode; 131. Filament; 14. First magnet; 15. Second magnet; 17. Heat sink; 171. Heat sink component; 1711. Cylinder section; 1712. Heat sink part; 18. Air duct component; 181. Air duct; 20. Frequency converter; 21. Transformer; 211. Primary winding; 212. Secondary winding; 213. Filament winding; 22. First insulated gate bipolar transistor; 23. Second insulated gate bipolar transistor; 24. Controller; 25. Filter circuit; 26. Rectifier bridge. Detailed Implementation

[0028] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0029] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention 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 the invention. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, and they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] This disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described herein. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, examples of various specific processes and materials are provided, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0033] Please see Figure 1 , Figure 2 and Figure 3According to an embodiment of the present invention, a magnetron 10 is used in a microwave appliance 100. The magnetron 10 includes a filament 131 with a wire diameter of 0.6 mm to 0.67 mm. The filament 131 is configured such that when the microwave appliance 100 is operating at low output power, the current of the filament 131 is greater than or equal to 8 amps.

[0034] Thus, by setting the wire diameter of the filament 131 of the magnetron 10 to between 0.6 mm and 0.67 mm, the wire diameter of the filament 131 is increased compared to that of the prior art. Without changing the length and resistivity of the filament 131, Ohm's law makes the resistance of the filament 131 smaller, thereby increasing the current of the magnetron 10 while keeping the voltage constant, and thus improving the stability of microwave output in the microwave oven.

[0035] The microwave appliance 100 can be a device that generates microwave energy to heat food. For example, the microwave appliance 100 can be a microwave oven, a microwave-steam-grill combo, a microwave oven, an integrated stove, etc. The microwave appliance 100 includes a magnetron 10, which acts as a microwave generator. The magnetron 10 converts the direct current energy flowing through it into microwave energy oscillations. This microwave energy is then transmitted through a waveguide to the inner cavity of the oven. Upon encountering polar molecules in the food (such as water, fat, and protein), it vibrates at extremely high speeds, generating frictional heat and thus heating the food.

[0036] Specifically, the magnetron 10 includes a filament 131, which can be made of thorium-tungsten wire or pure tungsten wire. This improves the conductivity and high-temperature resistance of the filament 131. The filament 131 is spirally installed within the magnetron 10. This spiral shape helps increase the heating area of ​​the filament 131, improving heating efficiency and allowing the filament 131 to uniformly heat the components within the magnetron 10. Thus, when the magnetron 10 is in operation, current can flow through the filament 131, generating heat to heat other components within the magnetron 10.

[0037] like Figure 2 As shown, while keeping the length and outer diameter of the filament 131 in the magnetron 10 constant, increasing the wire diameter of the filament 131 will, according to the law of resistance, reduce its resistance because the resistivity and length of the filament 131 remain constant while the cross-sectional area increases. Furthermore, according to Ohm's law, the decrease in the resistance of the filament 131, under the same voltage, results in an increase in the current flowing through the filament 131.

[0038] The pitch N of the filament 131 can be set from 1 mm to 1.32 mm, so that when the voltage of the input magnetron 10 is 220 volts, the current flowing through the filament 131 can be controlled to be greater than or equal to 8 amps.

[0039] In some examples, such as Figure 3 As shown, the wire diameter D of filament 131 is 0.6 mm, 0.62 mm, 0.64 mm, 0.67 mm, 0.68 mm, or other values ​​between 0.6 mm and 0.67 mm. Thus, by setting the wire diameter of filament 131 to a value between 0.6 mm and 0.67 mm, the wire diameter of filament 131 is increased, and the resistance of filament 131 is decreased without changing other parameters of filament 131, thereby increasing the current to filament 131.

[0040] In some examples, such as Figure 3 As shown, the outer diameter M of the filament 131 is 3.8 mm, 3.9 mm, 4 mm, 4.1 mm, 4.2 mm, or other values ​​between 3.8 mm and 4.2 mm. Thus, by setting the outer diameter of the filament 131 to a value between 3.8 mm and 4.2 mm, the wire diameter of the filament 131 and the size of the through hole 121 can be adapted.

[0041] In some examples, such as Figure 3 As shown, the pitch N of filament 131 is 1 mm, 1.15 mm, 1.2 mm, 1.25 mm, 1.32 mm, or other values ​​between 1 mm and 1.32 mm. Thus, by setting the pitch of filament 131 to a value between 1 mm and 1.32 mm, the wire diameter of filament 131 and the size of through-hole 121 can be adapted.

[0042] In some examples, such as Figure 3 As shown, the length L of the filament 131 is 10.5 mm, 11 mm, 11.2 mm, 11.5 mm, 12 mm, 12.5 mm, 13.5 mm, 13.8 mm, or other values ​​between 10.5 mm and 13.8 mm. Thus, by setting the length of the filament 131 to a value between 10.5 mm and 13.8 mm, the wire diameter of the filament 131 and the size of the through-hole 121 can be adapted.

[0043] Please see Figure 2 In some embodiments, the magnetron 10 includes an anode 12, a cathode 13, a first magnet 14, and a second magnet 15. The anode 12 and the cathode 13 are spaced apart and opposite each other. A filament 131 is arranged around the cathode 13. The anode 12, the filament 131, and the cathode 13 are located between the first magnet 14 and the second magnet 15.

[0044] Specifically, the magnetron 10 includes an anode 12, a cathode 13, a first magnet 14, and a second magnet 15. The anode 12 can be made of a highly conductive metal, for example, oxygen-free copper. The cathode 13 can be made of a material with high conductivity, good oxidation resistance, and high thermal stability, for example, tungsten oxide, tungsten wire, or a thorium-tungsten alloy. The anode 12 and cathode 13 are spaced apart and form an interaction space.

[0045] exist Figure 2 In the illustrated embodiment, the first magnet 14 is the upper magnet, and the second magnet 15 is the lower magnet. Both the first magnet 14 and the second magnet 15 are electromagnets. In one embodiment, the first magnet 14 is a permanent magnet, and the second magnet 15 is an electromagnet. In another embodiment, the first magnet 14 is an electromagnet, and the second magnet 15 is a permanent magnet.

[0046] The working principle of magnetron 10 is as follows: When magnetron 10 is working, if... Figure 1 As shown, a DC voltage (such as several kilovolts) is applied between the cathode 13 and the anode 12. Simultaneously, the first magnet 14 and the second magnet 15 provide a magnetic field to the interaction space. The DC electric field and DC magnetic field within the interaction space are perpendicular to each other. Electrons emitted from the cathode 13 are accelerated by the electric field and deflected by the magnetic field, resulting in stable oscillating motion within the interaction space. The electron velocity is proportional to the ratio E / B, where E is the electric field strength and B is the magnetic flux density. The energy gained from the electric field in the interaction space by the electron stream emitted from the cathode 13 is transferred to a high-frequency field under certain conditions and output through an energy output window to form microwaves.

[0047] When the first magnet 14 and the second magnet 15 are electromagnets, a magnetic field can be provided by energizing the first magnet 14 and the second magnet 15 (which can be a constant voltage or constant current source). By adjusting the electrical signal parameters of the electromagnets (such as operating voltage or operating current), the central magnetic field of the magnetron 10 can be adjusted. In conjunction with adjusting the high voltage power supply of the magnetron 10, the output power of the magnetron 10 can be adjusted between zero and the maximum power (for example, if the maximum operating current of the electromagnet is I, the maximum central magnetic field is B, the electric field is E, and the maximum output power is mW, then the output power of the magnetron 10 can be adjusted between 0W and mW). The relationship between the electrical signal parameters of the electromagnet, the central magnetic field, the electric field, and the output power can be pre-calibrated and stored in the microwave cooking appliance through simulation, testing, etc. Correspondingly, the relationship between the electrical signal parameters of the electromagnet, the voltage of the anode 12, the current of the cathode 13, and the output power can also be pre-calibrated and stored in the microwave appliance 100 through simulation, testing, etc. By setting the output power of the magnetron 10, the combination of the electromagnet's electrical signal parameters, the voltage of the anode 12, and the current of the cathode 13 can be obtained through the above relationship, thus obtaining the output power of the set magnetron 10.

[0048] Please see Figure 4 In some embodiments, the anode 12 is annular, and the cathode 13 passes through the through hole 121 formed by the anode 12.

[0049] This can improve the working efficiency of the magnetron 10.

[0050] Specifically, the annular anode 12 has a through hole 121 in the middle, and the cathode 13 passes through the through hole 121, so that the cathode 13 is opposite to the anode 12 at 0 degrees in the circumferential direction. The relative area between the anode 12 and the cathode 13 is large. When the magnetron 10 is working, the cathode 13 can emit electrons at 0 degrees in the circumferential direction, so that the cathode 13 emits more electrons, which can improve the working efficiency of the magnetron 10.

[0051] Please refer to it again. Figure 2 In some embodiments, the anode 12 includes an anode cylinder 122 and an anode blade 123. The anode blade 123 and the cathode 13 are located in the anode cylinder 122. The anode blade 123 is connected to the inner side of the anode cylinder 122, and a heat sink 17 is connected to the outer side of the anode cylinder 122.

[0052] In this way, the magnetron 10 can be cooled, ensuring its working performance and extending its service life.

[0053] Specifically, because the magnetron 10 has a high output power and generates a lot of heat, the anode 12 will have a high temperature rise. The high temperature rise will seriously affect the working performance and service life of the magnetron 10. Therefore, it is necessary to cool down the magnetron 10.

[0054] The anode 12 includes an anode cylinder 122 and an anode blade 123. The anode cylinder 122 has a receiving cavity, allowing the anode blade 123 and cathode 13 to be mounted in the anode cylinder 122 and connected to the anode 12 via an insulating support. The anode cylinder 122 can also be connected to a heat sink 17. The heat from the anode 12 and cathode 13 can be transferred to the heat sink 17 for dissipation, ensuring the magnetron 10 operates within its normal temperature range, guaranteeing its performance, and extending its lifespan. The heat sink 17 can be air-cooled, water-cooled, or a combination of both; no specific limitation is made here.

[0055] The present invention does not specifically limit the material of the heat sink 17. In one example, the heat sink 17 may be made of copper, aluminum or aluminum alloy.

[0056] Please see Figure 2 In some embodiments, the radiator 17 includes a plurality of heat dissipation components 171 arranged along the axial direction. Each heat dissipation component 171 includes a cylindrical portion 1711 and a heat dissipation portion 1712. The cylindrical portion 1711 is sleeved and connected to the anode cylinder 122, and the heat dissipation portion 1712 is connected to the side of the cylindrical portion 1711 away from the anode cylinder 122. The heat dissipation portion 1712 is bent.

[0057] This increases the heat dissipation area of ​​the radiator 17.

[0058] Specifically, on the one hand, multiple heat dissipation components 171 can be arranged sequentially along the axial direction of the anode cylinder 122. Multiple cylindrical portions 1711 are sleeved on and connected to the anode cylinder 122 along its axial direction, such that a larger surface area of ​​the anode cylinder 122 is connected to the cylindrical portions 1711, increasing the heat transfer area between the anode cylinder 122 and the cylindrical portions 1711. Figure 1 In this design, the axial direction of the anode cylinder 122 is parallel to the axial direction of the cylinder portion 1711, and both the axial directions of the anode cylinder 122 and the cylinder portion 1711 are in the vertical direction. The number of heat dissipation components 171 is 5. It is understood that the present invention does not specifically limit the number of heat dissipation components 171.

[0059] On the other hand, the heat dissipation section 1712 is connected to the side of the cylindrical section 1711 away from the anode cylinder 122. The heat from the anode 12 can be transferred to the anode cylinder 122, which can then transfer heat to the cylindrical section 1711, which in turn can transfer heat to the heat dissipation section 1712. The bent shape of the heat dissipation section 1712 increases the heat dissipation area of ​​the radiator 17. Moreover, during the heat transfer process, a portion of the heat is also dissipated.

[0060] In summary, the structure of the heat sink 17 increases the heat dissipation area of ​​the heat sink 17, further ensuring the working performance of the magnetron 10 and extending its service life.

[0061] The heat dissipation section 1712 may have at least one bend. Figure 1 In this device, there are 5 heat sinks 171. Some heat sinks 171 have 3 bends in their heat dissipation section 1712, while others have 4 bends in their heat dissipation section 1712.

[0062] Please see Figure 2 In some embodiments, the magnetron 10 includes a duct component 18, which has a duct 181. The anode 12, cathode 13, first magnet 14, second magnet 15 and heat sink 17 are located in the duct 181. One end of the heat sink 17 is connected to the anode cylinder 122, and the other end of the heat sink 17 is connected to the side wall of the duct component 18 facing the duct 181.

[0063] This can further improve the heat dissipation efficiency of the magnetron 10.

[0064] Specifically, an air duct 181 is formed within the air duct component 18. Cool air blown out by the fan can enter the air duct 181 from one side and flow out of the air duct 181 from the other side. Since the main heat-generating components of the magnetron 10—the anode 12 and the electromagnet—are located in the air duct 181, the heat from these components can be dissipated into the air duct 181 by the heat sink 17 and then carried away by the cool air within the air duct 181. At the same time, the heat from these components can also be directly carried away by the cool air, which can further improve the heat dissipation efficiency of the magnetron 10.

[0065] One end of the radiator 17 is connected to the anode cylinder 122, and the other end of the radiator 17 is connected to the side wall of the air duct component 18 facing the air duct 181. In addition to improving the structural strength of the air duct component 18, the air duct component 18 is usually made of metal. The radiator 17 can also transfer heat to the air duct component 18. The heat can be dissipated from the surface of the air duct component 18, increasing the heat dissipation area and further improving the heat dissipation efficiency of the magnetron 10.

[0066] Please see Figure 5 In some embodiments, the frequency converter 20 includes a transformer 21, which includes a primary winding 211, a secondary winding 212, and a filament winding 213. The secondary winding 212 and the filament winding 213 are magnetically coupled to the primary winding 211. The magnetron 10 includes an anode 12, the secondary winding 212 is electrically connected to the anode 12, and the filament winding 213 is electrically connected to the filament 131.

[0067] Specifically, the microwave appliance 100 also includes a frequency converter 20. By adjusting the output frequency and power of the frequency converter 20, the microwave appliance 100 can achieve precise control of its heating power. The frequency converter 20 includes a transformer 21, which converts the high voltage input to the frequency converter 20 into a stable voltage suitable for it. The transformer 21 includes a primary winding 211, a secondary winding 212, and a filament winding 213. The magnetic field of the secondary winding 212 can couple with the magnetic field of the primary winding 211, so that when the current in the primary winding 211 changes, an electromotive force is generated in the secondary winding 212. Similarly, the magnetic field of the filament winding 213 can couple with the magnetic field of the primary winding 211, so that when the current in the primary winding 211 changes, an electromotive force is generated in the filament winding 213.

[0068] The primary winding 211 can receive the current from the input transformer 21, and when the current flows through the primary winding 211, it causes the primary winding 211 to generate an alternating magnetic field.

[0069] The secondary winding 212 can induce a voltage in the alternating magnetic field generated by the primary winding 211 through the principle of electromagnetic induction, and the secondary winding 212 can be connected to the anode 12 of the magnetron 10, so that the secondary winding 212 can provide the voltage required by the anode 12 of the magnetron 10.

[0070] The filament winding 213 can be connected to the filament 131 in the magnetron 10 and can supply voltage to the filament 131. The filament winding 213 is located between the primary winding 211 and the secondary winding 212, so that the filament winding 213 can be located as close as possible in the magnetic circuit of the alternating magnetic field generated by the primary winding 211, thereby reducing the leakage flux of the filament winding 213 and increasing the magnetic flux through the filament winding 213. Under the principle of magnetic induction, the voltage generated by the filament winding 213 can be increased, thereby increasing the current supplied to the filament 131 in the magnetron 10.

[0071] Please see Figure 6 In some embodiments, the frequency converter 20 includes a first insulated-gate bipolar transistor 22, a second insulated-gate bipolar transistor 23, a controller 24, a filter circuit 25, and a rectifier bridge 26. The first insulated-gate bipolar transistor 22 and the second insulated-gate bipolar transistor 23 are connected to the primary winding 211. The controller 24 is configured to control the on and off of the first insulated-gate bipolar transistor 22 and the second insulated-gate bipolar transistor 23 to regulate the output power of the frequency converter 20. The filter circuit 25 is used to maintain voltage stability in the frequency converter 20, and the rectifier bridge 26 is used to convert the type of current input to the frequency converter 20.

[0072] Specifically, the frequency converter 20 also includes a first insulated-gate bipolar transistor (IGBT) 22, a second insulated-gate bipolar transistor (IGBT) 23, a controller 24, a rectifier bridge 26, and a filter circuit 25. The first IGBT 22 and the second IGBT 23 can be connected to the controller 24, and their on / off states can be controlled by adjusting the gate voltage. When the gate voltage is greater than the threshold voltage, the IGBT is in the on state; when the gate voltage is less than the threshold voltage, the IGBT is in the off state.

[0073] The controller 24 can be a microcontroller 24 or a digital signal processor. The controller 24 can quickly turn the circuit on and off by controlling the first insulated gate bipolar transistor 22 and the second insulated gate bipolar transistor 23, thereby precisely controlling the voltage and frequency of the output inverter 20 so that the inverter 20 can maintain a certain current. In this way, the inverter 20 can provide a more stable power supply to the magnetron 10 for operation.

[0074] The rectifier bridge 26 converts the input AC power into DC power, providing the required DC voltage for the filter circuit 25 and the transformer 21. The rectifier bridge 26 is typically composed of multiple rectifier diodes, forming a full-bridge rectifier circuit.

[0075] The filter circuit 25 is located after the rectifier circuit. It is mainly used to eliminate the high-order harmonic components in the pulsating DC voltage output by the rectifier circuit, making the DC voltage smoother, and providing a stable DC power supply for the transformer 21.

[0076] In the description of this specification, the references to terms such as "some embodiments," "in one example," and "exemplarily" indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the invention. 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 may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0077] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are optional and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A magnetron for use in microwave electrical appliances, characterized in that, The magnetron includes a filament with a wire diameter greater than or equal to 0.6 mm and less than or equal to 0.67 mm, and the filament is configured such that when the microwave appliance operates at an output power greater than or equal to 50 watts, the current of the filament is greater than or equal to 8 amps.

2. The magnetron according to claim 1, characterized in that, The filament has a length of 10.5 mm to 13.8 mm.

3. The magnetron according to claim 1, characterized in that, The outer diameter of the filament is 3.8 mm to 4.2 mm.

4. The magnetron according to claim 1, characterized in that, The filament pitch is 1 mm to 1.32 mm.

5. The magnetron according to claim 1, characterized in that, The magnetron includes an anode, a cathode, a first magnet, and a second magnet. The anode and the cathode are spaced apart and opposite each other. The cathode includes a filament. The anode and the cathode are located between the first magnet and the second magnet.

6. The magnetron according to claim 5, characterized in that, The anode is annular, and the cathode passes through a through hole formed by the anode.

7. The magnetron according to claim 5, characterized in that, The anode includes an anode cylinder and an anode blade. The anode blade and the cathode are located in the anode cylinder. The anode blade is connected to the inner side of the anode cylinder, and a heat sink is connected to the outer side of the anode cylinder.

8. The magnetron according to claim 7, characterized in that, The radiator includes a plurality of heat dissipation components arranged along the axial direction. Each heat dissipation component includes a cylindrical part and a heat dissipation part. The cylindrical part is sleeved and connected to the anode cylinder, and the heat dissipation part is connected to the side of the cylindrical part away from the anode cylinder. The heat dissipation part is bent.

9. The magnetron according to claim 8, characterized in that, The magnetron includes a duct component with an air duct inside. The anode, the cathode, the first magnet, the second magnet, and the heat sink are located in the air duct. One end of the heat sink is connected to the anode cylinder, and the other end of the heat sink is connected to the side wall of the duct component facing the air duct.

10. A microwave electrical appliance, characterized in that, It includes a frequency converter and a magnetron as described in any one of claims 1-9, wherein the frequency converter is electrically connected to the magnetron.

11. The microwave appliance according to claim 10, characterized in that, The frequency converter includes a transformer, which includes a primary winding, a secondary winding, and a filament winding. The filament winding is disposed between the primary winding and the secondary winding. The secondary winding and the filament winding are magnetically coupled to the primary winding. The magnetron includes an anode. The secondary winding is electrically connected to the anode, and the filament winding is electrically connected to the filament.

12. The microwave appliance according to claim 11, characterized in that, The frequency converter includes a first insulated-gate bipolar transistor (IGBT), a second IGBT, a controller, a filter circuit, and a rectifier bridge. The first IGBT and the second IGBT are connected to the primary winding. The controller is configured to control the on and off states of the first IGBT and the second IGBT to regulate the output power of the frequency converter. The filter circuit is used to maintain voltage stability in the frequency converter, and the rectifier bridge is used to convert the type of current input to the frequency converter.

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