Power supply control circuit, switching power supply and microwave oven

Abstract

The utility model relates to a power supply control circuit, a switching power supply and a microwave oven, the circuit comprises a transformer, a voltage doubling circuit and a frequency switching module, the primary end of the transformer is connected with a signal input circuit; the voltage doubling circuit is connected with the secondary end of the transformer; the first end of the fixed-frequency module is connected with the voltage doubling circuit, and the second end of the fixed-frequency module is connected with the output interface; the first end of the frequency conversion module is connected with the voltage doubling circuit; the second end of the frequency conversion module is connected with the output interface; the output interface is used for connecting a fixed-frequency magnetron or a variable-frequency magnetron; and the frequency switching module is configured to conduct the fixed-frequency module when the output interface is connected with the fixed-frequency magnetron and conduct the frequency conversion module when the output interface is connected with the frequency conversion magnetron, so that power supply control suitable for different magnetrons (fixed-frequency magnetrons or frequency conversion magnetrons) is realized, components in the circuit are reduced, and the cost is reduced. The circuit structure is simplified, the circuit cost is further reduced, and the universality of the switching power supply is improved.

Description

Technical Field

[0001] This application relates to the field of power supply technology, and in particular to a power control circuit, a switching power supply, and a microwave oven. Background Technology

[0002] Microwave oven power supplies are mainly divided into two types: inverter linear power supplies and switching power supplies. Linear power supplies use a transformer to reduce the input voltage to a suitable level and then directly supply the reduced voltage to the microwave oven. However, inverter linear power supplies have lower efficiency, less than ideal heating performance, and higher cost; additionally, inverter linear power supplies used in microwave ovens are typically heavy, increasing transportation and installation costs. Switching power supplies, on the other hand, regulate the output voltage by controlling the on and off time ratio of a switching transistor. Switching power supplies used in microwave ovens are smaller, lighter, and have higher operating efficiency.

[0003] Currently, among the existing switching power supplies used in microwave ovens, the switching power supplies have poor versatility, complex circuit structures, and high costs. Utility Model Content

[0004] Therefore, it is necessary to address the problems existing in the current switching power supplies used in microwave ovens by providing a power control circuit, a switching power supply, and a microwave oven that can simplify the circuit structure, reduce circuit costs, and improve the versatility of the switching power supply.

[0005] In a first aspect, this application provides a power control circuit, comprising:

[0006] A transformer; the primary end of a transformer is used to connect to the signal input circuit.

[0007] A voltage multiplier circuit is connected to the secondary side of a transformer.

[0008] The frequency switching module includes a fixed-frequency module and a variable-frequency module. The first end of the fixed-frequency module is connected to a voltage multiplier circuit, and the second end of the fixed-frequency module is used to connect to the output interface. The first end of the variable-frequency module is connected to the voltage multiplier circuit, and the second end of the variable-frequency module is used to connect to the output interface. The output interface is used to connect a fixed-frequency magnetron or a variable-frequency magnetron. The frequency switching module is configured to turn on the fixed-frequency module when the output interface is connected to the fixed-frequency magnetron, and to turn on the variable-frequency module when the output interface is connected to the variable-frequency magnetron.

[0009] In one embodiment, the fixed-frequency module includes a DC-DC conversion module and a signal oscillation suppression module;

[0010] The first end of the DC-DC converter module is connected to the voltage multiplier circuit, and the second end of the DC-DC converter module is connected to the first end of the signal oscillation suppression module. The second end of the signal oscillation suppression module is used to connect to the output interface.

[0011] In one embodiment, the DC-DC conversion module includes a first diode, and the signal oscillation suppression module includes a first inductor;

[0012] The cathode of the first diode is connected to the voltage multiplier circuit, the anode of the first diode is connected to the first terminal of the first inductor, and the second terminal of the first inductor is used to connect to the output interface.

[0013] In one embodiment, the frequency converter module includes a first lead;

[0014] The first end of the first lead is connected to the voltage multiplier circuit, and the second end of the first lead is used to connect to the output interface.

[0015] In one embodiment, the voltage multiplier circuit includes a first resistor, a first capacitor, a second capacitor, a second diode, and a third diode; the secondary side of the transformer includes a first secondary pin and a second secondary pin.

[0016] The first terminal of the first capacitor is connected to the first stage pin, and the second terminal of the first capacitor is connected to ground. The first terminal of the second capacitor is connected to the first stage pin, and the second terminal of the second capacitor is connected to the first terminal of the first resistor. The anode of the second diode is connected to the second stage pin, and the cathode of the second diode is connected to ground. The cathode of the third diode is connected to the second stage pin, and the anode of the third diode is connected to the first terminal of the first resistor. The second terminal of the first resistor is connected to ground, and the first terminal of the first resistor is connected to the fixed frequency module and the variable frequency module.

[0017] In one embodiment, the power control circuit further includes a control chip; the control chip is connected to the signal input circuit.

[0018] The control chip is used to connect to the communication module.

[0019] In one embodiment, the communication module includes a first matching circuit, a second matching circuit, a third matching circuit, a first optocoupler, and a second optocoupler;

[0020] The first terminal of the first matching circuit is used to connect to the control chip, the first terminal of the second matching circuit is used to connect to the control chip, the second terminal of the first matching circuit is connected to the first terminal of the first optocoupler, the third terminal of the first matching circuit is connected to the second terminal of the first optocoupler, the third terminal of the first optocoupler is connected to the first terminal of the third matching circuit, and the fourth terminal of the first optocoupler is used to connect to the processing module; the first terminal of the second optocoupler is connected to the second terminal of the third matching circuit, the second terminal of the second optocoupler is connected to the first terminal of the third matching circuit, the third terminal of the second optocoupler is connected to the second terminal of the second matching circuit, and the fourth terminal of the second optocoupler is used to connect to the external power supply; the third terminal of the third matching circuit is used to connect to the processing module, and the fourth terminal of the third matching circuit is used to connect to the processing module.

[0021] In one embodiment, the power control circuit further includes a circuit board;

[0022] The transformer, voltage multiplier circuit, frequency switching module, and output interface are mounted on the circuit board.

[0023] Secondly, this application provides a switching power supply, including a power control circuit as described in any of the above.

[0024] Thirdly, this application provides a microwave oven, including a switching power supply as described above.

[0025] One of the above technical solutions has the following advantages and beneficial effects:

[0026] The power control circuit described above includes a transformer, a voltage multiplier circuit, and a frequency switching module. The primary end of the transformer is used to connect to the signal input circuit; the voltage multiplier circuit is connected to the secondary end of the transformer; the frequency switching module includes a fixed-frequency module and a variable-frequency module; the first end of the fixed-frequency module is connected to the voltage multiplier circuit, and the second end of the fixed-frequency module is used to connect to the output interface; the first end of the variable-frequency module is connected to the voltage multiplier circuit, and the second end of the variable-frequency module is used to connect to the output interface; the output interface is used to connect to a fixed-frequency magnetron or a variable-frequency magnetron; the frequency switching module is configured to turn on the fixed-frequency module when the output interface is connected to a fixed-frequency magnetron, and to turn on the variable-frequency module when the output interface is connected to a variable-frequency magnetron, thereby achieving power control applicable to different magnetrons (fixed-frequency magnetrons or variable-frequency magnetrons). This application uses a transformer and a voltage multiplier circuit to convert and process the electrical signal input to the signal input circuit in order to supply power to the magnetron at the back end. By setting a frequency switching module between the voltage multiplier circuit and the output interface, the corresponding frequency module can be switched according to the type of magnetron connected to the output interface. For example, if the output interface is connected to a fixed-frequency magnetron, the fixed-frequency module is controlled to conduct; if the output interface is connected to a variable-frequency magnetron, the variable-frequency module is controlled to conduct. This reduces the number of components in the circuit, simplifies the circuit structure, reduces the circuit cost, and improves the versatility of the switching power supply. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the first structure of the power control circuit in one embodiment;

[0028] Figure 2 This is a schematic diagram of the second structure of the power control circuit in one embodiment;

[0029] Figure 3 This is a schematic diagram of the third structure of the power control circuit in one embodiment;

[0030] Figure 4 This is a schematic diagram of the fourth structure of the power control circuit in one embodiment;

[0031] Figure 5This is a schematic diagram of the fifth structure of the power control circuit in one embodiment;

[0032] Figure 6 This is a schematic diagram of the sixth structure of the power control circuit in one embodiment;

[0033] Figure 7 This is a first circuit diagram of the power control circuit in one embodiment;

[0034] Figure 8 This is a schematic diagram of the second circuit of the power control circuit in one embodiment;

[0035] Figure 9 This is a schematic diagram of the third circuit of the power control circuit in one embodiment.

[0036] Figure label:

[0037] 10. Transformer; 20. Voltage multiplier circuit; 30. Frequency switching module; 310. Fixed frequency module; 312. DC-DC conversion module; 314. Signal oscillation suppression module; 320. Frequency conversion module; 322. First lead; 40. Output interface; 50. Control chip; 60. Communication module; 610. First matching circuit; 620. Second matching circuit; 630. Third matching circuit; 640. First optocoupler; 650. Second optocoupler; 70. Fixed frequency magnetron; 80. Variable frequency magnetron;

[0038] L1, first inductor; R1, first resistor; C1, first capacitor; C2, second capacitor; D1, first diode; D2, second diode; D3, third diode. Detailed Implementation

[0039] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0040] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0041] In addition, the term "multiple" should mean two or more.

[0042] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0043] In one embodiment, such as Figure 1 and Figure 2 As shown, a power control circuit is provided, which includes a transformer 10, a voltage multiplier circuit 20, and a frequency switching module 30. The primary end of the transformer 10 is used to connect to a signal input circuit; the voltage multiplier circuit 20 is connected to the secondary end of the transformer 10; the frequency switching module 30 includes a fixed-frequency module 310 and a variable-frequency module 320; the first end of the fixed-frequency module 310 is connected to the voltage multiplier circuit 20, and the second end of the fixed-frequency module 310 is used to connect to an output interface 40; the first end of the variable-frequency module 320 is connected to the voltage multiplier circuit 20, and the second end of the variable-frequency module 320 is used to connect to the output interface 40; the output interface 40 is used to connect to a fixed-frequency magnetron 70 or a variable-frequency magnetron 80; the frequency switching module 30 is configured to turn on the fixed-frequency module 310 when the output interface 40 is connected to the fixed-frequency magnetron 70, and to turn on the variable-frequency module 320 when the output interface 40 is connected to the variable-frequency magnetron 80.

[0044] The power control circuit can be used in a microwave oven, and the signal input circuit is used to connect to the input power supply to convert and process the electrical signal transmitted by the input power supply, and then transmit the processed electrical signal to the transformer 10. For example, the signal input circuit can be used to rectify and filter the electrical signal transmitted by the input power supply to obtain a processed electrical signal. For example, the input power supply can be an AC power supply with an operating voltage of 220V or 110V. The signal input circuit may include a rectifier module and a filter module. The rectifier module is used to rectify the AC electrical signal transmitted by the input power supply and then output the rectified electrical signal; the filter module is used to filter the rectified electrical signal transmitted by the rectifier module to obtain a filtered electrical signal, thereby improving the reliability of the electrical signal provided to the transformer 10.

[0045] Transformer 10 can be used to perform voltage conversion processing on the electrical signal transmitted by the signal input circuit, and then transmit the voltage-converted electrical signal to the voltage multiplier circuit 20 so that the voltage multiplier circuit 20 can perform voltage multiplication conversion on the electrical signal. Since the primary end of transformer 10 is connected to the signal input circuit and the secondary end of transformer 10 is connected to the voltage multiplier circuit 20, the input power supply transmits the initial electrical signal to the signal input circuit. The signal input circuit converts the initial electrical signal to obtain a converted electrical signal and transmits the converted electrical signal to transformer 10. Transformer 10 transforms the converted electrical signal and transmits the transformed electrical signal to voltage multiplier circuit 20. Voltage multiplier circuit 20 multiplies the transformed electrical signal to obtain a voltage-doubled electrical signal.

[0046] The frequency switching module 30 may include a fixed-frequency module 310 and a variable-frequency module 320. The fixed-frequency module 310 drives the fixed-frequency magnetron 70, and the variable-frequency module 320 drives the variable-frequency magnetron 80. The power control circuit also includes an output interface 40. The first end of the output interface 40 is used to connect the fixed-frequency magnetron 70 or the variable-frequency magnetron 80, and the second end of the output interface 40 is used to connect the fixed-frequency module 310 or the variable-frequency module 320. For example, the fixed-frequency magnetron 70 or the variable-frequency magnetron 80 can be electrically connected to the first end of the output interface 40 via a plug-in connection, and the fixed-frequency module 310 or the variable-frequency module 320 can be electrically connected to the second end of the output interface 40 via a plug-in connection. The first end of the fixed-frequency module 310 can be electrically connected to the output end of the voltage multiplier circuit 20 via a plug-in connection or soldering connection, and the first end of the variable-frequency module 320 can be electrically connected to the output end of the voltage multiplier circuit 20 via a plug-in connection or soldering connection.

[0047] For example, when the fixed-frequency magnetron 70 is connected to the output interface 40, the fixed-frequency module 310 is turned on, the frequency conversion module 320 is turned off, and the frequency switching module 30 switches the fixed-frequency module 310 to turn on, so that the voltage-doubled electrical signal output by the voltage multiplier circuit 20 is transmitted to the voltage multiplier module 310. The voltage multiplier module 310 performs frequency-fixing processing on the voltage-doubled electrical signal and then transmits it to the voltage multiplier magnetron 70, thereby achieving a stable power supply to the fixed-frequency magnetron 70; when the frequency conversion magnetron 80 is connected to the output... When interface 40 is engaged, the frequency converter module 320 is turned on and the fixed frequency module 310 is turned off. Then, the frequency switching module 30 switches the frequency converter module 320 to be turned on, so that the voltage doubled electrical signal output by the voltage doubler circuit 20 is transmitted to the frequency converter module 320. The frequency converter module 320 performs frequency conversion processing on the voltage doubled electrical signal and transmits it to the frequency converter magnetron 80, thereby achieving stable power supply to the frequency converter magnetron 80 and realizing universal power control for the fixed frequency magnetron 70 and the frequency converter magnetron 80.

[0048] In the above embodiments, the primary end of the transformer 10 is connected to the signal input circuit; the voltage multiplier circuit 20 is connected to the secondary end of the transformer 10; the first end of the fixed frequency module 310 is connected to the voltage multiplier circuit 20, and the second end of the fixed frequency module 310 is connected to the output interface 40; the first end of the frequency conversion module 320 is connected to the voltage multiplier circuit 20, and the second end of the frequency conversion module 320 is connected to the output interface 40; the output interface 40 is connected to the fixed frequency magnetron 70 or the frequency conversion magnetron 80; the frequency switching module 30 is configured to turn on the fixed frequency module 310 when the output interface 40 is connected to the fixed frequency magnetron 70, and to turn on the frequency conversion module 320 when the output interface 40 is connected to the frequency conversion magnetron 80, thereby realizing power control applicable to different magnetrons (fixed frequency magnetron 70 or frequency conversion magnetron 80). This application uses a transformer 10 and a voltage multiplier circuit 20 to convert and process the electrical signal input to the signal input circuit in order to supply power to the magnetron at the back end. By setting a frequency switching module 30 between the voltage multiplier circuit 20 and the output interface 40, the corresponding frequency module can be switched according to the type of magnetron connected to the output interface 40. For example, if the output interface 40 is connected to a fixed-frequency magnetron 70, the fixed-frequency module 310 is controlled to conduct; if the output interface 40 is connected to a variable-frequency magnetron 80, the variable-frequency module 320 is controlled to conduct. This improves the versatility of power supply control, reduces the number of components in the circuit, simplifies the circuit structure, and thus reduces the circuit cost.

[0049] In one embodiment, such as Figure 3 As shown, the fixed frequency module 310 includes a DC-DC conversion module 312 and a signal oscillation suppression module 314; the first end of the DC-DC conversion module 312 is connected to the voltage multiplier circuit 20, the second end of the DC-DC conversion module 312 is connected to the first end of the signal oscillation suppression module 314, and the second end of the signal oscillation suppression module 314 is used to connect to the output interface 40.

[0050] The DC-DC conversion module 312 is used to convert the voltage-doubled electrical signal output by the voltage multiplier circuit 20 into a DC signal. The signal oscillation suppression module 314 is used to suppress the signal oscillation of the DC signal transmitted by the DC-DC conversion module 312, thereby obtaining a stable fixed-frequency electrical signal. The fixed-frequency electrical signal is then transmitted to the fixed-frequency magnetron 70 to achieve stable power supply to the fixed-frequency magnetron 70, effectively preventing signal oscillation and improving the reliability of power control for the fixed-frequency magnetron 70.

[0051] In one example, such as Figure 7 As shown, the DC-DC conversion module 312 includes a first diode D1, and the signal oscillation suppression module 314 includes a first inductor L1; the cathode of the first diode D1 is connected to the voltage multiplier circuit 20, the anode of the first diode D1 is connected to the first end of the first inductor L1, and the second end of the first inductor L1 is used to connect to the output interface 40.

[0052] Among them, the first diode D1 can be a Schottky diode, and the first inductor L1 can be a ferrite rod inductor.

[0053] The first diode D1 is connected in series between the voltage multiplier circuit 20 and the first inductor L1, and the first inductor L1 is connected in series between the first diode D1 and the output interface 40. When the output interface 40 is connected to the fixed-frequency magnetron 70, the first diode D1 and the first inductor L1 are controlled to conduct. The first diode D1 then performs DC-DC conversion on the voltage multiplier signal output from the voltage multiplier circuit 20 to obtain a DC signal. The first inductor L1 performs signal oscillation suppression processing on the DC signal transmitted by the DC-DC conversion module 312 to obtain a stable fixed-frequency signal, which is then transmitted to the fixed-frequency magnetron 70 to achieve stable power supply to the fixed-frequency magnetron 70, effectively preventing signal oscillation and improving the reliability of power supply control for the fixed-frequency magnetron 70.

[0054] In one embodiment, such as Figure 4 As shown, the frequency converter module 320 includes a first lead 322; the first end of the first lead 322 is connected to the voltage multiplier circuit 20, and the second end of the first lead 322 is used to connect to the output interface 40.

[0055] The first lead 322 is an electrical connection wire. The first end of the first lead 322 can be connected to the output terminal of the voltage multiplier circuit 20 by soldering or plugging, and the second end of the first lead can be connected to the output interface 40 by plugging in.

[0056] For example, when the variable frequency magnetron 80 is connected to the output interface 40, the fixed frequency module 310 is disconnected, and the second end of the first lead 322 is plugged into the output interface 40, making the first lead 322 conductive. The voltage-doubled electrical signal output by the voltage multiplier circuit 20 is then transmitted to the variable frequency magnetron 80 through the first lead 322, achieving stable power supply to the variable frequency magnetron 80. When the fixed frequency magnetron 70 is connected to the output interface 40, the second end of the first lead 322 is pulled out of the output interface 40, making the first lead 322 disconnected. The fixed frequency module 310 is then conductive, and the voltage-doubled electrical signal output by the voltage multiplier circuit 20 is processed by the fixed frequency module 310 and transmitted to the fixed frequency magnetron 70, achieving stable power supply to the fixed frequency magnetron 70. This simplifies the circuit structure, facilitates operation, reduces the number of components in the circuit, lowers the circuit cost, and improves the versatility of the switching power supply.

[0057] In one embodiment, such as Figure 7 and Figure 8As shown, the voltage multiplier circuit 20 includes a first resistor R1, a first capacitor C1, a second capacitor C2, a second diode D2, and a third diode D3; the secondary side of the transformer 10 includes a first secondary pin and a second secondary pin; the first terminal of the first capacitor C1 is connected to the first secondary pin, and the second terminal of the first capacitor C1 is connected to ground; the first terminal of the second capacitor C2 is connected to the first secondary pin, and the second terminal of the second capacitor C2 is connected to the first terminal of the first resistor R1; the anode of the second diode D2 is connected to the second secondary pin, and the cathode of the second diode D2 is connected to ground; the cathode of the third diode D3 is connected to the second secondary pin, and the anode of the third diode D3 is connected to the first terminal of the first resistor R1; the second terminal of the first resistor R1 is connected to ground, and the first terminal of the first resistor R1 is connected to the fixed frequency module 310 and the variable frequency module 320.

[0058] Among them, the first capacitor C1 and the second capacitor C2 are high-voltage capacitors, and the second diode D2 and the third diode D3 are high-voltage diodes.

[0059] A high-voltage voltage multiplier circuit 20 is formed by a first resistor R1, a first capacitor C1, a second capacitor C2, a second diode D2, and a third diode D3. Based on the energy storage function of the first and second capacitors C1 and C2, and the rectification function of the second and third diodes D2 and D3, a low-voltage electrical signal is converted into a high-voltage electrical signal. The first resistor R1 is used to control the current in the circuit, preventing the circuit from burning out due to excessive current. The first resistor R1 also distributes the high voltage to the first capacitor C1 and the second capacitor C2, thereby improving the stability and safety of the circuit.

[0060] For example, when the fixed-frequency magnetron 70 is connected to the output interface 40, the fixed-frequency module 310 is turned on and the frequency conversion module 320 is turned off, so that the signal input circuit transmits the electrical signal to the transformer 10. The transformer 10 transforms the electrical signal and transmits it to the voltage multiplier circuit 20. After transformation, the electrical signal is charged and discharged through the first capacitor C1 and the second capacitor C2, which multiplies the voltage. After rectification by the second diode D2 and the third diode D3, the voltage multiplier rectified electrical signal is output to the fixed-frequency module 310. The fixed-frequency module 310 performs frequency-fixing processing on the voltage multiplier rectified electrical signal and transmits it to the fixed-frequency magnetron 70, thereby realizing a stable power supply to the fixed-frequency magnetron 70. Similarly, when the variable frequency magnetron 80 is connected to the output interface 40, the variable frequency module 320 is turned on and the fixed frequency module 310 is turned off, so that the signal input circuit transmits the electrical signal to the transformer 10. The transformer 10 transforms the electrical signal and transmits it to the voltage multiplier circuit 20. After transformation, the electrical signal is charged and discharged through the first capacitor C1 and the second capacitor C2, which multiplies the voltage. After rectification by the second diode D2 and the third diode D3, the voltage multiplier rectified electrical signal is output to the variable frequency module 320. The variable frequency module 320 performs frequency conversion processing on the voltage multiplier rectified electrical signal and transmits it to the variable frequency magnetron 80, realizing a stable power supply to the variable frequency magnetron 80. This improves the versatility of power supply control, simplifies the circuit structure, reduces circuit cost, and improves the reliability of the switching power supply.

[0061] In one embodiment, such as Figure 5 and Figure 6 As shown, the power control circuit also includes a control chip 50; the control chip 50 is connected to the signal input circuit; the control chip 50 is used to connect to the communication module 60.

[0062] Among them, the control chip 50 is a switching power supply control chip 50 (MCU). The control chip 50 can be used to control the on and off of the signal input circuit, and the control chip 50 can also be used to control the channels of the communication module 60.

[0063] In one example, such as Figure 9As shown, the communication module 60 includes a first matching circuit 610, a second matching circuit 620, a third matching circuit 630, a first optocoupler 640, and a second optocoupler 650. The first terminal of the first matching circuit 610 is connected to the control chip 50, the first terminal of the second matching circuit 620 is connected to the control chip 50, the second terminal of the first matching circuit 610 is connected to the first terminal of the first optocoupler 640, and the third terminal of the first matching circuit 610 is connected to the second terminal of the first optocoupler 640. The third terminal of the first optocoupler 640 is connected to the third matching circuit 650. The first end of circuit 630 is connected to the first end of the first optocoupler 640, and the fourth end of the first optocoupler 640 is used to connect to the processing module; the first end of the second optocoupler 650 is connected to the second end of the third matching circuit 630, the second end of the second optocoupler 650 is connected to the first end of the third matching circuit 630, the third end of the second optocoupler 650 is connected to the second end of the second matching circuit 620, and the fourth end of the second optocoupler 650 is used to connect to an external power supply; the third end of the third matching circuit 630 is used to connect to the processing module, and the fourth end of the third matching circuit 630 is used to connect to the processing module.

[0064] The processing module may include a processing chip, which may be, but is not limited to, a 51 series microcontroller chip. The first optocoupler 640 and the second optocoupler 650 are used to isolate the signal transmission of the control chip 50, preventing the user from being electrocuted. The first terminal of the first matching circuit 610 is used to provide a feedback signal, and the first terminal of the second matching circuit 620 is used to receive signals.

[0065] For example, the first matching circuit 610 may include a second resistor and a third resistor; the second matching circuit 620 may include a fourth resistor, a fifth resistor, and a third capacitor; and the third matching circuit 630 may include a sixth resistor and a seventh resistor. The first terminal of the second resistor serves as the first terminal of the first matching circuit 610, and the second terminal of the second resistor serves as the third terminal of the first matching circuit 610. The first terminal of the third resistor is connected to an external power supply, and the first terminal of the third resistor also serves as the second terminal of the first matching circuit 610. The second terminal of the third resistor is connected to the second terminal of the second resistor. The first terminal of the fourth resistor serves as the first terminal of the second matching circuit 620, and the second terminal of the fourth resistor also serves as the second terminal of the second matching circuit 620. The first terminal of the third capacitor is connected to the first terminal of the fourth resistor, and the second terminal of the third capacitor is grounded. The first terminal of the fifth resistor is connected to the second terminal of the fourth resistor, and the second terminal of the fifth resistor is connected to the second terminal of the third capacitor. The first end of the sixth resistor is grounded, and the first end of the sixth resistor serves as the first end and the third end of the third matching circuit 630. The second end of the sixth resistor is connected to the first end of the seventh resistor, and the first end of the seventh resistor serves as the second end of the third matching circuit 630. The second end of the seventh resistor also serves as the fourth end of the third matching circuit 630.

[0066] The communication module 60 can be plugged into the control chip 50. When communication is required, the control chip 50 can activate the communication module 60; when communication is not needed, the control chip 50 disconnects the communication module 60, thereby further increasing the versatility of power control. For example, in the application scenario of microwave ovens, depending on whether the fixed-frequency magnetron 70 or the variable-frequency magnetron 80 is used, and whether the communication module 60 is present, a universal power control circuit can be matched to four different microwave oven functional requirements, greatly improving the versatility of the switching power supply.

[0067] In one embodiment, the power control circuit further includes a circuit board; a transformer, a voltage multiplier circuit, a frequency switching module, and an output interface are disposed on the circuit board.

[0068] The circuit board can be a PCB (Printed Circuit Board). By placing the transformer, voltage multiplier circuit, frequency switching module, and output interface on the circuit board, it is easier to assemble the power control circuit, further improve the circuit's versatility, facilitate disassembly and maintenance, reduce labor costs, and also achieve miniaturization and weight reduction of the circuit.

[0069] In one embodiment, a switching power supply is also provided, including a power control circuit as described in any of the above.

[0070] For a detailed description of the power control circuit, please refer to the specific description of the power control circuit in the above embodiments, which will not be repeated here.

[0071] In the above embodiments, the primary end of the transformer is connected to the signal input circuit; the voltage multiplier circuit is connected to the secondary end of the transformer; the frequency switching module includes a fixed-frequency module and a variable-frequency module; the first end of the fixed-frequency module is connected to the voltage multiplier circuit, and the second end of the fixed-frequency module is connected to the output interface; the first end of the variable-frequency module is connected to the voltage multiplier circuit, and the second end of the variable-frequency module is connected to the output interface; the output interface is connected to a fixed-frequency magnetron or a variable-frequency magnetron; the frequency switching module is configured to turn on the fixed-frequency module when the output interface is connected to the fixed-frequency magnetron, and to turn on the variable-frequency module when the output interface is connected to the variable-frequency magnetron, thereby realizing power control applicable to different magnetrons (fixed-frequency magnetron or variable-frequency magnetron). This application uses a transformer and a voltage multiplier circuit to convert and process the electrical signal input to the signal input circuit in order to supply power to the magnetron at the back end. By setting a frequency switching module between the voltage multiplier circuit and the output interface, the corresponding frequency module can be switched according to the type of magnetron connected to the output interface. For example, if the output interface is connected to a fixed-frequency magnetron, the fixed-frequency module is controlled to conduct; if the output interface is connected to a variable-frequency magnetron, the variable-frequency module is controlled to conduct. This reduces the number of components in the circuit, simplifies the circuit structure, and thus reduces the circuit cost. It can be applied to microwave products with variable or fixed frequencies, improving the versatility of the switching power supply.

[0072] In one embodiment, a microwave oven is also provided, including a switching power supply as described in any of the above.

[0073] For a detailed description of the switching power supply, please refer to the specific description of the switching power supply in the above embodiments, which will not be repeated here.

[0074] In the above embodiments, by placing the switching power supply on the microwave oven body, the switching power supply includes a power control circuit, which includes a transformer, a voltage multiplier circuit, and a frequency switching module. The transformer and voltage multiplier circuit convert and process the electrical signal input from the signal input circuit to supply power to the magnetron at the back end. By setting the frequency switching module between the voltage multiplier circuit and the output interface, the corresponding frequency module can be switched according to the type of magnetron connected to the output interface. For example, if the output interface is connected to a fixed-frequency magnetron, the fixed-frequency module is controlled to conduct; if the output interface is connected to a variable-frequency magnetron, the variable-frequency module is controlled to conduct. This reduces the number of components in the circuit, simplifies the circuit structure, and reduces the circuit cost. It can be applied to microwave products with variable or fixed frequencies, improving the versatility of the switching power supply.

[0075] It should be noted that the microwave oven may also include devices such as a cavity and a display. A specific microwave oven may include more components than those described in the above embodiments, or combine certain components, or have different component arrangements.

[0076] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A power supply control circuit, characterized in that, include: A transformer, wherein the primary end of the transformer is used to connect to a signal input circuit; A voltage multiplier circuit, wherein the voltage multiplier circuit is connected to the secondary terminal of the transformer; A frequency switching module includes a fixed-frequency module and a variable-frequency module. A first terminal of the fixed-frequency module is connected to the voltage multiplier circuit, and a second terminal of the fixed-frequency module is used to connect to an output interface. A first terminal of the variable-frequency module is connected to the voltage multiplier circuit, and a second terminal of the variable-frequency module is used to connect to the output interface. The output interface is used to connect a fixed-frequency magnetron or a variable-frequency magnetron. The frequency switching module is configured to turn on the fixed-frequency module when the output interface is connected to the fixed-frequency magnetron, and to turn on the variable-frequency module when the output interface is connected to the variable-frequency magnetron.

2. The power control circuit according to claim 1, characterized in that, The fixed-frequency module includes a DC-DC conversion module and a signal oscillation suppression module; The first end of the DC-DC converter module is connected to the voltage multiplier circuit, the second end of the DC-DC converter module is connected to the first end of the signal oscillation suppression module, and the second end of the signal oscillation suppression module is used to connect to the output interface.

3. The power control circuit according to claim 2, characterized in that, The DC-DC conversion module includes a first diode, and the signal oscillation suppression module includes a first inductor; The cathode of the first diode is connected to the voltage multiplier circuit, the anode of the first diode is connected to the first terminal of the first inductor, and the second terminal of the first inductor is used to connect to the output interface.

4. The power control circuit according to claim 1, characterized in that, The frequency conversion module includes a first lead; The first end of the first lead is connected to the voltage multiplier circuit, and the second end of the first lead is used to connect to the output interface.

5. The power control circuit according to claim 1, characterized in that, The voltage multiplier circuit includes a first resistor, a first capacitor, a second capacitor, a second diode, and a third diode; the secondary side of the transformer includes a first secondary pin and a second secondary pin. The first terminal of the first capacitor is connected to the first stage pin, and the second terminal of the first capacitor is connected to ground. The first terminal of the second capacitor is connected to the first stage pin, and the second terminal of the second capacitor is connected to the first terminal of the first resistor. The anode of the second diode is connected to the second stage pin, and the cathode of the second diode is connected to ground. The cathode of the third diode is connected to the second stage pin, and the anode of the third diode is connected to the first terminal of the first resistor. The second terminal of the first resistor is connected to ground, and the first terminal of the first resistor is connected to the fixed-frequency module and the variable-frequency module.

6. The power control circuit according to claim 1, characterized in that, It also includes a control chip; the control chip is connected to the signal input circuit; The control chip is used to connect to the communication module.

7. The power control circuit according to claim 6, characterized in that, The communication module includes a first matching circuit, a second matching circuit, a third matching circuit, a first optocoupler, and a second optocoupler. The first terminal of the first matching circuit is used to connect to the control chip, the first terminal of the second matching circuit is used to connect to the control chip, the second terminal of the first matching circuit is connected to the first terminal of the first optocoupler, and the third terminal of the first matching circuit is connected to the second terminal of the first optocoupler. The third terminal of the first optocoupler is connected to the first terminal of the third matching circuit, and the fourth terminal of the first optocoupler is used to connect to the processing module. The first terminal of the second optocoupler is connected to the second terminal of the third matching circuit, the second terminal of the second optocoupler is connected to the first terminal of the third matching circuit, and the third terminal of the second optocoupler is connected to the second terminal of the second matching circuit. The fourth terminal of the second optocoupler is used to connect to an external power supply. The third terminal of the third matching circuit is used to connect to the processing module, and the fourth terminal of the third matching circuit is used to connect to the processing module.

8. The power control circuit according to any one of claims 1 to 7, characterized in that, It also includes circuit boards; The transformer, the voltage multiplier circuit, the frequency switching module, and the output interface are mounted on the circuit board.

9. A switching power supply, characterized in that, Includes the power control circuit as described in any one of claims 1 to 8.

10. A microwave oven, characterized in that, Including the switching power supply as described in any one of claims 9.

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