Electromagnetic heating circuit and electromagnetic heating appliance

Abstract

The present application provides an electromagnetic heating circuit and an electromagnetic heating appliance. The electromagnetic heating circuit includes: a rectification circuit, a first heating main circuit, a first resistor, a first control circuit, a second heating main circuit, a second resistor, and a second control circuit; the positive output terminal of the rectification circuit is respectively connected to the first end of the first heating main circuit and the first end of the second heating main circuit; the first end of the first resistor is connected to the negative output terminal of the rectification circuit, and the second end of the first resistor is connected to the third end of the first heating main circuit and is connected to a first grounding point; the first end of the second resistor is connected to the negative output terminal of the rectification circuit, and the second end of the second resistor is connected to the third end of the second heating main circuit and is connected to a second grounding point, so that the design difficulty of the PCB is relatively small, and the area of the PCB is also relatively small.

Description

Technical Field

[0001] Embodiments of the present application relate to the technical field of household appliances, and particularly to an electromagnetic heating circuit and an electromagnetic heating appliance. Background Art

[0002] An electromagnetic heating appliance, such as an induction cooker or an induction hob, is a device that converts electrical energy into heat energy by using the electromagnetic induction phenomenon. With the progress of technology and the continuous improvement of the quality of components, the application of electromagnetic heating appliances has become more and more popular, and electromagnetic heating appliances with two or more cooking zones have emerged.

[0003] In an electromagnetic heating appliance with two or more cooking zones, different cooking zones respectively have their own heating circuits and independently perform heating control. When different cooking zones are heated simultaneously, due to different heating frequencies, electromagnetic interference will occur between them. In order to eliminate the electromagnetic interference between different cooking zones, usually the control systems of multiple cooking zones respectively adopt different ground wires. The ground wires of different cooking zones are separated by the complex circuits corresponding to each cooking zone. In order to meet the insulation requirements, higher requirements are imposed on the electrical clearance and creepage distance between components, the design difficulty of the PCB is greater, and the area of the PCB is also larger. Summary of the Invention

[0004] Embodiments of the present application provide an electromagnetic heating circuit and an electromagnetic heating appliance, which reduce the design difficulty of the PCB and reduce the area of the PCB.

[0005] In a first aspect, the present application provides an electromagnetic heating circuit, including: a rectification circuit, a first heating main circuit, a first resistor, a first control circuit, a second heating main circuit, a second resistor, and a second control circuit; wherein,

[0006] The rectification circuit is configured to rectify the input mains current, and the positive output terminal of the rectification circuit is respectively connected to the first terminal of the first heating main circuit and the first terminal of the second heating main circuit;

[0007] The second terminal of the first heating main circuit is connected to the first terminal of the first control circuit, the second terminal of the first control circuit is connected to the negative output terminal of the rectification circuit, the first terminal of the first resistor is connected to the negative output terminal of the rectification circuit, and the second terminal of the first resistor is connected to the third terminal of the first heating main circuit and is connected to a first grounding point;

[0008] The second terminal of the second heating main circuit is connected to the first terminal of the second control circuit, the second terminal of the second control circuit is connected to the negative output terminal of the rectification circuit, the first terminal of the second resistor is connected to the negative output terminal of the rectification circuit, and the second terminal of the second resistor is connected to the third terminal of the second heating main circuit and is connected to a second grounding point;

[0009] The first control circuit is used to detect the current of the first resistor and control the first main heating circuit to heat according to the current of the first resistor;

[0010] The second control circuit is used to detect the current of the second resistor and control the second main heating circuit to heat according to the current of the second resistor.

[0011] In this electromagnetic heating circuit, the circuits corresponding to multiple electromagnetic heating burners share a rectifying circuit, making the structure of the circuit between the reference grounds of the heating circuits and control circuits corresponding to multiple burners simple. As a result, the requirements for electrical clearance and creepage distance in PCB design are reduced, making the PCB design less difficult, with a smaller PCB area, and at the same time reducing costs.

[0012] In a feasible implementation, the electromagnetic heating circuit further includes: a first current sampling circuit, where the first end of the first current sampling circuit is connected to the negative output end of the rectifying circuit, and the second end of the first current sampling circuit is connected to the second end of the first control circuit;

[0013] The first control circuit is used to detect the current of the first resistor through the first current sampling circuit and control the first main heating circuit to heat according to the current of the first resistor.

[0014] In the electromagnetic heating circuit, the first control circuit controls the first main heating circuit to heat by detecting the current of the first resistor, improving the accuracy of heating power control.

[0015] In a feasible implementation, the electromagnetic heating circuit further includes: a second current sampling circuit, where the input end of the second current sampling circuit is connected to the negative output end of the rectifying circuit, and the output end of the second current sampling circuit is connected to the output end of the second control circuit;

[0016] The second control circuit is used to detect the current of the second resistor through the second current sampling circuit and control the second main heating circuit to heat according to the current of the second resistor.

[0017] In the electromagnetic heating circuit, the second control circuit controls the second main heating circuit to heat by detecting the current of the second resistor, improving the accuracy of heating power control.

[0018] In a feasible implementation, the first main heating circuit includes: a first filter circuit, a first resonant circuit, a first insulated gate bipolar transistor IGBT, and a first drive circuit;

[0019] Among them, the positive output terminal of the rectifier circuit is connected to the first input terminal of the first filter circuit, the first output terminal of the first filter circuit is connected to the first end of the first resonant circuit, the second end of the first resonant circuit is connected to the collector of the first IGBT, the second output terminal of the first filter circuit is connected to the emitter of the first IGBT and connected to the first grounding point, the gate of the first IGBT is connected to the output terminal of the first drive circuit, and the input terminal of the first drive circuit is connected to the first end of the first control circuit;

[0020] The first control circuit is specifically configured to detect the current of the first resistor and send a pulse width modulation signal to the first drive circuit according to the current of the first resistor;

[0021] The first drive circuit is configured to drive the first IGBT to conduct or disconnect according to the pulse width modulation signal to control the first resonant circuit to heat up.

[0022] In a feasible implementation manner, the second main heating circuit includes: a second filter circuit, a second resonant circuit, a second insulated gate bipolar transistor IGBT, and a second drive circuit;

[0023] Among them, the positive output terminal of the rectifier circuit is connected to the first input terminal of the second filter circuit, the first output terminal of the second filter circuit is connected to the first end of the second resonant circuit, the second end of the second resonant circuit is connected to the collector of the second IGBT, the second output terminal of the second filter circuit is connected to the emitter of the second IGBT and connected to the second grounding point, the gate of the second IGBT is connected to the output terminal of the second drive circuit, and the input terminal of the second drive circuit is connected to the first end of the second control circuit;

[0024] The second control circuit is specifically configured to detect the current of the second resistor and send a pulse width modulation signal to the second drive circuit according to the current of the second resistor;

[0025] The second drive circuit is configured to drive the second IGBT to conduct or disconnect according to the pulse width modulation signal to control the second resonant circuit to heat up.

[0026] In a feasible implementation manner, the resistance values of the first resistor and the second resistor are both in the milliohm level.

[0027] In the electromagnetic heating circuit, the first resistor and the second resistor are milliohm-level resistors. As a result, the voltages of the two resistors are relatively small, and the voltage difference is also small. The voltage difference is usually less than the supply voltage of the control circuit. Therefore, when designing the PCB, the requirements for the electrical clearance and creepage distance between components are relatively low, making the PCB design easier and the PCB area smaller.

[0028] In a feasible implementation manner, the first filtering circuit includes: a first filtering inductor and a first filtering capacitor; wherein, the positive output terminal of the rectifying circuit is connected to the first end of the first filtering inductor, the first filtering capacitor is connected between the second end of the first filtering inductor and the second end of the first resistor, and the first end of the first filtering capacitor is further connected to the first end of the first resonant circuit.

[0029] In a feasible implementation manner, the second filtering circuit includes: a second filtering inductor and a second filtering capacitor; wherein, the positive output terminal of the rectifying circuit is connected to the first end of the second filtering inductor, the second filtering capacitor is connected between the second end of the second filtering inductor and the second end of the second resistor, and the first end of the second filtering capacitor is further connected to the first end of the second resonant circuit.

[0030] In a feasible implementation manner, the electromagnetic heating circuit further includes: a mains input circuit, and the mains input circuit is connected to two-phase input terminals of the rectifying circuit.

[0031] In a second aspect, the present application provides an electromagnetic heating appliance, including: the electromagnetic heating circuit according to any one of the first aspect.

[0032] The present application provides an electromagnetic heating circuit and an electromagnetic heating appliance. In this electromagnetic heating circuit, the circuits corresponding to multiple electromagnetic heating burners share a rectifying circuit, making the structure of the circuit between the reference grounds of the heating circuits and control circuits corresponding to multiple burners simple. As a result, the requirements for electrical clearance and creepage distance in PCB design are reduced, making the PCB design easier, the PCB area smaller, and the cost lower at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the following will briefly introduce the drawings required for describing the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 It is a schematic structural diagram of an electromagnetic heating circuit in the prior art;

[0035] Figure 2 Structural schematic of an electromagnetic heating circuit provided for this application Figure 1 ;

[0036] Figure 3 Structural schematic of an electromagnetic heating circuit provided for this application Figure 2 ;

[0037] Figure 4 Structural schematic of an electromagnetic heating circuit provided for this application Figure 3 ;

[0038] Figure 5 Structural schematic of an electromagnetic heating circuit provided for this application Figure 4 ;

[0039] Figure 6 Structural schematic of an electromagnetic heating circuit provided for this application Figure 5 ;

[0040] Figure 7 Structural schematic of an electromagnetic heating circuit provided for this application Figure 6 。 Detailed implementation manners

[0041] To make the objectives, technical solutions and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some but not all of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts shall fall within the scope of protection of this application.

[0042] The electromagnetic heating circuit provided for this application is applied to double-stove or multi-stove electromagnetic heating appliances. Taking a double-stove induction cooker with stove A and stove B as an example, in the prior art, the double-stove induction cooker adopts a circuit structure as shown in Figure 1 . In the figure, circuit 101 is the heating circuit and control circuit of stove A, and circuit 102 is the heating circuit and control circuit of stove B.

[0043] As shown in Figure 1 , after the mains current passes through the filter circuit, the two output terminals AC1 and AC2 are respectively connected to the rectifier bridges of the two stoves, namely rectifier bridge BG1 and rectifier bridge BG2, to supply electrical energy to the circuits of the two stoves. The ground connection point of the heating circuit and control circuit of stove A is GND1, and the ground connection point of the heating circuit and control circuit of stove B is GND2. Two different reference grounds are used to reduce the interference between the two stoves. However, Figure 1There is a rectifier bridge BG1 and a rectifier bridge BG2 between the two grounding points GND1 and GND2. The operating voltages of the rectifier bridge BG1 and the rectifier bridge BG2 are relatively high. Therefore, during PCB design, to meet the insulation requirements, the requirements for the electrical clearance and creepage distance between components are relatively high, resulting in greater difficulty in PCB design and a larger PCB area.

[0044] To solve the above problems, this application proposes that for double-burner or multi-burner electromagnetic heating appliances, by improving their circuit structure and reducing the complexity of the circuit between the reference grounds of the circuits corresponding to different burners, the requirements for the electrical clearance and creepage distance between components are reduced, thereby reducing the difficulty of PCB design. The following describes the circuit improvement proposed in this application in combination with specific embodiments.

[0045] Figure 2 This is a schematic diagram of the structure of an electromagnetic heating circuit provided by this application Figure 1 As Figure 2 shown, the electromagnetic heating circuit includes: a rectifier circuit 200, a first heating main circuit 211, a first resistor R1, a first control circuit 212, a second heating main circuit 221, a second resistor R2, and a second control circuit 222.

[0046] Among them, the positive output terminal of the rectifier circuit 200 is respectively connected to the first end of the first heating main circuit 211 and the first end of the second heating main circuit 212. After rectifying the mains current, the rectifier circuit 200 transmits it to the first heating main circuit 211 and the second heating main circuit 221 respectively.

[0047] The second end of the first heating main circuit 211 is connected to the first end of the first control circuit 212. The second end of the first control circuit 212 is connected to the negative output terminal of the rectifier circuit 200. The first end of the first resistor R1 is connected to the negative output terminal of the rectifier circuit 200. The second end of the first resistor R1 is connected to the third end of the first heating main circuit 211 and is connected to the first grounding point GND1.

[0048] The second end of the second heating main circuit 221 is connected to the first end of the second control circuit 212. The second end of the second control circuit 212 is connected to the negative output terminal of the rectifier circuit 200. The first end of the second resistor R2 is connected to the negative output terminal of the rectifier circuit 200. The second end of the second resistor R2 is connected to the third end of the second heating main circuit 221 and is connected to the second grounding point GND2.

[0049] The first control circuit 212 is used to detect the current of the first resistor R1 and control the first heating main circuit 211 to heat according to the current of the first resistor R1.

[0050] The second control circuit 222 is used to detect the current of the second resistor R2 and control the second main heating circuit 221 to heat according to the current of the second resistor R2.

[0051] Figure 2 In the shown circuit, after the rectifier circuit 200 rectifies the input current, it supplies power to the first main heating circuit 211 and the second main heating circuit 221. The first main heating circuit 211 and the second main heating circuit 221 share the rectifier circuit 200. The output current of the rectifier circuit 200 is respectively output to the first main heating circuit 211 and the second main heating circuit 221.

[0052] The first resistor R1 is the current sampling resistor of the first main heating circuit 211. The first control circuit 212 detects the current of the first resistor R1 to determine the current of the first main heating circuit 211 when the corresponding burner is heating. The first control circuit 212 can further detect the voltage of the first main heating circuit 211 to determine the real-time heating power, so as to control the heating of the first main heating circuit 211.

[0053] The second resistor R2 is the current sampling resistor of the second main heating circuit 221. The second control circuit 222 detects the current of the second resistor R2 to determine the current of the second main heating circuit 221 when the corresponding burner is heating. The second control circuit 222 can further detect the voltage of the second main heating circuit 221 to determine the real-time heating power, so as to control the heating of the second main heating circuit 221.

[0054] The first resistor R1 is connected to the first main heating circuit 211 and is connected to the first ground point GND1. The first control circuit 212 is also connected to the first ground point GND1; the second resistor R2 is connected to the second main heating circuit 221 and is connected to the second ground point GND2. The second control circuit 222 is also connected to the second ground point GND2. The first ground point GND1 and the second ground point GND2 are different ground points, that is, the reference grounds of the first main heating circuit 211 and the second main heating circuit 221 are different, and the reference grounds of the first control circuit 212 and the second control circuit 222 are different, avoiding the interference problem when the two burners are heating simultaneously.

[0055] From Figure 2It can be seen that since the first heating main circuit 211 and the second heating main circuit 221 share the rectifier circuit 200, only the first resistor R1 and the second resistor R2 are spaced between the first ground point GND1 and the second ground point GND2. The first resistor R1 and the second resistor R2 are used as current sampling resistors, and their resistance values are usually small. For example, the first resistor R1 and the second resistor R2 can be milliohm-level constantan resistors or manganin resistors. The voltages of the two resistors are relatively small, and the voltage difference is also small. The voltage difference is usually less than the supply voltage of the control circuit. Therefore, when designing the PCB, the requirements for the electrical clearance and creepage distance between components are relatively low, which makes the design difficulty of the PCB small, and the area of the PCB is also small.

[0056] In the electromagnetic heating circuit provided in this embodiment, the circuits of multiple burners share the rectifier circuit, making the structure of the circuit spaced between the reference grounds of the heating circuits and control circuits corresponding to multiple burners simple. Thus, the requirements for electrical clearance and creepage distance during PCB design are reduced, making the design difficulty of the PCB small, the area of the PCB small, and the cost reduced at the same time.

[0057] It should be noted that the electromagnetic heating circuit shown in the above embodiment can be applied to dual-burner electromagnetic heating appliances or multi-burner electromagnetic heating appliances. When applied to a multi-burner electromagnetic heating appliance, its structure is similar to that in the above embodiment, and only the heating circuit and the control circuit need to be correspondingly increased. For example, Figure 3 shows an electromagnetic heating circuit that can be applied to a four-burner electromagnetic heating appliance. The four control circuits and the heating main circuits connected thereto in the figure respectively correspond to four burners.

[0058] In Figure 2 the shown embodiment, it has been described that both the first resistor R1 and the second resistor R2 are current sampling resistors. Correspondingly, the control circuit can collect the current sampling resistors through a sampling circuit. Figure 4 This is a schematic structure of an electromagnetic heating circuit provided by the present application Figure 3 As Figure 4 shown, the electromagnetic heating circuit further includes: a first current sampling circuit 213 and a second current sampling circuit 223.

[0059] Among them, the first end of the first current sampling circuit 213 is connected to the negative output end of the rectifier circuit 200, and the second end of the first current sampling circuit 213 is connected to the second end of the first control circuit 212. The first control circuit 212 is used to detect the current of the first resistor R1 through the first current sampling circuit 213 and control the first heating main circuit 211 to heat according to the current of the first resistor R1.

[0060] The input end of the second current sampling circuit 223 is connected to the negative output end of the rectification circuit 200, and the output end of the second current sampling circuit 223 is connected to the output end of the second control circuit 222; the second control circuit 222 is used to detect the current of the second resistor R2 through the second current sampling circuit 223, and control the second heating main circuit 221 to heat according to the current of the second resistor R2.

[0061] The heating main circuit in the above embodiment will be further introduced below. Figure 5 Structural schematic of an electromagnetic heating circuit provided by this application Figure 4 . As Figure 5 shown, the first heating main circuit 211 includes: a first filter circuit 2111, a first resonant circuit 2112, a first insulated gate bipolar transistor IGBT Q1, and a first drive circuit 2113; the second heating main circuit 221 includes: a second filter circuit 2211, a second resonant circuit 2212, a second insulated gate bipolar transistor IGBT Q2, and a second drive circuit 2213.

[0062] Among them, the positive output end of the rectification circuit 200 is connected to the first input end of the first filter circuit 2111, the first output end of the first filter circuit 2111 is connected to the first end of the first resonant circuit 2112, the second end of the first resonant circuit 2112 is connected to the collector of the first IGBT Q1, the second output end of the first filter circuit 2111 is connected to the emitter of the first IGBT Q1 and connected to the first ground GND1, and the second output end of the first filter circuit 2111 is connected to the second end of the first resistor R1; the gate of the first IGBT Q1 is connected to the output end of the first drive circuit 2113, and the input end of the first drive circuit 2113 is connected to the first end of the first control circuit 212.

[0063] The first control circuit 212 is specifically used to detect the current of the first resistor R1, and send a pulse width modulation signal to the first drive circuit 2113 according to the current of the first resistor R1; the first drive circuit 2113 is used to drive the first IGBT Q1 to conduct or disconnect according to the pulse width modulation signal, so as to control the first resonant circuit 2112 to heat.

[0064] Among them, the positive output terminal of the rectifier circuit 200 is connected to the first input terminal of the second filter circuit 2211. The first output terminal of the second filter circuit 2211 is connected to the first end of the second resonant circuit 2212. The second end of the second resonant circuit 2212 is connected to the collector of the second IGBT Q2. The second output terminal of the second filter circuit 2211 is connected to the emitter of the second IGBT Q2 and is connected to the second ground point GND2. The second output terminal of the second filter circuit 2211 is connected to the second end of the second resistor R2. The gate of the second IGBT Q1 is connected to the output terminal of the second drive circuit 2213. The input terminal of the second drive circuit 2213 is connected to the first end of the second control circuit 222.

[0065] The second control circuit 222 is specifically configured to detect the current of the second resistor R2, and send a pulse width modulation signal to the second drive circuit 2213 according to the current of the second resistor R2. The second drive circuit 2213 is configured to drive the second IGBT Q2 to conduct or disconnect according to the pulse width modulation signal, so as to control the second resonant circuit 2212 to heat up.

[0066] In Figure 5 Based on the circuit shown, for example, as Figure 6 shown, the first filter circuit 2111 includes: a first filter inductor L10 and a first filter capacitor C10. Among them, the positive output terminal of the rectifier circuit 200 is connected to the first end of the first filter inductor L10. The first filter capacitor C10 is connected between the second end of the first filter inductor L10 and the second end of the first resistor R1. The first end of the first filter capacitor C10 is further connected to the first end of the first resonant circuit 2112.

[0067] The second filter circuit 2211 includes: a second filter inductor L20 and a second filter capacitor C20. Among them, the positive output terminal of the rectifier circuit 200 is connected to the first end of the second filter inductor L20. The second filter capacitor C20 is connected between the second end of the second filter inductor L20 and the second end of the second resistor R2. The first end of the second filter capacitor C20 is further connected to the first end of the second resonant circuit 2212.

[0068] The first resonant circuit 2112 includes: a first resonant inductor L11 and a first resonant capacitor C11. The first end of the parallel connection of the first resonant inductor L11 and the first resonant capacitor C11 is connected to the second end of the first filter inductor L10. The second end of the parallel connection of the first resonant inductor L11 and the first resonant capacitor C11 is connected to the collector of the first IGBT Q1.

[0069] The second resonant circuit 2212 includes: a second resonant inductor L21 and a second resonant capacitor C21. The first end of the parallel combination of the second resonant inductor L21 and the second resonant capacitor C21 is connected to the second end of the second filter inductor L20, and the second end of the parallel combination of the second resonant inductor L21 and the second resonant capacitor C21 is connected to the collector of the second IGBT Q2.

[0070] The working process of the electromagnetic heating circuit will be described. By way of example, the first filter circuit 2111 filters the current output by the rectifier circuit 200 and then outputs it to the first resonant circuit 2112. The first control circuit 212 outputs a pulse width modulation signal to the first drive circuit 2113. The first drive circuit 2113 drives the first IGBT Q1 to conduct or turn off according to the pulse width modulation signal, so that the first resonant circuit 2112 generates resonance for heating.

[0071] Similarly, the second filter circuit 2211 filters the current output by the rectifier circuit 200 and then outputs it to the second resonant circuit 2212. The second control circuit 222 outputs a pulse width modulation signal to the second drive circuit 2213. The second drive circuit 2213 drives the second IGBT Q2 to conduct or turn off according to the pulse width modulation signal, so that the second resonant circuit 2212 generates resonance for heating.

[0072] Since the reference grounds of the two heating circuits are different, the interference when the two heating circuits heat simultaneously is small. In addition, the first filter inductor L10 in the first filter circuit 2111 and the second filter inductor L20 in the second filter circuit 2211 also reduce the mutual interference during simultaneous heating.

[0073] Based on the above embodiments, as Figure 7 shown, the electromagnetic heating circuit further includes: a mains input circuit 300, and the mains input circuit 300 is connected to two-phase input terminals of the rectifier circuit 200. Optionally, the mains input circuit 300 may include a filter circuit for filtering the mains current and then outputting it to the rectifier circuit 200.

[0074] This application also provides an electromagnetic heating appliance, including the electromagnetic heating circuit in any of the above embodiments.

[0075] In several embodiments provided by the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of modules is only a logical function division. In actual implementation, there may be other division methods. For example, multiple modules can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces, and the indirect coupling or communication connection of devices or modules can be in electrical, mechanical or other forms.

[0076] Those of ordinary skill in the art can understand that all or part of the steps for implementing the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps including the above method embodiments; and the foregoing storage medium includes various media that can store program codes, such as ROM, RAM, magnetic disks or optical discs.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, and not to limit them; although the embodiments of the present application have been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the embodiments of the present application.

Claims

1. An electromagnetic heating circuit, characterized in that, Comprising: A rectifier circuit (200), a first main heating circuit (211), a first resistor R1, a first control circuit (212), a first current sampling circuit (213), a second main heating circuit (221), a second resistor R2, a second control circuit (222), and a second current sampling circuit (223); Wherein, the rectifier circuit (200) is used to rectify the input current, and the positive output terminal of the rectifier circuit (200) is respectively connected to the first end of the first main heating circuit (211) and the first end of the second main heating circuit (221); The first end of the first current sampling circuit (213) is connected to the negative output terminal of the rectifier circuit (200), and the second end of the first current sampling circuit (213) is connected to the second end of the first control circuit (212); The second end of the first main heating circuit (211) is connected to the first end of the first control circuit (212), the first end of the first resistor R1 is connected to the negative output terminal of the rectifier circuit (200), and the second end of the first resistor R1 is connected to the third end of the first main heating circuit (211) and connected to a first grounding point; The first control circuit (212) is connected to the first grounding point; The first end of the second current sampling circuit (223) is connected to the negative output terminal of the rectifier circuit (200), and the second end of the second current sampling circuit (223) is connected to the second end of the second control circuit (222); The second end of the second main heating circuit (221) is connected to the first end of the second control circuit (222), the first end of the second resistor R2 is connected to the negative output terminal of the rectifier circuit (200), and the second end of the second resistor R2 is connected to the third end of the second main heating circuit (221) and connected to a second grounding point; The second control circuit (222) is connected to the second grounding point; The second grounding point and the first grounding point are different grounding points; The first control circuit (212) is used to detect the current of the first resistor R1 through the first current sampling circuit (213), and control the first main heating circuit (211) to heat according to the current of the first resistor R1; The second control circuit (222) is used to detect the current of the second resistor R2 through the second current sampling circuit (223), and control the second main heating circuit (221) to heat according to the current of the second resistor R2.

2. The electromagnetic heating circuit according to claim 1, characterized in that, The first main heating circuit (211) includes: a first filter circuit (2111), a first resonant circuit (2112), a first insulated gate bipolar transistor IGBT Q1, and a first drive circuit (2113); Among them, the positive output terminal of the rectifier circuit (200) is connected to the first input terminal of the first filter circuit (2111), the first output terminal of the first filter circuit (2111) is connected to the first end of the first resonant circuit (2112), the second end of the first resonant circuit (2112) is connected to the collector of the first IGBT Q1, the second output terminal of the first filter circuit (2111) is connected to the emitter of the first IGBT Q1 and is connected to the first grounding point, the gate of the first IGBT Q1 is connected to the output terminal of the first drive circuit (2113), and the input terminal of the first drive circuit (2113) is connected to the first end of the first control circuit (212); The first control circuit (212) is specifically configured to detect the current of the first resistor R1 and send a pulse width modulation signal to the first drive circuit (2113) according to the current of the first resistor R1; The first drive circuit (2113) is configured to drive the first IGBT Q1 to conduct or disconnect according to the pulse width modulation signal to control the first resonant circuit (2112) to heat up.

3. The electromagnetic heating circuit according to claim 1, wherein The second main heating circuit (221) includes: a second filter circuit (2211), a second resonant circuit (2212), a second insulated gate bipolar transistor IGBT Q2, and a second drive circuit (2213); Among them, the positive output terminal of the rectifier circuit (200) is connected to the first input terminal of the second filter circuit (2211), the first output terminal of the second filter circuit (2211) is connected to the first end of the second resonant circuit (2212), the second end of the second resonant circuit (2212) is connected to the collector of the second IGBT Q2, the second output terminal of the second filter circuit (2211) is connected to the emitter of the second IGBT Q2 and is connected to the second grounding point, the gate of the second IGBT Q2 is connected to the output terminal of the second drive circuit (2213), and the input terminal of the second drive circuit (2213) is connected to the first end of the second control circuit (222); The second control circuit (222) is specifically configured to detect the current of the second resistor R2 and send a pulse width modulation signal to the second drive circuit (2213) according to the current of the second resistor R2; The second drive circuit (2213) is configured to drive the second IGBT Q2 to conduct or disconnect according to the pulse width modulation signal to control the second resonant circuit (2212) to heat up.

4. The electromagnetic heating circuit according to claim 1, wherein The resistance values of the first resistor R1 and the second resistor R2 are both in the milliohm level.

5. The electromagnetic heating circuit according to claim 2, wherein The first filtering circuit (2111) includes: a first filtering inductor L10 and a first filtering capacitor C10; wherein, the positive output terminal of the rectifying circuit (200) is connected to the first end of the first filtering inductor L10, the first filtering capacitor C10 is connected between the second end of the first filtering inductor L10 and the second end of the first resistor R1, and the first end of the first filtering capacitor C10 is further connected to the first end of the first resonant circuit (2112).

6. The electromagnetic heating circuit according to claim 3, wherein The second filtering circuit (2211) includes: a second filtering inductor L20 and a second filtering capacitor C20; wherein, the positive output terminal of the rectifying circuit (200) is connected to the first end of the second filtering inductor L20, the second filtering capacitor C20 is connected between the second end of the second filtering inductor L20 and the second end of the second resistor R2, and the first end of the second filtering capacitor C20 is further connected to the first end of the second resonant circuit (2212).

7. The electromagnetic heating circuit according to claim 1, wherein The electromagnetic heating circuit further includes: a mains input circuit (300), and the mains input circuit (300) is connected to the input terminal of the rectifying circuit (200).

8. An electromagnetic heating appliance, characterized in that, including: The electromagnetic heating circuit according to any one of claims 1-7.

Images