Circuit board assembly, cooking utensil and control method of cooking utensil

Abstract

The invention discloses a circuit board assembly, a cooking utensil and a control method of the cooking utensil. The circuit board assembly comprises a control chip, a first capacitor, a switching circuit and a detection path, the first capacitor is used for being connected with the first inductance coil to form an electromagnetic heating resonance circuit together with the first inductance coil, and the two ends of the first capacitor are connected with a first connecting terminal and a second connecting terminal which are used for being connected with the first inductance coil respectively; wherein the first connecting terminal is used for connecting a power supply; the switching circuit is connected with the second connecting terminal and is used for opening or closing resonance; the detection path is connected to the first connection terminal and the second connection terminal and is used for outputting a first voltage signal representing the voltage of the first connection terminal and a second voltage signal representing the voltage of the second connection terminal; the control chip comprises a first pin and a second pin which are respectively used for acquiring a first voltage signal and a second voltage signal; the control chip controls the voltage of the first pin and the second pin according to the first voltage signal and the second voltage signal.

Description

Technical Field

[0001] The present application relates to the technical field of cooking appliances, and more particularly to a circuit board assembly for an electromagnetic heating cooking appliance, a cooking appliance, and a control method for a cooking appliance. Background Art

[0002] Existing electromagnetic heating cooking appliances generally achieve heating through the oscillation of inductors and capacitors. To ensure that the oscillation is in a resonant state, a detection path generally needs to be added between the capacitor and the inductor. Since the resonant voltage is generally relatively high, the detection path uses multiple resistors in series for sampling. However, if the resistors get damp, the sampling will be inaccurate, and at this time, the electromagnetic heating cooking appliance can only report an error to remind the user to repair.

[0003] The prior art generally solves the problem of resistor dampness by coating the resistors with moisture-proof paint, but this technical solution has many disadvantages. It not only increases the cost, but also the quality of the moisture-proof paint itself is difficult to control, and sometimes it has the opposite effect.

[0004] Therefore, there is a need for a circuit board assembly, a cooking appliance including the circuit board assembly, and a control method for a cooking appliance including the circuit board assembly to at least partially solve the above problems. Summary of the Invention

[0005] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further elaborated in the Detailed Description section. The Summary of the Invention section of the present application does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the protection scope of the claimed technical solution.

[0006] To at least partially solve the above problems, a first aspect of the present application provides a circuit board assembly for an electromagnetic heating cooking appliance, which includes:

[0007] A first capacitor, which is used to be connected in series with a first inductor coil of the electromagnetic heating cooking appliance to jointly form an electromagnetic heating resonant circuit with the first inductor coil. Both ends of the first capacitor are respectively connected with a first connection terminal and a second connection terminal for connecting the first inductor coil, wherein the first connection terminal is used to connect the power supply;

[0008] A switch circuit, connected to the second connection terminal, for turning on or off the resonance;

[0009] A detection path, connected between the first connection terminal and the second connection terminal, for outputting a first voltage signal representing the voltage of the first connection terminal and a second voltage signal representing the voltage of the second connection terminal; and

[0010] The control chip includes a first pin and a second pin. Both the first pin and the second pin are connected to the detection path. Among them, the first pin is used to obtain the first voltage signal, and the second pin is used to obtain the second voltage signal;

[0011] Among them, the control chip controls the voltage of the first pin according to the first voltage signal, and / or controls the voltage of the second pin according to the second voltage signal.

[0012] According to the present application, when the detection path is affected by moisture, the control chip can adjust the voltage of the first pin or the second pin, so that a larger pressure difference is applied to the detection path, thereby changing the current in the detection path, making the detection path generate heat, and then evaporating the moisture of the components in the detection path. Compared with the prior art, there is no need to apply moisture-proof paint, reducing costs.

[0013] Optionally, the detection path includes:

[0014] The first detection path includes a first voltage-dividing resistor component and a first grounding resistor component connected in series. The resistance value of the first voltage-dividing resistor component is less than the preset resistance upper limit. The first end of the first voltage-dividing resistor component is connected to the first connection terminal, the second end of the first voltage-dividing resistor component is connected to the first pin, one end of the first grounding resistor component is connected to the second end of the first voltage-dividing resistor component, and the other end of the first grounding resistor component is grounded, and

[0015] The second detection path includes a second voltage-dividing resistor component and a second grounding resistor component connected in series. The resistance value of the second voltage-dividing resistor component is less than the preset resistance upper limit. The first end of the second voltage-dividing resistor component is connected to the second connection terminal, the second end of the second voltage-dividing resistor component is connected to the second pin, one end of the second grounding resistor component is connected to the second end of the second voltage-dividing resistor component, and the other end of the second grounding resistor component is grounded,

[0016] According to the present application, the first detection path is used to detect the first voltage signal representing the voltage of the first connection terminal, and the second detection path is used to detect the second voltage signal representing the voltage of the second connection terminal. By setting two circuits to detect the first voltage signal and the second voltage signal respectively, the signals of the first detection path and the second detection path do not interfere with each other, which is convenient for accurately detecting the voltage signal across the first capacitor.

[0017] Optionally, the value range of the preset resistance upper limit is [50 kΩ, 200 kΩ].

[0018] According to the present application, when the resistance value is less than 50, the current flowing through the resistor is too large, which is likely to damage the control chip; when the resistance value is greater than 200, the current flowing through the resistor is too small, and the anti-interference ability is poor.

[0019] Optionally, the switch circuit includes a first power switch transistor;

[0020] The collector of the first power switch transistor is connected to the second connection terminal, the emitter of the first power switch transistor is grounded, and the gate of the first power switch transistor is connected to the control chip.

[0021] According to the present application, compared with ordinary switches, the power switch transistor has the advantages of high efficiency, high reliability, low cost, etc., and can quickly turn on or off the electromagnetic resonance function of the cooking appliance.

[0022] Optionally, the control chip includes a high-impedance resistance component, a pull-down resistance component, and a selection switch;

[0023] The high-impedance resistance component is connected in series with the pull-down resistance component, and the common end of the two is connected to the first free end of the selection switch. The end of the high-impedance resistance component that is not connected to the pull-down resistance component is connected to the function pin, the end of the pull-down resistance component that is not connected to the high-impedance resistance component is grounded, and the second free end of the selection switch is connected to the function pin.

[0024] Wherein, the resistance of the high-impedance resistance component is higher than that of the pull-down resistance component, and the function pin is the first pin or the second pin.

[0025] According to the present application, the control chip can control the selection switch to conduct the first free end or the second free end according to the first voltage and the second voltage; when the circuit board can resonate normally, the selection switch conducts the first free end, and at this time the control chip has a high-impedance state and can detect the first voltage and the second voltage; when the circuit board cannot resonate normally, the selection switch conducts the second free end, and the control chip can adjust the voltage at the first pin and the second pin to realize dehumidification of the components in the detection path.

[0026] Optionally, the circuit board assembly further includes a rectification module, the input end of the rectification module is used to connect to the mains, and the output end of the rectification module is connected to the first connection terminal.

[0027] According to the present application, the rectification module is used to provide a DC voltage for charging and energy storage of the first capacitor.

[0028] The second aspect of the present application provides a cooking appliance, including:

[0029] A cooking container for holding food ingredients, the cooking container includes a magnetic material;

[0030] A first inductance coil, disposed below the cooking container;

[0031] For the circuit board assembly according to any one of the first aspects, the first capacitor is connected to the first inductance coil to form an electromagnetic heating resonance circuit.

[0032] A third aspect of the present application provides a control method for a cooking appliance according to the second aspect, the control method comprising:

[0033] Controlling the switch circuit to turn on the resonance effect of the electromagnetic heating resonance circuit;

[0034] Obtaining a first voltage signal and a second voltage signal of the detection path;

[0035] When it is determined that the first voltage signal and the second voltage signal are abnormal resonance signals, controlling the switch circuit to turn off the resonance effect of the electromagnetic heating resonance circuit, and setting the voltage of the first pin and / or the second pin of the control chip to a low level.

[0036] According to the present application, if the first voltage signal and the second voltage signal are abnormal resonance signals, it indicates that moisture may enter the circuit board assembly, causing the electronic components to be damaged due to moisture. Outputting a low level to the first pin and the second pin, so that the current flowing through the detection path is relatively large, which can heat the detection path and evaporate the moisture entering the circuit board assembly.

[0037] Optionally, determining that the first voltage signal and the second voltage signal are abnormal resonance signals includes at least one of the following situations:

[0038] The first voltage signal is greater than a first preset value;

[0039] The second voltage signal is greater than a second preset value.

[0040] According to the present application, the method for determining that the first voltage signal and the second voltage signal are abnormal resonance signals is simple.

[0041] Optionally, after adjusting the first pin and / or the second pin of the control chip to a low level, the control method further includes:

[0042] Making the voltage of the first pin and / or the second pin periodically switch between a low level and a high level, wherein the duration ranges of the high level and the low level are both 4 - 6 s.

[0043] According to the present application, when the first pin and the second pin are at high level, the current in the detection path is small and the heat generation is low, thereby preventing the temperature from being too high. By periodically switching between low level and high level at the first pin and the second pin, the temperature can be prevented from being too high to burn out the circuit while evaporating water vapor for repair.

[0044] Optionally, the control method further includes:

[0045] Recording the number of times the voltage of the first pin and / or the second pin periodically switches between high level and low level;

[0046] When the number of times reaches the first preset cycle number, re-acquire the first voltage signal and the second voltage signal, and control the switch circuit to turn on the resonance function of the electromagnetic heating resonance circuit.

[0047] According to the present application, when the number of times of periodic switching reaches the first preset cycle number, the automatic repair program is completed, and the cooking appliance can resume normal operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The following drawings of the present application are used as part of the present application to understand the present application. The embodiments of the present application and their descriptions shown in the drawings are used to explain the principles of the present application.

[0049] In the drawings:

[0050] Figure 1 is an exploded schematic view of a cooking appliance according to a specific embodiment of the present application;

[0051] Figure 2 is Figure 1 a circuit schematic diagram in the circuit board assembly shown;

[0052] Figure 3 is Figure 1 an equivalent circuit schematic diagram of the control chip in the circuit board assembly shown;

[0053] Figure 4 is Figure 1 a step schematic diagram of the control method of the cooking appliance shown;

[0054] Figure 5 is Figure 1 a step schematic diagram of the automatic repair program of the cooking appliance shown.

[0055] Description of the reference numerals:

[0056] 10: Cooking appliance

[0057] 11: Pot body

[0058] 12: Lid

[0059] 13: Cooking container / pot liner

[0060] 20: Heating device

[0061] 21: First inductance coil

[0062] 100: Circuit board assembly

[0063] 101: First capacitor

[0064] 102: First connection terminal

[0065] 103: Second connection terminal

[0066] 104: First power switch transistor

[0067] 105: Rectification module

[0068] 106: Switching circuit

[0069] 110: Equivalent circuit

[0070] 113: Selection switch

[0071] 115A: High impedance state resistor component

[0072] 115B: Pull-down resistor component

[0073] 120: Detection path

[0074] 121: First detection path

[0075] 122: Second detection path

[0076] 123: First voltage-dividing resistor component

[0077] 123A: First end of the first voltage-dividing resistor component

[0078] 123B: Second end of the first voltage-dividing resistor component

[0079] 124: First grounding resistor component

[0080] 125: Second voltage-dividing resistor component

[0081] 125A: First end of the second voltage-dividing resistor component

[0082] 125B: Second end of the second voltage-dividing resistor component

[0083] 126: Second grounding resistor component

[0084] 130: Control chip

[0085] 131: First pin

[0086] 132: The second pin

[0087] 133: The first free end

[0088] 134: The second free end

[0089] 135: The fixed end

[0090] 136: The functional pin Detailed implementation manners

[0091] In the following description, numerous specific details are given to provide a more thorough understanding of the present application. However, it is obvious to those skilled in the art that the present application can be implemented without one or more of these details. In other instances, some technical features well known to those skilled in the art are not described to avoid confusion with the present application.

[0092] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, they specify the presence of the described features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0093] The ordinal numbers such as "first" and "second" cited in the present application are only identifiers and do not have any other meanings, such as a specific order, etc. Moreover, for example, the term "first component" does not imply the existence of a "second component" by itself, and the term "second component" does not imply the existence of a "first component" by itself.

[0094] It should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer" and similar expressions used herein are only for illustrative purposes and are not restrictive.

[0095] The present application provides a circuit board assembly for an electromagnetic heating cooking appliance, a control method for a cooking appliance including the circuit board assembly, and a cooking appliance including the circuit board assembly. The cooking appliance according to the present application is an electromagnetic heating cooking appliance.

[0096] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings.

[0097] As Figure 1As shown, the cooking appliance 10 according to the specific embodiments of the present application may include a cooking pot body 11 and a lid body 12. Generally, a cooking container 13 (such as a pot liner) is disposed inside the cooking pot body 11. The cooking pot body 11 may have a receiving portion in a cylindrical shape (or other shapes), and the pot liner 13 can be freely placed into or taken out from the receiving portion to facilitate the cleaning of the pot liner 13. The pot liner 13 is, for example, configured as a rotating body formed by a pot wall and having an opening and an inner cavity. The capacity of the pot liner 13 is generally below 6L. For example, the capacity of the pot liner 13 can be 2L or 4L, etc. At least part of the pot liner 13 is made of a ferromagnetic material to achieve electromagnetic induction heating.

[0098] The cooking appliance 10 includes a heating device 20. The heating device 20 includes a first inductance coil 21 and a circuit board assembly 100. The cooking container 13 is placed within the electromagnetic induction area of the first inductance coil 21, and the heating of the cooking container 13 is achieved through the first inductance coil 21. The first inductance coil 21 can be, for example, disposed on the side of the cooking container 13 for heating the side of the cooking container 13, or the first inductance coil 21 can be disposed below the cooking container 13 for heating the bottom of the cooking container 13. Alternatively, multiple first inductance coils 21 can be simultaneously provided to heat the side and the bottom of the cooking container 13, and the heating effect is more three-dimensional.

[0099] As Figure 2 and Figure 3 shown, the circuit board assembly 100 includes a control chip 130, a first capacitor 101, a switching circuit 106, and a detection path 120. The first capacitor 101 is used to connect with the first inductance coil 21 to jointly form an electromagnetic heating resonance circuit with the first inductance coil. Therefore, the first capacitor 101 is correspondingly disposed with the first inductance coil 21. Both ends of the first capacitor 101 are respectively connected with a first connection terminal 102 and a second connection terminal 103 for connecting the first inductance coil 21. The first capacitor 101 and the first inductance coil 21 are connected end to end to form an electromagnetic resonance circuit, thereby achieving heating. Among them, the first connection terminal 102 is used to connect to a power source.

[0100] The switch circuit 106 is connected to the second connection terminal 103 and is used to turn on or off the electromagnetic resonance function of the cooking appliance 10. The switch circuit 106 includes, for example, a first power switch tube 104. The first power switch tube 104 is configured as an insulated gate bipolar transistor, for example, and is used to efficiently and rapidly control the energy storage and discharge of the resonance circuit. The first power switch tube 104 is also correspondingly arranged with the first inductance coil 21. The collector of the first power switch tube 104 is connected to the second connection terminal 103, the emitter of the first power switch tube 104 is grounded, and the gate of the first power switch tube 104 is connected to the output pin of the control chip 130. The gate of the first power switch tube 104 is used to access a periodic trigger signal for turning on the first power switch tube 104. When there is a trigger signal, the first power switch tube 104 is turned on and the first capacitor 101 is charged. When the trigger signal is zero and the first power switch tube 104 is turned off, the first capacitor 101 discharges and forms an electromagnetic oscillation with the first inductance coil 21, thereby achieving heating.

[0101] The detection path 120 is connected to the first connection terminal 102 and the second connection terminal 103 and is used to output a first voltage signal representing the voltage of the first connection terminal 102 and a second voltage signal representing the voltage of the second connection terminal 103. As Figure 2 shown, the detection path 120 includes, for example, a first detection path 121 and a second detection path 122. The first detection path 121 includes a first voltage-dividing resistor component 123 and a first grounding resistor component 124 connected in series. The resistance value of the first voltage-dividing resistor component 123 is less than a preset resistance upper limit. The first end 123A of the first voltage-dividing resistor component is connected to the first connection terminal 102, the second end 123B of the first voltage-dividing resistor component is connected to the first pin 131, one end of the first grounding resistor component 124 is connected to the second end 123B of the first voltage-dividing resistor component, and the other end of the first grounding resistor component 124 is grounded. The second detection path 122 includes a second voltage-dividing resistor component 125 and a second grounding resistor component 126 connected in series. The resistance value of the second voltage-dividing resistor component 125 is less than a preset resistance upper limit. The first end 125A of the second voltage-dividing resistor component is connected to the second connection terminal 103, the second end 125B of the second voltage-dividing resistor component is connected to the second pin 132, one end of the second grounding resistor component 126 is connected to the second end 125B of the second voltage-dividing resistor component, and the other end of the second grounding resistor component 126 is grounded. Preferably, the value range of the preset resistance upper limit is [50 kΩ, 200 kΩ], and is set to 100 kΩ, for example. When the resistance value is less than 50 kΩ, the current flowing through the circuit is too large and it is easy to damage the control chip; when the resistance value is greater than 200 kΩ, the current flowing through the circuit is too small and the anti-interference ability of the circuit is poor.

[0102] The control chip 130 includes a first pin 131 and a second pin 132. Both the first pin 131 and the second pin 132 are connected to the detection path 120. Among them, the first pin 131 is used to obtain a first voltage signal, and the second pin 132 is used to obtain a second voltage signal. The control chip 130 controls the voltage of the first pin 131 according to the first voltage signal. The control chip 130 also controls the voltage of the second pin 132 according to the second voltage signal. For example, the control chip 130 is configured such that both the first pin 131 and the second pin 132 can switch functions between input / output pins and analog-to-digital conversion pins. Among them, the analog-to-digital conversion pin has both a high-impedance state and a grounding function at the same time. The control chip 130 is configured as an MCU or an MPU chip, for example.

[0103] It can be understood that the voltage at the second end 123B of the first voltage-dividing resistor component has the same voltage waveform as the voltage at the first connection terminal 102, and the amplitude is reduced proportionally. Similarly, the voltage at the second end 125B of the second voltage-dividing resistor component has the same voltage waveform as the voltage at the second connection terminal 103, and the amplitude is reduced proportionally. Thus, the control chip 130 can monitor the voltages at the second end 123B of the first voltage-dividing resistor component and the second end 125B of the second voltage-dividing resistor component through the first pin 131 and the second pin 132 to monitor the voltages at the first connection terminal 102 and the second connection terminal 103. Then, the control chip 130 selects an appropriate timing to turn on the first power switch 104. For example, the first power switch 104 is turned on when the voltages at the first connection terminal 102 and the second connection terminal 103 cross zero, thereby protecting the first power switch 104 and extending its service life.

[0104] Of course, the gate of the first power switch 104 can also be connected to other control chips similar to the control chip 130. That is to say, the cooking appliance 10 can include multiple control chips (one of which is the control chip 130), and the control chips are communicatively connected to each other, so as to achieve cooperative control.

[0105] Such as Figure 3As shown, inside the control chip 130, the circuit connected to the first pin 131 and the second pin 132 can be represented by an equivalent circuit 110. Among them, the equivalent circuit 110 includes a high-impedance resistance component 115A, a pull-down resistance component 115B, and a selection switch 113. For simplicity of description, hereinafter, the first pin 131 and the second pin 132 are referred to as function pins 136. The selection switch 113 is a single-pole double-throw switch. The high-impedance resistance component 115A is connected in series with the pull-down resistance component 115B, and the common end of the two is connected to the first free end 133 of the selection switch 113. One end of the high-impedance resistance component 115A that is not connected to the pull-down resistance component 115B is directly connected to the function pin 136. One end of the pull-down resistance component 115B that is not connected to the high-impedance resistance component 115A is grounded. The second free end 134 of the selection switch 113 is connected to the first pin 131. The fixed end 135 of the selection switch 113 is connected to other parts inside the control chip 130. The control chip 130 determines which free end the fixed end 135 of the selection switch 113 is connected to by executing a chip selection function, thereby setting the function of the function pin 136. When the control chip 130 controls the fixed end 135 to be connected to the first free end 133, the function pin 136 is selected as an analog-to-digital conversion pin, and the first voltage signal at the second end 123B of the first voltage-dividing resistance component 123 or the second voltage signal at the second end 125B of the second voltage-dividing resistance component 125 enters the control chip 130 through the high-impedance resistance component 115A. The high-impedance resistance component 115A is configured as a resistor with a relatively large resistance value, for example, a resistance value greater than 1 MΩ, so as to ensure a small current entering the control chip 130 when the function pin 136 is switched to an analog-to-digital conversion pin, that is, to provide a high-impedance function and avoid damage to the control chip 130. When the control chip 130 controls the fixed end 135 to be connected to the second free end 134, the function pin 136 is selected as an input / output pin. At this time, the control chip 130 can both detect the first voltage signal at the second end 123B of the first voltage-dividing resistance component 123 and the second voltage signal at the second end 125B of the second voltage-dividing resistance component 125, and can also output signals to the second end 123B of the first voltage-dividing resistance component 123 and the second end 125B of the second voltage-dividing resistance component 125.

[0106] Each of the first voltage-dividing resistor component 123, the first grounding resistor component 124, the second voltage-dividing resistor component 125, and the second grounding resistor component 126 can be equivalent to a resistor. Preferably, at least one of the first voltage-dividing resistor component 123, the first grounding resistor component 124, the second voltage-dividing resistor component 125, and the second grounding resistor component 126 is formed by connecting a plurality of resistors in series. Alternatively, at least one of the first voltage-dividing resistor component 123, the first grounding resistor component 124, the second voltage-dividing resistor component 125, and the second grounding resistor component 126 is configured as a single resistor. The first voltage-dividing resistor component 123, the first grounding resistor component 124, the second voltage-dividing resistor component 125, and the second grounding resistor component 126 can be composed of multiple resistors connected in series or only a single resistor, with flexible settings. Connecting a plurality of resistors in series facilitates adjusting the resistance value. Configuring as a single resistor is beneficial for simplifying the circuit structure.

[0107] At least one of the first voltage-dividing resistor component 123, the first grounding resistor component 124, the second voltage-dividing resistor component 125, and the second grounding resistor component 126 is not coated with moisture-proof paint on its surface. For example, none of the first voltage-dividing resistor component 123, the first grounding resistor component 124, the second voltage-dividing resistor component 125, and the second grounding resistor component 126 is coated with moisture-proof paint. In this application, a preset resistance upper limit is set. The resistance values of the first voltage-dividing resistor component 123 and the second voltage-dividing resistor component 125 are small, so the current in the circuit is large, less affected by water vapor, and has stronger anti-interference ability. Therefore, there is no need to coat moisture-proof paint, which not only saves costs but also avoids the problem that the quality of moisture-proof paint is difficult to control.

[0108] As Figure 2 shown, the circuit board assembly 100 further includes a rectification module 105. The input end of the rectification module 105 is used to connect to the mains power, and the output end of the rectification module 105 is connected to the first connection terminal 102. The rectification module 105 is used to provide a DC voltage for charging and energy storage for the first capacitor 101.

[0109] As Figure 4 shown, preferably, the control method of the cooking appliance 10 includes: during the preset resonance working period (the period when the first power switch tube 104 is turned off and the resonance circuit discharges) of the electromagnetic resonance circuit, switching both the first pin 131 and the second pin 132 to analog-to-digital conversion pins to detect the first voltage signal at the second end 123B of the first voltage-dividing resistor component and the second voltage signal at the second end 125B of the second voltage-dividing resistor component; when the first voltage signal and the second voltage signal are abnormal resonance signals, controlling the operation of the cooking appliance 10 according to the first voltage signal and the second voltage signal. Among them, the first voltage signal and the second voltage signal being abnormal resonance signals includes at least one of the following situations: the first voltage signal is greater than the first preset value; the second voltage signal is greater than the second preset value.

[0110] When the cooking appliance 10 is operating normally, the selection switch 113 is switched to the first free end 133, and the first pin 131 and the second pin 132 are switched to analog-to-digital conversion pins, so that the high-impedance resistance component 115A and the first voltage-dividing resistance component 123 or the second voltage-dividing resistance component 125 inside the control chip 130 form a series circuit. The high-impedance resistance component 115A is configured as a resistor with a relatively large resistance value, for example, configured as a resistor with a resistance value greater than 1 MΩ, which can ensure that the current entering the control chip 130 is small and effectively protect the control chip 130. If the first voltage signal and the second voltage signal are abnormal resonance signals and cannot resonate and heat normally, it indicates that the cooking appliance 10 has a fault. For example, moisture may enter the circuit board assembly 100, causing the electronic components to be damaged due to moisture.

[0111] Furthermore, the control method further includes that when the first voltage signal and the second voltage signal are abnormal resonance signals, the selection switch 113 is switched to the second free end 134, the first pin 131 and the second pin 132 are both switched to input / output pins, and the first power switch tube 104 is controlled to stop working, and then the cooking appliance 10 is controlled to operate according to the first voltage signal and the second voltage signal. Switching the first pin 131 and the second pin 132 to input / output pins facilitates detecting the first voltage signal and the second voltage signal. At the same time, controlling the first power switch tube 104 to stop working to turn off the resonance function facilitates the control chip 130 to judge the cause of the fault.

[0112] Controlling the cooking appliance 10 to operate according to the first voltage signal and the second voltage signal specifically includes: when the voltage value of the first voltage signal is within the first preset voltage range and the voltage value of the second voltage signal is within the second preset voltage range, controlling the cooking appliance 10 to report a fault; when the voltage value of the first voltage signal is greater than the first preset value, that is, the upper limit of the first preset voltage range, and / or when the voltage value of the second voltage signal is greater than the second preset value, that is, the upper limit of the second preset voltage range, controlling the cooking appliance 10 to execute an automatic repair program.

[0113] When the chip select is an input / output pin, if the detection path 120 does not have a fault, the first voltage signal and the second voltage signal should be the divided voltages of the power supply voltage. If the values of the first voltage signal and the second voltage signal are within the normal range at this time (i.e., the divided voltages of the power supply voltage), but the resonant circuit cannot work properly, it indicates that it may not be the electronic components of the detection path 120 that have failed, such as failure due to moisture, and a fault needs to be reported for further maintenance. If the values of the first voltage signal and the second voltage signal are not within the normal range (greater than the normal upper limit), it indicates that it is very likely that the electronic components of the detection path 120 have failed due to moisture (the resistance values of the first voltage-dividing resistor component 123 and the second voltage-dividing resistor component 125 decrease after being affected by moisture). Therefore, the next automatic repair program can be entered to try to repair the fault.

[0114] Optionally, the lower limit of the first preset voltage range is set to the product of the first preset voltage and the first ratio, and the upper limit of the first preset voltage range, that is, the first preset value, is set to the product of the first preset voltage and the second ratio. The first preset voltage is the divided voltage value of the power supply voltage by the first voltage-dividing resistor component 123 and the first grounding resistor component 124. Optionally, the lower limit of the second preset voltage range is set to the product of the second preset voltage and the third ratio, and the upper limit of the second preset voltage range, that is, the second preset value, is set to the product of the second preset voltage and the fourth ratio. The second preset voltage is the divided voltage value of the power supply voltage by the second voltage-dividing resistor component 125 and the second grounding resistor component 126. The first preset voltage and the second preset voltage are determined according to the divided voltage values of the power supply voltage by the first voltage-dividing resistor component 123 and the first grounding resistor component 124 and the divided voltage values of the power supply voltage by the second voltage-dividing resistor component 125 and the second grounding resistor component 126 when the circuit is fault-free, so as to further determine the first preset voltage range and the second preset voltage range, which is clear and reasonable. Preferably, the value range of the first ratio and / or the third ratio is [85%, 95%]. Preferably, the value range of the second ratio and / or the fourth ratio is [105%, 115%].

[0115] Specifically, such as Figure 5As shown, the automatic repair program of the cooking appliance 10 includes: when the voltage value of the first voltage signal is greater than the upper limit of the first preset voltage range, that is, the first preset value, making the voltage of the first pin 131 a low level; and / or when the voltage value of the second voltage signal is greater than the upper limit of the second preset voltage range, that is, the second preset value, making the voltage of the second pin 132 a low level. When the first pin 131 and the second pin 132 are at a low level, the pressure difference across the first voltage-dividing resistor assembly 123 and the second voltage-dividing resistor assembly 125 is relatively large. Since the resistance values of the first voltage-dividing resistor assembly 123 and the second voltage-dividing resistor assembly 125 are small, a relatively large current can be formed in the circuit. According to the energy consumption formula P = U2 / R, the larger the voltage and the smaller the resistance, the greater the energy consumption. A certain amount of heat can be generated at the first voltage-dividing resistor assembly 123 and the second voltage-dividing resistor assembly 125, thereby evaporating the water vapor entering the circuit board assembly 100 and repairing the faults caused by the moisture of the electronic components.

[0116] Furthermore, the automatic repair program further includes: when the voltage value of the first voltage signal is greater than the upper limit of the first preset voltage range, making the voltage of the first pin 131 periodically switch between a low level and a high level. In each cycle, after controlling the voltage of the first pin 131 to be at a low level for a first duration, then controlling the voltage of the first pin 131 to be at a high level for a second duration; and / or when the voltage value of the second voltage signal is greater than the upper limit of the second preset voltage range, making the voltage of the second pin 132 periodically switch between a low level and a high level. In each cycle, after controlling the voltage of the second pin 132 to be at a low level for a third duration, then controlling the voltage of the second pin 132 to be at a high level for a fourth duration. When the first pin 131 and the second pin 132 are at a high level, the pressure difference across the first voltage-dividing resistor assembly 123 and the second voltage-dividing resistor assembly 125 is small, and the heat at the first voltage-dividing resistor assembly 123 and the second voltage-dividing resistor assembly 125 decreases, thereby preventing the temperature from being too high. By periodically switching the first pin 131 and the second pin 132 between a low level and a high level, the circuit can be prevented from being burned out due to excessive temperature while evaporating the water vapor for repair. Preferably, the value range of the first duration and / or the third duration is [4s, 6s], such as 5s, and / or the value range of the second duration and / or the fourth duration is [4s, 6s], such as 5s.

[0117] In the automatic repair program, after the voltage of the first pin 131 is periodically switched between a high level and a low level for a first preset number of cycles, the automatic repair program ends, and a first voltage signal is detected. When the voltage value of the first voltage signal is still higher than the upper limit of the first preset voltage range, the automatic repair program is executed again. In the automatic repair program, after the voltage of the second pin 132 is periodically switched between a high level and a low level for a second preset number of cycles, the automatic repair program ends, and a second voltage signal is detected. When the voltage value of the second voltage signal is still higher than the upper limit of the second preset voltage range, the automatic repair program is executed again. When the voltage values of the first voltage signal and the second voltage signal cannot return to normal after one execution of the automatic repair program, the automatic repair program can be selected to be executed again to enhance the effect of automatic repair and make it more intelligent and efficient. Preferably, the first preset number of cycles and / or the second preset number of cycles is from 1 to 12 times. The first preset number of cycles and the second preset number of cycles can be the same.

[0118] During the repeated execution of the automatic repair program, if the voltage value of the first voltage signal continuously exceeds the upper limit of the first preset voltage range for a first preset number of times, the cooking appliance 10 is controlled to report a fault. During the repeated execution of the automatic repair program, if the voltage value of the second voltage signal continuously exceeds the upper limit of the second preset voltage range for a second preset number of times, the cooking appliance 10 is controlled to report a fault. When the voltage values of the first voltage signal and the second voltage signal still cannot return to normal after multiple repeated executions of the automatic repair program, the automatic repair fails, indicating that the circuit does not fail due to moisture, so a fault needs to be reported for further inspection. Preferably, the first preset number of times and / or the second preset number of times is from 2 to 5 times. The first preset number of times and the second preset number of times can be the same.

[0119] Further, after the automatic repair program ends, the first voltage signal and the second voltage signal are detected again. When the voltage value of the first voltage signal is within the first preset voltage range and the voltage value of the second voltage signal is within the second preset voltage range, both the first pin 131 and the second pin 132 are switched to analog-to-digital conversion pins, and the first power switch 104 is controlled to work normally. When the voltage values of the first voltage signal and the second voltage signal return to normal after the automatic repair program, it indicates that the moisture in the circuit has been evaporated through the automatic repair program, and the detection path 120 can work normally. At this time, both the first pin 131 and the second pin 132 are switched to analog-to-digital conversion pins, and the first power switch 104 is controlled to work normally. After the resonant circuit works, the detected first voltage signal and second voltage signal are normal resonant signals, indicating that the automatic repair program is successful.

[0120] Under normal circumstances, when the circuit board component is damp, the above-mentioned automatic repair program is executed. When the number of times the voltage of the first pin 131 and / or the second pin 132 periodically switches between the high level and the low level reaches the first preset cycle number, the effect of heating and dehumidifying can be achieved. At this time, the cooking appliance 10 can resume normal operation, the control chip 130 resumes the analog-to-digital conversion function of the first pin 131 and / or the second pin 132, re-acquires the first voltage signal and the second voltage signal, and controls the switch circuit 106 (specifically, the first power switch tube 104) to turn on the resonance of the electromagnetic heating resonance circuit.

[0121] In summary, the first pin 131 is at least used to output a low level to the second end 123B of the first voltage-dividing resistor component 123 in the input / output pin function. When the first pin 131 outputs a low level to the second end 123B of the first voltage-dividing resistor component in the input / output pin function, the voltage difference across the first voltage-dividing resistor component 123 is relatively large, so the flowing current is relatively large, and a certain amount of heat can be formed at the first voltage-dividing resistor component 123 to evaporate the water vapor entering the circuit board component 100. Similarly, the second pin 132 is at least used to output a low level to the second end 125B of the second voltage-dividing resistor component 125 in the input / output pin function, so that the voltage difference across the second voltage-dividing resistor component 125 is relatively large, and the flowing current is relatively large, and a certain amount of heat can be formed at the second voltage-dividing resistor component 125 to evaporate the water vapor entering the circuit board component.

[0122] It can be understood that the above-mentioned automatic repair program includes the automatic repair process of the first detection path 121 and the automatic repair process of the second detection path 122. The automatic repair processes of heating and dehumidifying of the first detection path 121 and the second detection path 122 can be executed independently of each other. For example, the first detection path 121 and the second detection path 122 only execute their own heating and dehumidifying processes only when they find that they may be faulty due to moisture, regardless of whether the other detection path is faulty or whether it is heating and dehumidifying. For another example, after the first detection path 121 and the second detection path 122 find that their dehumidification is successful and their functions are restored to normal, they can independently end their own automatic repair processes, regardless of whether the other detection path is faulty or whether the heating and dehumidification is successful. Only when both the first detection path 121 and the second detection path 122 are fault-free, the automatic repair program is considered to be completely executed.

[0123] The processes and steps described in all the above preferred embodiments are only examples. Unless adverse effects occur, various processing operations can be performed in an order different from the above process. The step order of the above process can also be increased, combined or deleted according to actual needs.

[0124] Unless otherwise defined, the technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the technical field of this application. The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application. The features described in one embodiment herein can be applied to another embodiment alone or in combination with other features, unless the feature is not applicable or otherwise stated in that other embodiment.

[0125] This application has been illustrated by the above embodiments, but it should be understood that the above embodiments are only for the purposes of illustration and example, and this application is not limited to the above embodiments. According to the teachings of this application, more variations and modifications can be made, and these variations and modifications all fall within the scope claimed by this application.

Claims

1. A circuit board assembly for an electromagnetic heating cooking appliance, characterized in that, Comprising: A first capacitor, which is used to be connected to a first inductance coil of an electromagnetic heating cooking appliance to jointly form an electromagnetic heating resonance circuit with the first inductance coil. Both ends of the first capacitor are respectively connected with a first connection terminal and a second connection terminal for connecting the first inductance coil, wherein the first connection terminal is used to connect to a power supply; A switch circuit, connected to the second connection terminal, for turning on or off the resonance; A detection path, connected between the first connection terminal and the second connection terminal, for outputting a first voltage signal representing the voltage of the first connection terminal and a second voltage signal representing the voltage of the second connection terminal; And A control chip, including a first pin and a second pin, both the first pin and the second pin are connected to the detection path. Wherein, the first pin is used to obtain the first voltage signal, and the second pin is used to obtain the second voltage signal; Wherein, the control chip controls the voltage of the first pin according to the first voltage signal, and / or controls the voltage of the second pin according to the second voltage signal.

2. The circuit board assembly according to claim 1, characterized in that The detection path includes: A first detection path, including a first voltage-dividing resistor component and a first grounding resistor component connected in series. The resistance value of the first voltage-dividing resistor component is less than a preset resistance upper limit. The first end of the first voltage-dividing resistor component is connected to the first connection terminal, the second end of the first voltage-dividing resistor component is connected to the first pin, one end of the first grounding resistor component is connected to the second end of the first voltage-dividing resistor component, and the other end of the first grounding resistor component is grounded; A second detection path, including a second voltage-dividing resistor component and a second grounding resistor component connected in series. The resistance value of the second voltage-dividing resistor component is less than the preset resistance upper limit. The first end of the second voltage-dividing resistor component is connected to the second connection terminal, the second end of the second voltage-dividing resistor component is connected to the second pin, one end of the second grounding resistor component is connected to the second end of the second voltage-dividing resistor component, and the other end of the second grounding resistor component is grounded.

3. The circuit board assembly according to claim 2, wherein, The value range of the preset resistance upper limit is [50 kΩ, 200 kΩ].

4. The circuit board assembly according to claim 1, wherein The switch circuit includes a first power switch tube; The collector of the first power switch tube is connected to the second connection terminal, the emitter of the first power switch tube is grounded, and the gate of the first power switch tube is connected to the control chip.

5. The circuit board assembly according to claim 1, wherein The control chip includes a high-impedance resistor component, a pull-down resistor component and a selection switch; The high-impedance resistor component and the pull-down resistor component are connected in series, and their common end is connected to the first free end of the selection switch. The end of the high-impedance resistor component not connected to the pull-down resistor component is connected to a function pin, the end of the pull-down resistor component not connected to the high-impedance resistor component is grounded, and the second free end of the selection switch is connected to the function pin, Wherein, the resistance of the high-impedance resistor component is higher than that of the pull-down resistor component, and the function pin is the first pin or the second pin.

6. The circuit board assembly according to claim 1, wherein The circuit board assembly further includes a rectification module, the input end of the rectification module is used to connect to the mains power, and the output end of the rectification module is connected to the first connection terminal.

7. A cooking appliance, characterized in that, Comprising: A cooking container for containing food materials, and the cooking container includes a magnetic material; A first inductance coil disposed below the cooking container; According to the circuit board assembly according to any one of claims 1 to 6, the first capacitor is connected to the first inductance coil to form an electromagnetic heating resonance circuit.

8. A control method for a cooking appliance according to claim 7, characterized in that, The control method includes: Controlling the switch circuit to turn on the resonance effect of the electromagnetic heating resonance circuit; Obtaining the first voltage signal and the second voltage signal of the detection path; When it is determined that the first voltage signal and the second voltage signal are abnormal resonance signals, controlling the switch circuit to turn off the resonance effect of the electromagnetic heating resonance circuit, and setting the voltage of the first pin and / or the second pin of the control chip to a low level.

9. The control method according to claim 8, wherein Determining that the first voltage signal and the second voltage signal are abnormal resonance signals includes at least one of the following situations: The first voltage signal is greater than a first preset value; The second voltage signal is greater than a second preset value.

10. The control method according to claim 8, wherein, After adjusting the first pin and / or the second pin of the control chip to a low level, the control method further includes: Periodically switching the voltage of the first pin and / or the second pin between a low level and a high level, wherein the duration ranges of both the high level and the low level are 4 - 6s.

11. The control method according to claim 10, wherein The control method further includes: Recording the number of times the voltage of the first pin and / or the second pin is periodically switched between a high level and a low level; When the number of times reaches the number of times of the first preset period, re-obtaining the first voltage signal and the second voltage signal, and controlling the switch circuit to turn on the resonance effect of the electromagnetic heating resonance circuit.

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