Circuit board assembly and electromagnetic heating cooking utensil

Abstract

The utility model discloses a circuit board assembly and an electromagnetic heating cooking utensil, the circuit board assembly comprises at least one first working circuit, and the first working circuit comprises a first capacitor, a first power switch tube, a first adjusting capacitor and a first adjusting resistor. The first capacitor is used for being connected with the first inductance coil in series so as to form an electromagnetic heating resonance circuit together with the first inductance coil, 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, and the first connecting terminal is used for being connected to a power supply; the collector of the first power switch tube is connected with the second connection terminal, and the emitter of the first power switch tube is grounded; a first end of the first adjusting capacitor is connected to a grid electrode of the first power switch tube, and a second end of the first adjusting capacitor is used for accessing a trigger signal for conducting the first power switch tube; one end of the first adjusting resistor is connected to the first end of the first adjusting capacitor, and the other end of the first adjusting resistor is grounded.

Description

Technical Field

[0001] The present application relates to the technical field of cooking appliances, and in particular to a circuit board assembly for an electromagnetic heating device and an electromagnetic heating cooking appliance comprising the circuit board assembly. Background Art

[0002] In order to achieve more three-dimensional heating, current electromagnetic heating cooking appliances have one or more side-wound heating coils installed along the insulation ring on the side of the inner pot, which work together with the bottom heating coil installed under the inner pot to improve the heating effect.

[0003] Usually, in order to ensure that the side-winding heating coils and the bottom heating coils can work properly, detection circuits are provided at both ends of each set of side-winding heating coils and the bottom heating coils, which increases both the cost and the area of ​​the circuit board assembly.

[0004] Therefore, a circuit board assembly, an electromagnetic heating device and an electromagnetic heating cooking appliance are needed to at least partially solve the above problems. Utility Model Content

[0005] A series of simplified concepts are introduced in the utility model content section, which will be further described in detail in the detailed implementation section. The utility model content section of this application does not mean to attempt to define the key features and essential technical features of the technical solution claimed for protection, nor does it mean to attempt to determine the scope of protection of the technical solution claimed for protection.

[0006] In order to at least partially solve the above problems, the first aspect of the present application provides a circuit board assembly for an electromagnetic heating device, which includes at least one first working circuit, wherein the first working circuit includes:

[0007] a first capacitor, the first capacitor is used to be connected in series with the first inductor to form an electromagnetic heating resonant circuit together with the first inductor, and two ends of the first capacitor are respectively connected to a first connection terminal and a second connection terminal for connecting to the first inductor, wherein the first connection terminal is used to be connected to a power source;

[0008] A first power switch tube, wherein the collector of the first power switch tube is connected to the second connection terminal, and the emitter of the first power switch tube is grounded;

[0009] a first regulating capacitor, wherein a first end of the first regulating capacitor is connected to a gate of the first power switch tube, and a second end of the first regulating capacitor is used to access a trigger signal for turning on the first power switch tube; and

[0010] A first regulating resistor, one end of the first regulating resistor is connected to the first end of the first regulating capacitor, and the other end of the first regulating resistor is grounded.

[0011] According to the present application, the second end of the first regulating capacitor is used to access the periodic trigger signal for turning on the first power switch tube, and the first end of the first regulating capacitor is connected to the gate of the first power switch tube to turn on the first power switch tube. When there is a trigger signal, the first power switch tube is turned on and the first capacitor is charged. After the trigger signal, after the voltage at the first end of the first regulating capacitor drops, when the first power switch tube is turned off, the first capacitor is discharged and forms an electromagnetic oscillation circuit with the first inductor coil to achieve electromagnetic heating. Therefore, the longer the first power switch tube is turned on, the more the first capacitor is charged, and the greater the electromagnetic heating power. By setting the duration of the first power switch tube being turned off to a suitable value, it is ensured that the first capacitor is fully discharged, and the working state of the first power switch tube when it is turned on next time is relatively stable. By adjusting the parameter values ​​of the first regulating capacitor and the first regulating resistor, the duration of the signal at the first end of the first regulating capacitor can be adjusted, and then the duration of the first power switch tube being turned on in each cycle can be adjusted, that is, the charging duration of the first capacitor is adjusted, and then the power during heating is adjusted, and there is no need to change the trigger signal connected to the second end of the first regulating capacitor, which is conducive to the standardization of the control program. This setting does not require a detection circuit and simplifies the circuit board assembly.

[0012] Optionally, the first working circuit also includes a first amplifying module, the input end of the first amplifying module is connected to the first end of the first adjusting capacitor, the output end of the first amplifying module is connected to the gate of the first power switching tube, and the first amplifying module is used to amplify the signal connected to the input end of the first amplifying module and output the amplified signal from the output end.

[0013] According to the present application, a first amplification module is provided to amplify the trigger signal to ensure that the first power switch tube is normally turned on.

[0014] Optionally, the first working circuit includes a pressure relief circuit, which is connected between the gate of the first power switch tube and the output end of the first amplification module, wherein the pressure relief circuit includes a first diode, the positive terminal of the first diode is connected to the gate of the first power switch tube, and the negative terminal of the first diode is connected to the output end of the first amplification module.

[0015] According to the present application, by setting a pressure relief circuit, when the first power switch tube needs to be turned off, the voltage at the gate of the first power switch tube can be released in time to ensure that the first power switch tube is turned off in time, which is conducive to accurately controlling the heating power.

[0016] Optionally, the pressure relief circuit further includes a first resistor, and the first resistor is connected in series with the first diode;

[0017] The first working circuit also includes a second resistor, one end of the second resistor is connected to the gate of the first power switch tube, and the other end of the second resistor is connected to the output end of the first amplification module.

[0018] According to the present application, the speed at which the first power switch tube is turned on and off can be controlled by adjusting the resistance values ​​of the first resistor and the second resistor.

[0019] Optionally, the first working circuit includes a first zener diode, a cathode terminal of the first zener diode is connected to a gate of the first power switch tube, and an anode terminal of the first zener diode is grounded.

[0020] According to the present application, the first voltage stabilizing diode is provided to ensure the stability of the voltage at the gate of the first power switch tube, thereby ensuring that the first power switch tube operates normally when turned on.

[0021] Optionally, the circuit board assembly further includes a control module and at least one second working circuit, and the second working circuit includes:

[0022] a second capacitor, the second capacitor being connected in series with the second inductor to form an electromagnetic heating resonant circuit together with the second inductor, the second capacitor having two ends respectively connected to a third connection terminal and a fourth connection terminal for connecting to the second inductor, wherein the third connection terminal is used to connect to a power source;

[0023] a second power switch tube, wherein the collector of the second power switch tube is connected to the fourth connection terminal, and the emitter of the second power switch tube is grounded; and

[0024] a detection circuit, the detection circuit being connected to the third connection terminal, the fourth connection terminal and the control module, and being used to feed back the voltage at the third connection terminal and the fourth connection terminal to the control module,

[0025] The first output end of the control module is connected to the second end of the first regulating capacitor, and the second output end of the control module is connected to the gate of the second power switch tube.

[0026] According to the present application, a detection circuit is set to detect the voltage value across the second capacitor to ensure that the second power switch tube is turned on in a suitable state. Optionally, the detection circuit includes:

[0027] A first detection path, the first detection path includes at least two first path resistors connected in series, one end of the first detection path is connected to the third connection terminal, the other end of the first detection path is grounded, and a common end of two adjacent first path resistors is connected to the first input end of the control module; and

[0028] A second detection path, the second detection path includes at least two second path resistors connected in series, one end of the second detection path is connected to the fourth connection terminal, the other end of the second detection path is grounded, and the common end of two adjacent second path resistors is connected to the second input end of the control module.

[0029] According to the present application, by setting up a first detection path and a second detection path, the voltage division signal of each first path resistor and the second path resistor is transmitted to the control module, so as to compare the voltage values ​​across the second inductor coil to ensure that the state of the second power switch tube is stable when it is turned on.

[0030] Optionally, the second working circuit also includes a second amplifier circuit, the input end of the second amplifier circuit is connected to the second output end of the control module, the output end of the second amplifier circuit is connected to the gate of the second power switch tube, and the second amplifier circuit is used to amplify the signal of the second output end of the control module and output the amplified signal from the output end.

[0031] According to the present application, a second amplifier circuit is provided to amplify the signal of the control module to ensure that the second power switch tube is normally turned on.

[0032] Optionally, the second working circuit further includes a second zener diode, a cathode terminal of the second zener diode is connected to the gate of the second power switch tube, and an anode terminal of the second zener diode is grounded.

[0033] According to the present application, the second voltage stabilizing diode is provided to ensure the stability of the voltage at the gate of the second power switch tube, thereby ensuring that the second power switch tube operates normally when turned on.

[0034] Optionally, the second working circuit includes a second diode, an anode terminal of the second diode is connected to the gate of the second power switch tube, and a cathode terminal of the second diode is connected to the positive electrode of the DC power supply.

[0035] According to the present application, the gate voltage of the second power switch tube is limited to a specified voltage by setting a second diode to avoid damage to the circuit board assembly due to overvoltage. Optionally, the circuit board assembly also includes a rectifier module, the input end of the rectifier module is used to connect to the mains, and the output end of the rectifier module is connected to the first connection terminal and the third connection terminal.

[0036] According to the present application, the rectifier module is used to provide a DC voltage for storing energy in the resonant circuit.

[0037] A second aspect of the present application provides an electromagnetic heating cooking appliance, comprising:

[0038] A cooking container for holding food, wherein the cooking container comprises a ferromagnetic material;

[0039] A circuit board assembly including a control module and a second working circuit according to the first aspect above;

[0040] at least one first inductor coil, the first inductor coil being arranged corresponding to the first working circuit, and two ends of the first inductor coil being respectively connected to the first connection terminal and the second connection terminal; and

[0041] At least one second inductor coil, the second inductor coil is arranged corresponding to the second working circuit, the two ends of the second inductor coil are respectively connected to the third connection terminal and the fourth connection terminal, wherein the cooking container is used to be placed in the electromagnetic induction area of ​​the first inductor coil and the second inductor coil.

[0042] According to the present application, the cooking container includes ferromagnetic material, so as to cooperate with the first inductor coil and the second inductor coil of the electromagnetic heating device to realize electromagnetic induction heating. For the first inductor coil, the power switch tube is turned on after the electromagnetic oscillation energy is exhausted, and no detection circuit is set, so that the circuit board assembly can be simplified. At the same time, different powers can be set for the first inductor coil and the second inductor coil, respectively, and the heating control is more flexible.

[0043] Optionally, two ends of the first inductor are connected to the first connection terminal and the second connection terminal respectively through two first wires.

[0044] Two ends of the second inductor are connected to the third connection terminal and the fourth connection terminal respectively through two second wires.

[0045] The first conductive line does not contact the second conductive line.

[0046] According to the present application, it is avoided that the magnetic fields of the first wire and the second wire interfere with each other, which may affect the heating control and even cause damage to the cooking appliance.

[0047] Optionally, a minimum distance between the first conductive wire and the second conductive wire is not less than 1 cm.

[0048] According to the present application, by setting a minimum distance, the first wire and the second wire are prevented from being too close to each other, thereby further preventing interference from affecting the normal operation of the cooking appliance.

[0049] Optionally, the first inductance coil is used to be arranged on a side of the cooking container, and the second inductance coil is used to be arranged below the cooking container.

[0050] According to the present application, the first inductance coil is used to heat the side of the cooking container, and the second inductance coil is used to heat the bottom of the cooking container, so that the heating is more three-dimensional and the heating effect is better.

[0051] Optionally, the number of the first inductor coils is 1, 2 or 3; and / or

[0052] The number of the second inductor is 1.

[0053] According to the present application, providing a plurality of first inductance coils is beneficial to more fully and evenly heating the cooking container, and setting the number of second inductance coils to 1 is beneficial to reducing the area and number of components of the circuit board assembly and saving space.

[0054] Optionally, the first inductor coil is sleeved on the outer circumference of the cooking container.

[0055] According to the present application, the first induction coil surrounds the outer circumference of the cooking container to facilitate more complete and uniform heating of the cooking container. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The following drawings of the present application are used as a part of the present application for understanding the present application. The drawings show the embodiments of the present application and their descriptions, which are used to explain the principle of the present application.

[0057] In the attached figure:

[0058] Figure 1 It is an exploded schematic diagram of an electromagnetic heating cooking device according to a specific embodiment of the present application;

[0059] Figure 2 for Figure 1 The structural schematic diagram of the electromagnetic heating device shown;

[0060] Figure 3 for Figure 2 A circuit diagram of the circuit board assembly shown;

[0061] Figure 4 for Figure 3 The enlarged schematic diagram of the circuit at A in the middle;

[0062] Figure 5 for Figure 3 A timing diagram of a first end signal and a second end signal of a first regulating capacitor.

[0063] Description of reference numerals:

[0064] 10: Electromagnetic heating cooking utensils

[0065] 11: Claypot

[0066] 12: Cover

[0067] 13: Cooking container / pot

[0068] 14: Bottom coil disc assembly

[0069] 15: First conductor

[0070] 16: Second wire

[0071] 20: Electromagnetic heating device

[0072] 21: First inductor coil

[0073] 22: Second inductor

[0074] 100: Circuit board assembly

[0075] 110: First working circuit

[0076] 111: First capacitor

[0077] 111A: First connection terminal

[0078] 111B: Second connection terminal

[0079] 112: First power switch tube

[0080] 113: First adjustment capacitor

[0081] 113A: The first terminal of the first adjustment capacitor

[0082] 113B: The second end of the first adjustment capacitor

[0083] 114: First adjustment resistor

[0084] 115: First amplification module

[0085] 116: Pressure relief circuit

[0086] 116A: First diode

[0087] 116B: First resistor

[0088] 117: Second resistor

[0089] 118: The first voltage regulator diode

[0090] 120: Second working circuit

[0091] 121: Second capacitor

[0092] 121A: The third connection terminal

[0093] 121B: Fourth connection terminal

[0094] 122: Second power switch tube

[0095] 123: Detection circuit

[0096] 123A: First detection channel

[0097] 123B: First path resistance

[0098] 123C: Second detection channel

[0099] 123D: Second path resistance

[0100] 123E: Public port

[0101] 123F: Connection terminal

[0102] 124: Second amplifier circuit

[0103] 124A: Second amplifier circuit input terminal

[0104] 124B: second amplifier circuit output terminal

[0105] 125: Second diode

[0106] 126: Second voltage zener diode

[0107] 130: Rectifier module

[0108] 131: Rectifier module input terminal

[0109] 132: Rectifier module output terminal DETAILED DESCRIPTION

[0110] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present application. However, it is apparent to those skilled in the art that the present application can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present application, some technical features well known in the art are not described.

[0111] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit 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, it indicates the presence of the features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0112] Ordinal numbers such as “first” and “second” cited in the present application are merely identifications and do not have any other meanings, such as a specific order, etc. Moreover, for example, the term “first component” itself does not imply the existence of the “second component”, and the term “second component” itself does not imply the existence of the “first component”.

[0113] It should be noted that the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside" and similar expressions used in this document are for illustrative purposes only and are not limiting.

[0114] The present application provides a circuit board assembly for an electromagnetic heating device, an electromagnetic heating device including the circuit board assembly, and an electromagnetic heating cooking appliance including the electromagnetic heating device.

[0115] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings.

[0116] like Figure 1 As shown, the electromagnetic heating cooking utensil 10 according to the specific embodiment of the present application may include a pot body 11 and a cover body 12. Usually, a cooking container 13 (such as a pot 13) is arranged in the pot body 11. The pot body 11 may have a storage portion in a cylindrical shape (or other shapes), and the pot 13 can be freely placed in the storage portion or taken out from the storage portion to facilitate the cleaning of the pot 13. The pot 13 is, for example, constructed as a rotating body with an opening and an inner cavity formed by a pot wall. The capacity of the pot 13 is usually less than 6L, for example, the capacity of the pot 13 can be 2L or 4L, etc. The pot 13 is at least partially made of ferromagnetic material, thereby realizing electromagnetic induction heating.

[0117] The electromagnetic heating cooking appliance 10 includes an electromagnetic heating device 20, which includes at least one first inductor coil 21, at least one second inductor coil 22 and a circuit board assembly 100. The cooking container 13 is placed in the electromagnetic induction area of ​​the first inductor coil 21 and the second inductor coil 22, and the cooking container 13 is heated by the first inductor coil 21 and the second inductor coil 22.

[0118] The first inductor 21 is, for example, disposed on the side of the cooking container 13, and is used to heat the side of the cooking container 13. Preferably, the first inductor 21 is sleeved on the outer circumference of the cooking container 13, so as to facilitate more sufficient and uniform heating of the cooking container 13. The electromagnetic heating cooking utensil 10 includes a bottom coil disk assembly 14, which is disposed at the bottom of the pot body 11. At least one second inductor 22 is disposed on the bottom coil disk assembly 14, and the second inductor 22 is used to heat the bottom of the cooking container 13 during cooking. Through the cooperation of the first inductor 21 and the second inductor 22, the heating is more three-dimensional and the heating effect is better.

[0119] like Figure 2 As shown, the two ends of the first inductor 21 are connected to the circuit board assembly 100 through two first wires 15. The two ends of the second inductor 22 are connected to the circuit board assembly 100 through two second wires 16. The first wire 15 and the second wire 16 are not in contact with each other, so as to avoid interference between the first wire 15 and the second wire 16, which may cause the inductance of the first inductor 21 and the second inductor 22 to change and affect the heating effect. Furthermore, the minimum distance between the first wire 15 and the second wire 16 is not less than 1 cm, so as to avoid interference between the first wire 15 and the second wire 16 due to being too close, which may affect the normal operation of the electromagnetic heating cooking device 10.

[0120] like Figure 3 As shown, the circuit board assembly 100 includes at least one first working circuit 110. The first working circuit 110 includes a first capacitor 111, and the first capacitor 111 is used to be connected in series with the first inductor 21 to form an electromagnetic heating resonant circuit together with the first inductor 21. The two ends of the first capacitor 111 are respectively connected with a first connection terminal 111A and a second connection terminal 111B for connecting the first inductor 21. The first connection terminal 111A is used to connect to a power supply. It can be understood that each first working circuit 110 corresponds to a first inductor 21, and the first connection terminal 111A and the second connection terminal 111B are respectively connected to the two ends of the first inductor 21 through two first wires 15. The first capacitor 111 and the first inductor 21 are connected end to end to form an electromagnetic resonant circuit in series.

[0121] like Figure 4 As shown, the first working circuit 110 includes a first power switch tube 112, and the first power switch tube 112 is configured as an insulated gate bipolar transistor, for example, for efficiently and quickly controlling the on and off of the first working circuit 110. The collector of the first power switch tube 112 is connected to the second connection terminal 111B, and the emitter of the first power switch tube 112 is grounded. The first working circuit 110 also includes a first adjustment capacitor 113 and a first adjustment resistor 114. Among them, the first end 113A of the first adjustment capacitor is connected to the gate of the first power switch tube 112, and the second end 113B of the first adjustment capacitor is used to access the trigger signal for turning on the first power switch tube 112. One end of the first adjustment resistor 114 is connected to the first end 113A of the first adjustment capacitor, and the other end of the first adjustment resistor 114 is grounded.

[0122] like Figure 5As shown, the second end 113B of the first regulating capacitor 113 is used to access the periodic trigger signal PWM1 that turns on the first power switch tube 112. The period of the trigger signal PWM1 is, for example, the second duration T2, and it lasts for the first duration T1 in one period. It can be understood that under the action of the first regulating capacitor 113 and the first regulating resistor 114, the first end 113A of the first regulating capacitor 113 forms a turn-on signal PWM2 with a period of the second duration T2. ​​In one period, the duration of the turn-on signal PWM2 is the third duration T3. The first end 113A of the first regulating capacitor 113 is connected to the gate of the first power switch tube 112 to turn on the first power switch tube 112. When there is a trigger signal PWM3, a turn-on signal PWM2 is generated, the first power switch tube 112 is turned on, and the first capacitor 111 is charged. After the trigger signal PWM3 passes and the turn-on signal PWM2 is zero, when the first power switch tube 112 is turned off, the first capacitor 111 is discharged, and an electromagnetic oscillation is formed with the first inductor 21 to achieve heating.

[0123] Therefore, the third duration T3 of the conduction signal PWM2 determines the conduction duration of the first power switch tube 112. The longer the conduction duration of the first power switch tube 112 is, the more the first capacitor 111 is charged, the more electromagnetic oscillation energy is, and the higher the electromagnetic heating power is. The third duration T3 can be adjusted by adjusting the parameter values ​​of the first adjustment capacitor 113 and the first adjustment resistor 114, and then the conduction duration of the first power switch tube 112 in each cycle is adjusted, that is, the charging duration of the first capacitor 111 is adjusted, and then the power during heating is adjusted. There is no need to change the trigger signal PWM3 connected to the second end 113B of the first adjustment capacitor 113, which is conducive to the standardization of the control program. For example, when the heating power is 200w, the third duration T3 is approximately 2us. Preferably, the third duration T3 does not exceed 5us. The third duration T3 can be calculated according to the following formula (1):

[0124] T3=1 / (2πRC) (1)

[0125] In formula (1), R is the resistance value of the first adjustment resistor 114 , and C is the capacitance value of the first adjustment capacitor 113 .

[0126] At the same time, the duration of the first power switch tube 112 being turned off can be set to a suitable value to ensure that the first capacitor 111 is fully discharged, and the working state of the first power switch tube 112 when it is turned on next time can be ensured to be relatively stable. For example, the first power switch tube 112 can be turned on again when the energy of the electromagnetic oscillation is exhausted or substantially exhausted (the collector voltage of the first power switch tube 112 is substantially zero or substantially zero). It can be understood that this can be achieved by controlling the second duration T2. ​​Therefore, the circuit board assembly 100 does not need to set a detection circuit for the oscillation circuit composed of the first capacitor 111 and the first inductor 21, which can simplify the circuit board assembly 100, so that the circuit board assembly 100 can be smaller to save space.

[0127] Furthermore, the first working circuit 110 further includes a first amplifying module 115, which is used to realize the function of signal amplification. The input end (such as pin 1) of the first amplifying module 115 is connected to the first end 113A of the first regulating capacitor, and the output end (such as pin 4) of the first amplifying module 115 is connected to the gate of the first power switch tube 112. The first amplifying module 115 is used to amplify the conduction signal PWM2 connected to the input end of the first amplifying module 115 and output the amplified conduction signal from the output end, so as to ensure that the gate potential of the first power switch tube 112 reaches a preset value and the first power switch tube 112 is normally turned on.

[0128] Preferably, the first working circuit 110 further includes a pressure relief circuit 116, which is connected between the gate of the first power switch tube 112 and the output end of the first amplification module 115. The pressure relief circuit 116 includes a first diode 116A, the positive terminal of the first diode 116A is connected to the gate of the first power switch tube 112, and the negative terminal of the first diode 116A is connected to the output end of the first amplification module 115. By providing the pressure relief circuit 116, when the conduction signal PWM2 drops, the voltage at the gate of the first power switch tube 112 can be released in time to ensure that the first power switch tube 112 is quickly turned off, so that the conduction time of the first power switch tube 112 can be accurately controlled, that is, the heating power can be accurately controlled.

[0129] Furthermore, the pressure relief circuit 116 further includes a first resistor 116B, which is connected in series with the first diode 116A. The first working circuit 110 further includes a second resistor 117, one end of which is connected to the gate of the first power switch tube 112, and the other end of which is connected to the output end of the first amplification module 115. The charging and discharging speed of the gate of the first power switch tube 112 can be controlled by adjusting the resistance values ​​of the first resistor 116B and the second resistor 117.

[0130] Optionally, the first working circuit 110 includes a first voltage stabilizing diode 118, the cathode end of the first voltage stabilizing diode 118 is connected to the gate of the first power switch tube 112, and the anode end of the first voltage stabilizing diode 118 is grounded. The first voltage stabilizing diode 118 can ensure the stability of the voltage at the gate of the first power switch tube 112, and ensure that the first power switch tube 112 works normally when it is turned on.

[0131] like Figure 3 As shown, the circuit board assembly 100 also includes at least one second working circuit 120, and the second working circuit 120 includes a second capacitor 121, a second power switch tube 122 and a detection circuit 123. Among them, the second capacitor 121 is used to be connected in series with the second inductor 22 to form an electromagnetic heating resonant circuit together with the second inductor 22. The two ends of the second capacitor 121 are respectively connected to a third connection terminal 121A and a fourth connection terminal 121B for connecting the second inductor 22, wherein the third connection terminal 121A is used to connect to a power supply. The collector of the second power switch tube 122 is connected to the fourth connection terminal 121B, and the emitter of the second power switch tube 122 is grounded. The detection circuit 123 is connected to the third connection terminal 121A and the fourth connection terminal 121B, and is used to collect the voltage at the third connection terminal 121A and the fourth connection terminal 121B. It can be understood that each second working circuit 120 corresponds to a second inductor 22 , and the third connection terminal 121A and the fourth connection terminal 121B are respectively connected to two ends of the first inductor 21 through two second wires 16 .

[0132] The circuit board assembly 100 generally further includes a control module (not shown), which is configured as an MCU chip, for example. The first output terminal of the control module is connected to the second terminal 113B of the first regulating capacitor, for outputting a preset trigger signal PWM3, and the second output terminal of the control module is connected to the gate of the second power switch tube 122, for controlling the conduction of the second power switch tube 122. In the second working circuit 120, the detection circuit 123 is connected to the control module, and the voltage at the third connection terminal 121A and the fourth connection terminal 121B is fed back to the control module. When the voltage at the third connection terminal 121A and the fourth connection terminal 121B is relatively stable, a conduction signal is sent to the gate of the second power switch tube 122 through the control module.

[0133] Furthermore, if Figure 3As shown, the detection circuit 123 includes a first detection path 123A and a second detection path 123C. Among them, the first detection path 123A includes at least two first path resistors 123B connected in series, one end of the first detection path 123A is connected to the third connection terminal 121A, and the other end of the first detection path 123A is grounded, wherein the common end 123E of two adjacent first path resistors 123B is connected to the first input end of the control module. It can be understood that the first detection path 123A forms a voltage divider circuit through a plurality of first path resistors 123B connected in series, and the voltage of the common end 123E is the same as the voltage waveform at the third connection terminal 121A, and the amplitude is proportionally reduced. Similarly, the second detection path 123C includes at least two second path resistors 123D connected in series, one end of the second detection path 123C is connected to the fourth connection terminal 121B, and the other end of the second detection path 123C is grounded, wherein the connection end 123F of two adjacent second path resistors 123D is connected to the second input end of the control module. It can be understood that the second detection path 123C forms a voltage divider circuit through a plurality of second path resistors 123D connected in series, and the voltage at the connection terminal 123F has the same waveform as the voltage at the fourth connection terminal 121B, and the amplitude is proportionally reduced. Thus, the control module can monitor the voltage at the third connection terminal 121A and the fourth connection terminal 121B by monitoring the voltage at the common terminal 123E and the connection terminal 123F, and, for example, turn on the second power switch tube 122 when the voltage at the third connection terminal 121A and the fourth connection terminal 121B passes zero.

[0134] The second working circuit 120 may further include a second amplifier circuit 124, wherein an input terminal 124A of the second amplifier circuit 124 is connected to a second output terminal of the control module, and an output terminal 124B of the second amplifier circuit 124 is connected to a gate of the second power switch tube 122, and the second amplifier circuit 124 is used to amplify a signal of the second output terminal of the control module and output the amplified signal from the output terminal 124B. The second amplifier circuit 124, for example, is composed of a plurality of triodes to form an amplifier circuit, which amplifies the signal input by the control module to ensure that the second power switch tube 122 is normally turned on.

[0135] Preferably, the second working circuit 120 further includes a second voltage stabilizing diode 126, the cathode end of the second voltage stabilizing diode 126 is connected to the gate of the second power switch tube 122, and the anode end of the second voltage stabilizing diode 126 is grounded. The second voltage stabilizing diode 126 is provided to ensure the stability of the voltage at the gate of the second power switch tube 122, thereby ensuring that the second power switch tube 122 works normally when turned on.

[0136] Preferably, the second working circuit 120 further includes a second diode 125, the anode end of the second diode 125 is connected to the gate of the second power switch tube 122, and the cathode end of the second diode 125 is connected to the positive pole of the DC power supply (e.g., +18V). By providing the second diode 125, the gate voltage of the second power switch tube 122 can be limited to a specified voltage to avoid damage to the circuit board assembly 100 caused by overvoltage. The second voltage stabilizing diode 126 and the second diode 125 provide double protection for the second power switch tube 122.

[0137] The circuit board assembly 100 generally further includes a rectifier module 130, wherein an input end 131 of the rectifier module 130 is used to connect to the mains, and an output end 132 of the rectifier module 130 is connected to the first connection terminal 111A and the third connection terminal 121A. The rectifier module 130 is used to connect to the mains, rectify the alternating current of the mains into direct current, and provide a direct current voltage for energy storage of the resonant circuit.

[0138] Preferably, the number of the first inductor coils 21 can be 1, 2 or 3, and the number of the second inductor coils 22 is 1. That is, the number of the correspondingly set first working circuits 110 is 1, 2 or 3, and the number of the second working circuits 120 is 1. Since the first working circuit 110 is not provided with a detection circuit similar to the detection circuit 123, the simultaneous provision of multiple first working circuits 110 has little effect on the area of ​​the circuit board assembly 100, and the provision of multiple first inductor coils 21 is conducive to more fully and evenly heating the cooking container 13. The number of the second inductor coils 22 is set to 1, which is conducive to reducing the area of ​​the circuit board assembly 100 and saving space. The first inductor coil 21 heats the cooking container 13 in the form of free oscillation, and is suitable for using a smaller heating power, for example, the power does not exceed 500w. The second inductor coil 22 works under the monitoring of the detection circuit 123, and a larger heating power can be set, for example, a power greater than or equal to 700w.

[0139] 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 a sequence different from the sequence of the above processes. The sequence of steps in the above processes can also be increased, merged or deleted according to actual needs.

[0140] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present application. The terms used herein are only for describing specific implementation purposes and are not intended to limit the present application. The features described herein in one embodiment may be applied to another embodiment individually or in combination with other features, unless the feature is not applicable or otherwise specified in the other embodiment.

[0141] The present application has been illustrated through the above-mentioned embodiments, but it should be understood that the above-mentioned embodiments are only for the purpose of example and explanation, and the present application is not limited to the above-mentioned embodiments. According to the teachings of the present application, more variations and modifications can be made, and these variations and modifications all fall within the scope of protection claimed by the present application.

Claims

1. A circuit board assembly for an electromagnetic heating device, characterized in that: The method comprises at least one first working circuit, wherein the first working circuit comprises: a first capacitor, the first capacitor is used to be connected in series with the first inductor to form an electromagnetic heating resonant circuit together with the first inductor, and two ends of the first capacitor are respectively connected to a first connection terminal and a second connection terminal for connecting to the first inductor, wherein the first connection terminal is used to be connected to a power source; A first power switch tube, wherein the collector of the first power switch tube is connected to the second connection terminal, and the emitter of the first power switch tube is grounded; a first regulating capacitor, wherein a first end of the first regulating capacitor is connected to a gate of the first power switch tube, and a second end of the first regulating capacitor is used to access a trigger signal for turning on the first power switch tube; and A first regulating resistor, one end of the first regulating resistor is connected to the first end of the first regulating capacitor, and the other end of the first regulating resistor is grounded.

2. The circuit board assembly according to claim 1, characterized in that: The first working circuit also includes a first amplifying module, the input end of the first amplifying module is connected to the first end of the first regulating capacitor, the output end of the first amplifying module is connected to the gate of the first power switch tube, and the first amplifying module is used to amplify the signal connected to the input end of the first amplifying module and output the amplified signal from the output end.

3. The circuit board assembly according to claim 2, characterized in that: The first working circuit includes a pressure relief circuit, which is connected between the gate of the first power switch tube and the output end of the first amplification module, wherein the pressure relief circuit includes a first diode, the positive terminal of the first diode is connected to the gate of the first power switch tube, and the negative terminal of the first diode is connected to the output end of the first amplification module.

4. The circuit board assembly according to claim 3, characterized in that: The pressure relief circuit further includes a first resistor, wherein the first resistor is connected in series with the first diode; The first working circuit also includes a second resistor, one end of the second resistor is connected to the gate of the first power switch tube, and the other end of the second resistor is connected to the output end of the first amplification module.

5. The circuit board assembly according to claim 1, characterized in that: The first working circuit includes a first voltage regulator diode, a cathode terminal of the first voltage regulator diode is connected to the gate of the first power switch tube, and an anode terminal of the first voltage regulator diode is grounded.

6. The circuit board assembly according to any one of claims 1 to 5, characterized in that: The circuit board assembly further includes a control module and at least one second working circuit, wherein the second working circuit includes: a second capacitor, the second capacitor being connected in series with the second inductor to form an electromagnetic heating resonant circuit together with the second inductor, the second capacitor having two ends respectively connected to a third connection terminal and a fourth connection terminal for connecting to the second inductor, wherein the third connection terminal is used to connect to a power source; a second power switch tube, wherein the collector of the second power switch tube is connected to the fourth connection terminal, and the emitter of the second power switch tube is grounded; and a detection circuit, the detection circuit being connected to the third connection terminal, the fourth connection terminal and the control module, and being used to feed back the voltage at the third connection terminal and the fourth connection terminal to the control module, The first output end of the control module is connected to the second end of the first regulating capacitor, and the second output end of the control module is connected to the gate of the second power switch tube.

7. The circuit board assembly according to claim 6, characterized in that: The second working circuit also includes a second amplifier circuit, the input end of the second amplifier circuit is connected to the second output end of the control module, the output end of the second amplifier circuit is connected to the gate of the second power switch tube, and the second amplifier circuit is used to amplify the signal of the second output end of the control module and output the amplified signal from the output end.

8. The circuit board assembly according to claim 6, characterized in that: The second working circuit also includes a second voltage regulator diode, a cathode terminal of the second voltage regulator diode is connected to the gate of the second power switch tube, and an anode terminal of the second voltage regulator diode is grounded.

9. The circuit board assembly according to claim 8, characterized in that: The second working circuit includes a second diode, an anode terminal of the second diode is connected to the gate of the second power switch tube, and a cathode terminal of the second diode is connected to the positive electrode of the DC power supply.

10. An electromagnetic heating cooking appliance, characterized in that: include: A cooking container for holding food, wherein the cooking container comprises a ferromagnetic material; The circuit board assembly according to any one of claims 6 to 9; at least one first inductor coil, the first inductor coil being arranged corresponding to the first working circuit, and two ends of the first inductor coil being connected to the first connection terminal and the second connection terminal respectively; and At least one second inductor coil, the second inductor coil is arranged corresponding to the second working circuit, the two ends of the second inductor coil are respectively connected to the third connection terminal and the fourth connection terminal, wherein the cooking container is used to be placed in the electromagnetic induction area of ​​the first inductor coil and the second inductor coil.

11. The electromagnetic heating cooking device according to claim 10, characterized in that: Two ends of the first inductor are connected to the first connection terminal and the second connection terminal respectively through two first wires. Two ends of the second inductor are connected to the third connection terminal and the fourth connection terminal respectively through two second wires. The first conductive line does not contact the second conductive line.

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