Control circuit and air fryer

Abstract

The invention discloses a control circuit and an air fryer. The control circuit comprises a frying basket detection module, a main control module, a variable frequency driving module and a heating control module, the frying basket detection module is used for generating a frying basket detection signal when it is detected that the frying basket is located in a preset area of the fryer; the main control module is used for generating a frequency conversion control signal and a heating control signal according to the frying basket detection signal; the variable-frequency driving module is used for responding to the variable-frequency control signal to generate a three-phase electric signal and outputting to the variable-frequency motor; the heating control module is used for controlling the heating pipe to work in response to the heating control signal. According to the air fryer, whether the frying basket is located in the preset area of the fryer or not is detected through the frying basket detection module, only when the frying basket is located in the preset area, the frying basket detection module generates the frying basket detection signal and outputs the frying basket detection signal to the main control module, the main control module controls the variable frequency motor and the heating pipe to work, and the use safety and reliability of the air fryer are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air fryers, in particular to a control circuit and an air fryer. BACKGROUND

[0002] An air fryer is a machine that can "fry" with air. Its working principle is "high-speed air circulation technology". It generates hot air by heating the heat pipe inside the machine, and then blows the hot air into the pot with a fan to heat the food. The hot air circulates in a closed space, uses the oil of the food itself to fry the food, so that the food dehydrates and the surface becomes golden and crispy, achieving the effect of frying.

[0003] After starting, the user can select heating temperature, heating mode and other working parameters through the keys on the display panel, so that the control circuit operates based on the selected parameters.

[0004] However, if the user operates improperly, the air fryer may run empty, which may cause the air fryer to malfunction, and even cause a safety accident. SUMMARY

[0005] In view of the above problems, the present application provides a control circuit and an air fryer to solve the above technical problems.

[0006] In a first aspect, the present application provides a control circuit for an air fryer, the control circuit comprising a basket detection module, a main control module, a variable frequency drive module and a heating control module, the main control module being connected with the basket detection module, the variable frequency drive module and the heating control module;

[0007] The basket detection module is configured to generate a basket detection signal and output the basket detection signal to the main control module when detecting that the basket of the air fryer is located in a preset area of the air fryer;

[0008] The main control module is configured to generate a variable frequency control signal and a heating control signal according to the basket detection signal and output the variable frequency control signal and the heating control signal;

[0009] The variable frequency drive module is configured to generate a three-phase electric signal and output the three-phase electric signal to a variable frequency motor of the air fryer in response to the variable frequency control signal, so as to drive the variable frequency motor to work;

[0010] The heating control module is configured to control a heating pipe of the air fryer to work in response to the heating control signal.

[0011] In a possible implementation manner of the present application, the basket detection module comprises a connection socket, a voltage dividing unit and a filter unit, the first end of the connection socket is connected with a power supply end, the second end of the connection socket is connected with the voltage dividing unit, the first end and the second end of the connection socket are connected with a micro switch, and the micro switch is arranged in the preset area;

[0012] A micro switch is used to turn on when the frying basket is in a preset area;

[0013] A voltage dividing unit is used to divide the voltage signal provided by the power supply end when the micro switch is turned on, and output a divided voltage signal to the filter unit;

[0014] The filter unit is used to filter the divided voltage signal and output a frying basket detection signal to the main control module.

[0015] In a possible implementation of the present application, the voltage dividing unit includes a first resistor circuit and a second resistor circuit, the first end of the first resistor circuit is connected to the second end of the connection socket, the second end of the first resistor circuit is connected to the first end of the second resistor circuit and the filter unit respectively, and the second end of the second resistor circuit is connected to the ground end.

[0016] In a possible implementation of the present application, the frequency conversion driving module includes a frequency conversion driving circuit, a current sampling unit, and an external socket for connecting the frequency conversion motor;

[0017] The frequency conversion driving circuit is used to generate a three-phase electric signal and output it to the frequency conversion motor in response to a frequency conversion control signal;

[0018] The current sampling unit is used to collect the current state of the frequency conversion motor when it is working, and output the collected current signal to the main control module;

[0019] The main control module is used to adjust the frequency conversion control signal according to the current signal, so as to protect the frequency conversion motor from open phase, overcurrent, open circuit, short circuit, and overvoltage.

[0020] In a possible implementation of the present application, the heating control module includes a relay driving circuit, a relay, and a diode, the diode is connected to both ends of the coil of the relay, the first end of the switch of the relay is connected to the power supply end, and the second end of the switch of the relay is connected to the heating pipe through the wiring terminal;

[0021] The relay driving circuit is connected to the main control module to access the heating control signal, and drives the switch of the relay to be closed according to the heating control signal, so as to supply power to the heating pipe through the output voltage signal of the power supply end.

[0022] In a possible implementation of the present application, the control circuit further includes a temperature detection module connected to the main control module;

[0023] The temperature detection module is used to detect the temperature in the frying basket and output a temperature detection signal to the main control module;

[0024] The main control module is used to control the heating pipe and the frequency conversion motor to stop working when the temperature detection signal indicates that the temperature in the frying basket reaches a preset temperature value.

[0025] In a possible implementation of the present application, the control circuit further comprises a lamp control module connected to the master module;

[0026] The master module is configured to generate a lamp control signal and output the signal to the lamp control module in response to an external instruction;

[0027] The lamp control module is configured to control the working state of the lamp of the air fryer in response to the lamp control signal.

[0028] In a possible implementation of the present application, the control circuit further comprises a buzzer control module connected to the master module;

[0029] The master module is configured to output an alarm signal to the buzzer control module when an abnormality of the variable frequency motor or the heating pipe is detected;

[0030] The buzzer control module is configured to control the buzzer to sound in response to the alarm signal.

[0031] In a possible implementation of the present application, the control circuit further comprises a power conversion module;

[0032] The power conversion module is configured to convert alternating current power into a first direct current voltage signal and output the signal to the variable frequency drive module, and convert the first direct current voltage signal into a second direct current voltage signal and output the signal to the master module.

[0033] In a second aspect, the present application further provides an air fryer, comprising a basket, a variable frequency motor, a heating pipe, a fryer for accommodating the basket, and the control circuit of the first aspect.

[0034] From the above, the present application has the following beneficial effects:

[0035] In the present application, the basket detection module is used to detect whether the basket is located in a preset area of the fryer, and only when the basket is located in the preset area, the basket detection module generates a basket detection signal and outputs the signal to the master module, so that the master module controls the variable frequency motor to work through the variable frequency drive module and controls the heating pipe to work through the heating control module, thereby avoiding the air fryer to run in an idle state, improving the use safety of the air fryer, ensuring that the food materials in the basket are heated when the air fryer is running, and improving the reliability of the air fryer. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0037] Figure 1is a module schematic diagram of the control circuit provided in the embodiments of the present application;

[0038] Figure 2 is a structural schematic diagram of the frying basket detection module provided in the embodiments of the present application;

[0039] Figure 3 is a circuit principle schematic diagram of the frying basket detection module provided in the embodiments of the present application;

[0040] Figure 4 is a circuit principle schematic diagram of the frequency conversion driving module provided in the embodiments of the present application;

[0041] Figure 5 is a circuit principle schematic diagram of the heating control module provided in the embodiments of the present application;

[0042] Figure 6 is another module schematic diagram of the control circuit provided in the embodiments of the present application;

[0043] Figure 7 is a circuit principle schematic diagram of the temperature detection module provided in the embodiments of the present application;

[0044] Figure 8 is a circuit principle schematic diagram of the furnace lamp control module provided in the embodiments of the present application;

[0045] Figure 9 is a circuit principle schematic diagram of the buzzer control module provided in the embodiments of the present application;

[0046] Figure 10 is a circuit principle schematic diagram of the power conversion module provided in the embodiments of the present application;

[0047] Figure 11 is a circuit principle schematic diagram of the communication interface module provided in the embodiments of the present application. DETAILED DESCRIPTION

[0048] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary, only for explaining the present application, and cannot be understood as limiting the present application.

[0049] In the following, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the accompanying drawings of the embodiments of the present application, so that those skilled in the art can better understand the solutions of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0050] It should be noted that in the embodiments of the present application, in this document, the terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations.

[0051] Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such article or device. Without more limitation, the element defined by the sentence "including a…" does not exclude the presence of another identical element in the article or device including the element.

[0052] In the description of the embodiments of the present application, the words "example" or "for example" are used to mean example, illustration or description. Any embodiment or design scheme described as "example" or "for example" in the embodiments of the present application is not interpreted as more preferred or having more advantages than another embodiment or design scheme. The words "example" or "for example" are intended to present the relative concept in a clear manner.

[0053] In addition, "multiple" in the embodiments of the present application means two or more, and therefore "multiple" in the embodiments of the present application can also be understood as "at least two". "At least one" can be understood as one or more, for example, as one, two or more. For example, including at least one means including one, two or more, and does not limit which ones are included, for example, including at least one of A, B and C, and the included can be A, B, C, A and B, A and C, B and C, or A and B and C.

[0054] It should be noted that "connection" in the embodiments of the present application can be understood as electrical connection, and the connection between two electrical elements can be direct or indirect connection between the two electrical elements. For example, A and B are connected, which can be direct connection between A and B, or indirect connection between A and B through one or more other electrical elements.

[0055] Before introducing the control circuit and air fryer of the present application, first introduce the related background information of the embodiments of the present application.

[0056] At present, after the air fryer is turned on, the user can select the heating mode, heating temperature and other working parameters through the keys on the display panel to control the air fryer to run based on the selected parameters.

[0057] However, if the user operates improperly and does not put the food material containing basket into the air fryer to directly control the air fryer to run, the air fryer will run empty, which will cause the air fryer to malfunction, even cause a safety accident, and the reliability is low.

[0058] Therefore, the control circuit and the air fryer provided in the embodiments of the present application are provided. The control circuit detects whether the basket is located in the preset area of the air fryer through the basket detection module. Only when the basket is located in the preset area, the basket detection module generates a basket detection signal and outputs it to the main control module, so that the main control module controls the variable frequency motor to work through the variable frequency drive module and controls the heating pipe to work through the heating control module, which avoids the air fryer running empty, improves the use safety of the air fryer, ensures that the food material in the basket is heated when the air fryer runs, and improves the reliability of the air fryer.

[0059] The control circuit and the air fryer provided in the embodiments of the present application will be introduced in detail below.

[0060] First, the control circuit provided in the embodiments of the present application can be applied to the air fryer to control the operation of the air fryer. Please refer to Figure 1 , Figure 1 is a module schematic diagram of the control circuit provided in the embodiments of the present application. The control circuit 100 can include a basket detection module 110, a main control module 120, a variable frequency drive module 130 and a heating control module 140. The main control module 120 can be connected with the basket detection module 110, the variable frequency drive module 130 and the heating control module 140 respectively.

[0061] The basket detection module 110 can be used to generate a basket detection signal and output it to the main control module 120 when it is detected that the basket of the air fryer is located in the preset area of the air fryer. The main control module 120 can be used to generate a variable frequency control signal and a heating control signal according to the basket detection signal. The variable frequency drive module 130 can be used to generate a three-phase electric signal and output it to the variable frequency motor of the air fryer in response to the variable frequency control signal, so as to drive the variable frequency motor to work. The heating control module 140 can be used to control the heating pipe of the air fryer to work in response to the heating control signal.

[0062] It can be understood that the basket of the air fryer can be used to contain food material to be fried. When in use, the basket containing food material can be put into the air fryer, and then the machine is run. The air fryer can heat the food material by using the flowing hot air to achieve the effect of frying.

[0063] In the embodiments of the present application, the frying basket detection module 110 can be used to detect whether the frying basket is located in the fryer. When it is detected that the frying basket is located in the fryer, the frying basket detection module 110 generates a frying basket detection signal and outputs the frying basket detection signal to the main control module 120.

[0064] When the main control module 120 receives the frying basket detection signal, it can be determined that the frying basket is located in the fryer. At this time, the variable frequency motor and the heating pipe can be controlled to work to heat the food materials in the frying basket. Therefore, the main control module 120 can generate a variable frequency control signal and a heating control signal in response to the frying basket detection signal, and output the variable frequency control signal and the heating control signal to the variable frequency drive module 130 and the heating control module 140, respectively.

[0065] When the variable frequency drive module 130 receives the variable frequency control signal, it can generate a three-phase electric signal in response to the variable frequency control signal and output the three-phase electric signal to the variable frequency motor, so as to drive the variable frequency motor to operate through the three-phase electric signal to drive the air in the fryer to flow rapidly.

[0066] When the heating control module 140 receives the heating control signal, it can control the heating pipe to heat and work in response to the heating control signal, so as to heat the air in the fryer, heat the food materials in the frying basket by using the rapidly flowing high-temperature air, and dehydrate the food materials to realize frying of the food materials.

[0067] In the embodiments of the present application, whether the frying basket is located in the preset area of the fryer is detected by the frying basket detection module 110. Only when the frying basket is located in the preset area, the frying basket detection module 110 generates a frying basket detection signal and outputs the frying basket detection signal to the main control module 120, so that the main control module 120 controls the variable frequency motor to work through the variable frequency drive module 130 and controls the heating pipe to work through the heating control module 140. This avoids the air fryer running in an empty state, improves the use safety of the air fryer, ensures that the food materials in the frying basket are heated when the air fryer is running, and improves the reliability of the air fryer.

[0068] Next, the various unit modules shown in Figure 1 and the specific implementation that can be adopted in actual applications will be described in detail.

[0069] As shown in Figure 2 In some embodiments of the present application, the frying basket detection module 110 can include a connection socket 1101, a voltage division unit 1102, and a filter unit 1103. The first end of the connection socket 1101 is connected with a power supply end, the second end of the connection socket 1101 is connected with the voltage division unit 1102, and a micro switch (not shown in the figure) is connected between the first end and the second end of the connection socket 1101. The micro switch is arranged in the preset area.

[0070] The micro switch can be used to turn on when the basket is located in a preset area; the voltage divider unit 1102 can be used to divide the voltage signal provided by the power supply when the micro switch is turned on, and output the divided voltage signal to the filter unit 1103; the filter unit 1103 can be used to filter the divided voltage signal and output the basket explosion detection signal to the main control module 120.

[0071] In this embodiment, the micro switch is located in a preset area of ​​the fryer. When the frying basket is placed in the preset area of ​​the fryer, the micro switch is pressed by force, thereby closing the micro switch and connecting the first and second ends of the connection socket 1101. The first end of the connection socket 1101 is connected to a power supply. Therefore, when the micro switch is closed, the power supply is electrically connected to the voltage divider unit 1102. The voltage divider unit 1102 can divide the voltage signal provided by the power supply and output the divided voltage signal to the filter unit 1103. After the filter unit 1103 filters the divided voltage signal, the frying basket detection signal is output to the main control module 120.

[0072] The voltage divider unit 1102 can be any existing voltage divider circuit, such as a resistor voltage divider circuit; the filter unit 1103 can be any existing filter, such as a resistor-capacitor filter circuit. The specific selection can be made according to the actual application scenario, and no limitation is made here.

[0073] In some embodiments of this application, the voltage divider unit 1102 may include a first resistor circuit and a second resistor circuit. The first end of the first resistor circuit is connected to the second end of the connection socket 1101, the second end of the first resistor circuit is connected to the first end of the second resistor circuit and the filter unit 1103, and the second end of the second resistor circuit is connected to the ground terminal.

[0074] In this embodiment of the application, the first resistor circuit and the second resistor circuit may each include at least one series resistor. The number of series resistors in the two resistor circuits may be the same or different. The specific number of series resistors can be determined according to the actual application scenario, and is not limited here.

[0075] like Figure 3 As shown, in one embodiment, the first resistor circuit includes the fifty-seventh resistor R57, the second resistor circuit includes the sixty-third resistor R63, and the filter unit 1103 includes the sixtieth resistor R60 and the thirty-sixth capacitor C36.

[0076] according to Figure 3It can be known that the first end of the socket CN9 (1101) is connected with the +24V power supply end, the second end of the socket CN9 (1101) is connected with one end of the fifty-seventh resistor R57, the other end of the fifty-seventh resistor R57 is connected with the sixty-third resistor R63 and the sixtieth resistor R60 respectively, the other end of the sixty-third resistor R63 is grounded GND, and the other end of the sixtieth resistor R60 is connected with the thirty-sixth capacitor C36 and the master control module 120.

[0077] When the frying basket is placed in the preset area of the frying pot, the micro switch is closed, the +24V voltage signal is divided by the fifty-seventh resistor R57 and the sixty-third resistor R63 in series, and a divided voltage signal is obtained. After the divided voltage signal is filtered by the resistance-capacitance filter circuit composed of the sixtieth resistor R60 and the thirty-sixth capacitor C36, a frying basket detection signal MOT VOL is obtained and output to the master control module 120.

[0078] In some embodiments of the present application, the variable frequency drive module 130 can include a variable frequency drive circuit, a current sampling unit, and an external socket for connecting the variable frequency motor; wherein the variable frequency drive circuit can be used to generate a three-phase electric signal in response to a variable frequency control signal and output to the variable frequency motor; the current sampling unit can be used to collect the current state of the variable frequency motor when working, and output the collected current signal to the master control module 120; the master control module 120 can be used to adjust the variable frequency control signal according to the current signal, to protect the variable frequency motor from open phase, overcurrent, open circuit, short circuit and overvoltage.

[0079] As shown in Figure 4 In the embodiments of the present application, the master control module 120 can be any existing microcontroller unit (MCU), the variable frequency motor MOTO can be a three-phase non-inductive variable frequency motor, the current sampling unit can include the nineteenth sampling resistor R19, the twentieth sampling resistor R20, the twenty-fifth sampling resistor R25 and the fifteenth sampling capacitor C15, and the fifth capacitor EC5 can filter the 24V DC voltage signal and input to the variable frequency drive circuit to power the variable frequency drive circuit.

[0080] Specifically, the MCU can output frequency conversion control signals UL\VL\WL\UH\VH\WH to the frequency conversion control circuit. The frequency conversion control circuit, in response to these signals, generates a three-phase electrical signal UVW, which is output to the frequency conversion motor (MOTO) connected to the external socket. This UVW drives the MOTO. Simultaneously, the current state of the MOTO during operation is collected through the nineteenth sampling resistor R19, the twentieth sampling resistor R20, the twenty-fifth sampling resistor R25, and the fifteenth sampling capacitor C15. The collected current signals, namely the differential signals OPA0_IN and OPA0_IP, are output to the MCU. The MCU analyzes these signals and adjusts the frequency conversion control signals UL\VL\WL\UH\VH\WH, thereby providing protection against phase loss, overcurrent, open circuit, short circuit, and overvoltage for the MOTO, ensuring its normal operation.

[0081] It is understood that the variable frequency drive circuit in the embodiments of this application can be any existing variable frequency motor drive circuit, and the specific choice can be made according to the actual application scenario, which is not limited here.

[0082] like Figure 5 As shown, in some embodiments of this application, the heating control module 140 may include a relay drive circuit, a relay RLY2, and a diode D13. The cathode of the diode D13 is connected to the +5V power supply terminal, and the anode is connected to the relay drive circuit. That is, the diode D13 is connected to both ends of the coil of the relay RLY2. The first end of the switch of the relay RLY2 is connected to the power supply terminal ACL, and the second end of the switch of the relay RLY2 is connected to the heating tube through the terminal CN3. The relay drive circuit is connected to the main control module 120 to receive the heating control signal HEAT2. According to the heating control signal, the switch of the relay RLY2 is driven to close, so as to supply power to the heating tube through the output voltage signal of the power supply terminal ACL.

[0083] In this embodiment, the main control module 120 can control the relay RLY2 to close via the heating control signal HEAT2, thereby energizing the heating element. Specifically, when the MCU outputs the heating control signal HEAT2, the relay drive circuit is turned on, energizing the coil of relay RLY2. This closes the switch of relay RLY2, supplying the output voltage signal of the power supply terminal ACL to the heating element connected to the terminal CN3, causing the heating element to heat the air inside the fryer. When the MCU does not output the heating control signal HEAT2, the relay drive circuit is turned off, the coil of relay RLY2 is de-energized, the switch of relay RLY2 is opened, and the heating element is de-energized and stops working.

[0084] It is understood that the relay driving circuit in the embodiments of this application can be any existing relay driving circuit, and the specific choice can be made according to the actual application scenario, which is not limited here.

[0085] like Figure 6 As shown, in some embodiments of this application, the control circuit 100 may further include a temperature detection module 150 connected to the main control module 120; the temperature detection module 150 may be used to detect the temperature inside the frying basket and output the temperature detection signal to the main control module 120; the main control module 120 may be used to control the heating tube and the frequency converter motor to stop working when the temperature detection signal indicates that the temperature inside the frying basket is greater than a preset temperature value.

[0086] Please see Figure 7 In this embodiment, the temperature detection module 150 may include a temperature sensor NTC1, a 21st resistor R21, an 18th resistor R18, and a 14th capacitor C14. The temperature sensor NTC1 is connected in series with the 21st resistor R21 through the fourth socket CN4. The temperature sensor NTC1 and the 21st resistor R21 form a voltage divider circuit to divide the +5V voltage. The voltage signal after voltage division is filtered by the filter circuit composed of the 18th resistor R18 and the 14th capacitor C14 to obtain the temperature detection signal NTC1, which is output to the MCU. The MCU can compare the temperature value represented by the temperature detection signal NTC1 with a preset temperature value. When the temperature value represented by the temperature detection signal NTC1 is less than or equal to the preset temperature value, the MCU controls the heating element and the variable frequency motor to continue working; when the temperature value represented by the temperature detection signal NTC1 is greater than the preset temperature value, the MCU controls the heating element and the variable frequency motor to stop working.

[0087] Understandably, the preset temperature value can be any temperature value set by the user according to their needs. The temperature sensor NTC1 can be any existing negative temperature coefficient thermistor or any existing positive temperature coefficient thermistor. The specific value can be determined according to the actual application scenario, and is not limited here.

[0088] Please continue reading. Figure 6 In some embodiments of this application, the control circuit 100 may further include an oven light control module 160 connected to the main control module 120; the main control module 120 may be used to generate an oven light control signal in response to an external command and output it to the oven light control module 160; the oven light control module 160 may be used to control the working state of the oven light of the air fryer in response to the oven light control signal.

[0089] like Figure 8As shown, in the embodiment of the present application, the oven lamp control module 160 can include a terminal CN5, a silicon controlled rectifier drive circuit and a silicon controlled rectifier Q8. When the user starts the air fryer, the MCU can generate an oven lamp control signal LAMP in response to the instruction given by the user and output to the silicon controlled rectifier drive circuit. The silicon controlled rectifier drive circuit makes the silicon controlled rectifier Q8 conductive in response to the oven lamp control signal LAMP, and the oven lamp connected to the terminal CN5 can be powered on to work. If the MCU has no oven lamp control signal LAMP output to the silicon controlled rectifier drive circuit, the silicon controlled rectifier Q8 is disconnected, and the oven lamp connected to the terminal CN5 is powered off and stops working at this time.

[0090] It can be understood that the silicon controlled rectifier drive circuit in the embodiment of the present application can use any existing silicon controlled rectifier drive circuit, which can be selected according to the actual application scene, which is not limited here.

[0091] Please continue to refer to Figure 6 In some embodiments of the present application, the control circuit 100 can further include a buzzer control module 170 connected to the main control module 120; the main control module 120 can be used to output an alarm signal to the buzzer control module 170 when detecting abnormality of the variable frequency motor or the heating tube; the buzzer control module 170 can be used to control the buzzer to sound in response to the alarm signal.

[0092] As shown in the Figure 9 embodiment of the present application, the buzzer control module 170 can include a buzzer BUZ1, a triode Q7 and some peripheral resistors. The buzzer BUZ1 can be selected from any existing buzzer, such as a piezoelectric buzzer, an electromagnetic buzzer, etc.

[0093] Specifically, the MCU can output an alarm signal BUZ to the buzzer control module 170 when detecting abnormality of the variable frequency motor, the heating tube or other devices of the air fryer; the triode Q7 is turned on in response to the alarm signal BUZ, so that the buzzer BUZ1 is powered on to start sounding; if the air fryer runs normally, the MCU has no alarm signal BUZ output, at this time the triode Q7 is cut off, and the buzzer BUZ1 is powered off to stop sounding. In the embodiment, the sounding of the buzzer BUZ1 can prompt the user that the air fryer is working abnormally, and the alarm is realized.

[0094] Please continue to refer to Figure 6 In some embodiments of the present application, the control circuit 100 can further include a power conversion module 180; the power conversion module 180 can be used to convert alternating current power into a first direct current voltage signal and output to the variable frequency drive module 130, and convert the first direct current voltage signal into a second direct current voltage signal and output to the main control module 120.

[0095] As shown in the Figure 10As shown, in the embodiment of the present application, the power conversion module 180 can include a filter, an AC-DC conversion circuit and a DC-DC conversion circuit. Specifically, after the alternating current commercial power is input into the power conversion module 180, the filtered alternating current commercial power is first input into the AC-DC conversion circuit for AC to DC conversion, i.e. high voltage to low voltage conversion, to obtain a first direct current voltage signal, i.e. a 24V direct current voltage signal, for power supply to the variable frequency motor. The 24V direct current voltage signal is rectified by the DC-DC conversion circuit into a second direct current voltage signal, i.e. a 5V direct current voltage signal, for power supply to the MCU.

[0096] It can be understood that the 5V direct current voltage signal can also be used for power supply to the coil of the relay RLY2, the buzzer BUZ1 and the temperature sensor NTC1, etc. The AC-DC conversion circuit can adopt any existing AD / DC converter, such as a BUCK topology circuit, a BOOST topology circuit, etc. The DC-DC conversion circuit can adopt any existing DC / DC converter, which can be selected according to the actual application scenario, which is not limited here.

[0097] As shown in the control circuit 100 can also include a serial communication interface CN1 connected with the host module 120, i.e. the MCU. The serial communication interface CN1 can also be connected with the display panel of the air fryer, for realizing the interaction of the communication signals (TXD and RXD) between the host module 120 and the display panel. Figure 11

[0098] In the embodiment of the present application, the serial communication interface CN1 can match the demand of different UI display effects, so that different UI display panels can share the same variable frequency power supply panel to realize the function of baking food of the air fryer.

[0099] In the embodiment of the present application, the standby power of the air fryer can meet the special requirement of standby power consumption less than 0.3W, which is environmentally friendly and energy saving. The variable frequency drive module 130 can control the smooth start of the variable frequency motor from low speed to high speed. The control circuit 100 has simple structure, uses general devices and has low cost, so it has wide application range.

[0100] Based on the control circuit in the above embodiment, the embodiment of the present application further provides an air fryer, which can include a basket, a variable frequency motor, a heating pipe, a fryer for accommodating the basket and a control circuit as Figures 1 to 11 corresponding to the control circuit in any embodiment.

[0101] Since the air fryer includes the control circuit as Figures 1 to 11 corresponding to the control circuit in any embodiment, the control circuit as Figures 1 to 11 ​The above-mentioned beneficial effects that can be achieved by the control circuit in any embodiment are described in detail in the foregoing description, and will not be repeated here.

[0102] The above merely describes the preferred embodiments of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed with the preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art can make some minor changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the technical solution of the present application. Any brief introduction, modification, equivalent change and modification of the above embodiments made according to the technical essence of the present application, without departing from the technical solution of the present application, still belongs to the scope of the technical solution of the present application.

Claims

1. A control circuit, characterized by The control circuit for the air fryer includes a basket detection module, a main control module, a variable frequency drive module and a heating control module, the main control module is connected with the basket detection module, the variable frequency drive module and the heating control module respectively; The basket detection module is used for generating a basket detection signal output to the main control module when detecting that the basket of the air fryer is located in a preset area of the air fryer; The main control module is used for generating a variable frequency control signal and a heating control signal according to the basket detection signal and outputting them; The variable frequency drive module is used for generating a three-phase electric signal output to a variable frequency motor of the air fryer to drive the variable frequency motor to work in response to the variable frequency control signal; The heating control module is used for controlling a heating tube of the air fryer to work in response to the heating control signal.

2. The control circuit of claim 1, wherein, The basket detection module includes a connection socket, a voltage dividing unit and a filter unit, a power supply end is connected to a first end of the connection socket, a second end of the connection socket is connected with the voltage dividing unit, a micro switch is connected between the first end and the second end of the connection socket, and the micro switch is arranged in the preset area; The micro switch is used for turning on when the basket is located in the preset area; The voltage dividing unit is used for dividing the voltage signal provided by the power supply end when the micro switch is turned on to obtain a divided voltage signal output to the filter unit; The filter unit is used for filtering the divided voltage signal to obtain the basket detection signal output to the main control module.

3. The control circuit of claim 2, wherein, The voltage dividing unit includes a first resistance circuit and a second resistance circuit, a first end of the first resistance circuit is connected to the second end of the connection socket, a second end of the first resistance circuit is connected with a first end of the second resistance circuit and the filter unit respectively, and a second end of the second resistance circuit is connected with a ground end.

4. The control circuit of claim 1, wherein, The variable frequency drive module includes a variable frequency drive circuit, a current sampling unit and an external socket connected with the variable frequency motor; The variable frequency drive circuit is used for generating the three-phase electric signal output to the variable frequency motor in response to the variable frequency control signal; The current sampling unit is used for collecting the current state of the variable frequency motor when working and outputting the collected current signal to the main control module; The main control module is used for adjusting the variable frequency control signal according to the current signal to protect the variable frequency motor from open circuit, short circuit, overvoltage and the like.

5. The control circuit of claim 1, wherein, The heating control module includes a relay drive circuit, a relay and a diode, the diode is connected across the coil of the relay, a power supply end is connected to a first end of the switch of the relay, and a second end of the switch of the relay is connected with the heating tube through a wiring terminal; The relay drive circuit is connected with the main control module to access the heating control signal, drive the switch of the relay to be closed according to the heating control signal, and supply the output voltage signal of the power supply end to the heating tube.

6. The control circuit of claim 1, wherein, The control circuit further includes a temperature detection module connected with the main control module. The temperature detection module is configured to detect the temperature in the basket and output a temperature detection signal to the main control module. The main control module is configured to control the heating pipe and the variable frequency motor to stop working when the temperature detection signal indicates that the temperature in the basket reaches a preset temperature value.

7. The control circuit of claim 1, wherein, The control circuit further comprises a lamp control module connected to the main control module. The main control module is configured to generate a lamp control signal and output the signal to the lamp control module in response to an external instruction. The lamp control module is configured to control the working state of the lamp of the air fryer in response to the lamp control signal.

8. The control circuit of claim 1, wherein, The control circuit further comprises a buzzer control module connected to the main control module. The main control module is configured to output an alarm signal to the buzzer control module when detecting that the variable frequency motor or the heating pipe is abnormal. The buzzer control module is configured to control the buzzer to sound in response to the alarm signal.

9. The control circuit according to any one of claims 1 to 8, characterized in that, The control circuit further comprises a power conversion module. The power conversion module is configured to convert alternating current power into a first direct current voltage signal and output the signal to the variable frequency drive module, and convert the first direct current voltage signal into a second direct current voltage signal and output the signal to the main control module.

10. An air fryer characterized in that, An air fryer comprising a basket, a variable frequency motor, a heating pipe, a fryer for accommodating the basket, and the control circuit according to any one of claims 1-9.

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