Multi-point temperature measurement circuit, electromagnetic heating appliance and multi-point temperature measurement method

Abstract

The invention provides a multi-point temperature measurement circuit, an electromagnetic heating appliance and a multi-point temperature measurement method. The multi-point temperature measurement circuit comprises a plurality of first sampling units and a first control unit, the plurality of first sampling units are respectively used for sampling temperatures of different positions through temperature sensors arranged at different positions of the electromagnetic heating appliance; the first control unit is used for determining a temperature value based on the sampling signals of the plurality of first sampling units, and outputting a pulse width modulation signal based on the temperature value, so that a second control unit on a power panel of the electromagnetic heating appliance filters the pulse width modulation signal to obtain a temperature signal, and determines a temperature value based on the temperature signal; and multi-point temperature measurement is realized.

Description

Technical Field

[0001] The present application relates to home appliance technologies, and particularly to a multi-point temperature measurement circuit, an electromagnetic heating appliance, and a multi-point temperature measurement method. Background Art

[0002] Electromagnetic heating appliances, such as induction cookers, have been highly standardized after years of development. For example, the temperature measurement of the cooking surface of an induction cooker is mainly completed by sampling through a sampling port on the power supply board of the induction cooker using a negative temperature coefficient (NTC) thermistor installed at the bottom of the cooking surface.

[0003] With the improvement of the control accuracy of electromagnetic heating appliances, higher requirements are also placed on the temperature measurement accuracy. In this case, multi-point temperature measurement can be considered to improve the accuracy, that is, installing multiple NTC thermistors for temperature detection. However, due to the relatively high standardization of the main board of the current induction cooker, that is, the power supply board, there are no reserved ports on the power supply board for sampling multiple NTC thermistors. Summary of the Invention

[0004] The present application provides a multi-point temperature measurement circuit, an electromagnetic heating appliance, and a multi-point temperature measurement method, which realize multi-point temperature measurement.

[0005] In a first aspect, the present application provides a multi-point temperature measurement circuit applied to an electromagnetic heating appliance. The multi-point temperature measurement circuit includes: a plurality of first sampling units and a first control unit;

[0006] The plurality of first sampling units are respectively used to sample the temperatures at different positions through temperature sensors disposed at different positions of the electromagnetic heating appliance;

[0007] The first control unit is used to determine a temperature value based on the sampling signals of the plurality of first sampling units, and output a pulse width modulation signal based on the temperature value, so that a second control unit on the power supply board of the electromagnetic heating appliance filters the pulse width modulation signal to obtain a temperature signal, and determines the temperature value based on the temperature signal.

[0008] By outputting the pulse width modulation signal corresponding to the temperature value to the power supply board through the multi-point temperature measurement circuit, the second control unit on the power supply board restores the temperature value based on the pulse width modulation signal, so that multi-point temperature measurement can be realized on the basis of the existing standardized power supply board.

[0009] In one implementation, the first control unit includes: a first control module and an isolation module;

[0010] The first control module is configured to determine the temperature value based on the sampling signals of the multiple first sampling units, and output an initial pulse width modulation signal through a pulse width modulation port based on the temperature value;

[0011] The isolation module is configured to isolate and output the pulse width modulation signal based on the initial pulse width modulation signal. Through the isolation function of the isolation module, there is no direct electrical connection between the isolated multi-point temperature measurement circuit and the power supply board, thus preventing interference.

[0012] In one implementation, the isolation module includes: an optocoupler;

[0013] The first input terminal of the optocoupler is used to connect to the pulse width modulation port, the second input terminal of the optocoupler is connected to the power supply through a first resistor, and the output terminal of the optocoupler is used to connect to the second control unit.

[0014] In one implementation, the first sampling unit includes a second resistor and a temperature sensor;

[0015] One end of the temperature sensor is connected to the power supply through the second resistor, the other end of the temperature sensor is grounded, and the connection point of the temperature sensor and the second resistor is connected to the analog-to-digital sampling port of the first control unit.

[0016] In one implementation, the multi-point temperature measurement circuit is powered by a power-taking coil, the power-taking coil is an independent winding of a switching power supply transformer, or the power-taking coil is an independent coil, and the independent coil is powered by coupling the induction coil of the electromagnetic heating appliance;

[0017] Or,

[0018] The power supply of the multi-point temperature measurement circuit is provided by the power supply of the power supply board.

[0019] In one implementation, the first control unit is configured to determine whether the multi-point temperature measurement circuit is open or short-circuited based on the sampling signals of the multiple first sampling units, and output the pulse width modulation signal based on whether the multi-point temperature measurement circuit is open or short-circuited.

[0020] In one implementation, the first control unit is configured to determine the highest temperature value sampled by the multiple first sampling units based on the sampling signals of the multiple first sampling units, and output the pulse width modulation signal based on the highest temperature value.

[0021] In one implementation, the multi-point temperature measurement circuit is disposed at a position other than the power supply board and the display board of the electromagnetic heating appliance.

[0022] In a second aspect, the present application provides a temperature measurement circuit applied to an electromagnetic heating appliance. The temperature measurement circuit includes: the multi-point temperature measurement circuit as described in the first aspect and a second control unit on the power supply board of the electromagnetic heating appliance.

[0023] In one implementation, the second control unit includes: an integration circuit and a second control module;

[0024] The integration circuit is configured to filter the pulse width modulation signal to obtain a temperature signal;

[0025] The second control module is configured to determine a temperature value based on the temperature signal.

[0026] In a third aspect, the present application provides an electromagnetic heating appliance, including: the temperature measurement circuit as described in the second aspect.

[0027] In a fourth aspect, the present application provides a multi-point temperature measurement method applied to the multi-point temperature measurement circuit as described in the first aspect. The method includes:

[0028] Obtaining sampling signals of a plurality of first sampling units;

[0029] Determining a temperature value based on the sampling signals of the plurality of first sampling units and outputting a pulse width modulation signal based on the temperature value, wherein the temperature signal obtained by filtering the pulse width modulation signal is used to determine the temperature value.

[0030] In a fifth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the method as described in the fourth aspect above is implemented.

[0031] In a sixth aspect, the present application provides a computer program product, including a computer program. When the computer program is executed by a processor, the method as described in the fourth aspect is implemented.

[0032] The present application provides a multi-point temperature measurement circuit, an electromagnetic heating appliance, and a multi-point temperature measurement method. The multi-point temperature measurement circuit includes: a plurality of first sampling units and a first control unit; the plurality of first sampling units are respectively used to sample the temperatures at different positions through temperature sensors disposed at different positions of the electromagnetic heating appliance; the first control unit is used to determine a temperature value based on the sampling signals of the plurality of first sampling units, and output a pulse width modulation signal based on the temperature value, so that a second control unit on the power supply board of the electromagnetic heating appliance filters the pulse width modulation signal to obtain a temperature signal, and determines the temperature value based on the temperature signal. By outputting the pulse width modulation signal corresponding to the temperature value to the power supply board through the multi-point temperature measurement circuit, the second control unit on the power supply board restores the temperature value based on the pulse width modulation signal, so that multi-point temperature measurement can be realized on the basis of the existing standardized power supply board. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0034] Figure 1 Module schematic diagram of a multi-point temperature measurement circuit provided by an embodiment of the present application Figure 1 ;

[0035] Figure 2 Module schematic diagram of a multi-point temperature measurement circuit provided by an embodiment of the present application Figure 2 ;

[0036] Figure 3 Circuit schematic diagram of a multi-point temperature measurement circuit provided by an embodiment of the present application;

[0037] Figure 4 Module schematic diagram of a temperature measurement circuit provided by an embodiment of the present application;

[0038] Figure 5 Circuit schematic diagram of a temperature measurement circuit provided by an embodiment of the present application;

[0039] Figure 6 Flow schematic diagram of a multi-point temperature measurement method provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some, but not all, of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without creative efforts shall fall within the protection scope of this application.

[0041] To improve the accuracy of temperature measurement, multiple NTC thermistors are installed in the electromagnetic heating appliance through multi-point temperature measurement for temperature detection. However, since the motherboard of the current induction cooker, i.e., the power supply board, has a relatively high degree of standardization, there are no reserved multiple ports on the power supply board for sampling multiple NTC thermistors. Considering that in addition to the power supply board in the electromagnetic heating appliance, there is also a display board for the display function, if the sampling of multiple NTC thermistors is implemented on the display board of the electromagnetic heating appliance, this solves the problem of insufficient resources on the power supply board. However, this will bring additional problems. One is that the wiring harness is relatively long and the wiring harness is prone to interfering with the electric fan, touch buttons, etc. Also, considering the fragility of the panel glass, it is necessary to isolate the NTC circuit on the display board to improve safety, which makes the circuit more complex and leads to insufficient space on the display board. Therefore, the usability of this solution is not high, and a new solution is urgently needed.

[0042] Therefore, in the embodiments of this application, a multi-point temperature measurement circuit is proposed. This multi-point temperature measurement circuit is independent of the power supply board and the display board. This multi-point temperature measurement circuit uses multiple temperature sensors arranged at different positions of the electromagnetic heating appliance to collect temperature signals to determine the temperature value, and converts the temperature value into a pulse width modulation signal, and outputs the pulse width modulation signal to the power supply board. Thus, the power supply board can determine the temperature according to the pulse width modulation signal. In this way, for the power supply board, only one sampling port is still required, without changing the existing power supply board and display board, realizing multi-point temperature measurement of the electromagnetic heating appliance.

[0043] The following will detail the multi-point temperature measurement circuit provided by this application through specific embodiments. It can be understood that the following several specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0044] Figure 1 Module schematic of a multi-point temperature measurement circuit provided by the embodiments of this application Figure 1 As Figure 1 shown, this multi-point temperature measurement circuit includes: multiple first sampling units 101 and a first control unit 102.

[0045] Among them, multiple first sampling units 101 are respectively used to sample the temperatures at different positions through temperature sensors arranged at different positions of the electromagnetic heating appliance. The number of the first sampling units 101 can be set as required, Figure 1 which is only for illustration rather than for limiting the number of the first sampling units 101.

[0046] The first control unit 102 is used to determine the temperature value based on the sampling signals of the multiple first sampling units 101, and output a Pulse Width Modulation (PWM) signal based on the temperature value, so that the second control unit on the power supply board of the electromagnetic heating appliance filters the pulse width modulation signal to obtain a temperature signal, and determines the temperature value based on the temperature signal. Optionally, the first control unit 102 can be a Microcontroller Unit (MCU).

[0047] To achieve multi-point temperature measurement, temperature sensors are respectively arranged at different positions of the electromagnetic heating appliance, and each first sampling unit 101 respectively uses one temperature sensor to achieve single-point temperature sampling. The first control unit 102 can obtain the temperature values of multi-point temperature measurement based on the sampling signals of the first sampling units 101. For example, the first control unit 102 can first process the sampling signals after each first sampling unit 101 performs temperature sampling respectively to obtain the processed sampling signals, and then determine the temperature value based on the processed sampling signals, or the first control unit 102 can first determine the initial temperature values detected by each temperature sensor based on the sampling signals of each first sampling unit 101 performing temperature sampling respectively, and then process each initial temperature value to obtain the temperature value.

[0048] Optionally, the first control unit 102 is used to determine the highest temperature value sampled by the multiple first sampling units based on the sampling signals of the multiple first sampling units 101, and output a pulse width modulation signal based on the highest temperature value. That is, based on the sampling signals of each first sampling unit 101, the initial temperature values detected by each temperature sensor are determined. Then, the initial temperature values are compared, and the highest temperature value among them is determined as the temperature value of multi-point detection, and the highest temperature value is output as a pulse width modulation signal.

[0049] Optionally, in a fault scenario, the first control unit 102 is used to determine whether the multi-point temperature measurement circuit is open or short-circuited based on the sampling signals of the multiple first sampling units 101, and output a pulse width modulation signal based on the open or short circuit of the multi-point temperature measurement circuit. For example, in the case where the voltage value of the sampling signal is too high or too low, the first control unit 102 can determine that the multi-point temperature measurement circuit is open or short-circuited, and at this time, a corresponding pulse width modulation signal can be output based on the open or short circuit.

[0050] The multi-point temperature measurement circuit according to the embodiment of the present application is disposed at a position other than the power supply board and the display board of the electromagnetic heating appliance. In order to transmit the temperature value to the power supply board of the electromagnetic heating appliance so that the power supply board performs subsequent heating control or function control operations based on the temperature value, the first control unit 102 converts the determined temperature value into a pulse width modulation signal. After the pulse width modulation signal is transmitted to the power supply board, the power supply board can recover the pulse width modulation signal to obtain the temperature value. In this way, by using the multi-point temperature measurement circuit provided by the embodiment of the present application and combining with the existing standardized power supply board, multi-point temperature measurement can be realized.

[0051] Optionally, after the first control unit 102 obtains the sampling signals of the first sampling units 101, it first determines whether there is an open circuit or a short circuit based on the sampling signals of the first sampling units 101. In the case of an open circuit or a short circuit, the pulse width modulation signal corresponding to the open circuit or the short circuit is output to the power supply board. In the case of no open circuit or short circuit, the temperature value is continuously determined based on the sampling signals of the first sampling units 101, and the pulse width modulation signal corresponding to the temperature value is output to the power supply board.

[0052] Based on the above embodiment, the first control unit 102 is described.

[0053] Optionally, as shown in Figure 2 the first control unit 102 includes: a first control module 1021 and an isolation module 1022.

[0054] Among them, the first control module 1021 is connected to a plurality of first sampling units 101. The first control module 1021 is configured to determine the temperature value based on the sampling signals of the plurality of first sampling units 101, and output an initial pulse width modulation signal through the pulse width modulation port based on the temperature value.

[0055] The isolation module 1022 is configured to isolate and output a pulse width modulation signal based on the initial pulse width modulation signal. Through the isolation function of the isolation module 1022, there is no direct electrical connection between the isolated multi-point temperature measurement circuit and the power supply board, thereby preventing interference and improving safety.

[0056] Optionally, as shown in Figure 3 the first control module 1021 is an MCU1, and the isolation module 1022 includes: an optocoupler IC1; the first input terminal of the optocoupler IC1 is used to connect to the pulse width modulation port of the first control module 1021, the second input terminal of the optocoupler IC1 is connected to the power supply through a first resistor R1, and the output terminal of the optocoupler IC1 is used to connect to the second control unit. The initial pulse width modulation signal output from the pulse width modulation port passes through the optocoupler IC, and under the action of the pull-up resistor R1, a PWM signal with the same duty cycle is output. Figure 3The wiring terminal CN1A at the output end of the optocoupler IC is shown, and this wiring terminal CN1A can be used to connect to the second control unit.

[0057] Optionally, the pulse width modulation port of the first control module 1021 is externally connected to an optocoupler IC1. After the MCU1 samples all the NTCs, data comparison is performed through a program to determine the highest temperature value, and based on this value, the duty cycle of the pulse width modulation signal is determined, and the pulse width modulation signal is output at the pulse width modulation port.

[0058] Optionally, referring to Figure 3 As shown, the first sampling unit 101 includes a second resistor R2 and a temperature sensor NTC.

[0059] Among them, one end of the temperature sensor NTC is connected to the power supply through the second resistor R2, the other end of the temperature sensor NTC is grounded, and the connection point of the temperature sensor NTC and the second resistor R2 is connected to the analog-to-digital sampling port (AD port) of the first control unit 102.

[0060] The position of the temperature sensor NTC on the electromagnetic heating appliance can be set as needed. When the temperature is different, the voltage on the temperature sensor NTC is different, so the voltage of the sampling signal at the analog-to-digital sampling port of the MCU1 is different, and the MCU1 can determine the temperature sampled by each temperature sensor NTC based on the sampling signals of each analog-to-digital sampling port.

[0061] Optionally, referring to Figure 3 As shown, the multi-point temperature measurement circuit is powered by a power-taking coil. Figure 3 The power supply circuit 300 is shown, in which the wiring terminal CN2 is shown, and this wiring terminal CN2 is used to connect to the power-taking coil. Optionally, the power-taking coil can be an independent winding of a switching power supply transformer, or the power-taking coil can be an independent coil, and the independent coil is powered by coupling the induction coil of the electromagnetic heating appliance. The above method is a method of independently powering the multi-point temperature measurement circuit. Optionally, the power supply of the multi-point temperature measurement circuit in the embodiments of the present application can be provided by the power supply of the power supply board.

[0062] Based on the above multi-point temperature measurement circuit, the second control unit provided on the power supply board is introduced. The second control unit cooperates with the multi-point temperature measurement circuit to jointly complete multi-point temperature measurement.

[0063] Optionally, the embodiments of the present application provide a temperature measurement circuit. Referring to Figure 4 As shown, the temperature measurement circuit includes: a multi-point temperature measurement circuit 100 and a second control unit 200 on the power supply board of the electromagnetic heating appliance. The multi-point temperature measurement circuit 100 is the multi-point temperature measurement circuit in any of the foregoing embodiments.

[0064] Among them, the multi-point temperature measurement circuit 100 is used to determine the temperature value based on multiple sampling signals and output a pulse width modulation signal based on the temperature value. The second control unit 200 is used to filter the pulse width modulation signal to obtain a temperature signal and determine the temperature value based on the temperature signal.

[0065] The second control unit 200 can be the existing MCU in the power supply board of the electromagnetic heating appliance.

[0066] Optionally, as shown in Figure 4 the second control unit 200 includes: an integration circuit 201 and a second control module 202.

[0067] Among them, the integration circuit 201 is used to filter the pulse width modulation signal to obtain a temperature signal.

[0068] The second control module 202 is used to determine the temperature value based on the temperature signal.

[0069] Optionally, as shown in Figure 5 the integration circuit 201 in the second control unit 200 includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a first capacitor C1. The second control module 202 is MCU2.

[0070] Among them, the first output terminal of the optocoupler IC is connected to the power supply through the third resistor R3, the second output terminal of the optocoupler IC is grounded, one end of the fourth resistor R4 is connected to the first output terminal of the optocoupler IC, the other end of the fourth resistor R4 is respectively connected to one end of the fifth resistor R5 and one end of the first capacitor C1, the other end of the first capacitor C1 is grounded, and the other end of the fifth resistor R5 is connected to the analog-to-digital sampling port of the second control module 202.

[0071] Figure 5 The wiring terminal CN1B is shown in , and this wiring terminal CN1B is used to connect to the multi-point temperature measurement circuit in the foregoing embodiment to obtain the pulse width modulation signal output by the multi-point temperature measurement circuit. After the pulse width modulation signal is integrated by the fourth resistor R4 and the first capacitor C1, the pulse width modulation signal is flattened and restored to a temperature signal. Thus, the second control module 202 samples the temperature signal through the analog-to-digital sampling port and determines the temperature value based on the sampled temperature signal, realizing the restoration from the pulse width modulation signal to the temperature value.

[0072] It can be understood that in the case where the pulse width modulation signal is the pulse width modulation signal corresponding to an open circuit or a short circuit, after the second control module 202 integrates and samples the pulse width modulation signal, it can determine whether the multi-point temperature measurement circuit is open or shorted based on the sampling result.

[0073] Figure 6It is a schematic flowchart of a multi-point temperature measurement method provided by an embodiment of the present application. The execution subject of this method is the multi-point temperature measurement circuit in the foregoing embodiment. As Figure 6 shown, this method includes:

[0074] S601. Obtain the sampling signals of multiple first sampling units.

[0075] S602. Determine the temperature value based on the sampling signals of multiple first sampling units, and output a pulse width modulation signal based on the temperature value. Among them, the temperature signal obtained by filtering the pulse width modulation signal is used to determine the temperature value.

[0076] Optionally, before determining the temperature value based on the sampling signals of multiple first sampling units, this method includes: determining whether the multi-point temperature measurement circuit is open or short-circuited based on the sampling signals of multiple first sampling units. If the multi-point temperature measurement circuit is not open or short-circuited, then continue to execute determining the temperature value based on the sampling signals of multiple first sampling units. If the multi-point temperature measurement circuit is open or short-circuited, then output a pulse width modulation signal corresponding to the open or short circuit.

[0077] For the second control unit, determine whether the multi-point temperature measurement circuit is open or short-circuited based on the pulse width modulation signal output by the multi-point temperature measurement circuit, or determine the temperature value corresponding to the pulse width modulation signal.

[0078] For the implementation principle and technical effects of this method, reference can be made to the description of the circuit part in the foregoing embodiment, which will not be elaborated here.

[0079] An embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the multi-point temperature measurement method in any of the foregoing embodiments is implemented.

[0080] An embodiment of the present application also provides a computer program product, including a computer program. When the computer program is executed by a processor, the multi-point temperature measurement method in any of the foregoing embodiments is implemented.

[0081] Optionally, the foregoing processor may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps in the method embodiments disclosed in combination with the present application can be directly embodied as being executed by a hardware processor, or executed by a combination of hardware and software modules in the processor.

[0082] All or part of the steps of the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a readable memory. When the program is executed, it performs the steps including those of the above method embodiments; and the foregoing memory (storage medium) includes: read-only memory (ROM), RAM, flash memory, hard disk, solid state drive, magnetic tape, floppy disk, optical disc, and any combination thereof.

[0083] The embodiments of the present application are described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, and the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processing unit of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processing unit of the computer or other programmable data processing devices generate for implementing in the process Figure 1 one process or multiple processes and / or blocks Figure 1 a device for the functions specified in one block or multiple blocks.

[0084] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured product including an instruction device, and the instruction device implements in the process Figure 1 one process or multiple processes and / or blocks Figure 1 a device for the functions specified in one block or multiple blocks.

[0085] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are performed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 a device for the functions specified in one block or multiple blocks.

[0086] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these changes and modifications.

[0087] In this application, the term "including" and its variations may refer to non-restrictive inclusion; the term "or" and its variations may refer to "and / or". In this application, terms such as "first", "second", etc. are used to distinguish similar objects and do not necessarily have to describe a specific order or sequence. In this application, "a plurality of" means two or more. "And / or" describes the relationship between related objects and indicates that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

Claims

1. A multi-point temperature measurement circuit, characterized in that Applied to an electromagnetic heating appliance, the multi-point temperature measurement circuit includes: a plurality of first sampling units and a first control unit; The plurality of first sampling units are respectively configured to sample the temperatures at different positions through temperature sensors disposed at different positions of the electromagnetic heating appliance; The first control unit is configured to determine a temperature value based on the sampling signals of the plurality of first sampling units, and output a pulse width modulation signal based on the temperature value, so that a second control unit on a power supply board of the electromagnetic heating appliance filters the pulse width modulation signal to obtain a temperature signal, and determines the temperature value based on the temperature signal.

2. The multi-point temperature measurement circuit according to claim 1, wherein The first control unit includes: a first control module and an isolation module; The first control module is configured to determine the temperature value based on the sampling signals of the plurality of first sampling units, and output an initial pulse width modulation signal through a pulse width modulation port based on the temperature value; The isolation module is configured to isolate and output the pulse width modulation signal based on the initial pulse width modulation signal.

3. The multi-point temperature measurement circuit according to claim 2, wherein The isolation module includes: an optocoupler; A first input terminal of the optocoupler is configured to connect to the pulse width modulation port, a second input terminal of the optocoupler is connected to a power supply through a first resistor, and an output terminal of the optocoupler is configured to connect to the second control unit.

4. The multi-point temperature measurement circuit according to any one of claims 1-3, characterized in that The first sampling unit includes a second resistor and a temperature sensor; One end of the temperature sensor is connected to the power supply through the second resistor, the other end of the temperature sensor is grounded, and a connection point of the temperature sensor and the second resistor is connected to an analog-to-digital sampling port of the first control unit.

5. The multi-point temperature measurement circuit according to any one of claims 1-3, characterized in that, The multi-point temperature measurement circuit is powered by a power-taking coil, the power-taking coil is an independent winding of a switching power supply transformer, or the power-taking coil is an independent coil, and the independent coil is powered by coupling an induction coil of the electromagnetic heating appliance; Or, The power supply of the multi-point temperature measurement circuit is provided by the power supply of the power supply board.

6. The multi-point temperature measurement circuit according to any one of claims 1-3, wherein The first control unit is configured to determine whether the multi-point temperature measurement circuit is open or short-circuited based on the sampling signals of the plurality of first sampling units, and output the pulse width modulation signal based on whether the multi-point temperature measurement circuit is open or short-circuited.

7. The multi-point temperature measurement circuit according to any one of claims 1-3, characterized in that, The first control unit is configured to determine a highest temperature value sampled by the plurality of first sampling units based on the sampling signals of the plurality of first sampling units, and output the pulse width modulation signal based on the highest temperature value.

8. The multi-point temperature measurement circuit according to any one of claims 1-3, characterized in that, The multi-point temperature measurement circuit is disposed at a position other than a power supply board and a display board of the electromagnetic heating appliance.

9. A temperature measurement circuit, characterized in that, Applied to an electromagnetic heating appliance, the temperature measurement circuit includes: the multi-point temperature measurement circuit according to any one of claims 1-8 and a second control unit on a power supply board of the electromagnetic heating appliance.

10. The temperature measurement circuit according to claim 9, wherein, The second control unit includes: an integration circuit and a second control module; The integration circuit is configured to filter the pulse width modulation signal to obtain a temperature signal; The second control module is configured to determine a temperature value based on the temperature signal.

11. An electromagnetic heating appliance, characterized in that, Including: The temperature measurement circuit according to claim 9 or 10.

12. A multi-point temperature measurement method, characterized in that, Applied to the multi-point temperature measurement circuit according to any one of claims 1-8, the method includes: Obtaining sampling signals of a plurality of first sampling units; Determining a temperature value based on the sampling signals of the plurality of first sampling units, and outputting a pulse width modulation signal based on the temperature value, wherein a temperature signal obtained by filtering the pulse width modulation signal is used to determine the temperature value.

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