Non-contact temperature measuring device and microwave oven

Abstract

The utility model provides a non-contact temperature measuring device and a microwave oven. The non-contact temperature measuring device comprises an MCU, an infrared temperature sensor U2, a temperature compensating circuit and a voltage stabilizing circuit, the MCU is electrically connected with a signal end of the infrared temperature sensor U2, one end of the temperature compensation circuit and one end of the voltage stabilizing circuit, a pin GND of the infrared temperature sensor U2, the other end of the temperature compensation circuit and the other end of the voltage stabilizing circuit are all grounded, and the other end of the voltage stabilizing circuit is connected with a pin VCC of the infrared temperature sensor U2; wherein the temperature compensation circuit comprises a thermistor RT, and the thermistor RT is arranged in the temperature compensation circuit; according to the non-contact temperature measuring device and the microwave oven provided by the utility model, the structure of the temperature measuring device can be simplified, the cost of the temperature measuring device can be reduced, the anti-interference capability of the device can be improved, and the accuracy and the reliability of the device for measuring the temperature of the inner cavity of the microwave oven can be improved; the energy consumption of the device is reduced and the service life of the sensor in the device is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of microwave oven technology, and more specifically, to a non-contact temperature measuring device with an infrared temperature sensor and a microwave oven. Background Technology

[0002] With the development of the times, household appliances have become increasingly common in people's lives. Microwave ovens, as one such appliance, are frequently used for heating, defrosting, baking, and steaming food. However, because traditional microwave ovens rely on user-set time and power to cook food, and typically lack a temperature sensor inside the cavity, they are prone to overheating or underheating. This is especially true in defrosting functions; if the temperature is too high, the food may be partially cooked, affecting the user experience. Therefore, researching ways to improve the accuracy and reliability of microwave oven cavity temperature measurement is of great significance.

[0003] Existing microwave ovens mostly employ a contact-based temperature measurement method, where temperature-sensing elements such as thermocouples and thermistors directly contact the object being measured, utilizing the principle of heat conduction to measure temperature. This contact-based temperature measurement improves the accuracy and stability of temperature control within the microwave oven cavity. For example, patent CN1106535C discloses a microwave oven in which the control unit is connected to a thermistor, an infrared sensor, a weight sensor, and a door detection switch. The thermistor is mounted on the outer wall of the cavity to indirectly measure the temperature inside. During cooking, the infrared sensor detects infrared radiation from food placed on a rotating disc within the cavity, and the control unit detects the food's temperature based on the detected infrared radiation. By using the infrared sensor to detect the food's temperature, combined with the thermistor's indirect temperature measurement of the microwave oven cavity, the microwave oven can achieve thorough heating of the food. However, this contact-based temperature measurement method is susceptible to microwave interference, leading to data jumps and potentially affecting the accuracy and reliability of real-time temperature measurement within the microwave oven cavity.

[0004] Patent CN1568098A discloses a microwave oven detection circuit, mainly comprising an array sensor composed of multiple infrared sensors with different viewing angles capable of detecting the internal temperature of the heating chamber; a multi-channel controller that sequentially outputs the temperatures detected by the array sensors; and an amplifier that amplifies the output signals of the multi-channel controller. The circuit also discloses a voltage compensation circuit containing a thermistor located at the end of the array sensor furthest from the controller. While utilizing an array sensor composed of multiple infrared sensors can read temperatures over a wide viewing angle range and use this temperature as basic information during cooking, thereby improving the microwave oven's cooking performance, the placement of the array sensors and thermistors still results in temperature drift problems inherent in existing infrared temperature sensor circuits. Therefore, it can easily affect the accuracy and reliability of real-time temperature measurement within the microwave oven cavity. Furthermore, the circuit structure is relatively complex, which can increase the cost of the detection circuit. Utility Model Content

[0005] In view of this, the present invention aims to propose a non-contact temperature measuring device and a microwave oven to solve the problems of existing technologies, such as microwave ovens using thermocouples, thermistors, and other measuring elements for temperature measurement, which are prone to sensor interference, resulting in low measurement accuracy and poor reliability; and the use of infrared temperature sensor circuits, which not only suffers from temperature drift affecting measurement accuracy but also has a complex measurement circuit structure, leading to high cost. The present invention simplifies the structure of the temperature measuring device, reduces its cost, avoids interference issues that easily occur when using measuring elements to measure the temperature of the microwave oven cavity, improves the device's anti-interference capability, and enhances the accuracy and reliability of the device's measurement of the microwave oven cavity temperature. It also avoids the temperature drift problem that easily occurs with infrared temperature sensors, reduces the device's energy consumption, and extends the service life of the sensors within the device.

[0006] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0007] This utility model relates to a non-contact temperature measuring device and a microwave oven. The non-contact temperature measuring device includes an MCU, an infrared temperature sensor U2, a temperature compensation circuit, and a voltage regulator circuit. The MCU is electrically connected to the signal terminal of the infrared temperature sensor U2, one end of the temperature compensation circuit, and one end of the voltage regulator circuit. The GND pin of the infrared temperature sensor U2, the other end of the temperature compensation circuit, and the voltage regulator circuit are all grounded. The other end of the voltage regulator circuit is connected to the VCC pin of the infrared temperature sensor U2. The temperature compensation circuit includes a thermistor RT, which is disposed within the temperature compensation circuit.

[0008] Furthermore, the temperature compensation circuit includes a fifth resistor R5 and a third capacitor C3. One end of the thermistor RT is connected to the power supply +Vcc, and the other end of the thermistor RT is connected to the fifth resistor R5, one end of the third capacitor C3, and the MCU pin P00. The other ends of the fifth resistor R5 and the third capacitor C3 are both grounded.

[0009] Furthermore, the voltage regulator circuit includes a voltage regulator circuit one and a voltage regulator circuit two; one end of the voltage regulator circuit one is electrically connected to the MCU pin P01, and the other end of the voltage regulator circuit one is electrically connected to the infrared temperature sensor U2 pin VCC through the voltage regulator circuit two.

[0010] Furthermore, the voltage regulator circuit includes a first resistor R1, a second resistor R2, and a transistor V1; one end of the first resistor R1 is electrically connected to pin P01 of the MCU, and the other end of the first resistor R1 is electrically connected to one end of the second resistor R2 and the base of the transistor V1; the other end of the second resistor R2 is connected in parallel with the emitter of the transistor V1 and then connected to the power supply +Vcc; the collector of the transistor V1 is connected to the voltage regulator circuit.

[0011] Furthermore, the voltage regulator circuit also includes a fourth resistor R4 and a fourth capacitor C4; the collector of transistor V1 is grounded in sequence through the fourth resistor R4 and the fourth capacitor C4.

[0012] Furthermore, the voltage regulator circuit includes a third resistor R3, a first capacitor C1, and a second capacitor C2; one end of the third resistor R3 is electrically connected to the collector of the transistor V1, and the other end of the third resistor R3 is electrically connected to one end of the first capacitor C1, one end of the second capacitor C2, and the VCC pin of the infrared temperature sensor U2, respectively. The other ends of the first capacitor C1 and the second capacitor C2 are both grounded.

[0013] Furthermore, the signal terminals of the infrared temperature sensor U2 include pin SCL and pin SDA; pin SCL of the infrared temperature sensor U2 is connected to pin P10 of the MCU via a clock line, and pin SDA of the infrared temperature sensor U2 is connected to pin P11 of the MCU via a data line.

[0014] Furthermore, the device also includes a sixth resistor R6, the two ends of which are connected to the MCU pin P10 and the infrared temperature sensor U2 pin SCL via clock lines, respectively.

[0015] Furthermore, the device also includes a seventh resistor R7, the two ends of which are connected to pin P11 of the MCU and pin SDA of the infrared temperature sensor U2 via data lines, respectively.

[0016] A microwave oven includes the aforementioned non-contact temperature measuring device, which is disposed inside the microwave oven.

[0017] Compared with the prior art, the non-contact temperature measuring device and microwave oven described in this utility model have the following advantages:

[0018] By incorporating this device within the microwave oven, the structure of the temperature measuring device can be simplified, its cost reduced, and interference issues that can easily arise when using measuring elements to measure the temperature inside the microwave oven cavity can be avoided. This improves the device's anti-interference capability and enhances the accuracy and reliability of its temperature measurement of the microwave oven cavity. Furthermore, it avoids the temperature drift problem that often occurs when using infrared temperature sensors, making the infrared temperature sensor controllable by the power supply and ensuring stable communication between the two. This also reduces the device's energy consumption and extends the lifespan of the sensors within the device. Attached Figure Description

[0019] The accompanying drawings, which constitute a part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments and descriptions of the utility model are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0020] Figure 1 This is a schematic diagram of the device's circuit principle.

[0021] Figure 2 This is a schematic diagram showing the placement of an infrared temperature sensor on a microwave oven.

[0022] Figure 3 This is a flowchart illustrating the application method of the non-contact temperature measuring device inside the microwave oven in this embodiment.

[0023] Explanation of reference numerals in the attached diagram: 20, temperature compensation circuit; 30, voltage regulator circuit; 31, voltage regulator circuit one; 32, voltage regulator circuit two. Detailed Implementation

[0024] The inventive concepts of this disclosure will be described below using terminology commonly used by those skilled in the art to convey the essence of their work to others skilled in the art. However, these inventive concepts may be embodied in many different forms and should not be construed as limited to the embodiments described herein.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0026] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0027] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] This embodiment is for a microwave oven. Similar to a conventional microwave oven, the overall structure consists of a magnetron, oven cavity, oven door, turntable system, and outer shell.

[0029] To address the problems of existing microwave ovens using thermocouples and thermistors for temperature measurement, which are prone to interference leading to low accuracy and reliability, and infrared temperature sensors which suffer from temperature drift affecting accuracy and complex circuitry resulting in high costs, this embodiment proposes a non-contact temperature measurement device and microwave oven. The non-contact temperature measurement device, used to measure the temperature inside the microwave oven cavity, includes an MCU, an infrared temperature sensor U2, a temperature compensation circuit 20, and a voltage regulator circuit 30. The MCU is electrically connected to the signal terminal of the infrared temperature sensor U2, one end of the temperature compensation circuit 20, and one end of the voltage regulator circuit 30. The GND pin of the infrared temperature sensor U2, the other end of the temperature compensation circuit 20, and the voltage regulator circuit 30 are all grounded. The other end of the voltage regulator circuit 30 is connected to the VCC pin of the infrared temperature sensor U2. The temperature compensation circuit 20 includes a thermistor RT, which is disposed within the temperature compensation circuit 20. The thermistor RT is used to sense changes in ambient temperature, correct errors caused by ambient temperature changes in the infrared temperature sensor U2, and improve the accuracy and reliability of the MCU's measurement of the actual temperature inside the microwave oven cavity.

[0030] By arranging the components within the device, the structure of the temperature measuring device can be simplified, the cost of the temperature measuring device can be reduced, the interference phenomenon that is easily caused when using measuring elements to measure the temperature of the microwave oven cavity can be avoided, the anti-interference ability of the device can be improved, and the accuracy and reliability of the device in measuring the temperature of the microwave oven cavity can be enhanced; it can also avoid the temperature drift problem that is easily caused when using infrared temperature sensor U2, make the infrared temperature sensor controlled by the power supply, and ensure the stability of communication between the two; reduce the energy consumption of the device and extend the service life of the sensors in the device.

[0031] The temperature compensation circuit 20 includes a fifth resistor R5 and a third capacitor C3. One end of the thermistor RT is connected to the power supply +Vcc, and the other end of the thermistor RT is connected to the fifth resistor R5, one end of the third capacitor C3, and the MCU pin P00. The other ends of the fifth resistor R5 and the third capacitor C3 are both grounded.

[0032] By connecting RT and R5 in series and C3 and R5 in parallel within the temperature compensation circuit 20, the ambient temperature change can be sensed in real time by the thermistor RT. The change in resistance is converted into a voltage signal by the circuit, correcting the error caused by ambient temperature changes in the infrared temperature sensor U2. This reduces the error in the MCU's calculation of the microwave oven cavity temperature and improves the accuracy of temperature measurement. Furthermore, non-contact temperature measurement is achieved through the infrared temperature sensor U2, while the thermistor RT provides temperature compensation for the infrared temperature sensor U2. This addresses the shortcomings of existing contact temperature measurement and the insufficient accuracy of non-contact temperature measurement, improving the accuracy and reliability of microwave oven cavity temperature measurement.

[0033] The voltage regulator circuit 30 includes a voltage regulator circuit 31 and a voltage regulator circuit 32. One end of the voltage regulator circuit 31 is electrically connected to the MCU pin P01, and the other end of the voltage regulator circuit 31 is electrically connected to the infrared temperature sensor U2 pin VCC through the voltage regulator circuit 32.

[0034] By configuring the voltage regulator circuit 30, the infrared temperature sensor U2 can be effectively controlled by the power supply, which is beneficial for stable communication between the infrared temperature sensor U2 and the MCU, improving the reliability and safety of the internal circuitry. It also facilitates on-demand power supply, reducing the energy consumption of the infrared temperature sensor U2 and extending its service life.

[0035] Specifically, voltage regulator circuit 31 includes a first resistor R1, a second resistor R2, and a transistor V1. One end of the first resistor R1 is electrically connected to pin P01 of the MCU, and the other end of the first resistor R1 is electrically connected to one end of the second resistor R2 and the base of the transistor V1. The other end of the second resistor R2 is connected in parallel with the emitter of the transistor V1 and then connected to the power supply +Vcc. The collector of the transistor V1 is connected to voltage regulator circuit 32. Voltage regulator circuit 31 also includes a fourth resistor R4 and a fourth capacitor C4. The collector of the transistor V1 is grounded through the fourth resistor R4 and the fourth capacitor C4 in sequence.

[0036] The voltage regulator circuit 32 includes a third resistor R3, a first capacitor C1, and a second capacitor C2. One end of the third resistor R3 is electrically connected to the collector of transistor V1, and the other end of the third resistor R3 is electrically connected to one end of the first capacitor C1, one end of the second capacitor C2, and the VCC pin of the infrared temperature sensor U2. The other ends of the first capacitor C1 and the second capacitor C2 are both grounded. R1, R2, R3, R4, R5, R6, and R7 are all fixed resistors.

[0037] The MCU's pin P01 is connected to the base of transistor V1 via resistor R1. The collector of V1 is connected to +Vcc via resistor R2. The emitter of V1 is connected to the filter circuit C1 and C2 via resistor R3, and then grounded via resistor R4. This not only enables stable communication between the infrared temperature sensor U2 and the MCU, but also provides voltage regulation, protecting the infrared temperature sensor U2 and ensuring the safety of power supply control of the infrared temperature sensor U2. Furthermore, the use of capacitors C1 and C2 provides filtering, improving circuit reliability and reducing interference.

[0038] The infrared temperature sensor U2 has two signal terminals: pin SCL and pin SDA. Pin SCL of the infrared temperature sensor U2 is connected to pin P10 of the MCU via a clock line, and pin SDA of the infrared temperature sensor U2 is connected to pin P11 of the MCU via a data line. Specifically, the device also includes a sixth resistor R6, whose two ends are connected to pin P10 of the MCU and pin SCL of the infrared temperature sensor U2 via clock lines, respectively. The device also includes a seventh resistor R7, whose two ends are connected to pin P11 of the MCU and pin SDA of the infrared temperature sensor U2 via data lines, respectively.

[0039] By configuring the fifth resistor R5 and the sixth resistor R6, pin P10 of the MCU is connected to pin SCL of U2 via R5, and pin P11 is connected to pin SDA of U2 via R6, thus constructing an I²C bus for data transmission. This effectively reduces wiring complexity and the occupation of too many pins, thereby lowering the manufacturing cost of the device. Furthermore, transmitting real-time data collected by the infrared temperature sensor U2 to the MCU via the I²C bus enables low-power and high-efficiency data transmission, and also improves the flexibility of data transmission.

[0040] A microwave oven includes the aforementioned non-contact temperature measuring device. An infrared temperature sensor U2 is disposed on the top or side of the microwave oven. A thermistor RT is disposed on the microwave oven near the infrared temperature sensor U2. The device is disposed inside the microwave oven.

[0041] By mounting U2 on the side or top of the microwave oven cavity, avoiding direct contact with the microwave emission source, the actual temperature value T1 of the microwave oven cavity is collected. The thermistor RT and the infrared temperature sensor U2 are installed close together, ensuring that the ambient temperature value T2 accurately reflects the operating environment temperature of the infrared temperature sensor U2. This improves the accuracy of the device's temperature measurement within the microwave oven cavity.

[0042] Working principle:

[0043] The microwave oven cavity temperature T1 is collected by U2, and the ambient temperature T2 near the infrared temperature sensor U2 is collected by the thermistor RT. The MCU integrates the data, eliminates the influence of ambient temperature changes through algorithms, and outputs the accurate cavity temperature T3.

[0044] Specifically, the method for implementing temperature compensation within the device includes the following steps:

[0045] Step 1: Reading raw data from infrared temperature sensor U2: The MCU reads the raw temperature register value of U2 through I²C and converts it into the actual temperature value T1 by parsing the register data format;

[0046] Step 2: Temperature acquisition of thermistor RT: The MCU acquires the voltage Uo of the voltage divider between RT and fixed resistor R5 through the ADC sampling port P00, and calculates the resistance value of thermistor RT according to the first formula; then, it uses the Steinhart-Hart equation to convert RT into the ambient temperature value T2.

[0047] The first formula is: RT=UoR5 / (Vcc-Uo); where Uo is the voltage divider value acquired by the ADC port of the MCU; Vcc is the power supply voltage value; and R5 is a fixed resistor.

[0048] The Steinhart-Hart equation is: T² = 1 / (A + BlnRT + C(lnRT)) 3 (); where A, B, and C are calibration coefficients for the thermistor RT, and the specific values ​​of A, B, and C are set as needed. RT is the resistance value of the thermistor at the current moment.

[0049] Step 3: Temperature compensation, calculate the final cavity temperature value T3: Establish the mathematical relationship between T2 and the error, and correct T1 through the compensation formula. Assuming that the measurement error between the ambient temperature T2 and the infrared temperature sensor U2 is approximately a linear function, then: T3=T1+α(T2-Tref); where α is the compensation coefficient and Tref is the reference ambient temperature.

[0050] The measured value T1 of the infrared temperature sensor U2 is easily affected by the ambient temperature T2, leading to errors. For example, when the ambient temperature rises, temperature drift and self-heating effects of the sensor's internal components can cause T1 to deviate from the true value. By calculating the final cavity temperature value T3, the influence of the ambient temperature on the temperature information collected by the infrared temperature sensor U2 can be effectively eliminated, thereby greatly improving the reliability and accuracy of the device's temperature detection within the cavity.

[0051] A method for applying a non-contact temperature measuring device inside a microwave oven, the method being applied to the aforementioned non-contact temperature measuring device, the method comprising the following steps:

[0052] Step S1: The microwave oven is powered on and starts: the temperature measurement process reaches the starting point.

[0053] Step S2: System Initialization: Initialize the microcontroller unit (MCU), including initializing I / O pins, configuring the I²C communication mode, and setting pin P00 of the MCU's sampling ADC port to analog input mode. Initialize the I²C communication protocol and set the communication rate to ensure stable communication between the MCU and the infrared temperature sensor U2. Next, load preset temperature compensation algorithm parameters, such as the ability to read compensation coefficients and reference temperatures from the MCU's storage area. Set the infrared temperature sensor U2 to power-saving mode initially to reduce system power consumption. This also provides the basic configuration for subsequent temperature acquisition, communication, and compensation calculation functions, ensuring normal operation of each module and optimizing initial power consumption.

[0054] Step S3: Cooking begins. Triggering condition: Receiving a cooking start signal, which can come from user operation or a command from the microwave oven control module. The microwave oven enters the cooking process, and the system begins monitoring the temperature during cooking. User operation includes pressing the microwave oven start button.

[0055] Step S4: Determine whether cooking is a critical moment based on the judgment criteria. If yes, proceed to the subsequent temperature measurement process, wake up the infrared temperature sensor U2 to work, and execute step S6; if no, it means that the current moment is not a necessary time for temperature measurement, execute "keep power saving mode", the infrared temperature sensor U2 maintains a low power consumption state to reduce energy consumption; execute step S5.

[0056] The judgment criteria are as follows:

[0057] Cooking start stage: It is necessary to obtain the initial temperature of the cavity to provide a data basis for the heating strategy.

[0058] Preset cooking time points: such as setting temperature measurement at regular intervals (or key moments in the cooking process) to monitor the cooking progress.

[0059] Final stage of cooking: Obtain the temperature just before the end of cooking to ensure the desired cooking effect is achieved.

[0060] Step S5: Maintain power saving mode: The operation mode is that the infrared temperature sensor U2 does not collect temperature data, but only maintains a basic low power consumption state, and the MCU waits for the next judgment.

[0061] By setting the parameters in step S5, system power consumption can be reduced during non-essential measurement periods, extending sensor lifespan and saving energy.

[0062] Step S6: Enter Working Mode: The operation involves the MCU sending a wake-up signal to the infrared temperature sensor U2, switching it from power-saving mode to normal working mode, preparing for temperature data acquisition. This puts the infrared temperature sensor U2 into a working state, providing hardware support for accurate acquisition of cavity temperature.

[0063] Step S7: Acquire the actual temperature value of the cavity. T1: The operation method is to send a read command to the infrared temperature sensor via the I²C communication protocol to obtain non-contact temperature data of the microwave oven cavity. The raw data is verified to ensure data integrity and accuracy.

[0064] Step S8: Acquire Ambient Temperature Value T2: The operation involves acquiring the voltage Uo of the thermistor RT via the MCU's ADC module. Based on the resistance-temperature characteristics of the thermistor RT, the voltage value is converted into the ambient temperature value T2. The acquired voltage signal is then filtered to eliminate noise interference. Moving average filtering can be used for this purpose.

[0065] Step S9: Temperature Compensation Calculation T3: The operation method is to calculate the final compensated cavity temperature value T3 based on the preset temperature compensation algorithm and the collected T1 and T2. The parameters in the compensation algorithm are optimized to ensure compensation accuracy.

[0066] Step S10: Temperature control / display: Control and display the heating of the appliance according to the compensated temperature T3.

[0067] Step S11: Infrared temperature sensor U2 enters power-saving mode: After temperature control and display are completed, the MCU sends a command to the infrared temperature sensor U2 to re-enter power-saving mode. This helps reduce overall system power consumption, optimize energy utilization, and prepare for the next measurement.

[0068] Step S12: Based on whether the microwave cooking process detected by the MCU meets the cooking end conditions, if yes, end the current cooking process and enter standby mode; otherwise, return to the "determine if it is a critical moment" step and continue to monitor the temperature during the cooking process.

[0069] The cooking end conditions include any one of the following: reaching the preset cooking time, the user manually stopping the cooking, or the temperature reaching the set end threshold.

[0070] Step S13: Return to Standby Mode: The system terminates cooking-related operations, the infrared temperature sensor U2 remains in power-saving mode, and the MCU waits for the next cooking start signal. This puts the device in a low-power standby state, ready to respond to new cooking tasks.

[0071] In this utility model, any microwave oven may include the non-contact temperature measuring device structure described in this embodiment. In addition to the temperature compensation circuit 20 and the related structure and assembly relationship of the MCU provided in this embodiment, the microwave oven also includes conventional components such as magnetron, oven cavity, oven door, turntable system, and outer shell. Since these are all prior art, they will not be described in detail here.

[0072] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A non-contact temperature measuring device, characterized by, The device comprises an MCU, an infrared temperature sensor U2, a temperature compensation circuit (20) and a voltage stabilizing circuit (30); the MCU is electrically connected with the signal end of the infrared temperature sensor U2, the temperature compensation circuit (20) and one end of the voltage stabilizing circuit (30) respectively, the pin GND of the infrared temperature sensor U2, the other end of the temperature compensation circuit (20) and the other end of the voltage stabilizing circuit (30) are grounded, and the other end of the voltage stabilizing circuit (30) is connected with the pin VCC of the infrared temperature sensor U2; wherein the temperature compensation circuit (20) comprises a thermistor RT, and the thermistor RT is arranged in the temperature compensation circuit (20).

2. The non-contact temperature measuring device according to claim 1, wherein The temperature compensation circuit (20) comprises a fifth resistor R5 and a third capacitor C3, one end of the thermistor RT is connected with a power supply +Vcc, the other end of the thermistor RT is connected with the fifth resistor R5, one end of the third capacitor C3 and the pin P00 of the MCU respectively, and the other ends of the fifth resistor R5 and the third capacitor C3 are grounded respectively.

3. The non-contact temperature measurement device of claim 1, wherein, The voltage stabilizing circuit (30) comprises a voltage stabilizing circuit (31) and a voltage stabilizing circuit (32); one end of the voltage stabilizing circuit (31) is electrically connected with the pin P01 of the MCU, and the other end of the voltage stabilizing circuit (31) is electrically connected with the pin VCC of the infrared temperature sensor U2 through the voltage stabilizing circuit (32).

4. The non-contact temperature measurement device of claim 3, wherein, The voltage stabilizing circuit (31) comprises a first resistor R1, a second resistor R2 and a triode V1; one end of the first resistor R1 is electrically connected with the pin P01 of the MCU, the other end of the first resistor R1 is electrically connected with one end of the second resistor R2 and the base of the triode V1 respectively; the other end of the second resistor R2 is connected with the emitter of the triode V1 in parallel and then connected with the power supply +Vcc; the collector of the triode V1 is connected with the voltage stabilizing circuit (32).

5. The non-contact temperature measurement device of claim 4, wherein, The voltage stabilizing circuit (31) further comprises a fourth resistor R4 and a fourth capacitor C4; the collector of the triode V1 is grounded through the fourth resistor R4 and the fourth capacitor C4 in sequence.

6. The non-contact temperature measurement device of claim 4, wherein, The voltage stabilizing circuit (32) comprises a third resistor R3, a first capacitor C1 and a second capacitor C2; one end of the third resistor R3 is electrically connected with the collector of the triode V1, the other end of the third resistor R3 is electrically connected with one end of the first capacitor C1, one end of the second capacitor C2 and the pin VCC of the infrared temperature sensor U2 respectively, and the other ends of the first capacitor C1 and the second capacitor C2 are grounded respectively.

7. The non-contact temperature measurement device of claim 1, wherein, The signal end of the infrared temperature sensor U2 comprises a pin SCL and a pin SDA; the pin SCL of the infrared temperature sensor U2 is communicatively connected with the pin P10 of the MCU through a clock line, and the pin SDA of the infrared temperature sensor U2 is communicatively connected with the pin P11 of the MCU through a data line.

8. The non-contact temperature measurement device of claim 7, wherein, The device further comprises a sixth resistor R6, and the two ends of the sixth resistor R6 are connected with the pin P10 of the MCU, the pin SCL of the infrared temperature sensor U2 through a clock line respectively.

9. The non-contact temperature measurement device of claim 7, wherein, The device further comprises a seventh resistor R7, and the two ends of the seventh resistor R7 are connected with the pin P11 of the MCU, the pin SDA of the infrared temperature sensor U2 through a data line respectively.

10. A microwave oven characterized by comprising: The microwave oven comprises a non-contact temperature measuring device according to any one of claims 1-9, which is arranged in the microwave oven.

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