Thermal shock resistant temperature sensor circuit and temperature measuring equipment

Abstract

The utility model discloses a thermal shock resistant temperature sensor circuit, and relates to the technical field of temperature measurement. The circuit comprises a temperature measuring module, an MCU, a constant current driving module and a heating module. The temperature measuring module collects environment temperature data and measured body temperature data and inputs the collected data to the MCU. The MCU outputs a control signal based on the environment temperature data and the measured body temperature data, and adjusts the working state of the constant current driving module; the constant current driving module starts or stops generation of driving current according to a control instruction of the MCU, or adjusts the size of the driving current, and inputs the driving current to the heating module; the heating module receives the driving current and adjusts the environment temperature of the temperature measuring module through impedance heating. According to the circuit, when the ambient temperature and the temperature of the measured object have significant difference, the ambient temperature of the temperature measurement module can be rapidly adjusted in an impedance heating mode, the influence of thermal shock in the temperature measurement process is effectively reduced, and the stability and accuracy of measurement are improved.

Description

Technical field

[0001] The present application relates to the field of temperature measurement technology, and in particular to a temperature sensor circuit that is resistant to thermal shock. [Background Technology]

[0002] Currently, ear and forehead thermometers, among other devices used to measure body temperature, are widely used in homes, healthcare, and public health settings. These devices typically use infrared sensors to measure body temperature. To ensure accurate measurement, each product undergoes high-precision blackbody calibration before shipment. This calibration process is typically performed at room temperature, where the difference between the measured temperature and the ambient temperature is minimal, minimizing noticeable thermal shock.

[0003] However, in actual use, temperature measurement equipment often encounters large temperature differences. For example, measuring a human body temperature of 36°C at room temperature of 10°C can cause significant thermal shock between the temperature sensor and the object being measured. This rapid temperature change directly impacts the infrared sensor's measurement stability and accuracy, and thus the precision and reliability of the temperature measurement results. To mitigate the impact of thermal shock on measurement accuracy, several methods are commonly used. One approach involves selecting materials with strong thermal shock resistance to manufacture the temperature sensor, thereby reducing the impact of sudden temperature changes on sensor performance. However, this method requires expensive materials, increasing product costs. Another approach involves placing a thermal shield or isolation layer between the temperature sensor and the object being measured to slow temperature conduction and thus reduce the impact of thermal shock. However, this method places high demands on design and production, increasing the structural complexity of the device. Yet another approach involves preheating or cooling the temperature sensor before measurement, bringing its ambient temperature close to that of the object being measured, thereby minimizing the impact of thermal shock. However, this method requires additional time and energy, affecting measurement speed and making it unsuitable for rapid temperature measurement. Therefore, although the existing technology has alleviated the problem of thermal shock to a certain extent, it still has limitations such as high cost, complex structure and limited measurement speed. [Utility Model Content]

[0004] The purpose of the utility model is to provide a temperature sensor circuit that is resistant to thermal shock, which reduces the influence of thermal shock on measurement by adjusting the ambient temperature of the temperature sensor, and improves the measurement accuracy and stability of the temperature measuring equipment in an environment with a significant temperature difference.

[0005] The purpose of this application is achieved through the following technical solutions:

[0006] In a first aspect of the present application, a temperature sensor circuit resistant to thermal shock is provided, the circuit comprising:

[0007] The temperature measurement module is used to collect ambient temperature data and measured body temperature data, and input the ambient temperature data and the measured body temperature data into the MCU;

[0008] MCU, connected to the temperature measurement module, controls the working state of the constant current driving module based on the ambient temperature data and the temperature data of the object being measured;

[0009] A constant current driving module is connected to the MCU, starts or stops the generation of the driving current, or adjusts the magnitude of the driving current according to the control signal of the MCU, and inputs the driving current to the heating module;

[0010] The heating module is connected to the constant current driving module and receives the driving current to perform impedance heating to adjust the ambient temperature of the temperature measuring module.

[0011] Optionally, the temperature sensor circuit further includes an LDO voltage regulator module for regulating the input voltage to the operating voltage of the MCU and the temperature measurement module.

[0012] Optionally, in the temperature sensor circuit, the temperature measurement module, the MCU, the constant current drive module, the heating module and the LDO voltage stabilization module are connected via an FPC.

[0013] Optionally, in the above-mentioned temperature sensor circuit, the temperature measurement module includes a temperature measurement chip, and the temperature measurement chip is provided with an infrared sensor and an NTC temperature sensor. The infrared sensor is used to collect temperature data of the measured object in a non-contact manner, and the NTC temperature sensor is used to collect temperature data of the measurement environment in real time.

[0014] Furthermore, in the above-mentioned temperature sensor circuit, the communication input terminal of the MCU is connected to the SCL terminal and the SDA terminal of the temperature measurement chip, and the ambient temperature data and the temperature data of the measured object are collected through the I2C protocol.

[0015] Optionally, in the above-mentioned temperature sensor circuit, the constant current drive module includes a constant current drive chip, the enable end of the constant current drive chip is connected to the output end of the MCU, and the generation of the drive current is started or shut down, or the size of the drive current is adjusted based on the control signal of the MCU.

[0016] Optionally, in the above-mentioned temperature sensor circuit, the heating module is a heating coil, which is connected between the power supply terminal and the switch terminal of the constant current driving chip and performs impedance heating based on the driving current.

[0017] Optionally, in the above-mentioned temperature sensor circuit, the FPC is designed as a multi-layer structure, wherein the temperature measuring chip is installed on the top layer of the FPC, and the heating coil is set on the middle layer and / or bottom layer of the FPC.

[0018] Optionally, in the above-mentioned temperature sensor circuit, the winding shape of the heating coil is circular, square or serpentine.

[0019] A second aspect of the present application provides a temperature measurement device, which includes the temperature sensor circuit as described in the first aspect.

[0020] The effects provided in the content of the utility model are only the effects of the embodiments, not all the effects. One of the above technical solutions has the following advantages or beneficial effects:

[0021] The present application provides a temperature sensor circuit that is resistant to thermal shock. Through the coordinated cooperation of a temperature measurement module, an MCU, a constant current drive module, and a heating module, the temperature measurement accuracy in an environment with a significant temperature difference is effectively improved. The temperature measurement module collects ambient temperature data and measured body temperature data, and inputs the collected data into the MCU; the MCU outputs a control signal based on these temperature data to adjust the working state of the constant current drive module; the constant current drive module starts or shuts down the generation of the driving current, or adjusts the size of the driving current, and inputs the driving current into the heating module according to the control instruction of the MCU; the heating module receives the driving current and adjusts the ambient temperature of the temperature measurement module through impedance heating. When there is a significant difference between the ambient temperature and the measured body temperature, this circuit does not require external heat shielding, thermal isolation devices, or adjustment of complex temperature sensing structures. The ambient temperature of the temperature measurement module can be quickly adjusted by impedance heating, which effectively reduces the impact of thermal shock during the temperature measurement process and improves the stability and accuracy of the measurement.

Brief Description of the Drawings

[0022] Figure 1 This is a schematic diagram of the circuit structure of a temperature sensor that is resistant to thermal shock according to an embodiment of the present application;

[0023] Figure 2 This is a schematic diagram of a temperature sensor circuit that is resistant to thermal shock according to an embodiment of the present application;

[0024] Figure 3 A schematic diagram of an FPC multi-layer structure according to an embodiment of the present application;

[0025] Reference numerals:

[0026] 110-temperature measurement module, 120-MCU, 130-constant current drive module, 140-heating module, 150-LDO voltage regulator module. [Specific implementation method]

[0027] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0028] It should be noted that references to "one embodiment," "an embodiment," "an example embodiment," etc., in this specification indicate that the described embodiment may include specific features, structures, or characteristics. However, not every embodiment must include these specific features, structures, or characteristics. In addition, such references do not necessarily refer to the same embodiment. Furthermore, when specific features, structures, or characteristics are described in conjunction with an embodiment, whether or not explicitly described, it is indicated that incorporating such features, structures, or characteristics into other embodiments is within the knowledge of those skilled in the art.

[0029] As described in the background technology, existing temperature measurement equipment is susceptible to thermal shock in environments with significant temperature differences, resulting in decreased measurement accuracy and stability. Traditional methods such as external heat shielding, thermal isolation devices, or complex temperature sensing structure adjustments can alleviate thermal shock to a certain extent, but often require high costs and complex designs. Based on this, the present embodiment provides a temperature sensor circuit that is resistant to thermal shock, which adjusts the ambient temperature of the sensor by impedance heating, thereby quickly reducing the impact of thermal shock when there is a significant difference between the ambient temperature and the temperature of the measured body, thereby improving the stability and accuracy of the measurement. It is particularly suitable for household temperature measurement equipment (such as ear thermometers, forehead thermometers), as well as scenarios that require fast response and high-precision temperature measurement, such as medical and public health testing fields.

[0030] refer to Figure 1 , Figure 11 is a schematic diagram of a temperature sensor circuit structure that is resistant to thermal shock according to an embodiment of the present application. The temperature sensor circuit includes a temperature measurement module 110, an MCU 120, a constant current driver module 130, and a heating module 140. Specifically, the temperature measurement module 110 is used to collect ambient temperature data and measured body temperature data, and input the collected temperature data into the MCU 120, providing the MCU 120 with accurate temperature change information. The MCU 120 is connected to the temperature measurement module 110, receives the ambient temperature data and measured body temperature data transmitted by the temperature measurement module 110, and performs temperature difference analysis based on these temperature data, and generates a control signal based on the temperature difference information to adjust the working state of the constant current driver module 130, so that the circuit can quickly and accurately respond to ambient temperature changes. The constant current driver module 130 is connected to the MCU 120, receives a control signal from the MCU 120, and starts or shuts down the generation of the drive current based on the control signal, or adjusts the size of the drive current, and then inputs the drive current into the heating module 140, thereby accurately controlling the heating power of the heating module 140 to adapt to the measurement requirements of the current environment. The heating module 140 is connected to the constant current drive module 130 and receives the drive current to perform impedance heating, thereby adjusting the ambient temperature of the temperature measurement module 110. When there is a significant temperature difference between the ambient temperature detected by the temperature measurement module 110 and the temperature of the object being measured, the heating module 140 responds quickly and adjusts the temperature around the temperature measurement module 110 to a temperature close to the temperature of the object being measured through impedance heating, thereby reducing the thermal shock to the temperature measurement module 110 caused by the sudden temperature change.

[0031] The circuit of this embodiment, through the coordination between the temperature measurement module 110, MCU120, constant current drive module 130 and heating module 140, can quickly adjust the ambient temperature of the temperature measurement module 110 by impedance heating without the need for external heat shielding, thermal isolation devices or complex temperature sensing structures, effectively reducing the impact of temperature differences on measurement results. It is suitable for various occasions requiring high-precision and high-reliability temperature measurement.

[0032] refer to Figure 2 , Figure 2 This is a schematic diagram of a thermal shock-resistant temperature sensor circuit according to an embodiment of the present application. In this embodiment, the temperature sensor circuit further includes an LDO voltage regulator module 150, which is connected to the temperature measurement module 110 and the MCU 120 and is used to regulate the input voltage (e.g., 5V) to the operating voltage required by the MCU 120 and the temperature measurement module 110, thereby ensuring that the circuit operates under stable power conditions.

[0033] Preferably, the temperature measurement module 110, MCU 120, constant current drive module 130, heating module 140 and LDO voltage regulator module 150 are connected via an FPC (flexible printed circuit) to reduce the volume and weight of the circuit and enhance the flexibility and layout of the circuit.

[0034] Continue to refer Figure 2 In this embodiment, the temperature measurement module 110 includes a temperature measurement chip U1, which is encapsulated with an infrared sensor and an NTC temperature sensor. The infrared sensor is used to collect temperature data of the object being measured in a non-contact manner, thereby obtaining temperature information of the object being measured conveniently and quickly; the NTC temperature sensor monitors temperature changes in the measurement environment in real time to provide accurate ambient temperature data. The communication input terminal of the MCU 120 is connected to the SCL and SDA terminals of the temperature measurement chip U1, and data transmission is achieved via the I2C protocol. The temperature measurement chip U1 can obtain the necessary temperature information in a short period of time, providing a real-time basis for subsequent data processing and ensuring the accuracy and reliability of the measurement results.

[0035] In some embodiments, the constant current driver module 130 includes a constant current driver chip U2. The enable terminal EN of the constant current driver chip U2 is connected to the output terminal of the MCU120, and can start or shut down the driving current based on the control signal of the MCU120, or adjust the size of the driving current. By adjusting the driving current, the constant current driver module 130 can effectively adjust the heating power of the heating module 140 to achieve precise temperature control. Preferably, the heating module 140 uses a heating coil, which is connected between the power supply terminal VCC and the switch terminal DR of the constant current driver chip U2, and can perform impedance heating based on the driving current, thereby adjusting the ambient temperature of the temperature measurement module 110.

[0036] To optimize space utilization and electrical performance, the FPC is designed as a multi-layer structure. The top layer of the FPC houses the temperature measurement chip U1, which includes an infrared sensor and an NTC temperature sensor. This facilitates non-contact acquisition of the measured object's temperature and real-time ambient temperature, improving temperature measurement accuracy and response speed. Heating coils are placed in the middle and / or bottom layers of the FPC to facilitate ambient temperature regulation of the temperature measurement chip U1 through impedance heating. The heating coils can adopt various winding styles, such as circular, square, or serpentine, to suit different application requirements and optimize the heating effect. Figure 3 This is a schematic diagram of a multi-layer FPC structure in an embodiment of the present application. In this embodiment, the FPC is designed as a three-layer device. The top layer of the FPC houses the temperature measurement chip U1, the middle layer houses the heating coil, and the bottom layer is used for circuit routing to connect various signals and power supplies. This FPC design effectively utilizes space while improving circuit performance and flexibility, particularly in portable devices and compact instruments, providing efficient temperature control and measurement performance.

[0037] Figure 3The circuit of the embodiment, after the circuit is powered on, first collects the ambient temperature through the NTC temperature sensor, and provides a benchmark for subsequent temperature adjustment after automatic calibration. When the MCU reads that the ambient temperature is lower than the set threshold temperature (such as 35°C), the constant current drive module is started, and current is transmitted to the heating coil through the FPC for heating, so that the ambient temperature rises and ensures that suitable temperature measurement conditions are reached. During the heating process, the MCU monitors the ambient temperature in real time through the NTC temperature sensor, adjusts the heating power according to the changes in the ambient temperature, and reduces the measurement error caused by the change in the ambient temperature difference. After the ambient temperature reaches the set threshold temperature, the heating current is reduced or cut off, and the circuit performs non-contact measurement of the temperature of the object being measured through the infrared sensor. The measurement results can be presented through a display circuit (not shown in this circuit).

[0038] From the above analysis, it can be seen that the temperature sensor circuit of this embodiment achieves high-precision, fast-response temperature control while ensuring system compactness and integration through the coordinated operation of the temperature measurement module, MCU, constant current drive module, heating module, and LDO voltage regulator module, combined with the integrated design of FPC flexible cables. This design does not require external heat shielding, thermal isolation devices, or adjustments to complex temperature sensing structures, simplifying the production process. This not only improves the accuracy and stability of temperature control, but also reduces production costs and complexity. It is suitable for fields requiring high-precision temperature measurement and control, such as home temperature measurement, medical equipment, and public health testing, and has broad application prospects.

[0039] In addition, embodiments of the present application further provide a temperature measurement device. This temperature measurement device includes the thermal shock-resistant temperature sensor circuit described in the above embodiments. For processes not described in detail in the temperature measurement device of this embodiment, reference can be made to the relevant sections of the above-described temperature sensor circuit embodiments, and will not be further elaborated here.

[0040] Although the present application has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications or improvements may be made based on the present application. Therefore, such modifications or improvements, which do not depart from the spirit of the present application, are within the scope of protection claimed in the present application.

Claims

1. A temperature sensor circuit resistant to thermal shock, characterized in that: include: The temperature measurement module is used to collect ambient temperature data and measured body temperature data, and input the ambient temperature data and the measured body temperature data into the MCU; MCU, connected to the temperature measurement module, controls the working state of the constant current driving module based on the ambient temperature data and the temperature data of the object being measured; A constant current driving module is connected to the MCU, starts or stops the generation of the driving current, or adjusts the magnitude of the driving current according to the control signal of the MCU, and inputs the driving current to the heating module; The heating module is connected to the constant current driving module and receives the driving current to perform impedance heating to adjust the ambient temperature of the temperature measuring module.

2. The temperature sensor circuit according to claim 1, wherein: The circuit further includes an LDO voltage stabilizing module, which is connected to the temperature measuring module and the MCU and is used to regulate the input voltage to the operating voltage of the MCU and the temperature measuring module.

3. The temperature sensor circuit according to claim 2, wherein: The temperature measurement module, the MCU, the constant current drive module, the heating module and the LDO voltage stabilization module are connected via an FPC.

4. The temperature sensor circuit according to claim 3, characterized in that: The temperature measurement module includes a temperature measurement chip, in which an infrared sensor and an NTC temperature sensor are provided. The infrared sensor is used to collect temperature data of the measured object in a non-contact manner, and the NTC temperature sensor is used to collect temperature data of the measurement environment in real time.

5. The temperature sensor circuit according to claim 4, characterized in that: The communication input terminal of the MCU is connected to the SCL terminal and the SDA terminal of the temperature measurement chip, and the ambient temperature data and the temperature data of the measured object are collected through the I2C protocol.

6. The temperature sensor circuit according to claim 4 or 5, characterized in that: The constant current drive module includes a constant current drive chip, the enable end of the constant current drive chip is connected to the output end of the MCU, and the generation of the drive current is started or stopped, or the size of the drive current is adjusted based on the control signal of the MCU.

7. The temperature sensor circuit according to claim 6, characterized in that: The heating module is a heating coil, which is connected between the power supply terminal and the switch terminal of the constant current driving chip and performs impedance heating based on the driving current.

8. The temperature sensor circuit according to claim 7, wherein: The FPC is designed as a multi-layer structure, wherein the temperature measuring chip is installed on the top layer of the FPC, and the heating coil is arranged on the middle layer and / or bottom layer of the FPC.

9. The temperature sensor circuit according to claim 8, characterized in that: The winding shape of the heating coil is circular, square or serpentine.

10. A temperature measuring device, characterized in that: The device comprises a temperature sensor circuit as claimed in any one of claims 1 to 9.

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