A temperature detection device based on temperature sensor

Abstract

The application relates to the field of temperature detection, in particular to a temperature detection device based on a temperature sensor. The device comprises a temperature sensor, a voltage stabilizing component, a detection processing unit and a control unit, a first input end of the voltage stabilizing component is used for connecting an external power supply; the detection processing unit is connected to a detection input end of the control unit; a first output end of the voltage stabilizing component is connected to a power input end of the control unit; a second output end of the voltage stabilizing component is connected to a reference voltage input end of the control unit; an output end of the control unit is connected to a first input end of the detection processing unit; an output end of the temperature sensor is connected to a second input end of the detection processing unit; a third output end of the voltage stabilizing component is connected to a third input end of the detection processing unit; the output end of the temperature sensor is connected to the third input end of the detection processing unit; and an input end of the temperature sensor is grounded. The device is used for solving the problem of low detection precision in the prior art.

Description

Technical Field

[0001] This utility model relates to the field of temperature detection, and more specifically, to a temperature detection device based on a temperature sensor. Background Technology

[0002] In the field of modern industrial automation control, temperature sensors are core sensing elements, mainly including NTC thermistor sensors and PT100 and PT1000 platinum resistance sensors. Essentially, they achieve accurate monitoring of the temperature of the environment or equipment by utilizing the physical property that the resistance of the material changes with temperature. They are widely used in industrial air conditioning control systems, heat pump air conditioning control systems, and other scenarios to provide real-time temperature data for various control systems to support dynamic regulation. In existing technologies, mainstream solutions such as constant current source detection or dedicated integrated chips are commonly used to obtain temperature values ​​based on temperature sensors. The constant current source solution calculates the resistance value by injecting a constant current into the temperature sensor and measuring the voltage drop, and then converts it into temperature. However, the constant current source solution has a complex circuit and multiple parallel paths, resulting in excessive PCB space usage. The dedicated integrated chip solution directly outputs digital signals through built-in algorithms. However, although the dedicated integrated chip solution simplifies the design, it is expensive when used in multiple applications. At the same time, when there are multiple types of temperature sensors in the control system, the signal adaptation problem becomes more prominent: the detection devices of conventional control systems are often only compatible with specific signal types, such as single voltage / current signals, or rely on manual jumper switching to identify signal types, making it difficult to meet the flexible access requirements of different temperature sensors in multiple scenarios. Utility Model Content

[0003] The present invention aims to overcome at least one of the defects of the prior art and provide a temperature detection device based on a temperature sensor to solve the problem of low detection accuracy of the detection device in the prior art.

[0004] According to a first aspect of this application, a temperature detection device based on a temperature sensor is provided, the temperature detection device comprising a temperature sensor, a voltage regulator component, a detection processing unit, and a control unit, wherein: A voltage regulator component, wherein the first input terminal of the voltage regulator component is used to connect to the output terminal of an external power supply; The control unit has an output terminal of the detection processing unit connected to a detection input terminal of the control unit; a first output terminal of the voltage regulator is connected to a power input terminal of the control unit; a second output terminal of the voltage regulator is connected to a reference voltage input terminal of the control unit; and an output terminal of the control unit is connected to a first input terminal of the detection processing unit. The output terminal of the temperature sensor is connected to the second input terminal of the detection and processing unit, the third output terminal of the voltage regulator is connected to the third input terminal of the detection and processing unit, the output terminal of the temperature sensor is connected to the third input terminal of the detection and processing unit, and the input terminal of the temperature sensor is grounded.

[0005] Optionally, the temperature detection device further includes a voltage reference chip; The output terminal of the voltage reference chip is connected to the second input terminal of the voltage regulator component, and the input terminal of the voltage reference chip is grounded.

[0006] Understandably, the addition of a voltage reference chip significantly improves detection accuracy and stability. The voltage reference chip, with its highly stable output characteristics, provides a precise reference voltage for the voltage regulator component, enabling the voltage regulator component to perform power distribution and signal conditioning based on a stable and reliable reference voltage. This ensures that the control unit obtains a more accurate reference when performing analog-to-digital conversion, thereby improving the accuracy of the temperature sensor's resistance signal acquisition. In particular, it can effectively suppress the impact of power fluctuations on the detection results in complex electromagnetic environments, ensuring high consistency and reliability of temperature detection values.

[0007] Optionally, the detection processing unit includes a signal processing subunit and a function switching circuit subunit; The output terminal of the control unit is connected to the input terminal of the function switching circuit unit; The output terminal of the function switching circuit unit is connected to the first input terminal of the signal processing subunit, the output terminal of the temperature sensor is connected to the second input terminal of the signal processing subunit, and the voltage regulator component is connected to the third input terminal of the signal processing subunit. The output of the signal processing subunit is connected to the detection input of the control unit.

[0008] Understandably, the control unit dynamically adjusts the signal path through the function switching circuit subunit, which can connect different detection scenarios and different types of temperature sensor signals to the signal processing subunit as needed, thereby achieving compatible access of multiple types of temperature sensor signals and significantly improving the flexibility and anti-interference capability of temperature detection.

[0009] The signal processing subunit includes a signal filtering subunit and a signal amplification subunit; The output terminal of the function switching circuit unit is connected to the first input terminal of the signal filtering subunit, the output terminal of the temperature sensor is connected to the second input terminal of the signal filtering subunit, and the third output terminal of the voltage regulator component is connected to the third input terminal of the signal filtering subunit. The output of the signal filtering subunit is connected to the input of the signal amplification subunit; Therefore, the output of the signal amplification subunit is connected to the detection input of the control unit.

[0010] Understandably, the raw signal from the temperature sensor is fed into the signal filtering subunit, which effectively suppresses high-frequency noise and electromagnetic interference. The clean signal is then transmitted to the signal amplification subunit for gain adjustment and amplitude enhancement. Finally, the optimized high signal-to-noise ratio analog signal is accurately delivered to the detection port of the control unit. Furthermore, the pre-filter avoids the risk of amplifier saturation, significantly improving the accuracy and anti-interference capability of temperature detection.

[0011] Optionally, the function switching circuit unit includes a field-effect transistor; The output terminal of the control unit is connected to the gate of the field-effect transistor; The drain of the field-effect transistor is connected to the first input terminal of the signal filtering subunit; The source of the field-effect transistor is grounded.

[0012] Understandably, the control unit output directly drives the gate of the field-effect transistor, and its on and off states can be adjusted in real time. This solid-state contactless switching method based on field-effect transistors has the characteristics of fast response speed, low power consumption and long life. It can effectively isolate crosstalk between different signal channels, and at the same time support rapid polling and dynamic switching of multiple sensor signals, which significantly improves the anti-interference ability and multi-task processing efficiency of temperature detection devices under complex working conditions.

[0013] Optionally, the signal amplification subunit includes a first operational amplifier and an operational amplifier assembly; The output of the signal filtering subunit is connected to the input of the operational amplifier assembly; The output terminal of the operational amplifier assembly is connected to the input terminal of the first operational amplifier; The output of the first operational amplifier is connected to the detection input of the control unit.

[0014] Understandably, the preprocessed signal output from the signal filtering subunit is first input to the operational amplifier assembly for initial amplification and voltage stabilization. Its output is then connected to the first operational amplifier for secondary amplification and drive enhancement. Finally, the high-quality analog signal after double amplification is stably transmitted to the detection port of the control unit, thereby effectively improving the signal-to-noise ratio of the weak temperature signal. Furthermore, by reasonably allocating the gain levels, the nonlinear distortion caused by single-stage amplification is avoided, significantly enhancing the detection sensitivity and stability of the temperature detection device.

[0015] Optionally, the signal amplification unit further includes a Schottky diode; The output terminal of the first operational amplifier is connected to the positive terminal of the Schottky diode; The negative terminal of the Schottky diode is connected to the detection input terminal of the control unit.

[0016] Understandably, the introduction of Schottky diodes can clamp and protect the output signal at the output terminal of the first operational amplifier, so that the detection signal finally input to the control unit has both high fidelity and anti-interference capability.

[0017] Optionally, the operational amplifier assembly includes a second operational amplifier and a third operational amplifier; The first output terminal of the signal filtering subunit is connected to the input terminal of the second operational amplifier, and the second output terminal of the signal filtering subunit is connected to the input terminal of the third operational amplifier. The output terminal of the second operational amplifier is connected to the first input terminal of the first operational amplifier, and the output terminal of the third operational amplifier is connected to the second input terminal of the first operational amplifier.

[0018] Understandably, this application is compatible with scenarios where a 3-wire temperature sensor is used for detection. In this detection scenario, the first output of the signal filtering subunit is connected to the second operational amplifier for main signal amplification, and the second output is connected to the third operational amplifier for auxiliary signal conditioning. The outputs of the two are respectively input to the two inputs of the first operational amplifier to form a composite signal path, thereby effectively improving the redundancy and fault tolerance of signal processing. Combined with the voltage stabilization strategy of the two-stage operational amplifier, the detection signal finally input to the control unit has a higher signal-to-noise ratio and stability.

[0019] Optionally, the temperature sensor includes one or more of the PT100 temperature sensor and the PT1000 temperature sensor.

[0020] Understandably, the temperature detection device demonstrates its flexibility and adaptability to various detection scenarios by being compatible with multiple temperature sensor types such as PT100 and PT1000.

[0021] Optionally, the control unit is a microcontroller chip that integrates an ADC analog-to-digital conversion module.

[0022] Understandably, the control unit uses a microcontroller chip with an integrated ADC analog-to-digital conversion module, which realizes high-precision real-time conversion of analog signals to digital signals, significantly improving the response speed and detection accuracy of temperature detection.

[0023] Based on any of the above aspects, the temperature detection device based on a temperature sensor provided in this application can achieve the following beneficial effects: The voltage of the stable and accurate temperature detection device is achieved through the integration of a voltage regulator and a voltage reference chip, creating a dual voltage stabilization mechanism. The first output of the voltage regulator provides a precise and stable operating power supply to the control unit, while the second output delivers a stable reference voltage, effectively isolating external power supply fluctuations. Combined with the voltage reference chip, the reference potential is further anchored, ensuring the stability of the power supply to the temperature sensor and control unit. This allows the temperature detection device to obtain a constant operating voltage even under complex operating conditions, avoiding detection deviations caused by power supply ripple or load changes, and laying a reliable power foundation for high-precision temperature detection.

[0024] Improving temperature detection accuracy: A low-cost bridge voltage divider circuit and a multi-stage operational amplifier architecture are employed, significantly optimizing the signal acquisition and processing flow. The weak resistance changes of the temperature sensor are suppressed by the signal filtering subunit, then amplified in stages by the operational amplifier assembly, and finally conditioned by the first operational amplifier. The introduction of Schottky diodes accelerates signal transmission response and provides clamping protection for the output signal. The control unit, integrating an ADC analog-to-digital converter module, can directly digitize the output signal. In practical applications, to improve detection accuracy, rail-to-rail precision operational amplifiers can be used for each operational amplifier, enabling the temperature detection device of this application to control the temperature deviation within 0.5°C, achieving high detection accuracy at low cost.

[0025] Improving the compatibility of temperature detection devices with various temperature sensor detection scenarios: This solution achieves compatible detection of various temperature sensors, including 2-wire and / or 3-wire sensors, through dynamic control of the field-effect transistors in the function switching circuit subunit. The control unit can flexibly switch signal paths by adjusting the gate voltage of the field-effect transistors to adapt to the sensor requirements of different wiring methods. This significantly expands the application range of the temperature detection device, making it suitable for scenarios requiring multiple temperature sensors to work together, such as programmable logic controllers (PLCs), direct digital controllers (DDCs), industrial air conditioning control systems, and heat pump air conditioning control systems. This reduces the complexity of equipment selection and maintenance costs. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a temperature detection device based on a temperature sensor according to an embodiment of this application.

[0028] Figure 2 This is a circuit diagram of the detection processing unit in an embodiment of this application.

[0029] Figure 3 This is a circuit diagram of the connection regulator component according to an embodiment of this application.

[0030] Figure 4 This is a circuit diagram of the control unit in an embodiment of this application.

[0031] Reference numerals: 100, External power supply; 200, Voltage regulator; 300, Temperature sensor; 400, Detection and processing unit; 500, Control unit; 410, Function switching subunit; 420, Signal filtering subunit; 430, Signal amplification subunit; 431, Operational amplifier assembly; CN1, First connector; CN2, Second connector; GND, Ground; C1, First capacitor; C2, Second capacitor; C3, Third capacitor; C4, Fourth capacitor; C5, Fifth capacitor; C6, Sixth capacitor; C7, Seventh capacitor; R1, First resistor; R2, Second resistor; R3, Third resistor R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; R8, eighth resistor; R9, ninth resistor; R10, tenth resistor; R11, eleventh resistor; R12, twelfth resistor; R13, thirteenth resistor; R14, fourteenth resistor; Q1, field-effect transistor; U1A, first operational amplifier; U1B, second operational amplifier; U1C, third operational amplifier; D1, Schottky diode; Vo_Vale, detection signal; voltage reference chip, IC1; first electrolytic capacitor, EC1; second electrolytic capacitor, EC2; Sensor EN, control signal; VREF, reference voltage input. Detailed Implementation

[0032] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this invention. To better illustrate the following embodiments, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0033] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0034] In this invention, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a system, product, or device that includes a series of objects or units is not necessarily limited to those objects or units that are explicitly listed, but may include other objects or units that are not explicitly listed or that are inherent to such systems, products, or devices.

[0035] Similarly, the terms "set up," "equipped with," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection via an intermediate medium, or an internal connection between two devices, elements, or components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0036] Similarly, the terms "upper," "lower," "left," "right," "inner," and "outer" are used only to indicate the relative orientation or positional relationship when this utility model is used, or the orientation or positional relationship shown in the accompanying drawings. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. Furthermore, some of the above terms may be used to indicate other meanings besides orientation or positional relationship; for example, the term "upper" may also be used in some cases to indicate a certain dependency or connection relationship. For those skilled in the art, the specific meaning of these terms in this application can be understood according to the specific circumstances.

[0037] Similarly, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order, sequence, quantity, or importance. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein.

[0038] Example 1 like Figure 1 As shown, this embodiment proposes a temperature detection device based on a temperature sensor. The temperature detection device includes a temperature sensor 300, a voltage regulator component 200, a detection and processing unit 400, and a control unit 500, wherein: A voltage regulator component 200, wherein the first input terminal of the voltage regulator component 200 is used to connect to the output terminal of an external power supply 100.

[0039] Preferably, the voltage regulator 200 can be a low dropout linear regulator (LDO).

[0040] The control unit 500 has an output terminal of the detection processing unit 400 connected to a detection input terminal of the control unit 500; a first output terminal of the voltage regulator 200 connected to a power input terminal of the control unit 500; a second output terminal of the voltage regulator 200 connected to a reference voltage input terminal of the control unit 500; and an output terminal of the control unit 500 connected to a first input terminal of the detection processing unit 400.

[0041] In this embodiment, the output terminal of the detection processing unit 400 outputs a detection signal Vo_Vale, and inputs the detection signal Vo_Vale to the detection input terminal of the control unit 500.

[0042] In this embodiment, as Figure 4 The diagram shows a circuit schematic of the control unit 500. Preferably, the first output terminal of the voltage regulator component 200 is connected to the power input terminals 1, 2, 3, and 4 of the control unit 500, respectively, to provide power to each area of ​​the control unit 500.

[0043] The third output terminal of the voltage regulator component 200 is connected to the second input terminal of the detection and processing unit 400, the output terminal of the temperature sensor 300 is connected to the third input terminal of the detection and processing unit 400, and the input terminal of the temperature sensor 300 is grounded; so that the control unit 500 can detect the detection resistance of the temperature sensor 300 and obtain the temperature value of the environment where the temperature sensor 300 is located based on the detection resistance.

[0044] The control unit 500 can be implemented using a conventional STM32 series controller. In this application, no substantial improvements are made to the conventional STM32 series controller. Temperature detection can be achieved by assembling and debugging the temperature detection device based on the temperature sensor in this embodiment according to the connection relationship in this embodiment.

[0045] Specifically, the detection processing unit 400 includes a signal processing subunit and a function switching circuit subunit 410; The output terminal of the control unit 500 is connected to the input terminal of the function switching circuit unit 410; The output terminal of the function switching circuit unit 410 is connected to the first input terminal of the signal processing subunit, the output terminal of the temperature sensor 300 is connected to the second input terminal of the signal processing subunit, and the voltage regulator component 200 is connected to the third input terminal of the signal processing subunit. The output of the signal processing subunit is connected to the detection input of the control unit 500.

[0046] In this embodiment, the control signal Sensor EN output by the output terminal of the control unit 500 can be input to the input terminal of the function switching circuit subunit 410, so that the function switching circuit subunit 410 can switch the detection circuit according to the control signal Sensor EN, thereby enabling compatibility with detection scenarios of different temperature sensors 300.

[0047] Specifically, the signal processing subunit includes a signal filtering subunit 420 and a signal amplification subunit 430; The output terminal of the function switching circuit unit 410 is connected to the first input terminal of the signal filtering subunit 420, the output terminal of the temperature sensor is connected to the second input terminal of the signal filtering subunit 420, and the third output terminal of the voltage regulator component 200 is connected to the third input terminal of the signal filtering subunit 420. The output terminal of the signal filtering subunit 420 is connected to the input terminal of the signal amplification subunit 430; Therefore, the output of the signal amplification subunit 430 is connected to the detection input of the control unit 500.

[0048] Preferably, such as Figure 2 As shown, the signal filtering subunit 420 includes a first connector CN1 and a second connector CN2. The output terminal of the temperature sensor 300 can be connected to either the first connector CN1 or the second connector CN2.

[0049] Specifically, the function switching circuit unit 410 includes a field-effect transistor Q1; The output terminal of the control unit 500 is connected to the gate of the field-effect transistor Q1; The drain of the field-effect transistor Q1 is connected to the first input terminal of the signal filtering subunit 420; The source of the field-effect transistor Q1 is grounded.

[0050] Understandably, when the temperature sensor 300 is connected to the first connector CN1, a two-wire detection scheme can be implemented for the temperature sensor 300. Specifically, after the temperature sensor 300 is connected to the first connector CN1, the control signal Sensor EN output by the control unit 500 is at a high level, and the field-effect transistor Q1 is turned on, thus enabling the two-wire detection scheme for the temperature sensor 300.

[0051] When the temperature sensor 300 is connected to the second connector CN2, a three-wire detection scheme can be implemented for the temperature sensor 300. Specifically, after the temperature sensor 300 is connected to the second connector CN2, the control signal Sensor EN output by the control unit 500 is at a low level, and the field-effect transistor Q1 is turned off, thus enabling the three-wire detection scheme for the temperature sensor 300.

[0052] Specifically, the signal amplification subunit 430 includes a first operational amplifier and an operational amplifier assembly 431; The output terminal of the signal filtering subunit 420 is connected to the input terminal of the operational amplifier assembly 431; The output terminal of the operational amplifier assembly 431 is connected to the input terminal of the first operational amplifier U1A; The output terminal of the first operational amplifier U1A is connected to the detection input terminal of the control unit 500.

[0053] Specifically, the signal amplification unit 430 further includes a Schottky diode D1; The output terminal of the first operational amplifier U1A is connected to the positive terminal of the Schottky diode D1; The negative terminal of the Schottky diode D1 is connected to the detection input terminal of the control unit 500.

[0054] In this embodiment, the Schottky diode D1 can clamp and protect the output signal of the signal amplification unit 430 to prevent circuit damage or malfunction caused by overvoltage.

[0055] Specifically, the operational amplifier assembly 431 includes a second operational amplifier U1B and a third operational amplifier U1C; The first output terminal of the signal filtering subunit 420 is connected to the input terminal of the second operational amplifier U1B, and the second output terminal of the signal filtering subunit 420 is connected to the input terminal of the third operational amplifier U1C. The output terminal of the second operational amplifier U1B is connected to the first input terminal of the first operational amplifier U1A, and the output terminal of the third operational amplifier U1C is connected to the second input terminal of the first operational amplifier U1A.

[0056] In this embodiment, as Figure 2 As shown, the output terminal of the second operational amplifier U1B outputs a bridge comparison voltage signal V2, and the second operational amplifier U1B can improve the stability of the bridge comparison voltage V2; the output terminal of the third operational amplifier U1C outputs a bridge comparison voltage signal V1, and the third operational amplifier U1C can improve the stability of the sensor voltage divider V1.

[0057] Preferably, in another embodiment, the signal amplification unit 430 further includes a fourth capacitor C4 and a fifth capacitor C5. The input terminal of the second operational amplifier U1B is connected to the input terminal of the fourth capacitor C4, and the output terminal of the fourth capacitor C4 is grounded; the input terminal of the third operational amplifier U1C is connected to the input terminal of the fifth capacitor C5, the input terminal of the second operational amplifier U1B is connected to the input terminal of the fifth capacitor C5, and the output terminal of the fifth capacitor C5 is grounded.

[0058] The fourth capacitor C4 can filter the bridge comparison voltage V2, and similarly, the fourth capacitor C5 can filter the bridge comparison voltage V1.

[0059] Preferably, in another embodiment, the signal amplification unit 430 further includes a third capacitor C3. The output terminal of the first operational amplifier U1A is connected to the input terminal of the third capacitor C3, the output terminal of the third capacitor C3 is connected to the positive terminal of the Schottky diode D1, and the negative terminal of the Schottky diode D1 is connected to the detection input port of the control unit 500.

[0060] The third capacitor C3 can filter the control signal Vo_Vale output from the output terminal of the first operational amplifier U1A.

[0061] In this embodiment, the voltage regulator 200 is connected to an external power supply and can convert the unstable and fluctuating high voltage input from the external power supply into a stable voltage. This allows the voltage regulator 200 to provide an accurate voltage divider for the temperature sensor 300, an accurate input voltage for the control unit 500, and an accurate reference voltage for the control unit 500 that is the same as the voltage divider voltage of the temperature sensor 300. This ensures that the entire detection process of the temperature sensor 300 is performed with a standard voltage, thereby improving the detection accuracy.

[0062] Specifically, the temperature detection device also includes a voltage reference chip; The output terminal of the voltage reference chip is connected to the second input terminal of the voltage regulator component, and the input terminal of the voltage reference chip is grounded.

[0063] Specifically, such as Figure 3 The system provides a connection circuit for the external power supply 100, the voltage regulator component 200, and the voltage reference chip IC1. The voltage reference chip IC1 can improve the accuracy of the output voltage of the voltage regulator component 200.

[0064] For example, the input voltage of the external power supply 100 can be +5V, and the output voltage is +3.3V. Wherein, the... Figure 3 The output voltage interface can be the first output terminal and / or the second output terminal and / or the third output terminal of the voltage regulator component (not shown in the figure).

[0065] Specifically, the control unit 500 is a microcontroller chip that integrates an ADC analog-to-digital conversion module.

[0066] Understandably, the ADC analog-to-digital converter module of the microcontroller chip can sample the input detection signal Vo_Vale to obtain sampled data, and then send the sampled data to the microcontroller chip for processing and detection, thereby obtaining the detection resistance of the temperature sensor 300.

[0067] Specifically, the temperature sensor 300 includes one or more of the PT100 temperature sensor and the PT1000 temperature sensor.

[0068] It is understood that the PT100 temperature sensor is a temperature sensor that is frequently used for temperature detection. It is a temperature detection device based on the temperature-dependent resistance characteristics of platinum (Pt) metal. The reference resistance value of the PT100 temperature sensor at 0℃ is 100Ω, and its resistance increases approximately linearly with the temperature, which can well reflect the temperature of the external environment.

[0069] The PT1000 temperature sensor is another type of temperature sensor commonly used for temperature detection. It is a temperature detection device based on the temperature-dependent resistance characteristics of platinum (Pt) metal. The reference resistance of the PT1000 temperature sensor at 0℃ is 1000Ω, and its resistance increases approximately linearly with temperature, which can well reflect the temperature of the external environment.

[0070] In this embodiment, the temperature detection device of this application can be used to accurately detect the external temperature based on the PT100 temperature sensor and the PT1000 temperature sensor, thereby improving the applicability and compatibility of the temperature detection device of this application. It is suitable for application scenarios in the technical fields of programmable controllers, direct digital controllers, industrial air conditioning control systems, heat pump air conditioning control systems, etc., that require multi-channel temperature sensor detection.

[0071] Preferably, in the temperature detection device of this application, in order to improve the accuracy of temperature detection, in the actual circuit design, all resistors used in the circuit can be resistors with an accuracy of one-thousandth (i.e., 0.1%).

[0072] Preferably, in order to improve the accuracy of temperature detection, in the actual circuit design, the first operational amplifier U1A, the second operational amplifier U1B and the first operational amplifier U1C can be rail-to-rail precision operational amplifiers.

[0073] Specifically, when the temperature sensor 300 is being detected, with the external power supply 100 providing power, the voltage regulator provides the control unit 500 with a precise reference voltage and accurate power, and provides accurate power to the detection processing unit. Next, the required detection scheme is selected, and the control unit 500 is instructed to send the corresponding control signal Sensor EN to the detection processing unit. The temperature sensor 300 is connected to the signal filtering subunit 420 through the first connector CN1 or the second connector CN2, and the preprocessed signal is divided by the signal filtering subunit 420 to obtain two preprocessed signals. The first preprocessed signal is passed through the third operational amplifier U1C to obtain the bridge comparison voltage signal V1; the second preprocessed signal is passed through the second operational amplifier U1B to obtain the bridge comparison voltage signal V2. The differential voltage signal V1-V2 is obtained based on the bridge comparison voltage signal V1 and the bridge comparison voltage signal V2. The differential voltage signal V1-V2 is amplified by A times by the first operational amplifier U1A and then output as the control signal Vo_Vale. The control signal Vo_Vale is input to the control unit 500 for sampling and detection, thereby completing the temperature detection.

[0074] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the technical solution of this utility model, and are not intended to limit the specific implementation of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A temperature detection device based on a temperature sensor, characterized in that, The temperature detection device includes a temperature sensor, a voltage regulator, a detection and processing unit, and a control unit, wherein: A voltage regulator component, wherein the first input terminal of the voltage regulator component is used to connect to the output terminal of an external power supply; The control unit has an output terminal of the detection processing unit connected to a detection input terminal of the control unit; a first output terminal of the voltage regulator is connected to a power input terminal of the control unit; a second output terminal of the voltage regulator is connected to a reference voltage input terminal of the control unit; and an output terminal of the control unit is connected to a first input terminal of the detection processing unit. The output terminal of the temperature sensor is connected to the second input terminal of the detection and processing unit, the third output terminal of the voltage regulator is connected to the third input terminal of the detection and processing unit, the output terminal of the temperature sensor is connected to the third input terminal of the detection and processing unit, and the input terminal of the temperature sensor is grounded.

2. The apparatus according to claim 1, characterized in that, The temperature detection device also includes a voltage reference chip; The output terminal of the voltage reference chip is connected to the second input terminal of the voltage regulator component, and the input terminal of the voltage reference chip is grounded.

3. The apparatus according to claim 1, characterized in that, The detection and processing unit includes a signal processing subunit and a function switching circuit subunit; The output terminal of the control unit is connected to the input terminal of the function switching circuit subunit; The output terminal of the function switching circuit subunit is connected to the first input terminal of the signal processing subunit, the output terminal of the temperature sensor is connected to the second input terminal of the signal processing subunit, and the voltage regulator component is connected to the third input terminal of the signal processing subunit. The output of the signal processing subunit is connected to the detection input of the control unit.

4. The apparatus according to claim 3, characterized in that, The signal processing subunit includes a signal filtering subunit and a signal amplification subunit; The output terminal of the function switching circuit subunit is connected to the first input terminal of the signal filtering subunit, the output terminal of the temperature sensor is connected to the second input terminal of the signal filtering subunit, and the third output terminal of the voltage regulator component is connected to the third input terminal of the signal filtering subunit. The output of the signal filtering subunit is connected to the input of the signal amplification subunit; Therefore, the output of the signal amplification subunit is connected to the detection input of the control unit.

5. The apparatus according to claim 4, characterized in that, The function switching circuit subunit includes a field-effect transistor; The output terminal of the control unit is connected to the gate of the field-effect transistor; The drain of the field-effect transistor is connected to the first input terminal of the signal filtering subunit; The source of the field-effect transistor is grounded.

6. The apparatus according to claim 5, characterized in that, The signal amplification subunit includes a first operational amplifier and an operational amplifier assembly; The output of the signal filtering subunit is connected to the input of the operational amplifier assembly; The output terminal of the operational amplifier assembly is connected to the input terminal of the first operational amplifier; The output terminal of the first operational amplifier is connected to the detection input terminal of the control unit.

7. The apparatus according to claim 6, characterized in that, The signal amplification subunit also includes a Schottky diode; The output terminal of the first operational amplifier is connected to the positive terminal of the Schottky diode; The negative terminal of the Schottky diode is connected to the detection input terminal of the control unit.

8. The apparatus according to claim 6, characterized in that, The operational amplifier assembly includes a second operational amplifier and a third operational amplifier; The first output terminal of the signal filtering subunit is connected to the input terminal of the second operational amplifier, and the second output terminal of the signal filtering subunit is connected to the input terminal of the third operational amplifier. The output terminal of the second operational amplifier is connected to the first input terminal of the first operational amplifier, and the output terminal of the third operational amplifier is connected to the second input terminal of the first operational amplifier.

9. The apparatus according to any one of claims 1 to 8, characterized in that, The temperature sensor includes one or more of the PT100 temperature sensor and the PT1000 temperature sensor.

10. The apparatus according to any one of claims 1 to 8, characterized in that, The control unit is a microcontroller chip that integrates an ADC analog-to-digital converter module.

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