Digital-to-analog quantity temperature sensing system
Through the digital to analog temperature sensing system, the digital signal is converted into an analog signal and the stable voltage is maintained, which solves the problem of insufficient accuracy under cost control of existing temperature sensors and realizes high-precision temperature measurement.
Patent Information
- Application Number
- CN202422388310.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2025-07-25
- Estimated Expiration
- 2034-09-29
AI Technical Summary
Existing temperature sensors are difficult to achieve high-precision measurements under cost control, and the cheap sensors on the market have large measurement errors, while expensive sensors have complex designs and high cost of use.
The digital to analog temperature sensing system is adopted, including linear voltage regulators, microcontrollers, digital temperature sensors, field effect tubes, digital to analog conversion chips and operational amplifiers. By converting digital signals into analog signals and maintaining a stable voltage, the accurate output of temperature data is achieved.
High-precision temperature measurements in the range of -55°C to +125°C are achieved, simplifying circuit design, reducing costs and improving measurement accuracy.
Smart Images
Figure CN223154390U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a temperature sensor, in particular to a digital-to-analog temperature sensing system. Background Art
[0002] A temperature sensor is a device used to measure the temperature of an object or environment, mainly applied in the fields of industrial automation, agriculture, food processing and storage, medical treatment, etc. By obtaining temperature data in real time, the production process can be optimized, efficiency can be improved, and at the same time, the safety of equipment can be ensured, and problems such as risk occurrence can be reduced.
[0003] However, there are a wide variety of temperature sensors on the market. Some are cheap, but have large measurement errors and do not meet the application requirements of special scenarios. Some are expensive, with complex designs and high usage costs, which are a bit of overkill.
[0004] In order to improve the measurement accuracy of the temperature sensor while controlling costs as much as possible, it is necessary to redesign the temperature sensor by utilizing the working principle of temperature sensor components. Summary of the Invention
[0005] To solve the problems of stable voltage and signal output, the utility model needs to provide a digital-to-analog temperature sensing system to convert the acquired digital signal into an analog signal.
[0006] The utility model provides the following technical solutions:
[0007] A digital-to-analog temperature sensing system includes a linear voltage regulator, a microcontroller, a digital temperature sensor, a field effect transistor, a digital-to-analog conversion chip, and an operational amplifier. The input side of the microcontroller is connected to the linear voltage regulator, the linear voltage regulator is connected to a power supply, the power supply outputs 5V voltage to the linear voltage regulator, and the linear voltage regulator converts the 5V voltage into 3.3V for the microcontroller;
[0008] The input side of the microcontroller is also connected to the field effect transistor, the input side of the field effect transistor is connected to the digital temperature sensor, and the digital temperature sensor delivers digital signals to the field effect transistor;
[0009] The output side of the microcontroller is connected to the digital-to-analog conversion chip, the output side of the digital-to-analog conversion chip is connected to the operational amplifier, the digital-to-analog conversion chip outputs a weak analog signal to the operational amplifier, and the operational amplifier outputs a normal analog signal.
[0010] Further, the linear voltage regulator adopts the model TLV702. A capacitor C1 is connected in parallel between the 1st and 2nd pins of the linear voltage regulator, and the 3rd pin of the linear voltage regulator is connected to a resistor R1.
[0011] Further, the microcontroller MCU uses the model STM32F030.
[0012] Further, the digital temperature sensor uses the model DS18B20. The second pin of the digital temperature sensor is connected to a field effect transistor Q1, and an external power supply is connected through the third pin of the digital temperature sensor for power supply.
[0013] Further, the field effect transistor uses the model AO3400.
[0014] Further, the digital-to-analog conversion chip uses the model DAC7311. After the digital-to-analog conversion chip converts the digital signal into an analog signal, it is transmitted through an operational amplifier. The 6th pin of the digital-to-analog conversion chip is connected to the 3rd pin of the operational amplifier, the 4th pin of the operational amplifier is connected to the 1st pin of the operational amplifier through a capacitor C8, and a capacitor C9 is connected in parallel between the 6th pin and the 5th pin of the digital-to-analog conversion chip.
[0015] Further, the operational amplifier uses the model OPA333.
[0016] The digital temperature sensor (DS18B20) outputs a digital signal. The digital signal is a discrete signal, and its value is usually represented in binary, only including two states of 0 and 1. Therefore, we need to process the obtained digital signal. In order to output the processed data, the digital signal can be converted into an analog voltage signal and finally analogized. In order to make the entire module work stably, it needs to be maintained at a stable voltage, and the stable voltage is generally 3.3V. Therefore, the problem of voltage stability needs to be solved.
[0017] Compared with the prior art, the beneficial effects of the present utility model are as follows: The system of the present utility model includes a linear voltage regulator, a microcontroller, a digital temperature sensor, a field effect transistor, a digital-to-analog conversion chip, and an operational amplifier, which processes the obtained digital signal. In order to output the processed data, the connection of the digital temperature sensor, the field effect transistor, the digital-to-analog conversion chip, and the operational amplifier can convert the digital signal into an analog voltage signal and finally analogize it to make the entire module work stably. The linear voltage regulator can maintain a stable voltage. The temperature sensor component used in the present utility model is a digital temperature sensor, which only requires one port to achieve communication, and the temperature measurement range is between -55°C and +125°C; it provides 9-12 bit Celsius temperature measurement. Description of the Drawings
[0018] Figure 1 It is the system schematic diagram of the present utility model.
[0019] Figure 2 It is the circuit diagram of the digital temperature sensor of the present utility model.
[0020] Figure 3This is the circuit diagram of the microcontroller of the present utility model.
[0021] Figure 4 This is the relationship diagram of the digital-to-analog conversion chip and the operational amplifier.
[0022] Figure 5 This is the circuit diagram of the linear voltage regulator of the present utility model.
[0023] 1. Linear voltage regulator; 2. Microcontroller, 3. Digital temperature sensor, 4. Field effect transistor, 5. Digital-to-analog conversion chip, 6. Operational amplifier, 7. Power supply. Embodiment
[0024] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.
[0025] Please refer to Figure 1 , a digital-to-analog temperature sensing system of the present utility model includes a linear voltage regulator 1, a microcontroller 2, a digital temperature sensor 3, a field effect transistor 4, a digital-to-analog conversion chip 5 and an operational amplifier 6. The input side of the microcontroller 2 is connected to the linear voltage regulator 1. The linear voltage regulator 1 is connected to the power supply 7. The power supply 7 outputs a 5V voltage to the linear voltage regulator 1. The linear voltage regulator 1 converts the 5V voltage into 3.3V and supplies it to the microcontroller 2;
[0026] The input side of the microcontroller 2 is also connected to the field effect transistor 4. The input side of the field effect transistor 4 is connected to the digital temperature sensor 3. The digital temperature sensor 3 transmits digital signals to the field effect transistor 4;
[0027] The output side of the microcontroller 2 is connected to the digital-to-analog conversion chip 5. The output side of the digital-to-analog conversion chip 5 is connected to the operational amplifier 6. The digital-to-analog conversion chip 5 outputs a weak analog signal to the operational amplifier 6. The operational amplifier 6 outputs a normal analog signal, and the output range is 0 - 5V.
[0028] In order to improve the stable voltage:
[0029] Figure 5 As shown, the linear voltage regulator U2 adopts the model TLV702, subtracts the excess voltage from the applied input voltage, and generates a regulated output voltage. Mainly converts the 5V voltage into 3.3V, and its function is to keep the voltage stable.
[0030] A capacitor C1 is connected in parallel between pin 1 and pin 2 of the linear voltage regulator U2, and pin 3 of the linear voltage regulator U2 is connected to a resistor R1.
[0031] Figure 3 As shown in the figure, the microcontroller MCU uses chip U1 (model STM32F030) to control each module by writing a program.
[0032] In order to convert the acquired digital signal into an analog signal:
[0033] Figure 2 As shown in the figure, the digital temperature sensor P3 uses the model DS18B20. The digital temperature sensor P3 internally contains a temperature sensing device. When the temperature changes, the electrical characteristics of the sensing device will change accordingly.
[0034] The power supply mainly adopts the "parasitic power supply mode", that is, a field effect transistor Q1 (AO3400) is connected to the 2nd pin of the digital temperature sensor P3 (DS18B20) to ensure sufficient power supply. Because the digital temperature sensor P3 (DS18B20) may have insufficient power supply when performing temperature conversion or transmitting data. It is also possible to connect an external power supply through the 3rd pin of the digital temperature sensor P3 (DS18B20). The two power supply modes are compatible.
[0035] The field effect transistor Q1 uses the model AO3400, and its working principle is based on controlling the electric field effect of the input circuit to control the current of the output circuit.
[0036] The digital-to-analog conversion chip U3 uses the model DAC7311, which is a device that converts discrete digital signals into continuous analog signals. It can convert the data received by the sensor into an analog quantity based on a standard quantity (or reference quantity). It mainly converts temperature data into voltage data, thus facilitating the realization of temperature control.
[0037] Figure 4 For the conversion and output of analog signals, after the digital-to-analog conversion chip U3 (DAC7311) converts the digital signal into an analog signal, it is transmitted to the P4 interface through the operational amplifier U4 (OPA333), and the output range is 0 - 5V.
[0038] The 6th pin of the digital-to-analog conversion chip U3 is connected to the 3rd pin of the operational amplifier U4. The 4th pin of the operational amplifier U4 is connected to the 1st pin of the operational amplifier U4 through the capacitor C8. A capacitor C9 is connected in parallel between the 6th pin and the 5th pin of the digital-to-analog conversion chip U3.
[0039] The operational amplifier uses OPA333. Since the amplitude and power of the acquired signal are not sufficient to drive the display, the deviation signal needs to be amplified to the required level and then sent to the instrument for display, so as to achieve the purpose of measurement.
[0040] Main working principle: The microcontroller MCU reads the temperature data of the digital temperature sensor (DS18B20) through a program, then inputs the temperature data to the DAC for conversion, and finally outputs the converted voltage signal, with an output range of 0 - 5V.
[0041] This utility model converts the digital signal obtained by the digital temperature sensor (DS18B20) into an analog signal. Finally, the measured temperature is analogized from the output voltage value. For example, 0 degrees Celsius is 2.5V, 100 degrees Celsius is 3V, -100 degrees Celsius is 2V, and so on. The entire circuit design is not only simple and practical, but also ensures the accuracy of temperature measurement as much as possible. It can usually be used in scenarios where the temperature needs to be controlled within a certain range.
[0042] This utility model can be used on solenoid valves to monitor their temperatures. During the use of solenoid valves, they are usually affected by temperature. Too high or too low temperature will affect their normal operation. When the temperature of the solenoid valve is abnormal, it may cause various problems such as coil damage, unstable performance, reduced safety, and shortened lifespan. Therefore, it is necessary to detect the temperature of the solenoid valve through a digital temperature sensor.
[0043] Although the embodiments of the present utility model have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.
Claims
1. A digital-to-analog temperature sensing system, characterized in that: It includes a linear voltage regulator (1), a microcontroller (2), a digital temperature sensor (3), a field effect transistor (4), a digital-to-analog conversion chip (5), and an operational amplifier (6). The input side of the microcontroller (2) is connected to the linear voltage regulator (1), and the linear voltage regulator (1) is connected to a power supply (7). The power supply (7) outputs a 5V voltage to the linear voltage regulator (1), and the linear voltage regulator (1) converts the 5V voltage into 3.3V for the microcontroller (2). The input side of the microcontroller (2) is also connected to the field effect transistor (4), the input side of the field effect transistor (4) is connected to the digital temperature sensor (3), and the digital temperature sensor (3) delivers a digital signal to the field effect transistor (4). The output side of the microcontroller (2) is connected to the digital-to-analog conversion chip (5), the output side of the digital-to-analog conversion chip (5) is connected to the operational amplifier (6). The digital-to-analog conversion chip (5) outputs a weak analog signal to the operational amplifier (6), and the operational amplifier (6) outputs a normal analog signal.
2. The digital-to-analog temperature sensing system according to claim 1, wherein: The linear voltage regulator uses the model TLV702. A capacitor C1 is connected in parallel between pin 1 and pin 2 of the linear voltage regulator, and pin 3 of the linear voltage regulator is connected to a resistor R1.
3. A digital-to-analog temperature sensing system according to claim 1, characterized in that: The microcontroller MCU uses the model STM32F030.
4. A digital-to-analog temperature sensing system according to claim 1, characterized in that: The digital temperature sensor uses the model DS18B20. The 2nd pin of the digital temperature sensor is connected to a field effect transistor Q1, and an external power supply is connected through the 3rd pin of the digital temperature sensor for power supply.
5. A digital-to-analog temperature sensing system according to claim 1, characterized in that: The field effect transistor uses the model AO3400.
6. The digital-to-analog temperature sensing system according to claim 1, wherein: The The digital-to-analog conversion chip uses the model DAC7311. After the digital-to-analog conversion chip converts the digital signal into an analog signal, it is transmitted through the operational amplifier. Pin 6 of the digital-to-analog conversion chip is connected to pin 3 of the operational amplifier, pin 4 of the operational amplifier is connected to pin 1 of the operational amplifier through a capacitor C8, and a capacitor C9 is connected in parallel between pin 6 and pin 5 of the digital-to-analog conversion chip.
7. A digital-to-analog temperature sensing system according to claim 1, characterized in that: The operational amplifier uses the model OPA333.