Multi-channel direct-current voltage acquisition device with self-calibration function

Abstract

The utility model discloses a multi-channel DC voltage acquisition device with self-calibration, comprising a multi-channel DC voltage acquisition device main body which is used for measuring and acquiring voltage signals in a circuit. A front sampling circuit, an analog-to-digital converter ADC, a microcontroller MCU and a communication module are arranged in the multi-channel DC voltage acquisition device main body, the front sampling circuit is in bidirectional connection with the analog-to-digital converter ADC, and the microcontroller MCU is respectively in bidirectional connection with the front sampling circuit, the analog-to-digital converter ADC and the communication module; wherein the front sampling circuit is used for conditioning a voltage signal in a tested circuit, and the analog-to-digital converter ADC is used for converting the conditioned analog voltage signal into a digital signal. According to the utility model, the multi-channel voltage acquisition task can be satisfied, the acquisition precision is high, the RS485 bus interface is adopted for communication with the upper computer, the expansion of multiple modules can be easily realized, and the complexity and the cost of the system are reduced.

Description

Technical Field

[0001] This utility model belongs to the field of multi-channel voltage acquisition technology, specifically relating to a multi-channel DC voltage acquisition device with self-calibration. Background Technology

[0002] Multi-channel voltage acquisition and monitoring is a technology that can simultaneously acquire analog, digital, or mixed signals from multiple channels to achieve accurate measurement and monitoring of physical quantities such as voltage. It is widely used in industries, scientific research, education, and other fields.

[0003] The core functions of existing multi-channel voltage acquisition and monitoring systems include: Analog signal acquisition: capable of acquiring various analog signals, such as voltage, current, temperature, pressure, flow rate, and speed; Data processing: performing real-time processing on the acquired data, such as filtering, integration, differentiation, and FFT; Data storage: storing the acquired data in internal or external memory for subsequent analysis and processing; Data transmission: transmitting the acquired data to a host computer or other devices via various communication interfaces (such as RS232, RS485, Ethernet, USB, etc.); Remote control: enabling remote control, allowing parameter setting and status monitoring of the data acquisition unit via a host computer or other devices.

[0004] With the development of industrial automation and control systems, the demand for multi-channel voltage acquisition and monitoring is increasing. In the past, to achieve multi-channel voltage acquisition, multiple independent voltage acquisition devices and channel switching devices were typically required, which increased system complexity and cost. In automated testing processes, it is also necessary to monitor and control the voltage signals of multiple sensors, actuators, and devices in real time; existing multi-channel voltage acquisition and monitoring systems are insufficient to meet these requirements.

[0005] Therefore, to address the aforementioned technical problems, it is necessary to provide a multi-channel DC voltage acquisition device with self-calibration.

[0006] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0007] The purpose of this invention is to provide a multi-channel DC voltage acquisition device with self-calibration, which can solve the problem of limitations in the use of multi-channel voltage acquisition and monitoring systems.

[0008] To achieve the above objectives, the technical solution provided by a specific embodiment of this utility model is as follows:

[0009] A self-calibrating multi-channel DC voltage acquisition device includes a multi-channel DC voltage acquisition device body. The multi-channel DC voltage acquisition device body is used to measure and acquire voltage signals in the circuit. The multi-channel DC voltage acquisition device body is provided with a pre-sampling circuit, an analog-to-digital converter (ADC), a microcontroller (MCU), and a communication module. The pre-sampling circuit is bidirectionally connected to the ADC, and the microcontroller (MCU) is bidirectionally connected to the pre-sampling circuit, the ADC, and the communication module.

[0010] The pre-sampling circuit is used to condition the voltage signal in the circuit under test, the analog-to-digital converter (ADC) is used to convert the conditioned analog voltage signal into a digital signal, and the microcontroller (MCU) is used to process and store the digital signal and transmit the collected voltage data to the host computer through the communication module.

[0011] In one or more embodiments of this utility model, the pre-sampling circuit includes a signal conditioning circuit and a relay switching circuit. The signal conditioning circuit is unidirectionally connected to the relay switching circuit, and the signal conditioning circuit is used to condition the voltage signal in the circuit under test.

[0012] The relay switching circuit is bidirectionally connected to the analog-to-digital converter (ADC). The relay switching circuit works in conjunction with the reference source to achieve voltage calibration, switching circuit lifespan management, and multi-level switching functions.

[0013] In one or more embodiments of this utility model, the signal conditioning circuit includes an overvoltage protection circuit, a differential conversion circuit, and a multi-channel switching circuit. The differential conversion circuit can effectively improve the anti-interference capability of signal transmission and the stability of the system. The multi-channel switching circuit is connected to several voltage channels, which can meet the multi-channel voltage acquisition task.

[0014] In one or more embodiments of this utility model, the analog-to-digital converter (ADC) includes a chip, on which a bias circuit and a reference source are integrated. The bias circuit has the advantages of stabilizing the operating point, reducing temperature drift, reducing noise, improving linearity, and setting a static operating point, thereby ensuring the stable operation of the circuit.

[0015] A reference source can provide a stable reference voltage or current to ensure the stable operation of a circuit or system;

[0016] By utilizing the chip's high-precision reference output, and in conjunction with a follower voltage converter, a high-precision voltage input can be provided to the signal conditioning circuit. Then, with the help of software control and calculation, the calibration function can be achieved.

[0017] In one or more embodiments of this utility model, the analog-to-digital converter (ADC) sends a reference signal to the relay switching circuit via a reference source, and the relay switching circuit is used to send an analog signal to the ADC.

[0018] In one or more embodiments of this utility model, the microcontroller (MCU) is responsible for processing analog-to-digital conversion data, range switching, conversion calculation of input voltage values, and RS485 communication processing;

[0019] The microcontroller (MCU) integrates an ADC and GPIO, and the MCU detects the output of the reference source and the operating status of the relay switching circuit through the ADC and GPIO.

[0020] In one or more embodiments of this utility model, the main body of the multi-channel DC voltage acquisition device is connected to an LDO and a DC / DC converter. The LDO is connected to the DC / DC converter, and the LDO can play a role in voltage regulation and step-down, while the DC / DC converter can play a role in step-down.

[0021] In one or more embodiments of this utility model, a power interface is connected to the DC / DC converter, and a DC power supply is externally connected to the power interface. The DC power supply is used to power the signal conditioning circuit, the analog-to-digital converter (ADC), the LDO, the microcontroller (MCU), and the RS485.

[0022] In one or more embodiments of this utility model, the input voltage range of the DC power supply is 9-30V, and the output voltage of the DC / DC is 5V.

[0023] In one or more embodiments of this utility model, the communication module includes an RS485 interface, which is bidirectionally connected to the microcontroller MCU.

[0024] Compared with the prior art, the multi-channel DC voltage acquisition device with self-calibration of this utility model can meet the multi-channel voltage acquisition task, and has high acquisition accuracy. It communicates with the host computer through an RS485 bus interface, which can easily realize the expansion of multiple modules, reducing the complexity and cost of the system. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1This is a perspective view of a self-calibrating multi-channel DC voltage acquisition device according to an embodiment of the present invention;

[0027] Figure 2 This is a system block diagram of a self-calibrating multi-channel DC voltage acquisition device according to an embodiment of the present invention;

[0028] Figure 3 This is a calibration principle diagram of a self-calibrating multi-channel DC voltage acquisition device according to an embodiment of the present invention;

[0029] Figure 4 This is a flowchart of the main loop of a self-calibrating multi-channel DC voltage acquisition device according to an embodiment of the present invention.

[0030] Figure 5 This is a flowchart illustrating the use of a self-calibrating multi-channel DC voltage acquisition device in one embodiment of the present invention.

[0031] Explanation of key figure labels:

[0032] 1-Main body of the multi-channel DC voltage acquisition device. Detailed Implementation

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

[0034] like Figures 1 to 5 As shown, a self-calibrating multi-channel DC voltage acquisition device according to one embodiment of the present invention includes a multi-channel DC voltage acquisition device body 1, which is used to measure and acquire voltage signals in the circuit.

[0035] The multi-channel DC voltage acquisition device, in its main body 1, includes a pre-sampling circuit, an analog-to-digital converter (ADC), a microcontroller (MCU), and a communication module. The pre-sampling circuit is bidirectionally connected to the ADC, and the MCU is bidirectionally connected to the pre-sampling circuit, the ADC, and the communication module. The MCU processes and stores digital signals and transmits the acquired voltage data to the host computer via the communication module.

[0036] like Figures 1 to 5 As shown, the pre-sampling circuit is used to condition the voltage signal in the circuit under test.

[0037] The pre-sampling circuit includes a signal conditioning circuit and a relay switching circuit. The signal conditioning circuit and the relay switching circuit are connected in one direction. The signal conditioning circuit is used to condition the voltage signal in the circuit under test.

[0038] In addition, the relay switching circuit is bidirectionally connected to the analog-to-digital converter (ADC), and the relay switching circuit works in conjunction with the reference source to achieve voltage calibration, switching circuit lifespan management, and multi-level switching functions.

[0039] Specifically, the signal conditioning circuit includes an overvoltage protection circuit, a differential conversion circuit, and a multi-channel switching circuit. The differential conversion circuit can effectively improve the anti-interference capability of signal transmission and the stability of the system, while the multi-channel switching circuit is connected to several voltage channels to meet the needs of multi-channel voltage acquisition.

[0040] Preferably, the number of voltage channels is 8.

[0041] like Figures 1 to 5 As shown, the analog-to-digital converter (ADC) is used to convert the conditioned analog voltage signal into a digital signal.

[0042] The analog-to-digital converter (ADC) contains a built-in chip, which integrates a bias circuit and a reference source. The bias circuit offers advantages such as stabilizing the operating point, reducing temperature drift, reducing noise, improving linearity, and setting a static operating point, ensuring stable circuit operation. The reference source provides a stable reference voltage or current, ensuring stable operation of the circuit or system.

[0043] Preferably, the chip model is AD7606, which has 16-bit resolution, a range of ±10V and up to 8 synchronous acquisition channels, which can meet the needs of multi-channel voltage acquisition tasks.

[0044] By utilizing the chip's high-precision reference output (2.5V±0.0025V / ±10ppm), and in conjunction with a voltage follower, a high-precision voltage input can be output to the signal conditioning circuit. With the help of software control and calculation, the calibration function can be realized, resulting in high voltage acquisition accuracy.

[0045] In addition, the analog-to-digital converter (ADC) sends a reference signal to the relay switching circuit via a reference source, and the relay switching circuit is used to send analog signals to the ADC.

[0046] like Figures 1 to 5 As shown, the microcontroller (MCU) is responsible for processing analog-to-digital conversion data, range switching, calculating input voltage values, and RS485 communication.

[0047] The microcontroller (MCU) integrates an ADC and GPIO, and uses the ADC and GPIO to detect the operating status of the reference source output and the relay switching circuit.

[0048] In addition, the main body 1 of the multi-channel DC voltage acquisition device is connected to an LDO and a DC / DC converter. The LDO is connected to the DC / DC converter. The LDO can play the role of voltage regulation and step-down, while the DC / DC converter can play the role of step-down.

[0049] Specifically, the DC / DC converter is connected to a power interface, which is connected to an external DC power supply. The DC power supply is used to power the signal conditioning circuit, the analog-to-digital converter (ADC), the LDO, the microcontroller (MCU), and the RS485.

[0050] Preferably, the input voltage range of the DC power supply is 9-30V, and the output voltage of the DC / DC power supply is 5V.

[0051] like Figures 1 to 5 As shown, the communication module includes an RS485 interface, which is bidirectionally connected to the microcontroller (MCU).

[0052] Conventional multi-channel acquisition boards often require manual testing and calibration to achieve high measurement accuracy, and further calibration is needed after long-term use. This invention incorporates a relay switching circuit and a reference source, and, with software control, achieves voltage calibration, switching circuit lifespan management, and multi-level switching functions. It can easily achieve multi-module expansion while reducing system complexity and cost. The specific implementation is as follows: Figure 3 As shown:

[0053] The microcontroller (MCU) uses its internal ADC and GPIO to detect the reference source output and the operating status of the relay switching circuit. The MCU switches the relay switching circuit to the reference source and controls the AD7606 chip for analog-to-digital conversion. The MCU uses the reference source's ADC value to calculate the linear calibration value for each voltage channel, and then switches the relay switching circuit to external measurement. The MCU detects the relay switching circuit's switching status to determine if the relay switching circuit is operating correctly. The MCU automatically switches ranges by operating the high-precision ADC to predict the voltage range, achieving automatic range control. The sampling quantity can be configured via a host computer to achieve average value acquisition of various signals.

[0054] The working principle of the main body 1 of the multi-channel DC voltage acquisition device is as follows: Figure 4As shown, the DC power supply voltage is converted to +5V via a DC / DC converter to power the signal conditioning circuit, analog-to-digital converter (ADC) chip, LDO, microcontroller (MCU), and communication chip. The MCU uses its built-in ADC to read the output voltage of the reference voltage generator circuit and determines if the reference voltage is output correctly. The MCU controls a relay switching circuit to connect the reference voltage to the signal conditioning circuit and reads the ADC conversion value to calculate and record the linear calibration value. The MCU checks if the linear calibration value is within the error range; if not, it triggers an alarm. The MCU then controls the relay switching circuit to switch the voltage channel to the signal conditioning circuit, initiating continuous analog data conversion. The MCU calibrates the converted analog data according to the linear calibration value and stores it in memory for the host computer to read. The host computer and the MCU exchange data using the Modbus RTU protocol. After the host computer sends a read command, the MCU receives it, verifies its correctness, and replies with the specified data, completing the upload of the acquired data.

[0055] In actual testing, such as Figure 5 As shown, prepare the test environment: ensure that the test environment meets the requirements, including proper power supply, grounding and shielding, to reduce the impact of interference on the test results, and then connect the product under test to the voltage acquisition board correctly and check for reliable connection.

[0056] Power-on self-test preparation: Check the power supply and enable output. The main body 1 of the multi-channel DC voltage acquisition device automatically performs the self-test and self-calibration process. The user can judge whether the self-test and self-calibration is successful by the indicator light (success: light is on, failure: light flashes).

[0057] Configure acquisition parameters: According to the test requirements, the host computer configures the sampling rate, gain, filter settings and other parameters of the main body 1 of the multi-channel DC voltage acquisition device to ensure that the acquisition parameters match the voltage range and accuracy of the product under test.

[0058] Start data acquisition: The host computer starts the data acquisition of the main body 1 of the multi-channel DC voltage acquisition device to ensure that the acquisition module can acquire voltage data from multiple channels at the same time.

[0059] Data analysis and processing: The host computer analyzes and processes the collected multi-channel data, determines the range of voltage signal values, and generates a test report.

[0060] Test complete.

[0061] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0062] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A self-calibrating multi-channel DC voltage acquisition device, comprising a multi-channel DC voltage acquisition device body, wherein the multi-channel DC voltage acquisition device body is used to measure and acquire voltage signals in a circuit, characterized in that, The multi-channel DC voltage acquisition device is equipped with a pre-sampling circuit, an analog-to-digital converter (ADC), a microcontroller (MCU), and a communication module. The pre-sampling circuit is bidirectionally connected to the ADC, and the microcontroller (MCU) is bidirectionally connected to the pre-sampling circuit, the ADC, and the communication module. The pre-sampling circuit is used to condition the voltage signal in the circuit under test, the analog-to-digital converter (ADC) is used to convert the conditioned analog voltage signal into a digital signal, and the microcontroller (MCU) is used to process and store the digital signal and transmit the collected voltage data to the host computer through the communication module.

2. The self-calibrating multi-channel DC voltage acquisition device according to claim 1, characterized in that, The pre-sampling circuit includes a signal conditioning circuit and a relay switching circuit. The signal conditioning circuit and the relay switching circuit are unidirectionally connected, and the relay switching circuit is bidirectionally connected to the analog-to-digital converter (ADC).

3. The self-calibrating multi-channel DC voltage acquisition device according to claim 2, characterized in that, The signal conditioning circuit includes an overvoltage protection circuit, a differential conversion circuit, and a multi-channel switching circuit, with several voltage channels connected to the multi-channel switching circuit.

4. A multi-channel DC voltage acquisition device with self-calibration according to claim 3, characterized in that, The analog-to-digital converter (ADC) has a built-in chip, on which a bias circuit and a reference source are integrated.

5. A multi-channel DC voltage acquisition device with self-calibration according to claim 4, characterized in that, The analog-to-digital converter (ADC) sends a reference signal to the relay switching circuit via a reference source, and the relay switching circuit is used to send an analog signal to the ADC.

6. A multi-channel DC voltage acquisition device with self-calibration according to claim 5, characterized in that, The microcontroller (MCU) integrates an ADC and GPIO. The MCU uses the ADC and GPIO to detect the reference source output and to perform voltage calibration, switching circuit lifespan management, and multi-level switching of the relay switching circuit.

7. A multi-channel DC voltage acquisition device with self-calibration according to claim 1, characterized in that, The main body of the multi-channel DC voltage acquisition device is connected to an LDO and a DC / DC converter, with the LDO and DC / DC converter connected together.

8. A multi-channel DC voltage acquisition device with self-calibration according to claim 7, characterized in that, The DC / DC converter is connected to a power interface, and the power interface is connected to an external DC power supply.

9. A multi-channel DC voltage acquisition device with self-calibration according to claim 8, characterized in that, The input voltage range of the DC power supply is 9-30V, and the output voltage of the DC / DC converter is 5V.

10. A multi-channel DC voltage acquisition device with self-calibration according to claim 1, characterized in that, The communication module includes an RS485 interface, which is bidirectionally connected to the microcontroller (MCU).

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