CN220292011U - Analog output circuit with self-calibration function - Google Patents
Analog output circuit with self-calibration function Download PDFInfo
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- CN220292011U CN220292011U CN202321209328.5U CN202321209328U CN220292011U CN 220292011 U CN220292011 U CN 220292011U CN 202321209328 U CN202321209328 U CN 202321209328U CN 220292011 U CN220292011 U CN 220292011U
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- 238000011897 real-time detection Methods 0.000 abstract description 2
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Abstract
The utility model discloses an analog output circuit with a self-calibration function, wherein a main controller in the circuit judges whether the current output is accurate or not through comparing the read voltage feedback information with preset control voltage, and if deviation occurs, the output voltage value is increased or decreased through adjusting a set value, and finally the current output is adjusted, so that the real-time and automatic calibration process of the circuit is completed. The circuit realizes real-time detection of analog output, and completes control of output precision through the whole closed loop system, so that the circuit avoids the problem of manual calibration in the production debugging process and avoids the defect of system precision reduction caused by change of the use environment.
Description
Technical Field
The present utility model relates to the field of analog signal output control, and in particular, to an analog output circuit with a self-calibration function.
Background
The 4-20 mA analog output is a standard analog signal in an industrial process control system, and the output of each batch of products is generally subjected to linear calibration in the production debugging stage so as to ensure the output precision; however, in the working environment of the actual equipment, the output current precision is affected due to the difference of loads and the change of the ambient temperature and humidity, so that the whole industrial process control system is deviated or even fails. Under such circumstances, there is a need for a manner of analog output control that facilitates product production and debugging while achieving self-tuning in varying environments.
Disclosure of Invention
According to the problems existing in the prior art, the utility model discloses an analog output circuit with a self-calibration function, which comprises: the input end of the controller is connected with an analog-to-digital conversion circuit, the input end of the analog-to-digital conversion circuit is connected with a voltage follower circuit, the output end of the controller is connected with a digital-to-analog conversion circuit, the output end of the digital-to-analog conversion circuit is connected with a voltage-to-current conversion circuit and the voltage follower circuit, and the voltage-to-current conversion circuit outputs 4-20 mA voltage.
The analog-to-digital conversion circuit adopts an ADC chip U22, the digital-to-analog conversion circuit adopts a DAC chip U6, the output end of the DAC chip U6 is connected with a voltage follower U23, the output end of the voltage follower U23 is connected with the ADC chip U22, and the output end of the ADC chip U22 is connected with the controller.
The output end of the DAC chip U6 is also connected with a filter, the output end of the filter is connected with an amplifier U7B, and the output end of the amplifier U7B is connected with a voltage-current conversion circuit.
The filter comprises a resistor R57 and a capacitor C16.
By adopting the technical scheme, the analog output circuit with the self-calibration function provided by the utility model realizes real-time detection of analog output, and the control of output precision is completed through the whole closed loop system, so that the problem of manual calibration in the production debugging process is avoided, and the defect of system precision reduction caused by the change of the use environment is avoided.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a block diagram of an analog output circuit with self-calibration in accordance with the present utility model;
fig. 2 is a schematic circuit diagram of an analog output circuit according to the present utility model.
Detailed Description
In order to make the technical scheme and advantages of the present utility model more clear, the technical scheme in the embodiment of the present utility model is clearly and completely described below with reference to the accompanying drawings in the embodiment of the present utility model:
an analog output circuit with self-calibration function as shown in fig. 1 comprises a main controller 1, a digital-to-analog conversion circuit 3, a voltage-to-current conversion circuit 5, a voltage follower circuit 4 and an analog-to-digital conversion circuit 2.
The analog-to-digital conversion circuit 2 adopts an ADC chip U22, the digital-to-analog conversion circuit 3 adopts a DAC chip U6, the output end of the DAC chip U6 is connected with a voltage follower U23, the output end of the voltage follower U23 is connected with the ADC chip U22, and the output end of the ADC chip U22 is connected with the controller 1.
The output end of the DAC chip U6 is also connected with a filter, the output end of the filter is connected with an amplifier U7B, and the output end of the amplifier U7B is connected with a voltage-current conversion circuit 5. The filter comprises a resistor R57 and a capacitor C16.
And the system obtains an analog quantity current output value to be controlled and output through algorithm processing by the collected operation data of the normal working device of the industrial process control system. The main controller 1 configures a DAC chip U6 through a bus to finish the output of analog voltage, voltage signals are filtered and amplified, modulated to an ideal amplitude value, and converted into current output in a range of 4-20 mA through a V-I voltage-current conversion circuit 5; meanwhile, the DAC chip U6 outputs analog voltage signals, the analog voltage signals are fed back to the ADC chip U22 through the voltage follower U23, analog quantities are converted into digital information which can be acquired by the main controller 1 through the processing of the ADC chip U22, and the main controller 1 reads all parts through a bus and works simultaneously to complete a closed loop system. The main controller 1 judges whether the current output is accurate or not through comparing the read voltage feedback information with the preset control voltage, and if deviation occurs, the output voltage value is increased or reduced through adjusting the set value, and finally the current output is adjusted, so that the real-time and automatic calibration process of the circuit is completed.
As shown in fig. 2, the DAC chip U6 and the ADC chip U22 are both connected by a main controller, and the main controller configures the voltage output of the DAC and reads the voltage amplitude of the ADC through a bus.
The direct current voltage V1 output by the U6 chip is modulated into V2 after passing through a filter formed by R57 and C16 and an amplifier U7B, and the amplification factor is as follows:
the output range of Iout between 4 mA and 20mA can be achieved by controlling the voltage of V1 within a proper range.
Meanwhile, a voltage follower U23A is added at the output end of the U6 chip, and the voltage follower has the characteristic of high input impedance, so that the collection of feedback voltage is ensured not to influence the normal 4-20 mA current output. The output V3 of the voltage follower is equal to the voltage output V1 of the U6 chip, and the voltage V3 directly enters the ADC chip U22, so that the main controller can read the accurate amplitude of the current output voltage, and real-time monitoring of the output is realized.
If the output of U6 deviates due to environmental changes, the data read from U7 can directly reflect the deviation, if the magnitude of the feedback is lower than the set value, the output voltage of U6 needs to be increased, otherwise the output voltage of U6 needs to be decreased. Such a closed loop control system achieves the self-calibration object proposed by the present utility model.
The foregoing is only a preferred embodiment of the present utility model, but the scope of the present utility model is not limited thereto, and any person skilled in the art, who is within the scope of the present utility model, should make equivalent substitutions or modifications according to the technical scheme of the present utility model and the inventive concept thereof, and should be covered by the scope of the present utility model.
Claims (1)
1. An analog output circuit with self-calibration function, comprising: the digital-to-analog conversion circuit (2) is connected to the input end of the controller (1), the voltage follower circuit (4) is connected to the input end of the analog-to-digital conversion circuit (2), the output end of the controller (1) is connected with the digital-to-analog conversion circuit (3), the output end of the digital-to-analog conversion circuit (3) is connected with the voltage-to-current conversion circuit (5) and the voltage follower circuit (4), and the voltage-to-current conversion circuit (5) outputs 4-20 mA voltage;
the analog-to-digital conversion circuit (2) adopts an ADC chip U22, the digital-to-analog conversion circuit (3) adopts a DAC chip U6, the output end of the DAC chip U6 is connected with a voltage follower U23, the output end of the voltage follower U23 is connected with the ADC chip U22, and the output end of the ADC chip U22 is connected with the controller (1);
the output end of the DAC chip U6 is also connected with a filter, the output end of the filter is connected with an amplifier U7B, and the output end of the amplifier U7B is connected with a voltage-current conversion circuit (5);
the filter comprises a resistor R57 and a capacitor C16.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321209328.5U CN220292011U (en) | 2023-05-18 | 2023-05-18 | Analog output circuit with self-calibration function |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321209328.5U CN220292011U (en) | 2023-05-18 | 2023-05-18 | Analog output circuit with self-calibration function |
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| Publication Number | Publication Date |
|---|---|
| CN220292011U true CN220292011U (en) | 2024-01-02 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202321209328.5U Active CN220292011U (en) | 2023-05-18 | 2023-05-18 | Analog output circuit with self-calibration function |
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| CN (1) | CN220292011U (en) |
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2023
- 2023-05-18 CN CN202321209328.5U patent/CN220292011U/en active Active
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