CN214707677U - Analog signal conditioning circuit based on operational amplifier and instrument simulation system - Google Patents
Analog signal conditioning circuit based on operational amplifier and instrument simulation system Download PDFInfo
- Publication number
- CN214707677U CN214707677U CN202121062036.4U CN202121062036U CN214707677U CN 214707677 U CN214707677 U CN 214707677U CN 202121062036 U CN202121062036 U CN 202121062036U CN 214707677 U CN214707677 U CN 214707677U
- Authority
- CN
- China
- Prior art keywords
- operational amplifier
- module
- signal
- circuit
- differential operational
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Amplifiers (AREA)
Abstract
In order to overcome the deficiencies of the prior art, the utility model provides an analog signal conditioning circuit and instrument simulation system based on operational amplifier, include: the device comprises a differential operational amplifier module, an isolation module and an adjustment module; the differential operational amplifier module is connected with the signal end and is used for amplifying the signal; the isolation module is arranged at the output end of the differential operational amplifier module and used for electrical isolation; the adjusting module is arranged at the output end of the differential operational amplifier module and is used for proportionally reducing or proportionally amplifying the signal through the differential operational amplifier module. The circuit of the utility model can weaken the direct current amount in the measured electric signal, and amplify the changed electric signal in the electric signal after obtaining the corresponding electric signal variable quantity, thereby realizing accurate measurement; the circuit constitute simply, the good reliability.
Description
Technical Field
The utility model relates to a signal modulation field, especially an analog signal conditioning circuit and instrument simulation system based on operational amplifier.
Background
With the development of science and technology, sensors have been developed and widely used in various fields. Most sensors convert measured values into analog quantity output, for example, some sensors convert measured values into proportional voltage output, and some sensors adopt current as a transmitted signal in order to improve transmission distance and ensure signal anti-interference capability, and then convert the current signal into a voltage signal through a current and voltage conditioning circuit at a receiving end. Various AD conversions have also been developed to convert data measured by sensors into signals that can be recognized by a processor, such as most processing chips incorporating one or more ADC modules. However, since different ADCs or processors can receive different voltage peaks of the analog signal, the analog signal measured by the sensor cannot be directly sent to the ADC converter or the processor with the ADC. Meanwhile, the measuring range of some sensors is relatively large, and the variable to be measured changes in a small range, so that the electric signal output by the sensor changes in a small range, and the measuring precision is reduced. Therefore, a conditioning device capable of proportionally changing the peak value of an analog signal without distortion is needed, and a signal which is not compatible with the ADC range is reasonably adjusted.
At present, a voltage signal is reduced according to a certain proportion by adopting series resistance voltage division; the voltage current signal is proportionally amplified by an amplifying circuit. However, there is a limit to the use of both circuits, i.e., the electrical signal can only be scaled down or up, and the useful measurement signal cannot be scaled down or up at the same time.
SUMMERY OF THE UTILITY MODEL
In order to overcome the deficiencies of the prior art, the utility model provides an analog signal conditioning circuit and instrument simulation system based on operational amplifier for solve at least one among the aforementioned technical problem.
Specifically, the technical scheme is as follows:
an operational amplifier based analog signal conditioning circuit comprising:
the differential operational amplifier module is connected with the signal end and used for amplifying the signal;
the isolation module is arranged at the output end of the differential operational amplifier module and used for electrical isolation;
and the adjusting module is arranged at the output end of the differential operational amplifier module and is used for proportionally reducing or proportionally amplifying the signal through the differential operational amplifier module.
The adjustment module includes:
a voltage follower circuit;
the adjustable voltage division circuit is arranged at the input end of the voltage follower circuit;
and the output end of the voltage following circuit is connected with the input end of the differential operational amplifier module and is connected with the signal end in parallel.
The adjustable voltage division circuit comprises:
a first resistor;
a second resistor connected in series with the first resistor;
the input end of the voltage follower circuit is arranged between the first resistor and the second resistor;
the second resistor is a slide rheostat.
The differential operational amplifier module comprises:
a second processor;
the third resistor is connected with the inverting input end of the second processor;
the fourth resistor is connected with the non-inverting input end of the second processor;
a fifth resistor disposed between the inverting input of the second processor and the output of the second processor;
and the sixth sensor is arranged between the fourth resistor and the non-inverting input end of the second processor and is connected with the signal end.
The input resistance of the non-inverting input of the second processor is equal to the input resistance of the inverting input of the second processor.
The isolation module includes: a photoelectric isolation unit;
the photoelectric isolation unit is arranged at the output end of the differential operational amplifier module and used for photoelectric isolation.
A meter simulation system comprising:
an analog signal conditioning circuit as described above;
the first instrument is arranged at the output end of the adjusting module and used for collecting the output voltage of the adjusting module;
the second instrument is arranged at the input end of the differential operational amplifier module and used for providing a signal source;
the third instrument is arranged at the output end of the differential operational amplifier module and is used for collecting the signal waveform of the output end of the differential operational amplifier module;
and the fourth instrument is arranged at the isolated end of the isolation module and is used for acquiring the signal waveform isolated by the isolation module.
The utility model discloses following beneficial effect has at least:
the circuit of the utility model can weaken the direct current amount in the measured electric signal, and amplify the changed electric signal in the electric signal after obtaining the corresponding electric signal variable quantity, thereby realizing accurate measurement; the circuit constitute simply, the good reliability.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
Fig. 1 is a schematic diagram of the circuit of the present invention.
Fig. 2 shows an embodiment of the present invention.
Detailed Description
In the prior art, a resistance voltage division circuit is adopted, although the voltage signal can be reduced in proportion, the variation of the slightly-changed voltage signal cannot be obtained very accurately, and the measurement accuracy is limited. For example, if the external signal measured by the sensor changes very slightly, the change amount of the electrical signal output by the sensor after the change is also small, which is not favorable for obtaining accurate data for short-time or relatively stable environmental measurement, and at this time, the external signal measured by the sensor changes in a range much smaller than the measurement range, or the existing sensor has a large measurement range without a smaller measurement range.
In order to solve the technical defects mentioned in the above problems and background art, the core idea of the present invention is: in order to refine data in a certain measuring range and convert signals into a range which can be tolerated by an ADC and a processor, the advantages of two circuits of series resistance voltage division and an amplifying circuit can be combined to form a new signal processing scheme, namely, a large signal transmitted by a sensor is properly and proportionally reduced, and a changed small signal is proportionally amplified.
In order to merge the two schemes, intermediate transition can be realized through operation of voltage signals, and terminal amplification can be realized through isolation operation, so that a larger signal can be proportionally reduced or amplified, and the voltage input into the processing unit is ensured to be within an allowable input range.
Specifically, as shown in fig. 1, an analog signal conditioning circuit based on an operational amplifier includes: the device comprises a differential operational amplifier module, an isolation module and an adjustment module; the differential operational amplifier module is connected with the signal end and is used for amplifying the signal; the isolation module is arranged at the output end of the differential operational amplifier module and used for electrical isolation; the adjusting module is arranged at the output end of the differential operational amplifier module and is used for proportionally reducing or proportionally amplifying the signal through the differential operational amplifier module.
The adjustment module includes: the voltage follower circuit and the adjustable voltage division circuit; the adjustable voltage division circuit is arranged at the input end of the voltage follower circuit; and the output end of the voltage following circuit is connected with the input end of the differential operational amplifier module and is connected with the signal end in parallel.
The differential operational amplifier module comprises: a second processor U2A, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth sensor R6; the third resistor R3 is connected with the inverting input end of the second processor U2A; the fourth resistor R4 is connected with the non-inverting input end of the second processor U2A; a fifth resistor R5 is disposed between the inverting input of the second processor U2A and the output of the second processor U2A; the sixth sensor R6 is disposed between the fourth resistor R4 and the non-inverting input terminal of the second processor U2A, and is connected to the signal terminal. Preferably, the input resistance of the non-inverting input of the second processor U2A is equal to the input resistance of the inverting input of the second processor U2A.
In fig. 1, the first resistor R1 and the second resistor R2 form a voltage divider circuit, VCC is a voltage or current signal input by the sensor, the voltage used by the system is 12V or other voltages, and the voltage value input to the arithmetic circuit can be adjusted by using a sliding rheostat.
The input voltage value U1 is: u1 VCC R2/R1+ R2
The power consumed by the two resistors P1 and P2 are:
P1＝VCC*R1/(R1+R2)
P2＝VCC*R2/(R1+R2)
in order to keep the voltage of the two ends of the potentiometer after being connected with the operation circuit in parallel unchanged or slightly changed, a first processor U1A is added to form a voltage follower, so that the purpose is to enable the input resistance to be as infinite as possible and reduce the current absorbed by the operation circuit.
The input voltage U2 and the output voltage U3 are: U3-U2-U1;
the operational circuit is used for simulating a voltage signal changed by the sensor by superposing an input voltage U3 and a signal U4 with a certain frequency, and is convenient for adjusting the isolation amplifier in the rear so as to enable the isolation amplifier to work in an amplification area. Then subtracting the fixed voltage VDD to obtain a fluctuation signal with a smaller amplitude as an input signal of the isolation amplifier; preferably, the isolation amplifier employs a photo-isolator device.
The voltage signal U5 output by the arithmetic circuit is: u5 ═ U3+ U4-VDD.
If the voltage signal input from the outside is small, the resistance of the second resistor R2 can be increased to enable the signal to be input into the circuit as much as possible, meanwhile, a proper direct-current component is added to the input voltage signal through the non-inverting input end of the differential operational amplifier module to ensure that the isolation amplifier can work in an amplification area, and the amplification factor of the isolation amplifier is properly adjusted before the signal is input, so that the voltage processing module can obtain the variable voltage in a larger range, and further more accurate measurement value is realized. If the fluctuation range of the input voltage signal is larger, the amplitude of the input voltage signal entering the circuit can be weakened by reducing the resistance of the second resistor R2, and the measurement of the reduced version of the voltage signal is realized. If the external environment is in a relative constant value and at a certain position of the sensor measuring range, the direct current component contained in the input signal is large, the voltage value of VDD can be increased, the amplification factor of the isolation operational amplifier is made to be as large as possible, and the direct current component in the operational circuit can be reduced while the accuracy of the sensor can be improved.
In order to ensure the symmetry of the differential operational amplifier module, the input resistance of the non-inverting input terminal is required to be equal to the input resistance of the inverting input terminal, i.e., R4// R6 is R5// R3.
The utility model discloses the input of module is put to well difference fortune adopts the potentiometre to replace fixed resistance, and the change through the resistance adapts to different input signal, and the voltage variation of output is the same with input signal's trend of change, makes things convenient for the processing conversion at the back.
A meter simulation system comprising: the analog signal conditioning circuit, the first meter 1, the second meter 2, the third meter 3, and the fourth meter 4 as described above; the first instrument 1 is arranged at the output end of the adjusting module and used for collecting the output voltage of the adjusting module; the second instrument 2 is arranged at the input end of the differential operational amplifier module and used for providing a signal source; the third instrument 3 is arranged at the output end of the differential operational amplifier module and is used for collecting the signal waveform of the output end of the differential operational amplifier module; the fourth meter 4 is arranged at the isolated end of the isolation module and used for collecting the signal waveform isolated by the isolation module.
Preferably, the first meter 1 is a voltmeter; the second instrument is a signal source; the third instrument is a first oscilloscope; the fourth instrument is a second oscilloscope.
In a specific embodiment I, a circuit is built according to the schematic diagram described in fig. 1, and the circuit diagram of fig. 2 is obtained.
As shown in fig. 2, the circuit comprises: the integrated circuit comprises an LM358 chip, a first interface J1, a second interface J2, a third interface J3, a first potentiometer VR1, a second potentiometer VR2, a third potentiometer VR3, a fourth potentiometer VR4 and a fifth potentiometer VR 5;
the third pin of the LM358 chip is connected with the adjustable end of the first potentiometer VR 1; the third pin of the LM358 chip is also connected with a third pin of a second interface J2; the second pin and the first pin of the second interface J2 are respectively connected to two ends of a first potentiometer VR 1; the fourth pin of the LM358 is connected with the first pin of the second interface J2;
the fifth pin of the LM358 is connected with the adjustable end of a fifth potentiometer VR 5; two ends of the fifth potentiometer are connected between the 12V power supply and the ground;
the sixth pin of the LM358 is connected with the adjustable end of a fourth potentiometer VR 4; two ends of the fourth potentiometer are connected between the 12V power supply and the ground;
the seventh pin of the LM358 is connected with the first pin of the first interface J1; the eighth pin of the LM358 is connected with a 12V power supply;
a second pin of the first interface J1 is connected with a first pin of the optical coupler OC 1; a second pin of the optical coupler OC1 is connected with one end of a second potentiometer VR 2; the other end of the second potentiometer VR2 is grounded;
a third pin of the optical coupler OC1 is connected with a second pin of the third interface J3, and one end of a third potentiometer VR3 is connected between the third pin and the second pin; the other end of the third potentiometer VR3 is grounded and is connected with the adjustable end of the third potentiometer VR 3; it should be noted that: the ADC is used as a built-in resource of the processor, and assuming that the maximum voltage allowed to be input by an I/O port of the processor is 3.3V, an appropriate voltage source may be selected according to actual conditions.
When debugging is performed using the specific circuit of fig. 2, the first potentiometer VR1 is slid to the end connected to ground, and then the fifth potentiometer VR5 is adjusted to place the isolation amplifier in the subsequent LM358 chip U1 at the appropriate quiescent operating point, at which time the short-circuited pad of the first interface J1 is removed to measure the voltage at the input.
Secondly, a short-circuit piece of the second interface J2 is taken down, the short-circuit piece of the first interface J1 is in short circuit, the input end of the signal generator is connected to the third pin of the second interface J2, and two input ends of the oscilloscope are respectively connected to one pin of the first interface J1 and the second pin of the third interface J3; adjusting the frequency of the signal generator to be the same as the maximum frequency of the signal source, and adjusting the amplitude of the signal generator to the amplitude of the isolation amplifier when the isolation amplifier is not distorted at the maximum; at this time, the amplitude of the input voltage signal and the amplitude of the output voltage signal input to the isolation amplifier are recorded, and the amplification factor is obtained.
Then, removing a short-circuit piece of the first interface J1, connecting the oscilloscope on a first pin at the input end of the first interface J1, connecting a second pin of the second interface J2 to the anode of the signal source, and connecting the first pin to the cathode of the signal source; adjusting the input resistance of the first potentiometer VR1 to a maximum value to allow the input voltage signal to fully enter the module; the input signal source can be changed within the interval of the worst value in the measured environment; then, the fourth potentiometer VR4 is adjusted to reduce the DC component on the signal source, when the DC component is reduced to the lowest, the first potentiometer VR1 is adjusted to make the waveform of the input signal consistent with the waveform during debugging, and finally the actual value of the signal to be measured is measured according to each link of the circuit.
By the circuit, the direct current quantity in the measurement signal can be weakened, the changed electric signal in the signal can be amplified, and accurate measurement can be realized; and the circuit is provided with an isolation amplifier, so that the voltage measuring element cannot be damaged even if the circuit is damaged under an unexpected condition.
Those skilled in the art will appreciate that the modules in the devices in the implementation scenario may be distributed in the devices in the implementation scenario according to the description of the implementation scenario, or may be located in one or more devices different from the present implementation scenario with corresponding changes. The modules of the implementation scenario may be combined into one module, or may be further split into a plurality of sub-modules.
The sequence numbers of the present invention are only for description, and do not represent the advantages and disadvantages of the implementation scenario.
The above disclosure is only a few specific implementation scenarios of the present invention, however, the present invention is not limited thereto, and any changes that can be considered by those skilled in the art shall fall within the protection scope of the present invention.
Claims (7)
1. An analog signal conditioning circuit based on an operational amplifier, comprising:
the differential operational amplifier module is connected with the signal end and used for amplifying the signal;
the isolation module is arranged at the output end of the differential operational amplifier module and used for electrical isolation;
and the adjusting module is arranged at the output end of the differential operational amplifier module and is used for proportionally reducing or proportionally amplifying the signal through the differential operational amplifier module.
2. The operational amplifier based analog signal conditioning circuit of claim 1, wherein the adjustment module comprises:
a voltage follower circuit;
the adjustable voltage division circuit is arranged at the input end of the voltage follower circuit;
and the output end of the voltage following circuit is connected with the input end of the differential operational amplifier module and is connected with the signal end in parallel.
3. The operational amplifier based analog signal conditioning circuit of claim 2, wherein the adjustable voltage divider circuit comprises:
a first resistor;
a second resistor connected in series with the first resistor;
the input end of the voltage follower circuit is arranged between the first resistor and the second resistor;
the second resistor is a slide rheostat.
4. The operational amplifier based analog signal conditioning circuit of claim 1, wherein the differential operational amplifier module comprises:
a second processor;
the third resistor is connected with the inverting input end of the second processor;
the fourth resistor is connected with the non-inverting input end of the second processor;
a fifth resistor disposed between the inverting input of the second processor and the output of the second processor;
and the sixth sensor is arranged between the fourth resistor and the non-inverting input end of the second processor and is connected with the signal end.
5. The operational amplifier based analog signal conditioning circuit of claim 4, wherein:
the input resistance of the non-inverting input of the second processor is equal to the input resistance of the inverting input of the second processor.
6. The operational amplifier based analog signal conditioning circuit of claim 1, wherein the isolation module comprises: a photoelectric isolation unit;
the photoelectric isolation unit is arranged at the output end of the differential operational amplifier module.
7. A meter simulation system, comprising:
an analog signal conditioning circuit as claimed in claims 1 to 6;
the first instrument is arranged at the output end of the adjusting module and used for collecting the output voltage of the adjusting module;
the second instrument is arranged at the input end of the differential operational amplifier module and used for providing a signal source;
the third instrument is arranged at the output end of the differential operational amplifier module and is used for collecting the signal waveform of the output end of the differential operational amplifier module;
and the fourth instrument is arranged at the isolated end of the isolation module and is used for acquiring the signal waveform isolated by the isolation module.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121062036.4U CN214707677U (en) | 2021-05-18 | 2021-05-18 | Analog signal conditioning circuit based on operational amplifier and instrument simulation system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121062036.4U CN214707677U (en) | 2021-05-18 | 2021-05-18 | Analog signal conditioning circuit based on operational amplifier and instrument simulation system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214707677U true CN214707677U (en) | 2021-11-12 |
Family
ID=78552917
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202121062036.4U Expired - Fee Related CN214707677U (en) | 2021-05-18 | 2021-05-18 | Analog signal conditioning circuit based on operational amplifier and instrument simulation system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN214707677U (en) |
-
2021
- 2021-05-18 CN CN202121062036.4U patent/CN214707677U/en not_active Expired - Fee Related
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100549704C (en) | Battery tension and impedance measuring circuit | |
| CN215296515U (en) | Pressure detection system | |
| CN108594020A (en) | The highly sensitive conductance of number display and high resistance measurement measuring circuit and method | |
| CN214707677U (en) | Analog signal conditioning circuit based on operational amplifier and instrument simulation system | |
| CN212410750U (en) | Data acquisition device suitable for single-phase earth fault line selection | |
| CN203785751U (en) | Weighing circuit and electronic scale possessing same | |
| CN110412485A (en) | A kind of output current detection circuit | |
| CN106291065B (en) | Voltage sampling circuit | |
| CN114460875B (en) | Power supply circuit and camera testing device | |
| CN214041538U (en) | Current and voltage detection circuit based on single chip microcomputer | |
| CN212965147U (en) | Voltage analog signal isolation differential acquisition circuit structure | |
| CN109709400B (en) | Constant current source circuit | |
| CN211317573U (en) | Temperature data acquisition circuit with isolation function | |
| US20110175596A1 (en) | Current measuring apparatus for power supply | |
| CN213069011U (en) | Full-range automatic switching resistance measurement CPCI board card | |
| CN202693752U (en) | Power supply IC high precision voltage test circuit | |
| CN221173660U (en) | High-precision engine temperature acquisition device | |
| CN214894985U (en) | Device for measuring soil salinity | |
| RU2754201C1 (en) | Device for measuring low currents of injected charges in condensed media | |
| CN216900728U (en) | Comprehensive electric system maintenance instrument | |
| CN213689744U (en) | Current acquisition circuit of double-range current divider | |
| CN220795349U (en) | Current detection circuit and current detection device | |
| CN213122661U (en) | Signal processor based on FPGA | |
| CN213544776U (en) | Battery power detection circuit applied to power quality device | |
| CN220855012U (en) | Digital multimeter with battery internal resistance measurement function |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20211112 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |