CN111721995A - Isolation sampling circuit of direct current voltage signal - Google Patents
Isolation sampling circuit of direct current voltage signalDownload PDFInfo
- Publication number
- CN111721995A CN111721995ACN202010584977.8ACN202010584977ACN111721995ACN 111721995 ACN111721995 ACN 111721995ACN 202010584977 ACN202010584977 ACN 202010584977ACN 111721995 ACN111721995 ACN 111721995A
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- operational amplifier
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- 238000002955isolationMethods0.000titleclaimsabstractdescription72
- 238000005070samplingMethods0.000titleclaimsabstractdescription20
- 230000003321amplificationEffects0.000claimsdescription16
- 238000003199nucleic acid amplification methodMethods0.000claimsdescription16
- 230000003287optical effectEffects0.000abstractdescription5
- 239000003990capacitorSubstances0.000description3
- 238000010586diagramMethods0.000description2
- 230000007613environmental effectEffects0.000description2
- 230000001419dependent effectEffects0.000description1
- 238000005259measurementMethods0.000description1
- 238000012544monitoring processMethods0.000description1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/0084—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring voltage only
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- General Physics & Mathematics (AREA)
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Abstract
Description
Technical Field
The present invention relates to an isolated sampling circuit, and more particularly, to an isolated sampling circuit for dc voltage signals.
Background
The power distribution automation system requires real-time monitoring of the states of various direct-current voltage signals and serves as an auxiliary judgment basis for judging whether the corresponding subsystems work normally, and the existing direct-current voltage sampling technology cannot meet the requirements of isolation, precision and interference resistance at the same time.
Disclosure of Invention
The purpose of the invention is as follows: the invention provides an isolation sampling circuit for direct-current voltage signals, which can safely and stably acquire various direct-current voltage signals in a power distribution network system in real time and reduce the influence of environmental interference on the sampling circuit.
The technical scheme is as follows: the technical scheme adopted by the invention is an isolation sampling circuit of a direct-current voltage signal, which is used for a power distribution automation system and comprises an input protection voltage division circuit, a signal isolation following circuit and a direct-current power supply isolation module; the input protection voltage division circuit is used for carrying out voltage limiting protection on the amplitude of the input voltage and matching the measuring range of the post-stage circuit through the voltage division circuit; the signal isolation following circuit is connected with the output of the input protection voltage division circuit, comprises an input end operational amplification circuit, an isolation linear optocoupler and an output end operational amplification circuit which are sequentially and electrically connected, and is used for isolating and linearly following the direct-current voltage signal output by the input protection voltage division circuit for output; the direct-current power supply isolation module is used for providing a stable isolation power supply for the input end operational amplification circuit.
The signal isolation follower circuit comprises an input end operational amplification circuit, an isolation linear optocoupler and an output end operational amplification circuit which are sequentially and electrically connected, the input end operational amplification circuit comprises a first operational amplifier, the output end operational amplification circuit comprises a second operational amplifier, the cathode of a photosensitive diode on one side of the input end of the isolation linear optocoupler is connected with the cathode of the first operational amplifier, and the anode of the photosensitive diode is connected with the ground end of the direct-current power supply isolation module; the cathode of a light emitting diode at one side of the input end of the isolation linear optocoupler is connected with the output end of the first operational amplifier through a resistor, and the anode of the light emitting diode is connected with the voltage output end of the direct-current power supply isolation module; and the cathode of a photosensitive diode at one side of the output end of the isolation linear optocoupler is connected with the cathode of the second operational amplifier, and the anode of the photosensitive diode is connected with the anode of the second operational amplifier.
The input protection voltage division circuit comprises a piezoresistor and a voltage division circuit connected with the piezoresistor in parallel, and the voltage division circuit comprises a first precise voltage division resistor and a second precise voltage division resistor which are connected in series.
Preferably, the piezoresistor is MYN12-121K, the precision of the first precise voltage-dividing resistor and the precision of the second precise voltage-dividing resistor are within 1%, and the temperature drift is 0-50 ppm.
Preferably, the model of the first operational amplifier and the model of the second operational amplifier are LMV358, and the model of the linear isolation optocoupler IC1 is HCNR 201.
The isolation voltage grades of the isolation linear optocoupler and the isolation module of the direct-current power supply in the scheme are both more than 1500V, so that the actual requirements of a power distribution automation system are met.
Has the advantages that: compared with the prior art, the invention has the following advantages: the isolation sampling circuit for the direct current voltage signal provided by the invention has the advantages that after the amplitude of the input voltage is subjected to voltage limiting protection, the direct current voltage input from the outside is divided and converted into DC2.5V through the precision resistor, so that the isolation sampling circuit can meet the isolation voltage grade and the rear-stage measurement range. Then, signals are isolated and linearly output along with the isolation linear optocoupler and operational amplifier combined circuit, so that the influence of environmental interference on the sampling circuit can be reduced, the collected signals are guaranteed not to be distorted, and various direct-current voltage signals in a power distribution network system are stably collected.
Drawings
Fig. 1 is a structural diagram of an isolated sampling circuit for dc voltage signals according to the present invention.
Detailed Description
The technical solution of the present invention is further described below with reference to the accompanying drawings and examples.
After the input voltage amplitude is subjected to voltage limiting protection, the direct current voltage input from the outside is divided and converted into DC2.5V through a precision resistor, and then the signal is isolated and linearly output along with the signal through an isolation linear optical coupler and operational amplifier combined circuit; the direct-current power supply isolation module is used for providing a stable isolation power supply for the input end operational amplifier circuit.
Fig. 1 is a schematic diagram of an isolated sampling circuit system for dc voltage signals according to the present invention, which mainly includes an input protection voltage divider circuit, a signal isolation follower circuit, and a dc power isolation module.
The input protection voltage division circuit comprises a piezoresistor RM, a first precise voltage division resistor R1 and a second precise voltage division resistor R2. Input protection voltage division circuit for preventing external direct current voltage signal uiAfter being disturbed by external connection, the signal rises instantly to protect a rear-stage circuit, and then the signal is reduced by R2/(R1+ R2) times through precise voltage dividing resistors R1 and R2, so that the measuring range of the rear-stage circuit is met.
The voltage dependent resistor RM is used for preventing an external direct current voltage signal from being instantly increased after being interfered by external connection, and protecting a rear-stage circuit. The proportion of the resistance value of the precise divider resistor is related to the signal reduction multiple. Preferably, the piezoresistor RM is MYN12-121K in model number. The resistances of the precision divider resistors R1 and R2 are both 10k omega/0.25W grade, the precision is 1 percent, and the temperature drift is 50 ppm.
The signal isolation following circuit comprises an input end operational amplification circuit, an isolation linear optocoupler and an output end operational amplification circuit which are sequentially and electrically connected. As shown in fig. 1, the circuit includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first capacitor C1, a second capacitor C2, a first operational amplifier U1, a second operational amplifier U2, and a linear isolation optocoupler IC 1. By combining an isolation linear optocoupler IC1 with operational amplifiers U1 and U2, a direct-current voltage signal within a front stage DC2.5V is isolated and linearly output along with the signal to obtain Uo. The signal isolation follower circuit isolates the direct current voltage signal within the front stage DC2.5V and linearly follows the output through the combination of an isolation linear optical coupler and an operational amplifier. Isolated linearityThe negative electrode of a photosensitive diode at one side of the input end of the optical coupler IC1 is connected with the negative electrode of the first operational amplifier U1, and the positive electrode of the photosensitive diode is connected with an isolation power supply ISOGND; the cathode of the light emitting diode at one side of the input end of the isolation linear optocoupler IC1 is connected with the output end of the first operational amplifier U1 through a fourth resistor R4, and the anode of the light emitting diode is connected with an isolation power supply ISO 5V. The negative electrode of a photosensitive diode at the output end side of the optical coupler IC1 is connected with the negative electrode of the second operational amplifier U2, and the positive electrode of the photosensitive diode is connected with the positive electrode of the second operational amplifier U2.
Preferably, the third resistor R3 and the fifth resistor R5 both have a resistance of about 150k Ω, and the fourth resistor R4 has a resistance of about 470 Ω. The capacitance values of the capacitors C1 and C2 are both about 470 pF. Operational amplifiers U1, U2 are model LMV 358. The linear isolation optocoupler IC1 is of the type HCNR 201.
The direct-current power supply isolation module adopts a power supply module with the model number of B0505LS and provides a stable isolation power supply ISO5V for the input end operational amplifier circuit.
The isolation voltage grades of the isolation linear optocoupler and the isolation module of the direct-current power supply are both more than 1500V, and the actual requirements of the power distribution automation system are met.
Claims (6)
1. An isolation sampling circuit of direct current voltage signal for distribution automation system, its characterized in that: the circuit comprises an input protection voltage division circuit, a signal isolation following circuit and a direct current power supply isolation module; the input protection voltage division circuit is used for carrying out voltage limiting protection on the amplitude of the input voltage and matching the measuring range of the post-stage circuit through the voltage division circuit; the signal isolation following circuit is connected with the output of the input protection voltage division circuit, comprises an input end operational amplification circuit, an isolation linear optocoupler and an output end operational amplification circuit which are sequentially and electrically connected, and is used for isolating and linearly following the direct-current voltage signal output by the input protection voltage division circuit for output; the direct-current power supply isolation module is used for providing a stable isolation power supply for the input end operational amplification circuit.
2. The isolated sampling circuit of a dc voltage signal of claim 1, wherein: the signal isolation follower circuit comprises an input end operational amplification circuit, an isolation linear optocoupler and an output end operational amplification circuit which are sequentially and electrically connected, the input end operational amplification circuit comprises a first operational amplifier (U1), the output end operational amplification circuit comprises a second operational amplifier (U2), the cathode of a photosensitive diode on one side of the input end of the isolation linear optocoupler (IC1) is connected with the cathode of the first operational amplifier (U1), and the anode of the photosensitive diode is connected with the ground end (ISOGND) of the direct-current power supply isolation module; the cathode of a light emitting diode at one side of the input end of the isolation linear optocoupler (IC1) is connected with the output end of a first operational amplifier (U1) through a resistor (R4), and the anode of the light emitting diode is connected with the voltage output end (ISO5V) of the direct-current power supply isolation module; the cathode of a photosensitive diode on one side of the output end of the isolation linear optocoupler (IC1) is connected with the cathode of a second operational amplifier (U2), and the anode of the photosensitive diode is connected with the anode of the second operational amplifier (U2).
3. The isolated sampling circuit of a dc voltage signal of claim 1, wherein: the input protection voltage division circuit comprises a piezoresistor (RM) and a voltage division circuit connected with the piezoresistor in parallel, wherein the voltage division circuit comprises a first precise voltage division resistor (R1) and a second precise voltage division resistor (R2) which are connected in series.
4. The isolated sampling circuit of a dc voltage signal of claim 1, wherein: the piezoresistor (RM) is MYN12-121K in type, the precision of the first precise voltage-dividing resistor (R1) and the precision of the second precise voltage-dividing resistor (R2) are within 1%, and the temperature drift is 0-50 ppm.
5. The isolated sampling circuit of a dc voltage signal of claim 1, wherein: the first operational amplifier (U1) and the second operational amplifier (U2) are of the type LMV358, and the linear isolation optocoupler (IC1) is of the type HCNR 201.
6. The isolated sampling circuit of a dc voltage signal of claim 1, wherein: the isolation voltage grades of the isolation linear optocoupler and the isolation module of the direct current power supply are both more than 1500V.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010584977.8ACN111721995A (en) | 2020-06-23 | 2020-06-23 | Isolation sampling circuit of direct current voltage signal |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010584977.8ACN111721995A (en) | 2020-06-23 | 2020-06-23 | Isolation sampling circuit of direct current voltage signal |
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| CN111721995Atrue CN111721995A (en) | 2020-09-29 |
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| CN202010584977.8APendingCN111721995A (en) | 2020-06-23 | 2020-06-23 | Isolation sampling circuit of direct current voltage signal |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112711207A (en)* | 2020-12-21 | 2021-04-27 | 国网北京市电力公司 | High-voltage direct current signal acquisition module and electronic device |
| CN112816771A (en)* | 2020-12-30 | 2021-05-18 | 南京爱睦能源自动化有限公司 | Board-level high-precision isolation direct-current voltage and current acquisition module with high protection capability |
| CN113037276A (en)* | 2021-03-02 | 2021-06-25 | 浙江禾川科技股份有限公司 | Modulation output circuit |
| CN118713613A (en)* | 2024-08-27 | 2024-09-27 | 中国电子产品可靠性与环境试验研究所（（工业和信息化部电子第五研究所）（中国赛宝实验室）） | AC/DC high voltage amplifier module and device |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202870145U (en)* | 2012-08-28 | 2013-04-10 | 长沙威胜信息技术有限公司 | DC simulation signal acquisition circuit for public transformation terminal |
| CN204065210U (en)* | 2014-07-02 | 2014-12-31 | 中国检验检疫科学研究院 | The isolated DC voltage collection circuit of linear change |
| CN206506517U (en)* | 2017-01-18 | 2017-09-19 | 珠海驰纬电气有限公司 | A kind of isolating device of d. c. voltage signal sampling |
- 2020
- 2020-06-23CNCN202010584977.8Apatent/CN111721995A/enactivePending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202870145U (en)* | 2012-08-28 | 2013-04-10 | 长沙威胜信息技术有限公司 | DC simulation signal acquisition circuit for public transformation terminal |
| CN204065210U (en)* | 2014-07-02 | 2014-12-31 | 中国检验检疫科学研究院 | The isolated DC voltage collection circuit of linear change |
| CN206506517U (en)* | 2017-01-18 | 2017-09-19 | 珠海驰纬电气有限公司 | A kind of isolating device of d. c. voltage signal sampling |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112711207A (en)* | 2020-12-21 | 2021-04-27 | 国网北京市电力公司 | High-voltage direct current signal acquisition module and electronic device |
| CN112816771A (en)* | 2020-12-30 | 2021-05-18 | 南京爱睦能源自动化有限公司 | Board-level high-precision isolation direct-current voltage and current acquisition module with high protection capability |
| CN113037276A (en)* | 2021-03-02 | 2021-06-25 | 浙江禾川科技股份有限公司 | Modulation output circuit |
| CN118713613A (en)* | 2024-08-27 | 2024-09-27 | 中国电子产品可靠性与环境试验研究所（（工业和信息化部电子第五研究所）（中国赛宝实验室）） | AC/DC high voltage amplifier module and device |
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