CN203643494U - Isolated current detection circuit - Google Patents
Isolated current detection circuit Download PDFInfo
- Publication number
- CN203643494U CN203643494U CN201420018459.XU CN201420018459U CN203643494U CN 203643494 U CN203643494 U CN 203643494U CN 201420018459 U CN201420018459 U CN 201420018459U CN 203643494 U CN203643494 U CN 203643494U
- Authority
- CN
- China
- Prior art keywords
- circuit
- operational amplifier
- resistance
- signal
- input end
- 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 - Lifetime
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 21
- 238000002955 isolation Methods 0.000 claims description 15
- 239000003990 capacitor Substances 0.000 claims description 12
- 102100039435 C-X-C motif chemokine 17 Human genes 0.000 claims description 3
- 101000889048 Homo sapiens C-X-C motif chemokine 17 Proteins 0.000 claims description 3
- 238000000034 method Methods 0.000 description 4
- 230000001105 regulatory effect Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005622 photoelectricity Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 238000009418 renovation Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Images
Landscapes
- Amplifiers (AREA)
Abstract
The utility model relates to an isolated current detection circuit. The isolated current detection circuit includes a signal input circuit (1), a photoelectric coupler circuit (2) and a signal output circuit (3); a signal output end of the signal input circuit (1) is connected with a signal input end of the photoelectric coupler circuit (2); and a signal input end of the signal output circuit (3) is connected with a signal output end of the photoelectric coupler circuit (2). The isolated current detection circuit of the utility model has the advantages of high safety, excellent anti-interference performance, simple structure, high reliability and high practicability, and can improve the stability and accuracy of a detection system. With the isolated current detection circuit of the utility model adopted, the problem of the burnout of a low voltage device, which is caused by a situation in which intermediate-high voltage and strong current can be easily connected in series into the low voltage device, can be solved.
Description
Technical field
The utility model is a kind of current detection circuit of isolation, belongs to the renovation technique of the current detection circuit of isolation.
Background technology
In many measuring systems such as some automated detection systems, computer data acquisition system, large scale electronic equipment, usually need to detect the electric signal in high voltage, heavy current device, these signals are very dangerous for the low-voltage device in next stage, so the two need to be kept apart.In the process of signals collecting, various undesired signals all can be along with measured signal enters digital control system in addition, and these signal superpositions can make the accuracy of measuring reduce in useful measured signal, cause the unstable of control system.In order to realize level linear transformation and on-the-spot electrical noise interference not to be incorporated into digital control system, circuit-under-test and control circuit must be realized to isolation on electric, analog photoelectricity isolation method and isolated amplifier method are two kinds of conventional partition methods.Analog photoelectricity isolator is structurally simple than isolated amplifier, and cost ratio isolated amplifier is low, and its linearity has sizable raising than isolated amplifier.
Utility model content
The purpose of this utility model is to consider the problems referred to above and provides a kind of safe, and good in anti-interference performance, can improve the current detection circuit of the accuracy of detection system and the isolation of stability.The utility model has solved equipment high voltage appearance, heavy current and has been easy to the problem that seals in low-voltage device so that burnt, and simple in structure, reliability is high.
The technical solution of the utility model is: the current detection circuit of isolation of the present utility model, include signal input circuit, optocoupler circuit, signal output apparatus, the signal output part of signal input circuit is connected with the signal input part of optocoupler circuit, and the signal input part of signal output apparatus is connected with the signal output part of optocoupler circuit.
Above-mentioned signal input circuit includes operational amplifier IC2A, resistance R 1, resistance R 4, capacitor C 1, optocoupler circuit includes precision photoelectric coupler U1 and resistance R 2, signal output apparatus includes operational amplifier IC1A, capacitor C 2 and resistance 3, the negative pole of the input end of operational amplifier IC2A is connected with one end of resistance R 1, the other end of resistance R 1 is by resistance R 4 ground connection, the plus earth of the input end of operational amplifier IC2A, capacitor C 1 is connected between the negative pole and output terminal of input end of operational amplifier IC2A, photoelectrical coupler U1 is connected with the output terminal of operational amplifier IC2A by resistance R 2, the output terminal of photoelectrical coupler U1 is connected with the input end of operational amplifier IC1A, the parallel circuit that capacitor C 2 and resistance 3 form is connected between the negative pole and output terminal of input end of operational amplifier IC1A, and the positive pole of the input end of operational amplifier IC1A meets insulating power supply VCC1, signal is exported by the output terminal of operational amplifier IC1A.
Above-mentioned photoelectrical coupler U1 includes light emitting diode D1, photodiode D2, photodiode D3, the positive pole of light emitting diode D1 in photodiode D2 connects power supply, the negative pole of photodiode D2 concatenation operation amplifier IC2A in photodiode D2 and ground, another photodiode D3 in photoelectrical coupler U1 connects the input end of operational amplifier IC1A.
The utility model compared with prior art, has following outstanding beneficial effect:
1) electrical security is high.By photoelectrical coupler, forceful electric power weak current part is kept apart, higher than the security performance of non-isolation scheme;
2) this circuit can not be incorporated into the electrical noise interference in upper level the digital control system of next stage, good in anti-interference performance.
The utility model improves accuracy and the stability of detection system, solved equipment high voltage appearance, heavy current and be easy to the problem that seals in low-voltage device so that burnt, and simple in structure, reliability is high, is that a kind of design is ingenious, function admirable, the current detection circuit of convenient and practical isolation.
Accompanying drawing explanation
Fig. 1 is schematic diagram of the present utility model.
Embodiment
Embodiment: schematic diagram of the present utility model as shown in Figure 1, the current detection circuit of isolation of the present utility model, include and comprise signal input circuit 1, optocoupler circuit 2, signal output apparatus 3, the signal output part of signal input circuit 1 is connected with the signal input part of optocoupler circuit 2, and the signal input part of signal output apparatus 3 is connected with the signal output part of optocoupler circuit 2.
In the present embodiment, above-mentioned signal input circuit 1 includes operational amplifier IC2A, resistance R 1, resistance R 4, capacitor C 1, optocoupler circuit 2 includes precision photoelectric coupler U1 and resistance R 2, signal output apparatus 3 includes operational amplifier IC1A, capacitor C 2 and resistance 3, the negative pole of the input end of operational amplifier IC2A is connected with one end of resistance R 1, the other end of resistance R 1 is by resistance R 4 ground connection, the plus earth of the input end of operational amplifier IC2A, capacitor C 1 is connected between the negative pole and output terminal of input end of operational amplifier IC2A, photoelectrical coupler U1 is connected with the output terminal of operational amplifier IC2A by resistance R 2, the output terminal of photoelectrical coupler U1 is connected with the input end of operational amplifier IC1A, the parallel circuit that capacitor C 2 and resistance 3 form is connected between the negative pole and output terminal of input end of operational amplifier IC1A, and the positive pole of the input end of operational amplifier IC1A meets insulating power supply VCC1, signal is exported by the output terminal of operational amplifier IC1A.
In the present embodiment, above-mentioned photoelectrical coupler U1 includes light emitting diode D1, photodiode D2, photodiode D3, the positive pole of light emitting diode D1 in photodiode D2 connects power supply, the negative pole of photodiode D2 concatenation operation amplifier IC2A in photodiode D2 and ground, another photodiode D3 in photoelectrical coupler U1 connects the input end of operational amplifier IC1A.
Principle of work of the present utility model is as follows: with reference to Fig. 1, photoelectrical coupler U1 is a kind of high-precision linear optocoupler, when in the light emitting diode D1 in photoelectrical coupler U1 when current flowing I1, its light sending can induce the photocurrent I2 and the I3 that are proportional to D1 luminous intensity in photodiode D2 and D3, so I2 and I3 have strict proportionate relationship.The importation of light emitting diode D1 and photodiode D2 composition isolation current detection circuit also forms negative feedback, is used for detecting and the intensity of stabilizing lumination of light emitting diode.D2 forms the output of isolation current detection circuit.Input current signal is first converted to input voltage vin by sampling resistor R4, then the negative pole input from elementary operational amplifier by resistance R 1, the effect of R2 is the size that regulates the input bias current of elementary operational amplifier IC2A, C1 plays retroactive effect, simultaneously filtering the burr signal in circuit, avoid the light emitting diode D1 in linear optical coupling to be subject to unexpected impact.R2 can control the luminous intensity of D1, and to control channel, gain plays a role.Amplifier IC2A mainly works to regulate electric current I 1 size of the light emitting diode D1 that flows through.In the time that input current I increases, the voltage at R4 two ends increases, and amplifier IC2A negative input voltage increases simultaneously, impels electric current I 1 to increase.Due to the contact between photodiode D1 and D2 electric current, the electric current I 2 that flows through photodiode D2 also can increase, and the negative input voltage of IC2A will be retracted to 0V again, forms negative feedback.If the input current of amplifier IC2A is very little, the electric current of the R1 that flows through is so just Vin/R1=Iin, apparent, between Vin and Iin, is linear ratio relation.Iin regulated linear changes, and I1 also regulated linear changes.Because D3 is subject to D1 illumination, and their electric current of flowing through also has strict proportionate relationship, thus I3 also and then regulated linear change.I3 is changed into output voltage V out=I3 × R3 by amplifier IC1A and resistance R 3, the principle of work of Here it is this circuit.
The above; it is only preferably specific embodiment of the utility model; but protection domain of the present utility model is not limited to this; any be familiar with those skilled in the art the utility model disclose scope in; be equal to replacement or changed according to the technical solution of the utility model and utility model design thereof, all being belonged to protection domain of the present utility model.
Claims (3)
1. the current detection circuit of an isolation, it is characterized in that including signal input circuit (1), optocoupler circuit (2), signal output apparatus (3), the signal output part of signal input circuit (1) is connected with the signal input part of optocoupler circuit (2), and the signal input part of signal output apparatus (3) is connected with the signal output part of optocoupler circuit (2).
2. the current detection circuit of isolation according to claim 1, it is characterized in that above-mentioned signal input circuit (1) includes operational amplifier IC2A, resistance R 1, resistance R 4, capacitor C 1, optocoupler circuit (2) includes precision photoelectric coupler U1 and resistance R 2, signal output apparatus (3) includes operational amplifier IC1A, capacitor C 2 and resistance 3, the negative pole of the input end of operational amplifier IC2A is connected with one end of resistance R 1, the other end of resistance R 1 is by resistance R 4 ground connection, the plus earth of the input end of operational amplifier IC2A, capacitor C 1 is connected between the negative pole and output terminal of input end of operational amplifier IC2A, photoelectrical coupler U1 is connected with the output terminal of operational amplifier IC2A by resistance R 2, the output terminal of photoelectrical coupler U1 is connected with the input end of operational amplifier IC1A, the parallel circuit that capacitor C 2 and resistance 3 form is connected between the negative pole and output terminal of input end of operational amplifier IC1A, and the positive pole of the input end of operational amplifier IC1A meets insulating power supply VCC1, signal is exported by the output terminal of operational amplifier IC1A.
3. the current detection circuit of isolation according to claim 1, it is characterized in that above-mentioned photoelectrical coupler U1 includes light emitting diode D1, photodiode D2, photodiode D3, the positive pole of light emitting diode D1 in photodiode D2 connects power supply, the negative pole of photodiode D2 concatenation operation amplifier IC2A in photodiode D2 and ground, another photodiode D3 in photoelectrical coupler U1 connects the input end of operational amplifier IC1A.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420018459.XU CN203643494U (en) | 2014-01-13 | 2014-01-13 | Isolated current detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420018459.XU CN203643494U (en) | 2014-01-13 | 2014-01-13 | Isolated current detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203643494U true CN203643494U (en) | 2014-06-11 |
Family
ID=50874729
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420018459.XU Expired - Lifetime CN203643494U (en) | 2014-01-13 | 2014-01-13 | Isolated current detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203643494U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104407193A (en) * | 2014-12-12 | 2015-03-11 | 东莞市精诚电能设备有限公司 | Linear voltage sampling circuit |
| CN104678247A (en) * | 2015-02-15 | 2015-06-03 | 北京航天计量测试技术研究所 | Device for measuring electric leakage of 28V power supply |
| CN106059563A (en) * | 2016-07-13 | 2016-10-26 | 上海富电科技有限公司 | Control guide signal collection circuit |
| CN107238746A (en) * | 2017-06-14 | 2017-10-10 | 国网河南省电力公司电力科学研究院 | A kind of micro current circuit tested for dielectric response |
-
2014
- 2014-01-13 CN CN201420018459.XU patent/CN203643494U/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104407193A (en) * | 2014-12-12 | 2015-03-11 | 东莞市精诚电能设备有限公司 | Linear voltage sampling circuit |
| CN104678247A (en) * | 2015-02-15 | 2015-06-03 | 北京航天计量测试技术研究所 | Device for measuring electric leakage of 28V power supply |
| CN106059563A (en) * | 2016-07-13 | 2016-10-26 | 上海富电科技有限公司 | Control guide signal collection circuit |
| CN107238746A (en) * | 2017-06-14 | 2017-10-10 | 国网河南省电力公司电力科学研究院 | A kind of micro current circuit tested for dielectric response |
| CN107238746B (en) * | 2017-06-14 | 2020-06-05 | 国网河南省电力公司电力科学研究院 | Micro-current measuring circuit for dielectric response test |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203084068U (en) | Analog voltage acquisition circuit with isolation function | |
| CN203643494U (en) | Isolated current detection circuit | |
| CN103389451B (en) | A kind of method of testing of avalanche photodide and proving installation | |
| CN103424606B (en) | A kind of low voltage electric power carrier communication zero cross detection circuit of frequency self-adaption | |
| CN203658433U (en) | High-sensitivity wide-range current amplification conversion circuit | |
| CN102739235B (en) | Switching value acquisition insulating circuit | |
| CN104020346A (en) | Micro-current signal extraction system | |
| CN102508016A (en) | Voltage detection circuit of motor controller for electric vehicle | |
| CN204495859U (en) | A kind of locomotive AC line insulation monitor signal spacer assembly | |
| CN102749501B (en) | Isolated direct current high voltage detection method and isolated direct current high voltage detection circuit | |
| CN108152557A (en) | Sample circuit is isolated in a kind of feedback current | |
| CN102788641B (en) | Detecting circuit for light intensity | |
| CN203259168U (en) | Special optical signal detection circuit | |
| CN204631100U (en) | Be applicable to the high-speed light isolation voltage sensor of lightning surge environment | |
| CN203870150U (en) | Isolation type power grid detector | |
| CN204166094U (en) | A kind of LED photovoltaic parameter measurement system | |
| CN103134529A (en) | Photoelectric sensor | |
| CN208730923U (en) | A kind of instruction control box | |
| CN215987067U (en) | APD reverse bias voltage generation circuit applied to DTS | |
| CN104407193A (en) | Linear voltage sampling circuit | |
| CN203745548U (en) | Railway signal detection circuit and railway signal detector | |
| CN103674241A (en) | Photosensitive circuit for detecting photosensitive signal | |
| CN209001931U (en) | A kind of analogue quantity output circuit | |
| CN203590236U (en) | Automatic optical power control device | |
| CN202757980U (en) | Analog signal isolation detection circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20140611 |