CN203870149U - Non-contact linear electrical network detector - Google Patents
Non-contact linear electrical network detector Download PDFInfo
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- CN203870149U CN203870149U CN201420315125.9U CN201420315125U CN203870149U CN 203870149 U CN203870149 U CN 203870149U CN 201420315125 U CN201420315125 U CN 201420315125U CN 203870149 U CN203870149 U CN 203870149U
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- optocoupler
- operational amplifier
- input end
- output terminal
- electrical network
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Abstract
The utility model relates to a non-contact linear electrical network detector formed by a feedback electrode and an output electrode; the feedback electrode comprises a first operation amplifier, a first optical coupler, a second optical coupler and a first feedback resistor; an output end of the first operation amplifier is connected with a photoelectric current input end of the first optical coupler; a photoelectric current output end of the first optical coupler is connected with a photoelectric current input end of the second optical coupler; a photoelectric current input end of the second optical coupler is grounded; the first feedback resistor is connected between an inverted input end of the first operation amplifier and a grounding line; the output electrode comprises a second operation amplifier and a second feedback resistor; a static discharge circuit is arranged between a non-inverted input end of the first operation amplifier and the ground. The non-contact linear electrical network detector has isolation function; an isolated output voltage is in direct proportion to the input voltage; isolated voltage and current signals can be detected; the non-contact linear electrical network detector is simple in structure, cheap in cost, high in precision, and good in linearity.
Description
Technical field
The utility model relates to electronic circuit field, particularly, relates to a kind of contactless linear electrical network detecting device.
Background technology
Along with the development of power technology, in electric system, communication system, use more and more widely the power-supply devices such as Switching Power Supply, UPS.These equipment will detect voltage, the current signal of main circuit bar none.Testing circuit is the interface of main circuit and control circuit, is the requisite important component part of power-supply device.Testing circuit must meet the requirement of following several respects:
(1) to there be very high precision and the linearity.Modern power supply, in order to reach very high voltage stabilization and current stabilization precision and to have good dynamic response characteristic, is all introduced the FEEDBACK CONTROL that electric current and voltage participates in system mostly.The precision of testing circuit and the linearity, determined output accuracy and the stability of whole power supply to a certain extent.
(2) must there is isolation features.Between the main circuit of most of power supplys and control circuit on electric mutually insulated.Otherwise power supply can be because main circuit be to the interference of control circuit and cisco unity malfunction, even entail dangers to commissioning staff's personal safety.
At present, on market, existing isolation detector is as isolated amplifier, voltage Hall, current Hall etc., and how very expensive price is, and feedback linearization degree is poor.
Utility model content
Expensive for overcoming existing isolation detector, the technological deficiency that feedback linearization degree is poor, the utility model discloses a kind of contactless linear electrical network detecting device.
Contactless linear electrical network detecting device described in the utility model, by feedback stage and output stage, formed, described feedback stage comprises the first operational amplifier, the first optocoupler, the second optocoupler and the first feedback resistance, the first operational amplifier output terminal connects the photocurrent input end of the first optocoupler, the photocurrent output terminal of described the first optocoupler connects the photocurrent input end of the second optocoupler, the photocurrent output head grounding of described the second optocoupler, induction current output terminal connects the inverting input of the first operational amplifier, described the first feedback resistance is connected between the inverting input and ground wire of the first operational amplifier,
Described output stage comprises the second operational amplifier and the second feedback resistance, the normal phase input end of described the second operational amplifier connects the induction current output terminal of the first optocoupler, the inverting input of the second operational amplifier is connected with output terminal, and described the second feedback resistance is connected between the normal phase input end and ground of the second operational amplifier;
The normal phase input end of described the first operational amplifier is connected with static leakage circuit between ground; described static leakage circuit is comprised of gate protection resistance, phasmajector and capacitance; the substrate of described phasmajector, source electrode are all connected with ground with grid; described capacitance is connected to and is connected with phasmajector drain electrode, and described gate protection resistance, phasmajector drain electrode are all connected with the first operational amplifier normal phase input end.
Preferably, described the first operational amplifier output terminal connects between the photocurrent input end of photocurrent input end the first optocoupler of the first optocoupler and is connected with current-limiting resistance.
Preferably, between described the first operational amplifier output terminal and inverting input, be connected with building-out capacitor.
Preferably, described the first optocoupler is identical with the model of the second optocoupler.
Contactless linear electrical network detecting device described in the utility model, has isolation features, and the output voltage after isolation is directly proportional to input voltage, can be used for detecting voltage, the current signal that needs are isolated.By the extremely low common separation device of use cost, significantly reduced manufacturing cost, there is simple in structure, low price, precision is high, the linearity is good feature.
Accompanying drawing explanation
Fig. 1 is a kind of embodiment schematic diagram of the utility model;
Mark and corresponding parts title in accompanying drawing: IN-test side, R1-current-limiting resistance, R2-the first feedback resistance; R3-the second feedback resistance, R4-gate protection resistance, C1-building-out capacitor; C2-capacitance, M-phasmajector, AMP1-the first operational amplifier; AMP2-the second operational amplifier; G1 – the first optocoupler, G2-the second optocoupler, D-optocoupler luminotron; T-optocoupler inductive output tube VCC-direct supply, OUT-signal output part.
Embodiment
Below in conjunction with embodiment and accompanying drawing, the utility model is done to detailed description further, but embodiment of the present utility model is not limited to this.
Contactless linear electrical network detecting device described in the utility model, by feedback stage and output stage, formed, described feedback stage comprises the first operational amplifier A MP1, the first optocoupler G1, the second optocoupler G2 and the first feedback resistance R2, the first operational amplifier output terminal connects the photocurrent input end of the first optocoupler, the photocurrent output terminal of described the first optocoupler connects the photocurrent input end of the second optocoupler, the photocurrent output head grounding of described the second optocoupler, induction current output terminal connects the inverting input of the first operational amplifier, described the first feedback resistance is connected between the inverting input and ground wire of the first operational amplifier,
Described output stage comprises the second operational amplifier and the second feedback resistance, the normal phase input end of described the second operational amplifier connects the induction current output terminal of the first optocoupler, the inverting input of the second operational amplifier is connected with output terminal, and described the second feedback resistance is connected between the normal phase input end and ground of the second operational amplifier.
As shown in Figure 1, optocoupler in dotted line frame is comprised of optocoupler luminotron D and optocoupler inductive output tube T, the electric current of operational amplifier output flows into from photocurrent input end, D is luminous for optocoupler luminotron, luminous flux is responded to by optocoupler inductive output tube, generation current, the power end of the optocoupler inductive output tube of each optocoupler connects external direct supply VCC.
The effect of two optocouplers is one, and as output, another is as feedback, and the first optocoupler is for compensating the non-linear of light emitting diode time, temperature characterisitic.In order to guarantee that the luminous flux that second output signal of optocoupler generation and the luminotron of the first optocoupler send is linear scaling, when selector, the characteristic of two photo-couplers should be consistent as far as possible, should preferably select the optocoupler that model is consistent.
During detection, the normal phase input end of the first operational amplifier A MP1 is connected with detected signal, signal is inputted from test side IN, in testing circuit adjustment process, detection signal has two kinds of variation tendencies, the detection voltage of take is example, when input voltage Ui raises, make Ui>R2*I2, I2 is the electric current from the second optocoupler photocurrent output terminal output, cause the output end voltage of the first operational amplifier to raise, electric current I 1 by luminotron in optocoupler also increases thereupon, the luminotron of two optocouplers forms series relationship, so I2=K1*I1, I3=K2*I1, K1 wherein, K2 is respectively the induction coefficient of two optocouplers, I2, I3 also increases, I3 is the electric current that flows through the second feedback resistance R3, two operational amplifiers are negative feedback type of attachment, two input terminal voltages equate respectively, can obtain the output voltage U O=(K1*R3/K2*R2 at signal output part OUT) * Ui, UO is linear increase along with the increase of Ui.
Otherwise when input voltage Ui reduces, the output end voltage of the first operational amplifier reduces, the electric current I 1 by luminotron in optocoupler also reduces thereupon, and with upper similar, output voltage is also with proportional the reducing of reduction of input voltage Ui.
Because test side IN is directly connected with external belt detection of grid, electric current and voltage value is all difficult to calculate, therefore need to connect electrostatic discharge protective circuit at test side IN, described static leakage circuit is by gate protection resistance R 4, phasmajector M and capacitance C2 form, the substrate of described phasmajector, source electrode is all connected with ground with grid, described capacitance is connected to and is connected with phasmajector drain electrode, described gate protection resistance, phasmajector drain electrode is all connected with the first operational amplifier normal phase input end, phasmajector is owing to being connected with ground, therefore get NMOS pipe, under normal condition, due to grounded-grid, NMOS pipe is not opened, not affecting circuit normally works, when static or uncontrollable large voltage and current signal come interim, high frequency characteristics due to static or uncontrollable voltage and current signal, by capacitance, be coupled to NMOS tube grid, make phasmajector conducting, large electric current flows away from the NMOS pipe R4 opening, avoid direct effect to the first operational amplifier normal phase input end, gate protection resistance R 4 forms Hi-pass filter jointly with C2, can set resistance with the electrostatic signal for characteristic frequency, at large electric current, come interim simultaneously, R4 can play certain dividing potential drop effect.
Can between connecting the photocurrent input end of photocurrent input end the first optocoupler of the first optocoupler, described the first operational amplifier output terminal connect current-limiting resistance R1, avoid the input current of optocoupler over the linear threshold scope of luminotron, because utilizing the luminous flux of the luminotron in optocoupler, the utility model is directly proportional to the electric current flowing through, therefore input current must change in linear threshold range, with current increases, the substantially linear growth of the luminous flux of luminotron.
A more excellent selection is between the first operational amplifier output terminal and inverting input, to connect building-out capacitor C1, the utility model is applied to detect AC network, clutter is disorderly, connect building-out capacitor C1, for the first operational amplifier provides a dominant pole, improved the closed loop stability of the first operational amplifier, the value of building-out capacitor C1 can be in nanofarad to microfarad rank, for example 1-1000 nanofarad.
As mentioned above, can realize preferably the utility model.
Claims (4)
1. contactless linear electrical network detecting device, it is characterized in that, by feedback stage and output stage, formed, described feedback stage comprises the first operational amplifier, the first optocoupler, the second optocoupler and the first feedback resistance, the first operational amplifier output terminal connects the photocurrent input end of the first optocoupler, the photocurrent output terminal of described the first optocoupler connects the photocurrent input end of the second optocoupler, the photocurrent output head grounding of described the second optocoupler, induction current output terminal connects the inverting input of the first operational amplifier, described the first feedback resistance is connected between the inverting input and ground wire of the first operational amplifier,
Described output stage comprises the second operational amplifier and the second feedback resistance, the normal phase input end of described the second operational amplifier connects the induction current output terminal of the first optocoupler, the inverting input of the second operational amplifier is connected with output terminal, and described the second feedback resistance is connected between the normal phase input end and ground of the second operational amplifier;
The normal phase input end of described the first operational amplifier is connected with static leakage circuit between ground; described static leakage circuit is comprised of gate protection resistance, phasmajector and capacitance; the substrate of described phasmajector, source electrode are all connected with ground with grid; described capacitance is connected to and is connected with phasmajector drain electrode, and described gate protection resistance, phasmajector drain electrode are all connected with the first operational amplifier normal phase input end.
2. contactless linear electrical network detecting device according to claim 1, is characterized in that, described the first operational amplifier output terminal connects between the photocurrent input end of photocurrent input end the first optocoupler of the first optocoupler and is connected with current-limiting resistance.
3. contactless linear electrical network detecting device according to claim 1, is characterized in that, between described the first operational amplifier output terminal and inverting input, is connected with building-out capacitor.
4. contactless linear electrical network detecting device according to claim 1, is characterized in that, described the first optocoupler is identical with the model of the second optocoupler.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420315125.9U CN203870149U (en) | 2014-06-14 | 2014-06-14 | Non-contact linear electrical network detector |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420315125.9U CN203870149U (en) | 2014-06-14 | 2014-06-14 | Non-contact linear electrical network detector |
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| Publication Number | Publication Date |
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| CN203870149U true CN203870149U (en) | 2014-10-08 |
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| CN201420315125.9U Expired - Fee Related CN203870149U (en) | 2014-06-14 | 2014-06-14 | Non-contact linear electrical network detector |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104931814A (en) * | 2015-05-23 | 2015-09-23 | 成都众孚理想科技有限公司 | Digital isolation type grid detector |
| CN110441579A (en) * | 2018-05-03 | 2019-11-12 | 基思利仪器有限责任公司 | Non-linear active shunts ampere meter |
| CN113218999A (en) * | 2021-03-22 | 2021-08-06 | 东莞理工学院 | Detector and detection device for weakening root surface iron membrane and promoting wetland plants to absorb heavy metals |
| CN113933646A (en) * | 2021-09-22 | 2022-01-14 | 中航光电科技股份有限公司 | Circuit and method for detecting voltage and grounding of low-voltage distribution network |
-
2014
- 2014-06-14 CN CN201420315125.9U patent/CN203870149U/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104931814A (en) * | 2015-05-23 | 2015-09-23 | 成都众孚理想科技有限公司 | Digital isolation type grid detector |
| CN104931814B (en) * | 2015-05-23 | 2018-01-26 | 成都众孚理想科技有限公司 | A kind of isolated power network detector of numeral |
| CN110441579A (en) * | 2018-05-03 | 2019-11-12 | 基思利仪器有限责任公司 | Non-linear active shunts ampere meter |
| CN113218999A (en) * | 2021-03-22 | 2021-08-06 | 东莞理工学院 | Detector and detection device for weakening root surface iron membrane and promoting wetland plants to absorb heavy metals |
| CN113218999B (en) * | 2021-03-22 | 2022-12-13 | 东莞理工学院 | Detector and detection device for weakening root surface iron membrane and promoting wetland plants to absorb heavy metals |
| CN113933646A (en) * | 2021-09-22 | 2022-01-14 | 中航光电科技股份有限公司 | Circuit and method for detecting voltage and grounding of low-voltage distribution network |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20141008 Termination date: 20180614 |