CN104101775A - Current measuring circuit - Google Patents
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- CN104101775A CN104101775A CN201310113598.0A CN201310113598A CN104101775A CN 104101775 A CN104101775 A CN 104101775A CN 201310113598 A CN201310113598 A CN 201310113598A CN 104101775 A CN104101775 A CN 104101775A
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Abstract
The application discloses a current measuring circuit comprising a current sensor. The current sensor is provided with at least one coil. The coil has a hollow tube structure formed by a conductive wire via coiling in a certain direction. The coil has no iron core material so that the magnetic saturation phenomenon does not occur. Induced voltage outputted by the current sensor and the measured current are constantly in a linear relation so that a problem that relatively high current cannot be accurately measured by existing non-contact type current measuring devices due to the magnetic saturation phenomenon is solved. Meanwhile, the situation that equipment and personnel safety are influenced by strong shock generated by the effect of alternating magnetic field force due to the fact that the iron core with high magnetic permeability is magnetized into a magnet in the magnetic field when the existing non-contact type current measuring devices measure high current is avoided. Besides, the current measuring circuit disclosed by the application does not use the iron core material so that manufacturing cost can be reduced to some extent.
Description
Technical field
The application relates to current measurement techniques, more particularly, relates to a kind of current measurement circuit.
Background technology
The ultimate principle of non-contact electric current measurement device is to use current sensor to obtain induction current, and rear end sample circuit is extrapolated tested current value by measuring faradic intensity.Current sensor in existing non-contact electric current measurement device mainly contains iron core+hall element type and iron core+coil type, and its common feature is: all use iron core that the high-permeability material such as silicon steel or permalloy the makes flux circuit as tested current field.
For the iron core of definite shape, volume, its ability that converges magnetic field is limited, has a ultimate value by magnetic flux wherein, there will be magnetic saturation phenomenon; In the time that the magnetic field that tested electric current produces is less than this ultimate value, induced voltage and the tested electric current of current sensor output are linear; But the magnetic field intensity producing when tested electric current is greater than this ultimate value, iron core occurs after magnetic saturation phenomenon, magnetic field in iron core no longer changes with the variation of tested current field, cause the induced voltage of sensor output and the linear relationship of tested electric current to occur distortion, the induced voltage of current sensor output no longer reflects the size of actual tested electric current, and now non-contact electric current measurement device cannot Measurement accuracy electric current.
Summary of the invention
In view of this, the application provides a kind of current measurement circuit, to solve the problem that existing non-contact electric current measurement device cannot Measurement accuracy measuring during compared with large electric current because there being magnetic saturation phenomenon.
To achieve these goals, the existing scheme proposing is as follows:
A kind of current measurement circuit, comprising: current sensor;
Current sensor is provided with at least one coil;
Coil is the hollow tubular structure that wire turns to by certain orientation.
Preferably, also comprise non-magnetic supporter;
The setting of non-magnetic supporter is in coil and along coil axis direction.
Preferably, current sensor also comprises sampling resistor; Wherein:
One end ground connection of coil, the other end is as the output terminal of current sensor, and by sampling resistor ground connection.
Preferably, also comprise amplifying circuit, filtering circuit, rectification circuit and analog to digital conversion circuit; Wherein:
The output terminal of current sensor is connected with the input end of amplifying circuit;
The output terminal of amplifying circuit is connected with the input end of filtering circuit circuit;
The output terminal of filtering circuit is connected with the input end of rectification circuit;
The output terminal of rectification circuit is connected with the input end of analog to digital conversion circuit.
Preferably, amplifying circuit comprises the first operational amplifier, the first input resistance, adjustable resistance, the first output resistance, the first nonpolar electric capacity; Wherein:
One end of the first input resistance is as the input end of amplifying circuit, and the other end of the first input resistance is connected with the normal phase input end of the first operational amplifier, and the output terminal of the first operational amplifier is as the output terminal of amplifying circuit;
The normal phase input end of the first operational amplifier is by the first nonpolar capacity earth;
The inverting input of the first operational amplifier is connected by the first output resistance with output terminal, and by adjustable resistance ground connection.
Preferably, filtering circuit comprises the second operational amplifier, the second input resistance, the 3rd input resistance, the second output resistance, the 3rd output resistance, the second nonpolar electric capacity and the 3rd nonpolar electric capacity; Wherein:
One end of the second input resistance is as the input end of filtering circuit, and the other end is connected by the 3rd input resistance with the normal phase input end of the second operational amplifier, and is connected by the 3rd nonpolar electric capacity with the output terminal of the second operational amplifier;
The positive input of the second operational amplifier is by the second nonpolar capacity earth;
The inverting input of the second operational amplifier passes through the second output resistance ground connection, and is connected by the 3rd output resistance with the output terminal of the second operational amplifier;
The output terminal of the second operational amplifier is as the output terminal of filtering circuit.
Preferably, rectification circuit comprises the 3rd operational amplifier, the 4th output resistance, the 5th output resistance, the 6th output resistance, the 7th output resistance, the 8th output resistance, the 4th nonpolar electric capacity, the 5th nonpolar electric capacity, the first polar capacitor, the second polar capacitor, the 3rd polar capacitor, the first diode, the second diode, the 3rd diode; Wherein:
The normal phase input end of the 3rd operational amplifier is as the input end of rectification circuit;
The inverting input of the 3rd operational amplifier is connected by the 5th nonpolar electric capacity with output terminal;
The inverting input of the 3rd operational amplifier is connected with one end of the 4th output resistance with the negative pole of the first polar capacitor; The other end of the 4th output resistance is connected with one end of the 5th output resistance, is connected with the positive pole of the first diode, and by the 4th nonpolar capacity earth; The other end of the 5th output resistance is connected with the output terminal of the 3rd operational amplifier;
The first polar capacitor is anodal by the 8th output resistance ground connection;
The negative pole of the second polar capacitor is connected with the output terminal of the 3rd operational amplifier, and the positive pole of the second polar capacitor is connected with the positive pole of the 3rd diode, and is connected with the negative pole of the second diode;
One end of the 7th output resistance is connected with the negative pole of the 3rd diode, and the other end is connected with the negative pole of the first polar capacitor, and is connected with the positive pole of the second diode;
The 6th output resistance one end is connected with the negative pole of the 3rd diode, and the other end is connected with the positive pole of the 3rd polar capacitor, and as the output terminal of rectification circuit; The minus earth of the 3rd polar capacitor;
Preferably, rectification circuit comprises AD737 chip, quadripolarity electric capacity, the 5th polar capacitor and the 6th polar capacitor; Wherein:
The 1st pin of AD737 chip is connected to the positive pole of the 6th polar capacitor; The minus earth of the 6th polar capacitor;
The 2nd pin of AD737 chip is as the input end of real effective rectification circuit;
The 4th pin of AD737 chip is connected with the negative pole of quadripolarity electric capacity;
The 5th pin of AD737 chip is connected with the positive pole of quadripolarity electric capacity;
The 6th pin of AD737 chip is as the output terminal of rectification circuit, and is connected with the negative pole of the 5th polar capacitor; The plus earth of the 5th polar capacitor;
The 8th pin ground connection of AD737 chip;
Can find out from above-mentioned technical scheme, in the coil of the current sensor setting of the current measurement circuit in the application, there is no core material, therefore there will not be magnetic saturation phenomenon, the induced voltage of current sensor output is linear with tested electric current all the time, the problem that the existing non-contact electric current measurement device of avoiding knowing clearly cannot Measurement accuracy in the time of the larger electric current of measurement because there is magnetic saturation phenomenon.
In addition, in existing non-contact electric current measurement device in the time carrying out large electric current (being greater than 1000 peace AC value), the iron core of high magnetic permeability is easy to be geomagnetic into a magnet in magnetic field, under the magnetic field force effect of alternation, can produce strong vibrations, tested electric current is larger, shakes byer force, can cause very large impact to equipment and personnel's safety, and the current measurement circuit providing in the application is not because use core material, so can avoid this problem.Meanwhile, because do not use core material in the application, also can reduce to a certain extent manufacturing cost.
Brief description of the drawings
In order to be illustrated more clearly in the embodiment of the present application or technical scheme of the prior art, to the accompanying drawing of required use in embodiment or description of the Prior Art be briefly described below, apparently, accompanying drawing in the following describes is only some embodiment of the application, for those of ordinary skill in the art, do not paying under the prerequisite of creative work, can also obtain according to these accompanying drawings other accompanying drawing.
The block diagram of a kind of current measurement circuit that Fig. 1 provides for the embodiment of the present application;
The circuit diagram of a kind of current sensor that Fig. 2 provides for the embodiment of the present application;
The circuit diagram of a kind of amplifying circuit that Fig. 3 provides for the embodiment of the present application;
The circuit diagram of a kind of filtering circuit that Fig. 4 provides for the embodiment of the present application;
The circuit diagram of a kind of rectification circuit that Fig. 5 provides for the embodiment of the present application;
The circuit diagram of the another kind of rectification circuit that Fig. 6 provides for the embodiment of the present application;
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present application, the technical scheme in the embodiment of the present application is clearly and completely described, obviously, described embodiment is only some embodiments of the present application, instead of whole embodiment.Based on the embodiment in the application, those of ordinary skill in the art are not making the every other embodiment obtaining under creative work prerequisite, all belong to the scope of the application's protection.
The block diagram of a kind of current measurement circuit that Fig. 1 provides for the embodiment of the present application
Metering circuit as shown in Figure 1 comprises: current sensor 101, amplifying circuit 102, filtering circuit 103, rectification circuit 104 and analog to digital conversion circuit 105; Wherein the output terminal of current sensor 101 is connected with the input end of amplifying circuit 102, the output terminal of amplifying circuit 102 is connected with the input end of filtering circuit 103 circuit, the output terminal of filtering circuit 103 is connected with the input end of rectification circuit 104, and the output terminal of rectification circuit 104 is connected with the input end of analog to digital conversion circuit 105;
The AC signal that current sensor 101 produces is amplified, is converted to direct current signal through rectification circuit 104 after the filtering of filtering circuit 103 through amplifying circuit 102, convert digital signal to through analog to digital conversion circuit 105 again, digital signal can be input to MCU, MCU obtains the effective value of tested electric current and carries out corresponding error correction in predefined ratio, finally by display unit, measured value is shown, complete the whole flow process of measurement.
The effect of current sensor 101 is the magnetic field for responding to tested wire, produces induced voltage; The circuit diagram of a kind of current sensor that Fig. 2 provides for the embodiment of the present application.
Current sensor as shown in Figure 2 comprises: coil L, sampling resistor r1.One end ground connection of its coil L, the other end is as the output terminal V1out of current sensor 101, and by sampling resistor r1 ground connection.
When current sensor work, coil L surrounds tested wire 200, make the magnetic field of tested wire through coil L, coil L produces induction current, induction current flow through that sampling resistor r1 produces induced voltage and by output terminal V1out by the induced voltage signal output producing, so that back-end circuit is further processed this voltage signal.
Coil is the hollow tubular structure being formed by wire coiling; Sometimes for easy to make or make the structure of coil more firm, non-magnetic supporter can be set, so-called non-magnetic supporter, be make with non-magnetic material for described coil being played to the bar-shaped or tubular articles of bracing reinforcement effect.Because the magnetic permeability of air and non-magnet material is substantially equal, so the function of coil is not affected substantially after supporter is set, supporter can select the flexible material such as plastics or rubber to make, when making, by certain orientation, wire is wrapped on supporter, supporter two ends can respectively arrange a larger thrust, to prevent that wire from coming off from supporter two ends.Using flexible material is by the embowment easily of straight shape coil, u shape or the notched circle made as the benefit of supporter, to meet the current measuring device of different profiles, as movable pincerlike current measuring device or u shape bayonet socket current measuring device.In the time using in movable current measuring device, need to a coil be respectively set in binding clip moved end and the binding clip fixed end of the movable binding clip of device, at this moment need two identical coiling direction coils to join end to end and connect, be specially, two identical coils of coiling direction are all placed perpendicular to desktop, be positioned at one end, top and can be seen as stem, the other end is afterbody, when wiring, the stem of one of them coil is as an output terminal of coil groups, afterbody is connected with the stem of another coil, the afterbody of another coil is as another output terminal of coil groups, the induced voltage that such two coils produce is superimposed, can improve the effect of output.The diameter of wire and the number of turn of coil need to be according to used environmental selections.
Owing to not having iron core to converge tested wire magnetic field around in coil, its magnetic field of responding to is only a part for tested wire magnetic fields, therefore the voltage signal that adopts this coil to produce as the current sensor of inductive means is generally the ac small signal of millivolt level, process and sampling for the ease of the signal of rear end, need amplify to the signal of its generation the circuit diagram of a kind of amplifying circuit that Fig. 3 provides for the embodiment of the present application.
Amplifying circuit comprises as shown in Figure 3: the first operational amplifier u1, the first nonpolar electric capacity c1, the first input resistance r2, the first output resistance r3 and adjustable resistance r4; One end of the first input resistance r2 is as the input end V2in of amplifying circuit, and the other end is connected with the normal phase input end of the first operational amplifier u1; The output terminal of the first operational amplifier u1 is connected by the first output resistance r3 with output terminal, and as the output terminal V2out of amplifying circuit; The normal phase input end of the first operational amplifier u1 is by the first nonpolar electric capacity c1 ground connection; The reverse input end of the first operational amplifier u1 is by adjustable resistance r4 ground connection; Adjustable resistance r4 can be used for the gain of amplifying circuit to regulate;
Amplifying circuit amplifies the ac small signal of current sensor output, and can regulate enlargement factor by adjustable resistance r4, and to meet, back-end circuit is processed and the demand of sampling.
Coil is an inductance in essence, in the time of the constant and frequency change of the effective value of tested electric current, its voltage signal inducing also can change, frequency is higher, induced voltage is larger, the inconsistent problem of the actual current value recording will cause like this measuring the identical and signal that frequency is different of effective value essence time.Because the frequency of general power frequency component concentrates on 50-60Hz, therefore in order to solve the identical and actual different problem of numerical value that records of tested electric current essence, to meet the accuracy of measured value within the scope of general power frequency, need to carry out filtering processing to the ac voltage signal after amplifying, the circuit diagram of a kind of filtering circuit that Fig. 4 provides for the embodiment of the present application.
Filtering circuit as shown in Figure 4 comprises: the second operational amplifier u2, the second input resistance r5, the 3rd input resistance r6, the second output resistance r7, the 3rd output resistance r8, the second nonpolar electric capacity c2 and the 3rd nonpolar electric capacity c3.
Wherein one end of the second input resistance r5 is as the input end V3in of filtering circuit, the other end is connected with the normal phase input end of the second operational amplifier u2 by the 3rd input resistance r6, and is connected with the output terminal of the second operational amplifier u2 by the 3rd nonpolar electric capacity c3; The positive input of the second operational amplifier u2 is by the second nonpolar electric capacity c2 ground connection; The inverting input of the second operational amplifier u2 is connected with the output terminal of the second operational amplifier u2 by the 3rd output resistance r8, and by the second output resistance r7 ground connection; The output terminal of the second operational amplifier u2 is as the output terminal V3out of filtering circuit.
The second operational amplifier u2, the first input resistance r5, the second input resistance r6, the second nonpolar electric capacity c2 and the 3rd nonpolar electric capacity c3 form second order active low-pass filter circuit, in the situation that tested current value is actual consistent, while making 60Hz frequency, the decay measured value that gets off can be with 50Hz frequency time of measured value bigger than normal is consistent.Signal has decay in various degree after low-pass filtering, can be by regulating the ratio of the second output resistance r7 and the 3rd output resistance r8 to realize the gain of signal after low-pass filtering, the part of decay before offsetting.
Voltage signal after the regulation of electrical circuit or an AC signal after filtering, in order to make sampling below simpler, need to use rectification circuit that AC signal is converted to DC voltage, according to the different demands of product, can lower mean value rectification circuit or the real effective rectification circuit of alternative costs.The circuit diagram of a kind of rectification circuit that Fig. 5 provides for the embodiment of the present application, sort circuit is lower-cost mean value rectification circuit;
Rectification circuit as shown in Figure 5 comprises: the 3rd operational amplifier u3, the 4th output resistance r9, the 5th output resistance r10, the 6th output resistance r11, the 7th output resistance r12, the 8th output resistance r13, the 4th nonpolar electric capacity c4, the 5th nonpolar electric capacity c5, the first polar capacitor c6, the second polar capacitor c7, the 3rd polar capacitor c8, the first diode d1, the second diode d2, the 3rd diode d3;
Wherein the normal phase input end of the 3rd operational amplifier u3 is as the input end V4in of rectification circuit; The inverting input of the 3rd operational amplifier u3 is connected by the 4th nonpolar electric capacity c4 with output terminal; The inverting input of the 3rd operational amplifier u3 is connected with one end of the 4th output resistance r9 with the negative pole of the first polar capacitor c6; The other end of the 4th output resistance r9 is connected with the positive pole of the first diode d1 with one end of the 5th output resistance r10, and by the 4th nonpolar electric capacity c4 ground connection, the other end of the 5th output resistance r10 is connected with the output terminal of the 3rd operational amplifier u3; The positive pole of the first polar capacitor c6 is by the 8th output resistance r13 ground connection; The negative pole of the second polar capacitor c7 is connected with the output terminal of the 3rd operational amplifier u3, and positive pole is connected with the negative pole of the second diode d2 with the positive pole of the 3rd diode d3; One end of the 7th output resistance r112 is connected with the negative pole of the 3rd diode d3, and the other end is connected with the negative pole of the first polar capacitor c6, the positive pole of the second diode d2; The 6th output resistance r11 one end is connected with the negative pole of the 3rd diode d3, and the other end is connected with the positive pole of the 3rd polar capacitor c8; The minus earth of the 3rd polar capacitor c8; The positive pole of the 3rd polar capacitor c8 is made the output terminal V4out of rectification circuit.
The another kind of rectification circuit that Fig. 6 provides for the embodiment of the present application, this is a kind of real effective rectification circuit, cost is relatively high;
Rectification circuit as shown in Figure 6 comprises: AD737 chip, quadripolarity electric capacity c9, the 5th polar capacitor c10 and the 6th polar capacitor c11;
Wherein, the 1st pin of AD737 chip is connected with the positive pole of the 6th polar capacitor c11; The minus earth of the 6th polar capacitor c11; The 2nd pin of AD737 chip is as the input end V4in of rectification circuit; The 4th pin of AD737 chip is connected with the negative pole of quadripolarity electric capacity c9; The 5th pin of AD737 chip is connected with the positive pole of quadripolarity electric capacity c9; The 6th pin of AD737 chip is as the output terminal of rectification circuit, and is connected with the negative pole of the 5th polar capacitor c10; The plus earth of the 5th polar capacitor c10; The 8th pin ground connection of AD737 chip.
The technical scheme providing from above embodiment can be found out, in the coil that the current sensor of the current measurement circuit in the application adopts, there is no core material, therefore there will not be magnetic saturation phenomenon, the induced voltage of current sensor output is linear with tested electric current all the time, has solved the problem that existing non-contact electric current measurement device cannot Measurement accuracy in the time of the larger electric current of measurement because there is magnetic saturation phenomenon.
In addition, in existing non-contact electric current measurement device in the time carrying out large electric current (being greater than 1000 peace AC value), the iron core of high magnetic permeability is easy to be geomagnetic into a magnet in magnetic field, under the magnetic field force effect of alternation, can produce strong vibrations, tested electric current is larger, shakes byer force, can cause very large impact to equipment and personnel's safety, and the current measurement circuit providing in the application is not because use core material road, so can avoid this problem.Meanwhile, because do not use core material in the application, also can reduce to a certain extent manufacturing cost.
All or part of of above circuit can be applied in current measuring instrument instruments and meters or main equipment, and the electric current recording by above circuit can directly show by pointer or display, for electricity operator, circuit be monitored; Or be applied in main equipment, according to the measured protection of current value completing circuit or other operations.
Finally, also it should be noted that, in this article, relational terms such as the first and second grades is only used for an entity or operation to separate with another entity or operational zone, and not necessarily requires or imply and between these entities or operation, have the relation of any this reality or sequentially.And, term " comprises ", " comprising " or its any other variant are intended to contain comprising of nonexcludability, thereby the process, method, article or the equipment that make to comprise a series of key elements not only comprise those key elements, but also comprise other key elements of clearly not listing, or be also included as the intrinsic key element of this process, method, article or equipment.The in the situation that of more restrictions not, the key element being limited by statement " comprising ... ", and be not precluded within process, method, article or the equipment that comprises described key element and also have other identical element.
In this instructions, each embodiment adopts the mode of going forward one by one to describe, and what each embodiment stressed is and the difference of other embodiment, between each embodiment identical similar part mutually referring to.
To the above-mentioned explanation of the disclosed embodiments, make professional and technical personnel in the field can realize or use the application.To be apparent for those skilled in the art to the multiple amendment of these embodiment, General Principle as defined herein can, in the case of not departing from the application's spirit or scope, realize in other embodiments.Therefore, the application will can not be restricted to these embodiment shown in this article, but will meet the widest scope consistent with principle disclosed herein and features of novelty.
Claims (8)
1. a current measurement circuit, is characterized in that: comprise current sensor;
Described current sensor is provided with at least one coil;
Described coil is the hollow tubular structure that wire turns to by certain orientation.
2. current measurement circuit as claimed in claim 1, is characterized in that: also comprise non-magnetic supporter;
Described non-magnetic supporter is arranged in described coil and along described coil axis direction.
3. metering circuit as claimed in claim 1 or 2, is characterized in that: described current sensor also comprises sampling resistor; Wherein:
One end ground connection of described coil, the other end is as the output terminal of described current sensor, and by described sampling resistor ground connection.
4. current measurement circuit as claimed in claim 3, is characterized in that: also comprise amplifying circuit, filtering circuit, rectification circuit and analog to digital conversion circuit; Wherein:
The output terminal of described current sensor is connected with the input end of described amplifying circuit;
The output terminal of described amplifying circuit is connected with the input end of described filtering circuit circuit;
The output terminal of described filtering circuit is connected with the input end of described rectification circuit;
The output terminal of described rectification circuit is connected with the input end of analog-digital conversion circuit as described.
5. current measurement circuit as claimed in claim 4, is characterized in that: described amplifying circuit comprises the first operational amplifier, the first input resistance, adjustable resistance, the first output resistance, the first nonpolar electric capacity; Wherein:
One end of described the first input resistance is as the input end of described amplifying circuit, and the other end of described the first input resistance is connected with the normal phase input end of described the first operational amplifier, and the output terminal of described the first operational amplifier is as the output terminal of amplifying circuit;
The normal phase input end of described the first operational amplifier is by the first nonpolar capacity earth;
The inverting input of described the first operational amplifier is connected by the first output resistance with output terminal, and by described adjustable resistance ground connection.
6. current measurement circuit as claimed in claim 4, is characterized in that: described filtering circuit comprises the second operational amplifier, the second input resistance, the 3rd input resistance, the second output resistance, the 3rd output resistance, the second nonpolar electric capacity and the 3rd nonpolar electric capacity; Wherein:
One end of described the second input resistance is as the input end of described filtering circuit, the other end is connected by described the 3rd input resistance with the normal phase input end of described the second operational amplifier, and is connected by described the 3rd nonpolar electric capacity with the output terminal of described the second operational amplifier;
The positive input of described the second operational amplifier is by described the second nonpolar capacity earth;
The inverting input of described the second operational amplifier passes through described the second output resistance ground connection, and is connected by the 3rd output resistance with the output terminal of described the second operational amplifier;
The output terminal of described the second operational amplifier is as the output terminal of described filtering circuit.
7. current measurement circuit as claimed in claim 4, is characterized in that: described rectification circuit comprises the 3rd operational amplifier, the 4th output resistance, the 5th output resistance, the 6th output resistance, the 7th output resistance, the 8th output resistance, the 4th nonpolar electric capacity, the 5th nonpolar electric capacity, the first polar capacitor, the second polar capacitor, the 3rd polar capacitor, the first diode, the second diode, the 3rd diode; Wherein:
The normal phase input end of described the 3rd operational amplifier is as the input end of described rectification circuit;
The inverting input of described the 3rd operational amplifier is connected by described the 5th nonpolar electric capacity with output terminal;
The inverting input of described the 3rd operational amplifier is connected with one end of described the 4th output resistance with the negative pole of described the first polar capacitor; The other end of described the 4th output resistance is connected with one end of described the 5th output resistance, is connected with the positive pole of described the first diode, and by described the 4th nonpolar capacity earth; The other end of described the 5th output resistance is connected with the output terminal of described the 3rd operational amplifier;
Described the first polar capacitor is anodal by described the 8th output resistance ground connection;
The negative pole of described the second polar capacitor is connected with the output terminal of described the 3rd operational amplifier, and the positive pole of described the second polar capacitor is connected with the positive pole of described the 3rd diode, and is connected with the negative pole of described the second diode;
One end of described the 7th output resistance is connected with the negative pole of described the 3rd diode, and the other end is connected with the negative pole of described the first polar capacitor, and is connected with the positive pole of described the second diode;
Described the 6th output resistance one end is connected with the negative pole of described the 3rd diode, and the other end is connected with the positive pole of described the 3rd polar capacitor, and as the output terminal of described rectification circuit; The minus earth of described the 3rd polar capacitor.
8. current measurement circuit as claimed in claim 4, is characterized in that: described rectification circuit comprises AD737 chip, quadripolarity electric capacity, the 5th polar capacitor and the 6th polar capacitor; Wherein:
The 1st pin of described AD737 chip is connected to the positive pole of described the 6th polar capacitor; The minus earth of described the 6th polar capacitor;
The 2nd pin of described AD737 chip is as the input end of described real effective rectification circuit;
The 4th pin of described AD737 chip is connected with the negative pole of described quadripolarity electric capacity;
The 5th pin of described AD737 chip is connected with the positive pole of described quadripolarity electric capacity;
The 6th pin of described AD737 chip is as the output terminal of described rectification circuit, and is connected with the negative pole of described the 5th polar capacitor; The plus earth of described the 5th polar capacitor;
The 8th pin ground connection of described AD737 chip.
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| CN201310113598.0A CN104101775A (en) | 2013-04-02 | 2013-04-02 | Current measuring circuit |
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| CN201310113598.0A CN104101775A (en) | 2013-04-02 | 2013-04-02 | Current measuring circuit |
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| CN107167647A (en) * | 2017-05-31 | 2017-09-15 | 王怀德 | Non-contact current sensor |
| CN107462758A (en) * | 2017-08-31 | 2017-12-12 | 无锡乐尔科技有限公司 | A kind of closed-loop current sensors |
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| CN2779411Y (en) * | 2005-04-22 | 2006-05-10 | 张贵新 | An air-core coil current sensor for measuring power frequency heavy current |
| US20070257663A1 (en) * | 2006-05-08 | 2007-11-08 | Mende Michael J | Current sensing circuit for use in a current measurement probe |
| CN101477145A (en) * | 2009-02-13 | 2009-07-08 | 华中科技大学 | AC great current sensor |
| CN102103156A (en) * | 2009-12-22 | 2011-06-22 | 江苏省电力公司宝应县供电公司 | Digital current transformer and method for measuring current of AC (Alternating Current) transmission conductor |
| CN202305637U (en) * | 2011-10-18 | 2012-07-04 | 刘庆庆 | Alternating current sensor |
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| CN107167647A (en) * | 2017-05-31 | 2017-09-15 | 王怀德 | Non-contact current sensor |
| CN107462758A (en) * | 2017-08-31 | 2017-12-12 | 无锡乐尔科技有限公司 | A kind of closed-loop current sensors |
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Application publication date: 20141015 |