CN108519508B - Comparator for measuring alternating current and direct current - Google Patents
Comparator for measuring alternating current and direct current Download PDFInfo
- Publication number
- CN108519508B CN108519508B CN201810217665.6A CN201810217665A CN108519508B CN 108519508 B CN108519508 B CN 108519508B CN 201810217665 A CN201810217665 A CN 201810217665A CN 108519508 B CN108519508 B CN 108519508B
- Authority
- CN
- China
- Prior art keywords
- winding
- alternating current
- detection
- direct current
- secondary winding
- 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.)
- Active
Links
- 238000004804 winding Methods 0.000 claims abstract description 138
- 238000001514 detection method Methods 0.000 claims abstract description 74
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 49
- 230000001360 synchronised effect Effects 0.000 claims abstract description 14
- 229910000976 Electrical steel Inorganic materials 0.000 claims description 4
- 238000000137 annealing Methods 0.000 claims description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 2
- 239000011889 copper foil Substances 0.000 claims description 2
- 239000000463 material Substances 0.000 claims 1
- 230000003321 amplification Effects 0.000 abstract 1
- 238000003199 nucleic acid amplification method Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000003990 capacitor Substances 0.000 description 3
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
Classifications
-
- 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
- G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
Abstract
The invention discloses a comparator for measuring alternating current and direct current. The comparator comprises a sensing head, a modulating transformer, a direct current side standard resistor, an alternating current side standard resistor, a band-pass filter, a synchronous demodulator, a direct current power amplifier, an alternating current voltage amplifier and an alternating current power amplifier, wherein the measuring head comprises three units with the same structure, and each unit comprises an annular detection iron core, a detection winding, an electrostatic shielding layer, a magnetic shielding iron core and a secondary winding; the first unit, the second unit, the modulating transformer, the band-pass filter, the synchronous demodulator, the direct current power amplification and the direct current side standard resistor form a direct current detection system based on the principle of a double-iron-core magnetic modulator; the third unit, the standard resistor at the alternating current side, the alternating voltage amplifier and the alternating power amplifier form an alternating current detection system based on a single iron core.
Description
Technical Field
The invention belongs to current measuring equipment in the electrotechnical field, and particularly relates to a comparator for measuring alternating current and direct current.
Background
Patent No. ZL92103969.7 entitled "a.c. and d.c. current comparator", which is a.c. main iron core T in the measuring head 2 Outside is wound with an alternating current detection winding W D And then winding the monitoring winding W around the outside of the winding K At W K External winding AC zero-setting winding W a The method comprises the steps of carrying out a first treatment on the surface of the In two DC main cores T 3 Outside is respectively wound with exciting windings W e The method comprises the steps of carrying out a first treatment on the surface of the Then assembling the above-mentioned AC and DC winding iron cores, winding electrostatic shielding E on their outer surfaces, placing it in magnetic shielding iron core T 1 In T 1 Outside winding up AC/DC secondary winding W S The method comprises the steps of carrying out a first treatment on the surface of the The device can measure direct current, alternating current and alternating current simultaneously. But has the following drawbacks: in an alternating current main iron core T 2 On which is arranged an alternating current zero-setting winding W a The winding is connected in series with the parallel branch of the potential source e and the resistor rc in order to suppress the influence of the ripple of the dc system on the zero point of the ac system. This effect occurs because the ac system and the dc system share a set of ac/dc secondary windings W S And a coupling iron core T 1 Its influence is unavoidable; in addition, direct current systemThe ripple is related to the measured object, environment and the like, the constant state cannot be realized, the potential source e, the resistor R and the capacitor C connected with the zeroing winding cannot track the ripple change of the direct current system, and the industrial application is limited, so that the problem is solved by the invention.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a comparator for measuring alternating current and direct current, which solves the technical problem that the existing comparator device has interference between a direct current system and an alternating current system.
In order to achieve the above object, the present invention provides a comparator for measuring ac and dc currents, comprising:
the device comprises a sensing head, a modulating transformer, a direct current side standard resistor, an alternating current side standard resistor, a band-pass filter, a synchronous demodulator, a direct current power amplifier, an alternating current voltage amplifier and an alternating current power amplifier;
the sensing head comprises a first annular detection iron core, a first detection winding wound on the first annular detection iron core, a first electrostatic shielding layer surrounding the first detection winding, a first magnetic shielding iron core arranged outside the first electrostatic shielding layer and a first secondary winding wound on the first magnetic shielding iron core;
the sensing head further comprises a second annular detection iron core, a second detection winding wound on the second annular detection iron core, a second electrostatic shielding layer surrounding the second detection winding, a second magnetic shielding iron core arranged outside the second electrostatic shielding layer and a second secondary winding wound on the second magnetic shielding iron core;
the sensing head further comprises a third annular detection iron core, a third detection winding wound on the third annular detection iron core, a third electrostatic shielding layer surrounding the third detection winding, a third magnetic shielding iron core arranged outside the third electrostatic shielding layer and a third secondary winding wound on the third magnetic shielding iron core;
the homonymous end of the first secondary winding is connected with the direct current side standard resistor and then grounded, and the heteronymous end of the first secondary winding is connected with the homonymous end of the second secondary winding; the same-name end of the first detection winding is connected with the same-name end of the secondary winding of the modulation transformer, the different-name end of the first detection winding is connected with the different-name end of the second detection winding and is grounded, the same-name end of the second detection winding is connected with the different-name end of the secondary winding of the modulation transformer, a center tap of the secondary winding of the modulation transformer is connected with the input end of the band-pass filter, the output end of the band-pass filter is connected with the input end of the synchronous demodulator, the output end of the synchronous demodulator is connected with the input end of the direct current power amplifier, and the output end of the direct current power amplifier is connected with the different-name end of the second secondary winding; the synonym end of the third detection winding is connected with the ground, the homonym end of the third detection winding is connected with the input end of the alternating current voltage amplifier, the output end of the alternating current voltage amplifier is connected with the input end of the alternating current power amplifier, the output end of the alternating current power amplifier is connected with the synonym end of the third secondary winding and is grounded, and the homonym end of the third secondary winding is connected with the standard resistor of the alternating current side and then is grounded.
Preferably, all of the electrostatic shielding layers are made of copper foil.
Preferably, all the magnetic shielding iron cores have the same shape, are formed by winding cold-rolled silicon steel strips into a ring shape and assembling after annealing treatment.
Preferably, all annular detection iron cores have the same shape, and are obtained by winding cold-rolled silicon steel strips into a ring shape and annealing.
Preferably, the number of turns of the first detection winding, the number of turns of the second detection winding, and the number of turns of the third detection winding are the same.
Preferably, the number of turns of the first secondary winding, the number of turns of the second secondary winding, and the number of turns of the third secondary winding are the same.
In general, the above technical solutions conceived by the present invention, compared with the prior art, enable the following beneficial effects to be obtained:
(1) The invention reasonably sets the sensing head as three same independent units, and each unit consists of an annular detection iron core, a detection winding, an electrostatic shielding layer, an annular magnetic shielding iron core and a secondary winding; the first unit and the second unit form a direct current detection system based on the principle of a double-iron-core magnetic modulator, the system takes a magnetic modulation detection signal out of a center tap of a secondary winding of a modulation transformer, outputs direct current to a first secondary winding and a second secondary winding which are connected in series in the first unit and the second unit through a band-pass filter, a synchronous demodulator and a direct current power amplifier, and the direct current flows through a direct current side standard resistor to obtain a direct current measured voltage signal; the third unit forms an alternating current detection system based on a single iron core, the system takes an alternating current detection signal out of the same-name end of the third detection winding, outputs alternating current to a third secondary winding in the third unit through an alternating current voltage amplifier and an alternating current power amplifier, and the alternating current flows through an alternating current side standard resistor to obtain an alternating current detected voltage signal; therefore, the prior art that an alternating current system and a direct current system share a set of alternating current-direct current secondary winding and a coupling iron core is completely broken through, the problem that the ripple wave of the direct current system affects the zero point of the alternating current system is solved from the source, the arrangement of an alternating current zero-setting winding, a potential source, a resistor and a capacitor parallel branch is eliminated, and the device is more convenient and reliable to debug and operate.
(2) The invention can measure not only direct current but also alternating current, and can also measure direct current component and alternating current component of mixed current of direct current and alternating current.
(3) The invention sets the sensing head as three schemes of the same independent units, has excellent structure and performance and higher cost performance of the whole machine.
Drawings
FIG. 1 is a diagram showing the appearance of a sensor head in a comparator for measuring AC and DC current according to the present invention;
FIG. 2 is a cross-sectional view of a sensor head in a comparator for measuring AC and DC current provided by the invention;
fig. 3 is a circuit diagram of a comparator for measuring ac and dc current according to the present invention.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.
Fig. 1 is a diagram showing the appearance of a sensing head of a comparator for measuring alternating current and direct current, and the section of the sensing head is shown in fig. 2. The whole measuring head is annular, and the measuring head T comprises a first annular detection iron core C 12 Second annular detecting iron core C 22 Third annular detecting iron core C 32 First detection winding W 11 Second detection winding W 21 Third detection winding W 31 A first electrostatic shielding layer E 1 A second electrostatic shielding layer E 2 A third electrostatic shielding layer E 3 First annular magnetic shielding iron core C 11 Second annular magnetic shielding iron core C 21 Third annular magnetic shielding iron core C 31 First secondary winding W 12 Second secondary winding W 22 And a third secondary winding W 32 The method comprises the steps of carrying out a first treatment on the surface of the The first shape detecting iron core C 12 Second-shape detecting iron core C 22 And a third annular detecting core C 32 The shape is the same, the first annular detecting iron core C 12 Second annular detecting iron core C 22 And a third annular detecting core C 32 The first detection windings W with the same number of turns are respectively wound on 11 Second detection winding W 21 And a third detection winding W 31 First detection winding W 11 Second detection winding W 21 And a third detection winding W 31 Outside is respectively covered with a first electrostatic shielding layer E 1 A second electrostatic shielding layer E 2 And a second electrostatic shielding layer E 3 Then, the first magnetic shielding iron cores C with the same shape are respectively arranged in the cavity structures formed by the outer ring and the inner ring 11 Second magnetic shielding iron core C 21 And a third magnetic shielding iron core C 31 In the cavity of the first magnetic shielding core C 11 Second magnetic shielding iron core C 21 And a third magnetic shielding iron core C 31 The first secondary windings W with the same number of turns are respectively wound outside 12 Second secondary winding W 22 And a third secondary winding W 32 。
Fig. 3 shows a circuit diagram of a comparator for measuring alternating and direct currents. The primary winding W shown in FIG. 3 1 I.e. transmitting the AC and DC current I to be measured 1 From the center circle of the sensor head as shown in FIG. 1The hole passes through. The comparator comprises a sensing head T and a modulating transformer T 1 Standard resistor R on DC side SD Standard resistor R on AC side SA A band-pass filter 1, a synchronous demodulator 2, a DC power amplifier 3, an AC voltage amplifier 4 and an AC power amplifier 5.
First secondary winding W in sensor head T 12 Is connected with a direct current side standard resistor R at the same name end SD Rear ground, first secondary winding W 12 Is connected with a second secondary winding W 22 Is the same as the same name end of the first part; first detection winding W 11 Is connected with modulation transformer T 1 The same name end of the secondary winding, the first detection winding W 11 Is connected with a second detection winding W 21 Is grounded, a second detection winding W 21 Is connected with modulation transformer T 1 Different name end of secondary winding, modulating transformer T 1 The center tap of the secondary winding is connected with the input end of the band-pass filter 1, the output end of the band-pass filter 1 is connected with the input end of the synchronous demodulator 2, the output end of the synchronous demodulator 2 is connected with the input end of the DC power amplifier 3, and the output end of the DC power amplifier 3 is connected with the second secondary winding W 22 Is a heterogeneous end of (a).
Third detection winding W 31 Is connected with the ground, and a third detection winding W 31 The homonymous terminal of the AC voltage amplifier 4 is connected with the input terminal of the AC voltage amplifier 4, the output terminal of the AC voltage amplifier 4 is connected with the input terminal of the AC power amplifier 5, and the output terminal of the AC power amplifier 5 is connected with the third secondary winding W 32 Is the synonym end of the third secondary winding W 32 Is connected with an alternating current side standard resistor R at the same name end SA And the rear is grounded.
After the device is put into operation, the modulation transformer T 1 First detection winding W 11 Second detection winding W 21 First annular detecting iron core C 12 Second annular detecting iron core C 22 The DC detection system based on the principle of double-core magnetic modulator is composed to modulate DC signal from modulation transformer T 1 The center tap of the secondary winding is taken out and passes through a band-pass filter 1, a synchronous demodulator 2 and direct current powerAn amplifier 3 for outputting a secondary DC current I 2D For the first secondary windings W connected in series with each other 12 Second secondary winding W 22 Realizing primary direct current I 1D Balanced with the magnetic potential of the secondary DC ampere-turns, i.e. I 1D W 1 ＝I 2D (W 12 +W 22 ) Secondary direct current I 2D Flow through DC standard resistor R SD Obtaining a measured voltage signal I of direct current 2D R SD ；
From a third sense winding W 31 Third annular detecting iron core C 32 An alternating current detection system comprising a third detection winding W for detecting an alternating current signal 31 Is taken out from the same-name end of the transformer and outputs secondary alternating current I through an alternating voltage amplifier 4 and an alternating power amplifier 5 2A For the third secondary winding W 32 Realizing primary alternating current I 1A Balanced with the magnetic potential of the secondary ac ampere-turns, i.e. I 1A W 1 ＝I 2A W 32 Secondary ac current I 2A Through the standard resistor R at the AC side SA Obtaining a measured voltage signal I of alternating current 2A R SA 。
The invention breaks through the prior art that the alternating current system and the direct current system share a set of alternating current-direct current secondary winding and a coupling iron core, solves the problem of influence of the ripple wave of the direct current system on the zero point of the alternating current system from the source, eliminates the arrangement of the alternating current zero-setting winding, the potential source, the resistor and the capacitor parallel branch, and ensures that the device is more convenient and reliable to debug and operate. The invention can measure not only direct current but also alternating current, and can measure direct current component and alternating current component of mixed current of direct current and alternating current.
It will be readily understood by those skilled in the art that the foregoing description is merely a preferred embodiment of the invention and is not intended to limit the invention, but any modifications, equivalents, improvements or the like falling within the spirit and principles of the invention are intended to be included within the scope of the invention.
Claims (6)
1. Measuring deviceA comparator for measuring alternating and direct currents, comprising: sensor head (T), modulation transformer (T) 1 ) Standard resistor on DC side (R) SD ) Standard resistor on AC side (R) SA ) The device comprises a band-pass filter (1), a synchronous demodulator (2), a direct current power amplifier (3), an alternating current voltage amplifier (4) and an alternating current power amplifier (5);
the sensor head comprises a first annular detecting core (C 12 ) Around the first annular detecting core (C) 12 ) An outer first detection winding (W 11 ) Surrounds the first detection winding (W 11 ) Is a first electrostatic shielding layer (E) 1 ) Is disposed on the first electrostatic shielding layer (E 1 ) Outer first magnetic shield core (C) 11 ) Around the first magnetic shielding core (C) 11 ) An outer first secondary winding (W 12 )；
The sensor head further comprises a second annular detecting core (C 22 ) Around the second annular detecting core (C) 22 ) An outer second detection winding (W 21 ) Surrounds the second detection winding (W 21 ) Is a second electrostatic shielding layer (E) 2 ) Is disposed on the second electrostatic shielding layer (E 2 ) Outer second magnetic shielding core (C) 21 ) Around a second magnetic shielding core (C) 21 ) An outer secondary winding (W 22 )；
The sensor head further comprises a third annular detecting core (C 32 ) Around the third annular detecting core (C) 32 ) An outer third detection winding (W 31 ) Surrounding the third detection winding (W 31 ) Is a third electrostatic shielding layer (E) 3 ) Is disposed on the third electrostatic shielding layer (E 3 ) Outer third magnetic shield core (C) 31 ) Around a third magnetic shielding core (C) 31 ) An outer third secondary winding (W 32 )；
The first secondary winding (W 12 ) Is connected with a direct current side standard resistor (R SD ) And is grounded at the rear, the first secondary winding (W 12 ) Is connected to the second secondary winding (W 22 ) Is the same as the same name end of the first part; first detection winding (W) 11 ) Is connected with a modulation transformer (T) 1 ) Secondary winding identityName end, first detection winding (W 11 ) Is connected to the second detection winding (W 21 ) Is grounded, and a second detection winding (W 21 ) Is connected with a modulation transformer (T) 1 ) The opposite end of the secondary winding, modulating transformer (T) 1 ) The center tap of the secondary winding is connected with the input end of a band-pass filter (1), the output end of the band-pass filter (1) is connected with the input end of a synchronous demodulator (2), the output end of the synchronous demodulator (2) is connected with the input end of a direct current power amplifier (3), and the output end of the direct current power amplifier (3) is connected with a second secondary winding (W) 22 ) Is a heteronym terminal of (a); third detection winding (W) 31 ) Is connected to ground, and a third detection winding (W 31 ) The same name end of the alternating current power amplifier (5) is connected with the input end of the alternating current voltage amplifier (4), the output end of the alternating current voltage amplifier (4) is connected with the input end of the alternating current power amplifier (5), and the output end of the alternating current power amplifier (5) is connected with the third secondary winding (W) 32 ) Is the opposite end of the third secondary winding (W 32 ) Is connected with an alternating current side standard resistor (R SA ) Rear ground;
after the comparator is put into operation, the comparator is controlled by a modulating transformer (T 1 ) A first detection winding (W 11 ) A second detection winding (W 21 ) First annular detecting iron core (C) 12 ) Second annular detecting iron core (C) 22 ) A DC current detection system based on the principle of dual-core magnetic modulator is composed of a DC current modulation signal generator, a modulation transformer (T) 1 ) The center tap of the secondary winding is taken out and outputs secondary direct current I through a band-pass filter (1), a synchronous demodulator (2) and a direct current power amplifier (3) 2D To the first secondary windings (W 12 ) A second secondary winding (W 22 ) Realizing primary direct current I 1D Balanced with the magnetic potential of the secondary direct current ampere turn, and the secondary direct current I 2D Flow through DC standard resistor R SD Obtaining a measured voltage signal I of direct current 2D R SD ；
Is formed by a third detection winding (W 31 ) Third annular detecting iron core (C) 32 ) The alternating current detection system is formed by leading alternating current detection signals of alternating current to pass through a third detection windingW 31 ) Is taken out from the same-name end of the transformer and outputs secondary alternating current I through an alternating voltage amplifier (4) and an alternating power amplifier (5) 2A Giving the third secondary winding (W 32 ) Realizing primary alternating current I 1A Balanced with the magnetic potential of the secondary alternating current ampere-turn, and the secondary alternating current I 2A Through the standard resistor R at the AC side SA Obtaining a measured voltage signal I of alternating current 2A R SA 。
2. The comparator of claim 1 wherein the material of all of the electrostatic shielding layers is copper foil.
3. The comparator as claimed in claim 1 or 2, wherein all the magnetic shielding iron cores have the same shape, are formed by winding cold-rolled silicon steel into a ring shape and are assembled after annealing treatment.
4. The comparator as claimed in claim 1 or 2, wherein all the annular detecting cores are identical in shape and are obtained by winding a cold-rolled silicon steel strip into a ring shape and annealing the ring-shaped detecting cores.
5. The comparator of claim 1 or 2, wherein the number of turns of the first sense winding, the number of turns of the second sense winding, and the number of turns of the third sense winding are the same.
6. The comparator of claim 1 or 2, wherein the number of turns of the first secondary winding, the number of turns of the second secondary winding, and the number of turns of the third secondary winding are the same.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810217665.6A CN108519508B (en) | 2018-03-16 | 2018-03-16 | Comparator for measuring alternating current and direct current |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810217665.6A CN108519508B (en) | 2018-03-16 | 2018-03-16 | Comparator for measuring alternating current and direct current |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108519508A CN108519508A (en) | 2018-09-11 |
| CN108519508B true CN108519508B (en) | 2023-12-05 |
Family
ID=63432859
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810217665.6A Active CN108519508B (en) | 2018-03-16 | 2018-03-16 | Comparator for measuring alternating current and direct current |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108519508B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115469139B (en) * | 2022-10-31 | 2023-04-11 | 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）） | Current measuring device and method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1079053A (en) * | 1992-05-21 | 1993-12-01 | 华中理工大学 | A kind of AC/dc current comparison instrument |
| CN1109975A (en) * | 1995-02-24 | 1995-10-11 | 华中理工大学 | DC and AC three-purpose current comparator |
| JPH0831672A (en) * | 1994-07-20 | 1996-02-02 | Toshiba Corp | Current transformer |
| CN101571557A (en) * | 2009-06-09 | 2009-11-04 | 华中科技大学 | DC high-current metering device |
| JP2013250243A (en) * | 2012-06-04 | 2013-12-12 | Soft Energy Controls Inc | Current detector and current detection method |
| CN207937510U (en) * | 2018-03-16 | 2018-10-02 | 华中科技大学 | A kind of comparator measuring exchange and DC current |
-
2018
- 2018-03-16 CN CN201810217665.6A patent/CN108519508B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1079053A (en) * | 1992-05-21 | 1993-12-01 | 华中理工大学 | A kind of AC/dc current comparison instrument |
| JPH0831672A (en) * | 1994-07-20 | 1996-02-02 | Toshiba Corp | Current transformer |
| CN1109975A (en) * | 1995-02-24 | 1995-10-11 | 华中理工大学 | DC and AC three-purpose current comparator |
| CN101571557A (en) * | 2009-06-09 | 2009-11-04 | 华中科技大学 | DC high-current metering device |
| JP2013250243A (en) * | 2012-06-04 | 2013-12-12 | Soft Energy Controls Inc | Current detector and current detection method |
| CN207937510U (en) * | 2018-03-16 | 2018-10-02 | 华中科技大学 | A kind of comparator measuring exchange and DC current |
Non-Patent Citations (2)
| Title |
|---|
| An Improved AC/DC Current Comparator;Shiyan Ren 等;《IEEE Xplore》;第1-4页 * |
| 新型交直流比较仪在暂态电流测量中的应用;任士焱 等;《华中科技大学学报》;第29卷(第11期);第85-87页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108519508A (en) | 2018-09-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101329240B1 (en) | Non-contact current measuring apparatus using flux gate | |
| US9383392B2 (en) | Current sensor | |
| US10502778B2 (en) | Method and apparatus for electric arc detection | |
| CN110036303A (en) | Earth detector | |
| CN210071931U (en) | Automatic detection device for B-type residual current size and type | |
| CN108732404A (en) | A kind of current sensor and its more balance of flux control circuits | |
| CN105304303A (en) | Precise AC-DC large current transformer | |
| CN111157776A (en) | Double-magnetic-core sensor for insulation leakage current of power equipment | |
| CN110794193A (en) | Flexible non-contact magnetic sensor array current measuring device and measuring method | |
| CN108519508B (en) | Comparator for measuring alternating current and direct current | |
| CN105510673B (en) | A kind of direct current measuring devices | |
| CN105353193A (en) | Low direct current clamp-shaped measuring device | |
| CN108508397B (en) | A kind of comparator for ac current measurement | |
| CN107942124B (en) | Direct current comparison measuring device | |
| JP2012247191A (en) | Current detection device | |
| CN105807117A (en) | Current sensing circuit for current measuring probe and current measuring probe | |
| GB2062250A (en) | Detecting fault in insulated electric cable | |
| CN108226610A (en) | A kind of clamp measuring device for alternating current-direct current low current | |
| CN107817372B (en) | Direct current and alternating current heavy current sensing head and metering device | |
| CN207937510U (en) | A kind of comparator measuring exchange and DC current | |
| CN108490239B (en) | Transient current measuring device | |
| CN114019218B (en) | Binary channels zero magnetic flux current sensor | |
| RU100291U1 (en) | INTEGRATED MEASURING CONVERTER OF CURRENT AND VOLTAGE PARAMETERS WHEN OPERATING ELECTRICAL EQUIPMENT OF VARIOUS PURPOSE | |
| CN219225055U (en) | Flux gate sensor and magnetic measuring system for long-distance transmission | |
| CN215575380U (en) | Isotropic electromagnetic field sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |