CN108519508A - A kind of comparator measuring exchange and DC current - Google Patents
A kind of comparator measuring exchange and DC current Download PDFInfo
- Publication number
- CN108519508A CN108519508A CN201810217665.6A CN201810217665A CN108519508A CN 108519508 A CN108519508 A CN 108519508A CN 201810217665 A CN201810217665 A CN 201810217665A CN 108519508 A CN108519508 A CN 108519508A
- Authority
- CN
- China
- Prior art keywords
- winding
- iron core
- detection
- secondary winding
- exchange
- 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.)
- Granted
Links
- 238000004804 winding Methods 0.000 claims abstract description 122
- 238000001514 detection method Methods 0.000 claims abstract description 79
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 60
- 230000001360 synchronised effect Effects 0.000 claims abstract description 11
- 238000000137 annealing Methods 0.000 claims description 4
- 238000007689 inspection Methods 0.000 claims description 3
- 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 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims 2
- 229910052710 silicon Inorganic materials 0.000 claims 2
- 239000010703 silicon Substances 0.000 claims 2
- 238000005097 cold rolling Methods 0.000 claims 1
- 238000005259 measurement Methods 0.000 abstract description 4
- 230000003321 amplification Effects 0.000 abstract description 2
- 238000003199 nucleic acid amplification method Methods 0.000 abstract description 2
- 239000000203 mixture Substances 0.000 description 3
- 229910000976 Electrical steel Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 229910052742 iron Inorganic materials 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
- 238000005303 weighing 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
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
- Measurement Of Current Or Voltage (AREA)
Abstract
The invention discloses a kind of comparators measuring exchange and DC current.The comparator includes sensing head, modulation transformer, DC side measuring resistance, exchange side measuring resistance, bandpass filter, synchronous demodulator, amplidyne, alternating voltage amplifier and AC power amplifier, measurement head includes identical three units of structure, and each unit includes annular detection iron core, detection winding, electrostatic screen layer, magnetic screen iron core and secondary winding；Unit first and second, modulation transformer, bandpass filter, synchronous demodulator, dc power amplification and DC side measuring resistance constitute the DC detecting system based on double-iron core magnetic modulator principle；Third unit, exchange side measuring resistance, alternating voltage amplifier and AC power amplifier are constituted exchanges detecting system based on single iron core, the present invention can not only measure direct current or measure alternating current, also can measure the DC component and AC compounent of the mixed type electric current of DC stacked exchange.
Description
Technical field
The invention belongs to the current measure device in electrotechnics, more particularly to a kind of ratio measuring exchange and DC current
Compared with instrument.
Background technology
Patent No. ZL92103969.7 entitled " a kind of AC/dc current comparison instrument ", it is the main iron of exchange in measurement head
Core T2Outside is around upper exchange detection winding WD, then around upper monitoring winding W outside the windingK, in WKOutside is around exchange zeroing winding
Wa；In two direct current main iron core T3Outside is rotating around upper field winding We；Then above-mentioned alternating current and direct current winding iron core is assembled,
Their outsides place it into magnetic screen iron core T around upper electrostatic screen E1In, in T1Outside is around submitting direct-current secondary winding WS；It should
Device both can measure direct current, also can measure exchange, can also measure ac and dc current simultaneously.But there are following defects：It is led in exchange
Iron core T2It is upper to be provided with exchange zeroing winding Wa, the parallel branch of the winding and potential source e and resistance R capacitances C is in series, in order to
Inhibit the influence due to straight-flow system ripple to AC system zero.Why this influence occurs, because of AC system and straight
Streaming system shares a set of alternating current-direct current secondary winding WSWith coupled iron cores T1, influence inevitable；In addition straight-flow system ripple and quilt
It is related to survey object, environment etc., it is impossible to be constant, the connect potential source e of zeroing winding, resistance R and capacitance C can not track direct current
The problem of system ripple changes, and commercial Application is restricted, is resolved here it is the present invention.
Invention content
For the drawbacks described above of the prior art, the present invention provides a kind of comparator measuring exchange and DC current, solutions
Certainly existing comparator device there is technical issues that generate between direct current and AC system.
To achieve the above object, the comparator proposed by the present invention for measuring exchange and DC current, including：
Sensing head, modulation transformer, DC side measuring resistance, exchange side measuring resistance, bandpass filter, synchronous demodulation
Device, amplidyne, alternating voltage amplifier, AC power amplifier；
Sensing head includes first annular detection iron core, is around in the first detection winding of first annular detection iron core, surrounds the
First electrostatic screen layer of one detection winding, the first magnetic screen iron core being placed in outside the first electrostatic screen layer and it is around in the first magnetic cup
Cover the first secondary winding of iron core；
Sensing head further includes the second annular detection iron core, is around in the second detection winding of the second annular detection iron core, surrounds
Second electrostatic screen layer of the second detection winding, the second magnetic screen iron core being placed in outside the second electrostatic screen layer and it is around in the second magnetic
The second secondary winding of shielding iron core；
Sensing head further includes third annular detection iron core, the third detection winding for being around in third annular detection iron core, encirclement
The third electrostatic screen layer of third detection winding, the third magnetic screen iron core being placed in outside third electrostatic screen layer and it is around in third magnetic
The third secondary winding of shielding iron core；
It is grounded after the Same Name of Ends connection DC side measuring resistance of first secondary winding, the different name end connection of the first secondary winding
The Same Name of Ends of second secondary winding；The Same Name of Ends of the Same Name of Ends connection modulation transformer vice-side winding of first detection winding, first
The different name end of detection winding connects the different name end of the second detection winding and is grounded, and the Same Name of Ends connection modulation of the second detection winding becomes
The different name end of depressor vice-side winding, the input terminal of the centre cap connection bandpass filter of modulation transformer vice-side winding, band logical
The input terminal of the output end connection synchronous demodulator of filter, the input of the output end and amplidyne of synchronous demodulator
End is connected, and the output end of amplidyne connects the different name end of second secondary winding；The different name end of third detection winding with
Ground connects, the input terminal of the Same Name of Ends connection alternating voltage amplifier of third detection winding, the output end of alternating voltage amplifier
The input terminal of AC power amplifier is connected, the different name end of the output end connection third secondary winding of AC power amplifier simultaneously connects
Ground, third secondary winding Same Name of Ends connection exchange side measuring resistance after be grounded.
Preferably, the material of all electrostatic screen layers is copper foil.
Preferably, all magnetic screen core configurations are identical, circlewise and assembled after annealing by cold-rolled silicon steel tape winding
It forms.
Preferably, all annular detection core configurations are identical, circlewise and after making annealing treatment obtained by cold-rolled silicon steel tape winding
It arrives.
Preferably, the number of turns of the number of turns of the first detection winding, the number of turns of the second detection winding and third detection winding is identical.
Preferably, the number of turns of the number of turns of the first secondary winding, the number of turns of second secondary winding and third secondary winding is identical.
In general, through the invention it is contemplated above technical scheme is compared with the prior art, can obtain down and show
Beneficial effect：
(1) present invention reasonably sets sensing head to three identical independent units, and each unit is detected by annular
Iron core, detection winding, electrostatic screen layer, annular magnetic shielding iron core and secondary winding are constituted；First unit and second unit composition
Based on the DC detecting system of double-iron core magnetic modulator principle, the system is by magnetic modulated detection signal from the secondary side of modulation transformer
Winding centre cap takes out, and through bandpass filter, synchronous demodulator, amplidyne, exports DC current to the first He
The first and second secondary windings being in series in second unit, the DC current flow through DC side measuring resistance, obtain direct current
Stream is tested voltage signal；Third unit forms the exchange detecting system based on single iron core, and the system is by alternating-current detection signal from the
The Same Name of Ends of three detection windings takes out, and through alternating voltage amplifier, AC power amplifier, exports alternating current to third unit
In third secondary winding, which flows through exchange side measuring resistance, obtains alternating current and is tested voltage signal；Thus
AC system is breached completely and straight-flow system shares the prior art of a set of alternating current-direct current secondary winding and coupled iron cores, from source
On solve the problems, such as straight-flow system ripple on AC system zero influence, eliminate exchange zeroing winding, potential source, resistance and
The setting of capacitance parallel branch keeps device debugging, operation more convenient, reliable.
(2) present invention not only both can measure DC current, also can measure alternating current, also can measure DC stacked exchange
The DC component and AC compounent of mixed type electric current.
(3) present invention sets sensing head to the scheme of three identical separate units, and properity is superior, complete machine
Energy price compares higher.
Description of the drawings
Fig. 1 is sensing head external form figure in the comparator provided by the invention for measuring exchange and DC current；
Fig. 2 is sensing head sectional view in the comparator provided by the invention for measuring exchange and DC current；
Fig. 3 is the comparator circuit diagram that the present invention measures exchange and DC current.
Specific implementation mode
In order to make the purpose , technical scheme and advantage of the present invention be clearer, with reference to the accompanying drawings and embodiments, right
The present invention is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, and
It is not used in the restriction present invention.In addition, technical characteristic involved in the various embodiments of the present invention described below, as long as
It does not constitute a conflict with each other and can be combined with each other.
Fig. 1 is a kind of sensing head external form figure measuring exchange and the comparator of DC current provided by the invention, section
As shown in Figure 2.For entire measurement head in annular shape, measurement head T includes first annular detection iron core C12, second annular detection iron core
C22, third annular detection iron core C32, the first detection winding W11, the second detection winding W21, third detection winding W31, the first electrostatic
Shielded layer E1, the second electrostatic screen layer E2, third electrostatic screen layer E3, first annular magnetic screen iron core C11, the second annular magnetic screen
Iron core C21, third annular magnetic shielding iron core C31, the first secondary winding W12, second secondary winding W22With third secondary winding W32；
The first shape detection iron core C12, the second shape detection iron core C22With third annular detection iron core C32Shape is identical, first annular inspection
Survey iron core C12, the second annular detection iron core C22With third annular detection iron core C32It is upper to be wound with identical first detection of the number of turns respectively
Winding W11, the second detection winding W21With third detection winding W31, the first detection winding W11, the second detection winding W21It is examined with third
Survey winding W31Outside is respectively coated by the first electrostatic screen layer E1, the second electrostatic screen layer E2With the second electrostatic screen layer E3Afterwards, respectively
It is placed in the identical first magnetic screen iron core C of cavity structure shape being made of outer shroud and inner ring11, the second magnetic screen iron core C21With
Third magnetic screen iron core C31Cavity in, in the first magnetic screen iron core C11, the second magnetic screen iron core C21With third magnetic screen iron core
C31It is outer to be wound with the identical first secondary winding W of the number of turns respectively12, second secondary winding W22With third secondary winding W32。
Fig. 3 gives a kind of comparator circuit diagram measuring exchange and DC current.First winding W shown in Fig. 31Pass
Defeated tested exchange and DC current I1Busbar, passed through from sensing head center hole as shown in Figure 1.The comparator includes sensing
Head T, modulation transformer T1, DC side measuring resistance RSD, exchange side measuring resistance RSA, it is bandpass filter 1, synchronous demodulator 2, straight
Flow power amplifier 3, alternating voltage amplifier 4, AC power amplifier 5.
First secondary winding W in sensing head T12Same Name of Ends connection DC side measuring resistance RSDAfter be grounded, first it is secondary around
Group W12Different name end connect second secondary winding W22Same Name of Ends；First detection winding W11Same Name of Ends connect modulation transformer
T1The Same Name of Ends of vice-side winding, the first detection winding W11Different name end connect the second detection winding W21Different name end and be grounded,
Two detection winding W21Same Name of Ends connection modulation transformer T1The different name end of vice-side winding, modulation transformer T1In vice-side winding
Heart tap connects the input terminal of bandpass filter 1, and the input terminal of the output end connection synchronous demodulator 2 of bandpass filter 1 is synchronous
The output end of demodulator 2 is connected with the input terminal of amplidyne 3, the output end connection second of amplidyne 3
Secondary winding W22Different name end.
Third detection winding W31Different name end be connected to ground, third detection winding W31Same Name of Ends connection alternating current press
The input terminal of big device 4, the input terminal of the output end connection AC power amplifier 5 of alternating voltage amplifier 4, AC power amplification
The output end connection third secondary winding W of device 532Different name end, third secondary winding W32Same Name of Ends connect exchange side standard electric
Hinder RSAAfter be grounded.
After the present apparatus puts into operation, by modulation transformer T1, the first detection winding W11, the second detection winding W21, the first ring
Shape detects iron core C12, the second annular detection iron core C22The direct current detection system based on double-iron core magnetic modulator principle of composition
System, by the modulated signal of DC current from modulation transformer T1Vice-side winding centre cap takes out, and through bandpass filter 1, synchronizes
Demodulator 2, amplidyne 3 export secondary DC current I2DTo being serially connected the first secondary winding W12, it is second secondary
Winding W22, realize a DC current I1DWith the magnetic potential balance of secondary direct current ampere-turn, i.e. I1DW1=I2D(W12+W22), it is secondary straight
Galvanic electricity stream I2DIt flows through direct current and surveys measuring resistance RSD, obtain the tested voltage signal I of DC current2DRSD；
By third detection winding W31, third annular detection iron core C32The alternating current detecting system of composition, by alternating current
Alternating-current detection signal from third detection winding W31Same Name of Ends take out, through alternating voltage amplifier 4, AC power amplifier 5,
Export secondary AC electric current I2AGive third secondary winding W32, realize an alternating current I1AIt is flat with the magnetic potential of secondary AC ampere-turn
Weighing apparatus, i.e. I1AW1=I2AW32, secondary AC electric current I2AFlow through exchange side measuring resistance RSA, obtain the tested voltage letter of alternating current
Number I2ARSA。
The present invention breaches AC system and straight-flow system shares the existing of a set of alternating current-direct current secondary winding and coupled iron cores
Technology solves the problems, such as that straight-flow system ripple influences AC system zero from source, eliminates exchange zeroing winding, electricity
The setting of potential source, resistance and capacitance parallel branch keeps device debugging, operation more convenient, reliable.The present invention not only can both survey
Amount direct current can also measure alternating current, also can measure the DC component of the mixed type electric current of DC stacked exchange and exchange point
Amount, properity is superior, and complete machine is cost-effective.
As it will be easily appreciated by one skilled in the art that the foregoing is merely illustrative of the preferred embodiments of the present invention, not to
Limitation the present invention, all within the spirits and principles of the present invention made by any modification, equivalent replacement and improve etc., should all include
Within protection scope of the present invention.
Claims (6)
1. a kind of comparator measuring exchange and DC current, which is characterized in that including：Sensing head (T), modulation transformer (T1)、
DC side measuring resistance (RSD), exchange side measuring resistance (RSA), bandpass filter (1), synchronous demodulator (2), dc power put
Big device (3), alternating voltage amplifier (4), AC power amplifier (5)；
The sensing head includes first annular detection iron core (C12), be around in the first annular detection iron core (C12) outside first inspection
Survey winding (W11), surround the first detection winding (W11) the first electrostatic screen layer (E1), be placed in first electrostatic screen
Layer (E1) outer the first magnetic screen iron core (C11) and be around in the first magnetic screen iron core (C11) outer the first secondary winding (W12)；
The sensing head further includes the second annular detection iron core (C22), be around in the second annular detection iron core (C22) outside second
Detection winding (W21), surround the second detection winding (W21) the second electrostatic screen layer (E2), be placed in second electrostatic sheild
Cover layer (E2) outer the second magnetic screen iron core (C21) and be around in the second magnetic screen iron core (C21) outer second secondary winding (W22)；
The sensing head further includes third annular detection iron core (C32), be around in third annular detection iron core (C32) outer third
Detection winding (W31), surround the third detection winding (W31) third electrostatic screen layer (E3), be placed in the third electrostatic sheild
Cover layer (E3) outer third magnetic screen iron core (C31) and be around in third magnetic screen iron core (C31) outer third secondary winding (W32)；
First secondary winding (the W12) Same Name of Ends connection DC side measuring resistance (RSD) be grounded afterwards, the first secondary winding
(W12) different name end connect second secondary winding (W22) Same Name of Ends；First detection winding (W11) Same Name of Ends connection modulation become
Depressor (T1) vice-side winding Same Name of Ends, the first detection winding (W11) different name end connect the second detection winding (W21) different name end
And it is grounded, the second detection winding (W21) Same Name of Ends connection modulation transformer (T1) vice-side winding different name end, modulation transformer
(T1) vice-side winding centre cap connection bandpass filter (1) input terminal, bandpass filter (1) output end connection synchronize
The output end of the input terminal of demodulator (2), synchronous demodulator (2) is connected with the input terminal of amplidyne (3), direct current work(
The output end of rate amplifier (3) connects second secondary winding (W22) different name end；Third detection winding (W31) different name end with ground
Connection, third detection winding (W31) Same Name of Ends connection alternating voltage amplifier (4) input terminal, alternating voltage amplifier (4)
Output end connection AC power amplifier (5) input terminal, AC power amplifier (5) output end connection third it is secondary around
Group (W32) different name end, third secondary winding (W32) Same Name of Ends connection exchange side measuring resistance (RSA) be grounded afterwards.
2. comparator as described in claim 1, which is characterized in that the material of all electrostatic screen layers is copper foil.
3. comparator as claimed in claim 1 or 2, which is characterized in that all magnetic screen core configurations are identical, by cold rolling
Silicon strip winding is circlewise and assembled after annealing.
4. comparator as claimed in claim 1 or 2, which is characterized in that all annular detection core configurations are identical, by cold
Silicon strip winding is rolled circlewise and after making annealing treatment to obtain.
5. comparator as claimed in claim 1 or 2, which is characterized in that the number of turns of first detection winding, second inspection
The number of turns of the number of turns and the third detection winding for surveying winding is identical.
6. comparator as claimed in claim 1 or 2, which is characterized in that the number of turns of first secondary winding, the described 2nd 2
The number of turns of the number of turns of secondary winding and the third secondary winding is identical.
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 true CN108519508A (en) | 2018-09-11 |
| CN108519508B 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) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112816760A (en) * | 2020-12-30 | 2021-05-18 | 西安西驰电气股份有限公司 | Alternating-current high-voltage detection device and method for medium-high voltage soft starter |
| CN112834806A (en) * | 2021-02-26 | 2021-05-25 | 上海市计量测试技术研究院 | Direct current proportion conversion device |
| CN115469139A (en) * | 2022-10-31 | 2022-12-13 | 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 |
|---|
| SHIYAN REN 等: "An Improved AC/DC Current Comparator", 《IEEE XPLORE》, pages 1 - 4 * |
| 任士焱 等: "新型交直流比较仪在暂态电流测量中的应用", 《华中科技大学学报》, vol. 29, no. 11, pages 85 - 87 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112816760A (en) * | 2020-12-30 | 2021-05-18 | 西安西驰电气股份有限公司 | Alternating-current high-voltage detection device and method for medium-high voltage soft starter |
| CN112834806A (en) * | 2021-02-26 | 2021-05-25 | 上海市计量测试技术研究院 | Direct current proportion conversion device |
| CN115469139A (en) * | 2022-10-31 | 2022-12-13 | 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 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108519508B (en) | 2023-12-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108519508A (en) | A kind of comparator measuring exchange and DC current | |
| CN104914358B (en) | Shelf depreciation monitoring arrangement and shelf depreciation monitoring system | |
| CN105304303B (en) | A kind of accurate alterating and direct current current transformer | |
| CN104181429B (en) | On-line loss measurement system for three-winding transformer | |
| CN106324539B (en) | A kind of high-precision current comparator | |
| CN103336186A (en) | Method for testing transformer equipment without disassembling lead | |
| CN108369112A (en) | Rotation angle detection apparatus and electric rotating machine | |
| CN105510673B (en) | A kind of direct current measuring devices | |
| CN207937510U (en) | A kind of comparator measuring exchange and DC current | |
| CN104142487B (en) | Electrified detecting device for tank type capacitor voltage transformer | |
| CN105353193B (en) | A kind of DC low current clamp measuring device | |
| Fubin et al. | Effects of geometrical parameters on the performance of Rogowski coil for current measuring | |
| CN108226610A (en) | A kind of clamp measuring device for alternating current-direct current low current | |
| CN107271847A (en) | A kind of flexible direct current circuit fault distance measurement exported based on Rogowski coil differential | |
| CN208140773U (en) | A kind of measurement of transient current device | |
| CN208140774U (en) | A kind of clamp measuring device for alternating current-direct current low current | |
| CN207557333U (en) | A kind of DC current compares measuring device | |
| CN205427023U (en) | Optics current measuring device | |
| CN105548664B (en) | A kind of optical current measuring device | |
| CN206975165U (en) | A kind of low current synchronous signal sensor device | |
| CN108508397A (en) | A kind of comparator for ac current measurement | |
| CN207882324U (en) | A kind of direct current and AC great current sensing head and metering device | |
| CN101571557A (en) | DC high-current metering device | |
| CN107942124B (en) | Direct current comparison measuring device | |
| CN204008784U (en) | Anti-electricity-leakage device for monitoring transformation ratio of primary side alternating current transformer |
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 |