CN209387735U - Wire current measuring device - Google Patents
Wire current measuring device Download PDFInfo
- Publication number
- CN209387735U CN209387735U CN201821968785.1U CN201821968785U CN209387735U CN 209387735 U CN209387735 U CN 209387735U CN 201821968785 U CN201821968785 U CN 201821968785U CN 209387735 U CN209387735 U CN 209387735U
- Authority
- CN
- China
- Prior art keywords
- axis
- current
- wire
- measured
- conducting wire
- 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
- 238000009826 distribution Methods 0.000 claims description 6
- 230000003321 amplification Effects 0.000 claims description 3
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 3
- 230000035945 sensitivity Effects 0.000 abstract description 7
- 238000002360 preparation method Methods 0.000 abstract description 5
- 238000005259 measurement Methods 0.000 description 14
- 238000000034 method Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 230000036651 mood Effects 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
Landscapes
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
Abstract
The utility model discloses a wire current measuring device, which comprises a housing, and further comprises an x-axis one-dimensional magnetic resistance chip, a y-axis one-dimensional magnetic resistance chip, an ADC module and a control module, wherein the x-axis one-dimensional magnetic resistance chip is arranged in the housing and used for measuring the magnetic field vector of the wire to be measured in the x-axis direction, the y-axis one-dimensional magnetic resistance chip and the X-axis one-dimensional magnetic resistance chip are vertically distributed at the same position and used for measuring the magnetic field vector of the wire to be measured in the y-axis direction, a first input end of the ADC module is connected with an output end of the x-axis one-; the input end of the control module is respectively connected with the first output end and the second output end of the ADC module and used for obtaining the current value of the wire to be tested according to the Biao-Saval law, the distance between the x-axis one-dimensional magnetic resistance chip and the circle center of the wire to be tested, the magnetic field vector in the x-axis direction and the magnetic field vector in the y-axis direction which are converted into digital quantities, the size is reduced, the preparation cost is reduced, the temperature drift is small, and the sensitivity is high.
Description
Technical field
The utility model relates to current measurement techniques fields, more particularly to a kind of current in wire measuring device.
Background technique
Current sensor is the basis of measurement of power, relay protection, control and monitoring system, in grid operation,
It needs to analyze operation states of electric power system in real time by monitoring the parameters such as the electric current in power grid.Estimated current measurement is divided into intrusive mood
Measurement and non-intrusion measurement.Intrusive mood measurement needs to concatenate measuring cell in measuring circuit, and measure the range of electric current compared with
Small, use is very limited, and non-intrusion measurement has become essential detection means.
Non-intrusion measurement device mainly includes electromagnetic current transducer and Hall sensor in the prior art.But electromagnetism
Formula current transformer there are insulation systems complicated, iron core saturation, the disadvantages of measurement error is big, Hall sensor is in measurement high current
When there are saturated phenomenons, and have biggish temperature drift.Further, since the installation space on transmission line of electricity, distribution line and bus
It is extremely limited, and electromagnetic current transducer and Hall sensor require iron core and carry out poly- magnetic, are made into cyclic structure, volume phase
To larger, inconvenience installation.And its production needs to consume a large amount of metal resource, cost of manufacture is high.
Therefore, how to provide a kind of scheme of solution above-mentioned technical problem is that those skilled in the art need to solve at present
Problem.
Utility model content
The purpose of the utility model is to provide a kind of current in wire measuring devices, and volume and preparation cost are low, are easily installed,
And temperature drift is small, high sensitivity.
In order to solve the above technical problems, the utility model provides a kind of current in wire measuring device, including shell, also wrap
Include the one-dimensional magnetoresistive chip of x-axis for being set to the intracorporal magnetic vector for measuring conducting wire x-axis direction to be measured of the shell and institute
The one-dimensional magnetoresistive chip of x-axis is stated in same position and vertical distribution, the y-axis of magnetic vector for measuring conducting wire y-axis to be measured direction
One-dimensional magnetoresistive chip, ADC module and control module, in which:
The first input end of the ADC module is connect with the output end of the one-dimensional magnetoresistive chip of the x-axis, the second input terminal with
The output end of the one-dimensional magnetoresistive chip of y-axis connects；
The input terminal of the control module is connect with the first output end and second output terminal of the ADC module respectively, is used
In the distance between center of circle according to Biot-Savart law, the one-dimensional magnetoresistive chip of the x-axis and the conducting wire to be measured, conversion
The current value of the conducting wire to be measured is obtained for the magnetic vector of the x-axis direction of digital quantity and the magnetic vector in y-axis direction.
Preferably, further includes:
First be set between the output end of the one-dimensional magnetoresistive chip of the x-axis and the first input end of the ADC module
Amplifier is amplified for the magnetic vector to x-axis direction；
Second be set between the output end of the one-dimensional magnetoresistive chip of the y-axis and the second input terminal of the ADC module
Amplifier is amplified for the magnetic vector to y-axis direction.
Preferably, further includes:
It is set on the shell, for the conducting wire to be measured to be fixed fixation device on the housing.
Preferably, the fixed device is U-shaped buckle.
Preferably, Open Side Down for the U-shaped buckle, a port of the U-shaped buckle and the housing hinge, another
A port is detachably connected with the shell.
Preferably, the shell is equipped with and the mutually matched inner concave of conducting wire to be measured.
Preferably, the U-shaped buckle is the Elastic buckle of opening upwards.
Preferably, the U-shaped buckle is plastic buckle.
The application in view of one-dimensional magnetoresistive sensor have height can integrated level, high sensitivity, small size, cheap, small temperature drift,
The wide advantage of measurement range, therefore, the application acquire conducting wire to be measured by two one-dimensional magnetoresistive chips of vertical distribution respectively and exist
Magnetic vector at magnetoresistive chip position, in conjunction with the one-dimensional magnetoresistive chip of x-axis (or could also say that the one-dimensional magnetoresistive chip of y-axis)
The distance between center of circle of conducting wire to be measured and Biot-Savart law can obtain the current value of conducting wire to be measured, to make
Volume and the preparation cost for obtaining current in wire measuring device are low, are easily installed, and temperature drift is small, high sensitivity.
Detailed description of the invention
It, below will be to the prior art and embodiment in order to illustrate more clearly of the technical scheme in the embodiment of the utility model
Needed in attached drawing be briefly described, it should be apparent that, the accompanying drawings in the following description is only the utility model
Some embodiments for those of ordinary skill in the art without creative efforts, can also be according to this
A little attached drawings obtain other attached drawings.
Fig. 1 is a kind of structural schematic diagram of current in wire measuring device provided by the utility model；
Fig. 2 is a kind of original for the current value that conducting wire to be measured is obtained using Biot-Savart law provided by the utility model
Reason figure；
Fig. 3 is a kind of current in wire measuring device for being provided with the U-shaped buckle that Open Side Down provided by the utility model
Structural schematic diagram.
Specific embodiment
The core of the utility model is to provide a kind of current in wire measuring device, and volume and preparation cost are low, is easily installed,
And temperature drift is small, high sensitivity.
It is practical new below in conjunction with this to keep the objectives, technical solutions, and advantages of the embodiments of the present invention clearer
Attached drawing in type embodiment, the technical scheme in the utility model embodiment is clearly and completely described, it is clear that is retouched
The embodiment stated is the utility model a part of the embodiment, instead of all the embodiments.Based on the implementation in the utility model
Example, every other embodiment obtained by those of ordinary skill in the art without making creative efforts belong to
The range of the utility model protection.
Fig. 1 is please referred to, Fig. 1 is a kind of structural schematic diagram of current in wire measuring device provided by the utility model, the dress
Set including shell 1, further include be set to magnetic vector in shell 1, for measuring conducting wire x-axis direction to be measured x-axis it is one-dimensional
Magnetoresistive chip 2 and the one-dimensional magnetoresistive chip 2 of x-axis are in same position and vertical distribution, the magnetic for measuring conducting wire y-axis to be measured direction
The one-dimensional magnetoresistive chip 3 of the y-axis of field vector, ADC module 4 and control module 5, in which:
The first input end of ADC module 4 is connect with the output end of the one-dimensional magnetoresistive chip 2 of x-axis, the second input terminal and y-axis one
Tie up the output end connection of magnetoresistive chip 3；
The input terminal of control module 5 is connect with the first output end and second output terminal of ADC module 4 respectively, is used for basis
The distance between the one-dimensional magnetoresistive chip 2 of Biot-Savart law, x-axis and the center of circle of conducting wire to be measured are converted to the x-axis of digital quantity
The magnetic vector in direction and the magnetic vector in y-axis direction obtain the current value of conducting wire to be measured.
Specifically, in current in wire measuring device provided by the present application, measured provided with two one-dimensional magnetoresistive chips to
The magnetic vector of conducting wire is surveyed, the two one-dimensional magnetoresistive chips are respectively the one-dimensional magnetoresistive chip 2 of x-axis and the one-dimensional magnetoresistive chip 3, x of y-axis
The one-dimensional magnetoresistive chip 2 of axis and the one-dimensional setting of magnetoresistive chip 3 of y-axis are at same position and orthogonal, to measure the x at the position
The magnetic vector B of axis directionxWith the magnetic vector B in y-axis directiony.The application magnetoresistive chip 2 one-dimensional for x-axis and y-axis One-Dimension Magnetic
The setting position of resistance chip 3 does not limit particularly, determines according to the actual situation.
(exist because the one-dimensional magnetoresistive chip 2 of x-axis and the one-dimensional magnetoresistive chip 3 of y-axis are arranged measuring the one-dimensional magnetoresistive chip 2 of x-axis
At same position, therefore, the one-dimensional magnetoresistive chip 3 of y-axis could also say that here) magnetic vector of the x-axis direction of position
BxWith the magnetic vector B in y-axis directionyAfterwards, ADC module 4 is by the magnetic vector B of x-axis directionxWith the magnetic vector B in y-axis directionyBy
Analog quantity is converted to digital quantity, magnetic vector B of the control module 5 in the x-axis direction for receiving digital quantityxWith the magnetic in y-axis direction
Field vector ByIt is obtained afterwards in conjunction with the distance between the one-dimensional magnetoresistive chip 2 of x-axis and the center of circle of conducting wire to be measured, Biot-Savart law
To the current value of conducting wire to be measured.
In addition, it should be noted that, conducting wire can be understood as with current in wire measuring device it is a little tangent, in practical application
In, conducting wire to be measured only has very short one section tangent with current in wire measuring device, for convenience of calculating, can will survey with current in wire
That section of tangent conducting wire (cylindrical body of high very little) to be measured of amount device is understood as a face, the center of circle in this face namely the application
The center of circle mentioned.
According to Biot-Savart law, the magnetic vector of the available one-dimensional magnetoresistive chip 2 of x-axis are as follows:
Wherein, μ0For space permeability, value is 4 π × 10-7Tm/A, and d is the one-dimensional magnetoresistive chip 2 of x-axis and conducting wire to be measured
The distance between the center of circle, can be previously obtained.
Again
Then
Referring to figure 2., Fig. 2 is provided by the utility model a kind of to obtain conducting wire to be measured using Biot-Savart law
The schematic diagram of current value.
Assuming that the electric current of conducting wire to be measured is I, radius is unknown, and conducting wire to be measured abuts current in wire measuring device, and O point is to lead
The contact point (namely point of contact) of line current measuring device and conducting wire to be measured, A point be current in wire measuring device central point (namely
Preset in the application), C point is the position of the one-dimensional magnetoresistive chip 2 (or the one-dimensional magnetoresistive chip 3 of y-axis) of x-axis, and 3 points of AOB exists
On straight line, the distance between AC l is it is known that setting the distance between AO, BO, BC is m, r, d respectively, wherein known to the value of m.It is logical
The conducting wire can directly be measured in the magnetic field strength of C point, respectively B by crossing twin shaft magnetoresistive chipxAnd By, then:
R value can be calculated by above formula, are as follows:
Then
Then
To sum up, the application difference and other current sensors in the prior art, it is contemplated that one-dimensional magnetoresistive sensor has height
Can the wide advantage of integrated level, high sensitivity, small size, cheap, small temperature drift, measurement range, therefore, the application passes through vertical distribution
Two one-dimensional magnetoresistive chips acquire magnetic vector of the conducting wire to be measured at magnetoresistive chip position respectively, in conjunction with x-axis One-Dimension Magnetic
Resistance the distance between chip 2 (or could also say that the one-dimensional magnetoresistive chip 3 of y-axis) and the center of circle of conducting wire to be measured and Biot-Sa are cut down
Your law can obtain the current value of conducting wire to be measured, so that the volume of current in wire measuring device and preparation cost are low,
It is easily installed, and temperature drift is small, high sensitivity.
On the basis of the above embodiments:
As a kind of preferred embodiment, ADC module 4 is double channel A/D C.
Due to the magnetic vector B for the x-axis direction for needing to export the one-dimensional magnetoresistive chip of x-axis 2xAnalog-to-digital conversion is carried out, is needed
To the magnetic vector B in the y-axis direction that the one-dimensional magnetoresistive chip of y-axis 3 exportsyIt carries out analog-to-digital conversion and therefore needs exist for two ADC,
Double channel A/D C has been selected in the present embodiment, compared with two single channel ADC, integrated level is high, and it is small in size, it further reduces and leads
The volume of line current measuring device.
As a kind of preferred embodiment, further includes:
The first amplifier being set between the output end of the one-dimensional magnetoresistive chip 2 of x-axis and the first input end of ADC module 4,
It is amplified for the magnetic vector to x-axis direction；
The second amplifier being set between the output end of the one-dimensional magnetoresistive chip 3 of y-axis and the second input terminal of ADC module 4,
It is amplified for the magnetic vector to y-axis direction.
Signal processing is carried out in order to facilitate control module 5, improves signal processing precision, in the present embodiment, is also provided with the
One amplifier and the second amplifier, for being amplified respectively to the magnetic vector of x-axis direction and to the magnetic vector in y-axis direction
It amplifies.The first amplifier and the second amplifier in the present embodiment can with but not only limit is the amplification based on operational amplifier
Circuit.
As a kind of preferred embodiment, further includes:
It is set on shell 1, the fixation device 6 for being fixed on conducting wire to be measured on shell 1.
Specifically, current in wire measuring device provided in this embodiment further includes the fixation device 6 being set on shell 1,
For conducting wire to be measured to be fixed on shell 1, to guarantee that conducting wire to be measured will not tamper, the magnetic vector of x-axis direction ensure that
With the measurement precision of the magnetic vector in y-axis direction, and then the measurement precision of the current value of conducting wire to be measured ensure that.As one
Kind preferred embodiment, fixed device 6 are U-shaped buckle.
Specifically, fixed device 6 can be U-shaped buckle, and U-shaped buckle has the advantages that structure is simple.Certainly, consolidating here
Determining device 6 can not also particularly be limited herein with other kinds of fixed device 6, the present embodiment.
As a kind of preferred embodiment, Open Side Down for U-shaped buckle, and a port and shell 1 of U-shaped buckle are hinged,
Another port is detachably connected with shell 1.
As a kind of preferred embodiment, shell 1 is equipped with and the mutually matched inner concave of conducting wire to be measured.
Specifically, referring to figure 3., Fig. 3 is provided by the utility model a kind of to be provided with leading for the U-shaped buckle that Open Side Down
The structural schematic diagram of line current measuring device.
Before placing conducting wire to be measured, the detachable port of U-shaped buckle is not connect with shell 1, is placing conducting wire to be measured
Afterwards, the detachable port of U-shaped buckle is connect with shell 1, and conducting wire to be measured is fixed on shell 1.In addition, in order to further will
Conducting wire to be measured is fixed, and is additionally provided with inner concave on shell 1, and the inner concave and conducting wire to be measured cooperate.
As a kind of preferred embodiment, U-shaped buckle is the Elastic buckle of opening upwards.
As a kind of preferred embodiment, U-shaped buckle is plastic buckle.
Specifically, U-shaped buckle here can also be the Elastic buckle of opening upwards, and the length of the opening is less than to be measured lead
The diameter of line, when placing conducting wire to be measured, since Elastic buckle has elasticity, which can become larger, be placed into conducting wire to be measured
After going, opening can be restored as former state.Compared with the Elastic buckle that Open Side Down, the structure of the U-shaped buckle is simpler.
Here U-shaped buckle can with but be not only limited to plastic buckle, on the one hand, plastic buckle insulation reduces to conducting wire electricity
Influence when flow measuring apparatus measures；On the other hand, the lighter in weight of plastic buckle further reduces current in wire measurement dress
The weight set.
It should be noted that in the present specification, relational terms such as first and second and the like are used merely to one
A entity or operation with another entity or operate distinguish, without necessarily requiring or implying these entities or operation it
Between there are any actual relationship or orders.Moreover, the terms "include", "comprise" or its any other variant are intended to
Cover non-exclusive inclusion, so that the process, method, article or equipment for including a series of elements not only includes those
Element, but also including other elements that are not explicitly listed, or further include for this process, method, article or setting
Standby intrinsic element.In the absence of more restrictions, the element limited by sentence "including a ...", it is not excluded that
There is also other identical elements in the process, method, article or apparatus that includes the element.
The foregoing description of the disclosed embodiments can be realized professional and technical personnel in the field or using originally practical new
Type.Various modifications to these embodiments will be readily apparent to those skilled in the art, and determine herein
The General Principle of justice can be realized in other embodiments without departing from the spirit or scope of the present utility model.Cause
This, the present invention will not be limited to the embodiments shown herein, and is to fit to and principles disclosed herein
The widest scope consistent with features of novelty.
Claims (8)
1. a kind of current in wire measuring device, which is characterized in that further include being set to that the shell is intracorporal, is used for including shell
The one-dimensional magnetoresistive chip of x-axis and the one-dimensional magnetoresistive chip of the x-axis for measuring the magnetic vector of conducting wire x-axis direction to be measured are in same position
It sets and the one-dimensional magnetoresistive chip of y-axis, ADC module and the control of vertical distribution, magnetic vector for measuring conducting wire y-axis to be measured direction
Module, in which:
The first input end of the ADC module is connect with the output end of the one-dimensional magnetoresistive chip of the x-axis, the second input terminal with it is described
The output end of the one-dimensional magnetoresistive chip of y-axis connects；
The input terminal of the control module is connect with the first output end and second output terminal of the ADC module respectively, is used for root
The distance between center of circle according to Biot-Savart law, the one-dimensional magnetoresistive chip of the x-axis and the conducting wire to be measured is converted to number
The magnetic vector of the x-axis direction of word amount and the magnetic vector in y-axis direction obtain the current value of the conducting wire to be measured.
2. current in wire measuring device as described in claim 1, which is characterized in that further include:
The first amplification being set between the output end of the one-dimensional magnetoresistive chip of the x-axis and the first input end of the ADC module
Device is amplified for the magnetic vector to x-axis direction；
The second amplification being set between the output end of the one-dimensional magnetoresistive chip of the y-axis and the second input terminal of the ADC module
Device is amplified for the magnetic vector to y-axis direction.
3. such as the described in any item current in wire measuring devices of claim 1-2, which is characterized in that further include:
It is set on the shell, for the conducting wire to be measured to be fixed fixation device on the housing.
4. current in wire measuring device as claimed in claim 3, which is characterized in that the fixed device is U-shaped buckle.
5. current in wire measuring device as claimed in claim 4, which is characterized in that Open Side Down for the U-shaped buckle, described
The a port of U-shaped buckle and the housing hinge, another port is detachably connected with the shell.
6. current in wire measuring device as claimed in claim 5, which is characterized in that the shell is equipped with and the conducting wire to be measured
Mutually matched inner concave.
7. current in wire measuring device as claimed in claim 4, which is characterized in that the U-shaped buckle is the bullet of opening upwards
Property buckle.
8. current in wire measuring device as claimed in claim 4, which is characterized in that the U-shaped buckle is plastic buckle.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821968785.1U CN209387735U (en) | 2018-11-27 | 2018-11-27 | Wire current measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821968785.1U CN209387735U (en) | 2018-11-27 | 2018-11-27 | Wire current measuring device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209387735U true CN209387735U (en) | 2019-09-13 |
Family
ID=67865584
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201821968785.1U Active CN209387735U (en) | 2018-11-27 | 2018-11-27 | Wire current measuring device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209387735U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109188067A (en) * | 2018-11-27 | 2019-01-11 | 南方电网科学研究院有限责任公司 | Wire current measuring device and method |
-
2018
- 2018-11-27 CN CN201821968785.1U patent/CN209387735U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109188067A (en) * | 2018-11-27 | 2019-01-11 | 南方电网科学研究院有限责任公司 | Wire current measuring device and method |
| CN109188067B (en) * | 2018-11-27 | 2024-03-19 | 南方电网科学研究院有限责任公司 | Wire current measuring device and method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109188067A (en) | Wire current measuring device and method | |
| CN106018942B (en) | It is a kind of for measuring the current sensor array and measurement method of three-phase current | |
| CN102323459A (en) | Alternating magnetic field-resistant manganin current divider | |
| CN103245824A (en) | Non-contact D-dot voltage transformer and voltage detection self-correcting method thereof | |
| CN107328980A (en) | Multicore cable noninvasive current measurement method and measurement apparatus | |
| CN206515387U (en) | Current sensing means and current detecting system | |
| CN209387735U (en) | Wire current measuring device | |
| CN103682862B (en) | A kind of ring main unit cable connector | |
| CN113721071A (en) | System and method for measuring non-intrusive voltage to ground | |
| CN202177647U (en) | Alternating magnetic field resistant manganin diverter | |
| US9547026B1 (en) | Plug-through energy monitor | |
| CN211453790U (en) | Non-contact electric field measurement system for fault indicator | |
| CN108761368A (en) | Aeolian vibration for transmission line of electricity monitors calibration method | |
| CN108195480A (en) | A kind of high-precision temperature detection circuit | |
| CN108535603A (en) | A kind of power circuit automatic fault detection positioning system | |
| CN216847923U (en) | Open-loop current clamp | |
| CN216956221U (en) | Non-invasive AC-DC line conductor current sensing device | |
| CN208937210U (en) | A kind of micro-structure fast temperature sensor and miniaturization Acquisition Circuit | |
| CN202350927U (en) | Intelligently universal digital display device | |
| CN206489220U (en) | One kind is based on single-chip microcomputer microresistivity survey system | |
| CN202854248U (en) | Lightning arrester on-line detection device | |
| CN206038177U (en) | Three -way formula platinum resistance PT100 temperature measuring system | |
| CN217133253U (en) | No magnetic core open-close type current detection circuit and current sensor | |
| CN115219959B (en) | Dry air reactor turn-to-turn short circuit magnetic field detection device based on magnetic resistance effect | |
| CN210243738U (en) | Three-core cable current detection device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |