CN107167696B - Device and method for detecting open circuit of inductor - Google Patents
Device and method for detecting open circuit of inductor Download PDFInfo
- Publication number
- CN107167696B CN107167696B CN201710428994.0A CN201710428994A CN107167696B CN 107167696 B CN107167696 B CN 107167696B CN 201710428994 A CN201710428994 A CN 201710428994A CN 107167696 B CN107167696 B CN 107167696B
- Authority
- CN
- China
- Prior art keywords
- inductor
- connecting rod
- electric field
- open circuit
- detecting
- 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
- 238000000034 method Methods 0.000 title claims abstract description 18
- 230000005684 electric field Effects 0.000 claims abstract description 73
- 238000001514 detection method Methods 0.000 claims abstract description 41
- 239000002184 metal Substances 0.000 claims description 37
- 238000012360 testing method Methods 0.000 claims description 16
- 239000000523 sample Substances 0.000 claims description 14
- 230000003287 optical effect Effects 0.000 claims description 8
- 230000001360 synchronised effect Effects 0.000 claims 2
- 239000000919 ceramic Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 230000001066 destructive effect Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
Abstract
The invention relates to a device and a method for detecting an open circuit of an inductor. A device for detecting an open circuit of an inductor, the inductor being a stacked inductor; comprising the following steps: a voltage providing device for providing a voltage between an input and an output of the inductor; and the electric field detection device is used for detecting and acquiring the electric field distribution of the surface of the inductor and judging the open circuit position of the inductor according to the electric field distribution of the surface of the inductor. The above-described apparatus for detecting an open circuit of an inductor supplies a voltage to the inductor through a voltage supply device. The electric field distribution of the inductor surface is detected and acquired by an electric field detection device. And judging the open circuit position of the inductor according to the electric field distribution of the surface of the inductor. Therefore, the open position inside the inductor can be detected by the device for detecting the open of the inductor.
Description
Technical Field
The present invention relates to the field of electronic information technology, and in particular, to a device and a method for detecting an open circuit of an inductor.
Background
Inductor open is a common form of inductor failure. The way to check the inductor for an open circuit is: pulse methods, microscopic observation methods, and the like. The pulse method tests the open circuit position by transmitting the pulse current through the delay line, generating reflection at the open circuit point, and determining the position of the open circuit point by the product of the feedback time of the pulse current and the propagation speed of electromagnetic wave. But the pulse method is widely used for testing the open-circuit point position of long-distance conveying lines, and is not suitable for detecting the open-circuit point of a short-distance ceramic inductor. Microscopic observation is to determine the location of an open circuit by magnifying the gap at the location of the open circuit, as is commonly used to analyze the open circuit condition of the surface inductors of a PCB board. In the case of an internal open circuit of an LTCC (low temperature cofired ceramic) electronic component, it is difficult to observe the internal open circuit directly by a microscope due to the shielding of solid substances such as ceramics and ferrite.
Disclosure of Invention
Based on this, it is necessary to provide an apparatus for detecting an open circuit of an inductor capable of detecting an open circuit position of a ceramic inductor, and a method for detecting an open circuit of an inductor.
A device for detecting an open circuit of an inductor, the inductor being a stacked inductor; comprising the following steps: a voltage providing device for providing a voltage between an input and an output of the inductor; and the electric field detection device is used for detecting and acquiring the electric field distribution of the surface of the inductor so as to judge the open circuit position of the inductor according to the electric field distribution of the surface of the inductor.
In one embodiment, the electric field detection device comprises a probe; the probe includes a charged test device.
In one embodiment, the apparatus further comprises a mechanical movement system; the mechanical moving system is connected with the probe, and the probe is moved to drive the testing equipment to move close to the surface of the inductor in a scanning mode so as to obtain electric field distribution on the surface of the inductor.
In one embodiment, the test device is a metal ball; the electric field detection device further comprises a connecting rod; the mechanical moving system is connected with the metal ball through the connecting rod.
In one embodiment, the connecting rods include a first connecting rod and a second connecting rod; the first connecting rod is connected with the metal ball; the second connecting rod is respectively connected with the first connecting rod and the mechanical moving system; the first connecting rod is used for enabling the metal ball to be close to the surface of the inductor for scanning movement; the second connecting rod is used for fixedly connecting the first connecting rod and the metal ball with a mechanical moving system.
In one embodiment, the first connecting rod is an insulating rod; the second connecting rod is a metal rod.
In one embodiment, the electric field detection device further comprises a detection module; the detection module is used for detecting the deformation state of the second connecting rod; the electric field detection equipment acquires electric field distribution on the surface of the inductor according to the deformation state of the second connecting rod.
In one embodiment, the detection module includes an optical transmitter and an optical receiver; the light emitter is used for emitting light to the connecting rod; the light receiver is used for receiving the reflected light; the detection module acquires the electric field distribution of the surface of the inductor according to the reflected light.
In one embodiment, the voltage providing device is a power supply.
A method of detecting an open circuit of an inductor, the inductor being a stacked inductor; comprising the following steps: providing a voltage between an input and an output of the inductor; detecting an electric field of the inductor surface to obtain an electric field distribution of the inductor surface; the electric field distribution of the inductor surface is analyzed to determine the open circuit location of the inductor.
The above-described apparatus for detecting an open circuit of an inductor supplies a voltage to the inductor through a voltage supply device. The electric field distribution of the inductor surface is detected and acquired by an electric field detection device. And judging the open circuit position of the inductor according to the electric field distribution of the surface of the inductor. Therefore, the open position inside the inductor can be detected by the device for detecting the open of the inductor.
Drawings
FIG. 1 is a schematic diagram of an apparatus for detecting an open inductor in an embodiment;
FIG. 2 is a schematic diagram of an apparatus for detecting an open inductor circuit in an embodiment;
FIG. 3 is a flow chart of a method of detecting an open inductor in one embodiment.
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.
As shown in fig. 1, an apparatus for detecting an open circuit of an inductor 10 includes a voltage providing device 200 and an electric field detecting device 300. Wherein the inductor 10 is a ceramic laminate inductor. The voltage supply device 200 is electrically connected to the inductor 10. The voltage supply device 200 is used to supply a voltage to the inductor 10. The electric field detecting apparatus 300 is configured to detect an electric field distribution of the surface of the inductor 10, and obtain the electric field distribution of the surface of the inductor 10, so as to determine an open position of the inductor 10 according to the electric field distribution of the surface of the inductor 10.
In the present embodiment, when the voltage supply device 200 supplies a voltage between the input terminal and the output terminal of the inductor 10, the electric field detection device 300 detects the electric field of the surface of the inductor 10 and acquires the electric field distribution of the surface of the inductor 10. The electric field detection apparatus 300 judges the open position of the inductor 10 according to the electric field distribution of the surface of the inductor 10.
The above-described apparatus for detecting an open circuit of an inductor supplies a voltage to the inductor 10 through the voltage supply device 200. The electric field distribution of the surface of the inductor 10 is detected and acquired by the electric field detection device 300. The open position of the inductor 10 is determined based on the electric field distribution at the surface of the inductor 10. Therefore, the open position inside the inductor 10 can be detected by the device for detecting the open of the inductor.
Meanwhile, the device for detecting the open circuit of the inductor 10 can obtain the open circuit point of the inductor 10 without carrying out destructive analysis on the inductor 10, avoids introducing a new failure mode in failure analysis, and can accurately obtain the open circuit position information of the inductor 10. Compared with destructive analysis experiments, the method avoids the introduction of new failure modes and improves the detection efficiency.
The electric field detection apparatus 300 includes a probe and a connection rod. The means for detecting the opening of the inductor 10 further comprises a mechanical movement system. The probe includes a charged test device. In this embodiment, the test device is a metal ball. I.e. the probe comprises a metal sphere with an electrical charge. Wherein the charge on the metal sphere can be either positive or negative. The mechanical moving system is connected with the probe through a connecting rod. The mechanical moving system drives the test equipment to be close to the surface of the inductor 10 but not in contact with the surface of the inductor 10 through the moving probe so as to perform scanning movement, thereby obtaining electric field distribution of the surface of the inductor 10. The connecting rod comprises a first connecting rod and a second connecting rod. The first connecting rod is connected with the metal ball. The second connecting rod is connected with the first connecting rod and the mechanical moving system respectively. The first connecting rod makes the metal ball to move in scanning mode near the surface of the inductor. The second connecting rod fixedly connects the first connecting rod and the metal ball with the mechanical moving system. The first connecting rod is an insulating rod to prevent the charge of the metal ball from diffusing.
The electric field detection device 300 further comprises a detection module. The detection module is used for detecting the deformation state of the second connecting rod so as to detect the electric field distribution condition of the surface of the inductor 10 according to the deformation state of the second connecting rod. In this embodiment, the detection module includes an optical transmitter and an optical receiver. The light emitter is used for emitting light to the second connecting rod. The light receiver is used for receiving the reflected light. The detection module detects and acquires the electric field distribution of the surface of the inductor 10 from the reflected light. In the scanning process, the metal ball connected with the first connecting rod generates a certain electric field force on the metal ball by an electric field generated at the open-circuit part of the inductor 10, so that the second connecting rod is deformed. After the light emitted by the light emitter irradiates the second connecting rod, the position of the light spot of the reflected light changes due to the deformation of the second connecting rod, so that the stress condition of the metal ball is deduced, and the electric field distribution on the surface of the inductor 10 is obtained. Based on the electric field distribution, an open circuit location of the inductor 10 can be obtained. In this embodiment, the second connection rod is a metal rod to reflect the emitted light through the metal rod.
Fig. 2 is a schematic diagram of an apparatus for detecting an open circuit of an inductor. As shown in fig. 2, an apparatus for detecting an open circuit of an inductor includes a voltage source V1 as a voltage providing device 200, a metal ball 311, a first connection rod 313, a second connection rod 315, a mechanical moving system 410, and a detection module 510. The first connection rod 313 is an insulating rod. The second connecting rod 315 is a metal rod. The metal ball 311 is connected to the mechanical movement system 410 through a first connection rod 313 and a second connection rod 315. The detection module 510 includes an optical transmitter and an optical receiver. In this embodiment, the light emitter is a laser light emitter. The light receiver is a laser light receiver. The laser transmitter emits laser light to the second link 315. The laser receiver receives the reflected laser light.
The inductor 10 is placed on an insulated horizontal surface 20. The inductor 10 is connected across the voltage source V1 by wires. The mechanical movement system 410 moves the metal balls 311 over the surface of the inductor 10 to scan the surface of the inductor 10 point by point. Wherein, the metal balls 311 are not in contact with the surface of the inductor 10 during the moving scan. During the movement, the metal ball 311 receives the electric field force generated at the open circuit portion of the inductor 10. The electric field force causes the second connecting rod 315 to deform. When the laser irradiates the second link 315, the second link 315 deforms to change the position of the reflected light spot. By recording the change in spot position, the electric field distribution at the surface of the inductor 10 is deduced, thereby obtaining the open circuit position of the inductor 10.
In one embodiment, the detection module 510 moves synchronously with the second connecting rod 315 to eliminate interference of the relative movement of the second connecting rod 315 and the detection module 510 with the reflected light spot position.
The invention also provides a method for detecting the open circuit of the inductor. The inductor is a laminated inductor. In one embodiment, the method may use the aforementioned means for detecting an open inductor to perform open inductor detection. As shown in fig. 3, a method of detecting an inductor open circuit includes:
step S101 provides a voltage between the input and the output of the inductor.
In this embodiment, the inductor is connected to a voltage source through metal wires at both ends of the inductor to supply voltage to the inductor.
In step S103, the electric field of the inductor surface is detected to obtain the electric field distribution of the inductor surface.
After the inductor turns on the voltage, the electric field at the inductor surface is detected. In this embodiment, the electric field at the inductor surface is detected by placing a metal ball with a charge on the inductor surface but not in contact with the inductor surface. Specifically, the metal balls with charges (the charges on the metal balls can be positive charges or negative charges) are connected with a mechanical moving system through a horizontal connecting rod, and the metal balls are moved on the surface of the inductor through the mechanical moving system so as to scan the surface of the inductor point by point.
In the scanning process, an electric field generated at the open-circuit part of the inductor can generate certain electric field force on the metal ball, so that the horizontal connecting rod is deformed. After the laser is irradiated on the horizontal connecting rod through the laser transmitter, the position of a light spot of laser reflected light changes due to the deformation of the horizontal connecting rod. The stress condition of the metal ball can be deduced by receiving the emitted light through the laser receiver, so that the electric field distribution on the surface of the inductor is obtained. By the electric field distribution of the inductor surface, an open circuit portion of the inductor can be obtained.
Step S105, the electric field distribution of the inductor surface is analyzed to determine the open circuit position of the inductor.
In this embodiment, the open circuit position of the inductor can be determined according to the distribution of the electric field lines. The open position of the inductor is different from the electric field line distribution of the position of the inductor where the open circuit does not exist, so the open circuit position of the inductor can be judged according to the acquired electric field distribution of the surface of the inductor.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.
Claims (8)
1. A device for detecting an open circuit of an inductor, the inductor being a stacked inductor; characterized by comprising the following steps:
a voltage providing device for providing a voltage between an input and an output of the inductor;
the electric field detection device is used for detecting and acquiring electric field distribution of the surface of the inductor so as to judge the open circuit position of the inductor according to the electric field distribution of the surface of the inductor;
the electric field detection device comprises a probe, a connecting rod and a detection module, wherein the probe comprises a testing device with charges, the connecting rod comprises a first connecting rod and a second connecting rod, and the first connecting rod is connected with the testing device so as to enable the testing device to perform scanning movement;
the second connecting rod is connected with the first connecting rod and the mechanical moving system respectively, the detection module is used for detecting the deformation state of the second connecting rod, and the electric field detection equipment acquires the electric field distribution on the surface of the inductor according to the deformation state of the second connecting rod;
wherein, detection module with the synchronous removal of second connecting rod.
2. The apparatus of claim 1, wherein the mechanical movement system moves the probe to cause the test device to perform a scanning motion proximate the inductor surface to obtain an electric field distribution across the inductor surface.
3. The apparatus of claim 2, wherein the test device is a metal sphere; the mechanical moving system is connected with the metal ball through the connecting rod.
4. A device according to claim 3, wherein the first connecting rod is connected to the metal ball; the first connecting rod is used for enabling the metal ball to be close to the surface of the inductor for scanning movement; the second connecting rod is used for fixedly connecting the first connecting rod and the metal ball with a mechanical moving system.
5. The apparatus of claim 4, wherein the first connecting rod is an insulating rod; the second connecting rod is a metal rod.
6. The apparatus of claim 1, wherein the detection module comprises an optical transmitter and an optical receiver; the light emitter is used for emitting light to the connecting rod; the light receiver is used for receiving the reflected light; the detection module acquires the electric field distribution of the surface of the inductor according to the reflected light.
7. The apparatus of claim 1, wherein the voltage providing device is a power source.
8. A method of detecting an open circuit of an inductor, the inductor being a stacked inductor; characterized by comprising the following steps:
a voltage providing device providing a voltage between an input and an output of the inductor;
the electric field detection equipment detects the deformation state of a second connecting rod, acquires the electric field distribution of the surface of the inductor according to the deformation state of the second connecting rod, and analyzes the electric field distribution of the surface of the inductor to judge the open circuit position of the inductor;
the electric field detection device comprises a probe, a connecting rod and a detection module, wherein the probe comprises a testing device with charges, the connecting rod comprises a first connecting rod and a second connecting rod, and the first connecting rod is connected with the testing device so as to enable the testing device to perform scanning movement; the second connecting rod is respectively connected with the first connecting rod and the mechanical moving system, the detection module is used for detecting the deformation state of the second connecting rod, and the electric field detection equipment acquires the electric field distribution on the surface of the inductor according to the deformation state of the second connecting rod; wherein, detection module with the synchronous removal of second connecting rod.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710428994.0A CN107167696B (en) | 2017-06-08 | 2017-06-08 | Device and method for detecting open circuit of inductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710428994.0A CN107167696B (en) | 2017-06-08 | 2017-06-08 | Device and method for detecting open circuit of inductor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107167696A CN107167696A (en) | 2017-09-15 |
| CN107167696B true CN107167696B (en) | 2024-04-09 |
Family
ID=59825656
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710428994.0A Active CN107167696B (en) | 2017-06-08 | 2017-06-08 | Device and method for detecting open circuit of inductor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107167696B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107817416A (en) * | 2017-12-01 | 2018-03-20 | 深圳振华富电子有限公司 | Electric conductor off position detection means and detection method |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4321254A1 (en) * | 1993-06-25 | 1995-01-05 | Horst Dr Ing Habil Ahlers | Force sensor |
| JPH07159465A (en) * | 1993-12-10 | 1995-06-23 | Dainippon Printing Co Ltd | Surface potential reading device |
| KR20000011081A (en) * | 1997-03-17 | 2000-02-25 | 아키노리 이토 | Method and equipment for treating electrostatic field and electrode used therein |
| US6377048B1 (en) * | 2000-11-08 | 2002-04-23 | Topspin Medical (Israel) Limited | Magnetic resonance imaging device for operation in external static magnetic fields |
| CN1700026A (en) * | 2004-05-18 | 2005-11-23 | Lg电子有限公司 | Apparatus and method of detecting breakdown of conducting wires |
| CN102156218A (en) * | 2011-03-17 | 2011-08-17 | 重庆大学 | Device and method for measuring voltage of noncontact charge induced high-voltage transmission line |
| CN102526745A (en) * | 2012-02-02 | 2012-07-04 | 西安交通大学 | Slow-release method for controlling medicine-carrying molecules of lyotopic liquid crystal by using micro electric field |
| CN103926475A (en) * | 2014-04-08 | 2014-07-16 | 沈阳工业大学 | Electric field measuring method and measuring system thereof |
| CN103983887A (en) * | 2014-05-23 | 2014-08-13 | 工业和信息化部电子第五研究所 | Automatic locating method and device for open circuit of circuit |
| CN204789902U (en) * | 2015-07-03 | 2015-11-18 | 中国科学院物理研究所 | System for an electric charge and electric field response for detecting semiconductor device |
| CN105301199A (en) * | 2015-11-11 | 2016-02-03 | 北京大学 | Probe system multi-filed loading device |
| CN207067297U (en) * | 2017-06-08 | 2018-03-02 | 深圳振华富电子有限公司 | Detect the device of inductor open circuit |
-
2017
- 2017-06-08 CN CN201710428994.0A patent/CN107167696B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4321254A1 (en) * | 1993-06-25 | 1995-01-05 | Horst Dr Ing Habil Ahlers | Force sensor |
| JPH07159465A (en) * | 1993-12-10 | 1995-06-23 | Dainippon Printing Co Ltd | Surface potential reading device |
| KR20000011081A (en) * | 1997-03-17 | 2000-02-25 | 아키노리 이토 | Method and equipment for treating electrostatic field and electrode used therein |
| US6377048B1 (en) * | 2000-11-08 | 2002-04-23 | Topspin Medical (Israel) Limited | Magnetic resonance imaging device for operation in external static magnetic fields |
| CN1700026A (en) * | 2004-05-18 | 2005-11-23 | Lg电子有限公司 | Apparatus and method of detecting breakdown of conducting wires |
| CN102156218A (en) * | 2011-03-17 | 2011-08-17 | 重庆大学 | Device and method for measuring voltage of noncontact charge induced high-voltage transmission line |
| CN102526745A (en) * | 2012-02-02 | 2012-07-04 | 西安交通大学 | Slow-release method for controlling medicine-carrying molecules of lyotopic liquid crystal by using micro electric field |
| CN103926475A (en) * | 2014-04-08 | 2014-07-16 | 沈阳工业大学 | Electric field measuring method and measuring system thereof |
| CN103983887A (en) * | 2014-05-23 | 2014-08-13 | 工业和信息化部电子第五研究所 | Automatic locating method and device for open circuit of circuit |
| CN204789902U (en) * | 2015-07-03 | 2015-11-18 | 中国科学院物理研究所 | System for an electric charge and electric field response for detecting semiconductor device |
| CN105301199A (en) * | 2015-11-11 | 2016-02-03 | 北京大学 | Probe system multi-filed loading device |
| CN207067297U (en) * | 2017-06-08 | 2018-03-02 | 深圳振华富电子有限公司 | Detect the device of inductor open circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107167696A (en) | 2017-09-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11421986B2 (en) | Method, apparatus, system and sensor for detecting multi-mode electromagnetic acoustic and magnetic flux leakage | |
| US8474320B2 (en) | Method and apparatus for locating cable faults | |
| Okabe et al. | New aspects of UHF PD diagnostics on gas-insulated systems | |
| US20170168024A1 (en) | Monitoring systems and methods for electrical machines | |
| US6853196B1 (en) | Method and apparatus for electrical cable testing by pulse-arrested spark discharge | |
| CN203799002U (en) | Data acquisition device for verification testing of partial discharge supersonic reflectoscope | |
| CN103323682A (en) | Low level scanning filed high and strong radiation field testing system and low level scanning filed high and strong radiation field testing method | |
| JP2008032587A (en) | Ae sensor using interference-type optical fiber, and partial discharge measuring device by ae sensor | |
| CN107167696B (en) | Device and method for detecting open circuit of inductor | |
| Soomro et al. | Study on different techniques of partial discharge (PD) detection in power transformers winding: Simulation between paper and EPOXY resin using UHF method | |
| JP2013152155A (en) | Evaluation method and apparatus for non-contact discharge | |
| CN108008279B (en) | Circuit radio frequency noise test system, method and device | |
| CN105074451A (en) | Ultrasonic inspection device and ultrasonic inspection method | |
| CN103744004A (en) | Transformer/reactor partial discharge online monitoring method and monitoring system | |
| CN207067297U (en) | Detect the device of inductor open circuit | |
| CN103983887B (en) | Automatic locating method and device for open circuit of circuit | |
| CN210222183U (en) | Equipment and device for testing consistency of ultrahigh frequency-optical signals in GIS | |
| RU2440568C1 (en) | Method for high-speed detailed ultrasonic inspection of rails | |
| Rahbarimagham et al. | Determination of transformer HV winding axial displacement occurrence, direction, and extent using time‐domain analysis of UWB signals | |
| Wang et al. | Electromagnetic Thermoacoustic Technique for Online Dynamic Detection of High-Speed Rail Internal Defect at Early Stage: Theory, Implementation, and Field Trial | |
| CN207675862U (en) | Electric conductor off position detection device | |
| CN110082658A (en) | Superfrequency-optical signal uniformity test unit and method in GIS | |
| Ji et al. | An ESD immunity test for battery-operated control circuit board in myoelectric artificial hand system | |
| CN111879960A (en) | Laser ranging-based linear pull rod circuit breaker speed testing system and testing method | |
| KR102331029B1 (en) | Optical damage detection device |
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 |