CN207964957U - A kind of three-phase power detection circuit - Google Patents
A kind of three-phase power detection circuit Download PDFInfo
- Publication number
- CN207964957U CN207964957U CN201820120658.XU CN201820120658U CN207964957U CN 207964957 U CN207964957 U CN 207964957U CN 201820120658 U CN201820120658 U CN 201820120658U CN 207964957 U CN207964957 U CN 207964957U
- Authority
- CN
- China
- Prior art keywords
- diode
- phase
- resistance
- coupler
- photo
- 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.)
- Withdrawn - After Issue
Links
Landscapes
- Emergency Protection Circuit Devices (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
Abstract
The utility model discloses a kind of three-phase power detection circuits, the detection method for solving the prior art is to detect whether three-phase electricity has misphase, phase shortage by three chip pins, three ports of chip detect the square wave of some cycles, if detecting three-phase signal not is changed by 120 degree of difference sequences, then explanation is phase sequence mistake, needs the test for carrying out phase, and there are three external interrupt pins, result in cumbersome, of high cost technical problem.
Description
Technical field
The utility model is related to field of power detection more particularly to a kind of three-phase power detection circuits.
Background technology
Currently, electric appliance in the market is required for detecting three-phase electricity in advance, to prevent three-phase electricity from occurring when using three-phase electricity
Misphase or phase shortage make equipment damage, and whether the detection method of the prior art is wrong by three chip pins detection three-phase electricities
Three ports of phase, phase shortage, chip detect the square wave of some cycles, if detecting three-phase signal not is differed by 120 degree
Sequence changes, then explanation is phase sequence mistake, needs the test for carrying out phase, and there are three external interrupt pins, result in operation
Cumbersome, of high cost technical problem.
Utility model content
The utility model provides a kind of three-phase power detection circuit, and the detection method for solving the prior art is by three
Whether a chip pin detection three-phase electricity has misphase, phase shortage, three ports of chip to detect the square wave of some cycles, if inspection
Measuring three-phase signal not is changed by 120 degree of difference sequences, then explanation is phase sequence mistake, needs the test for carrying out phase, and have
Three external interrupt pins, result in cumbersome, of high cost technical problem.
A kind of three-phase power detection circuit provided by the utility model, including：
First diode, first resistor, the second diode, the first photo-coupler, second resistance, the first capacitance, third electricity
Resistance, the first pull-up power supply, third diode, the 4th resistance, the 4th diode, the second photo-coupler, the 5th resistance, the second electricity
Appearance, the 6th resistance and the second pull-up power supply；
One end of first diode is electrically connected with first in the three-phase electricity, first diode it is another
End is electrically connected with one end of the first resistor, and the other end of the first resistor and the cathode of second diode are electrically connected
Connect, the luminescent device of first photo-coupler is connected in parallel on second diode both ends, first photo-coupler it is photosensitive
First output end of device is electrically connected with one end of the second resistance, first capacitance and the 3rd resistor respectively, institute
The other end for stating 3rd resistor is connect with first pull-up power supply, the second output of the light-sensitive device of first photo-coupler
End is electrically connected with the other end of first capacitance；
One end of the third diode is electrically connected with second in the three-phase electricity, the third diode it is another
End is electrically connected with one end of the 4th resistance, and the cathode of the other end and the 4th diode of the 4th resistance is electrically connected
Connect, the luminescent device of second photo-coupler is connected in parallel on the 4th diode both ends, second photo-coupler it is photosensitive
First output end of device is electrically connected with one end of the 5th resistance, second capacitance and the 6th resistance respectively, institute
The other end for stating the 6th resistance is connect with second pull-up power supply, the second output of the light-sensitive device of second photo-coupler
End is electrically connected with the other end of second capacitance.
Preferably, the second output terminal ground connection of the light-sensitive device of first photo-coupler.
Preferably, the second output terminal ground connection of the light-sensitive device of second photo-coupler.
Preferably, first pull-up power supply is 5V.
Preferably, second pull-up power supply is 5V.
A kind of three-phase power detection circuit provided by the utility model, including：First diode, first resistor, the two or two pole
Pipe, the first photo-coupler, second resistance, the first capacitance, 3rd resistor, the first pull-up power supply, third diode, the 4th resistance,
4th diode, the second photo-coupler, the 5th resistance, the second capacitance, the 6th resistance and the second pull-up power supply；One or two pole
One end of pipe is electrically connected with first in the three-phase electricity, the other end of first diode and the one of the first resistor
End electrical connection, the other end of the first resistor are electrically connected with the cathode of second diode, first photo-coupler
Luminescent device is connected in parallel on second diode both ends, the first output end of the light-sensitive device of first photo-coupler respectively with
One end of the second resistance, first capacitance and the 3rd resistor is electrically connected, the other end of the 3rd resistor and institute
The connection of the first pull-up power supply is stated, the second output terminal of the light-sensitive device of first photo-coupler is another with first capacitance
End electrical connection；One end of the third diode is electrically connected with second in the three-phase electricity, the third diode it is another
One end is electrically connected with one end of the 4th resistance, and the cathode of the other end and the 4th diode of the 4th resistance is electrically connected
Connect, the luminescent device of second photo-coupler is connected in parallel on the 4th diode both ends, second photo-coupler it is photosensitive
First output end of device is electrically connected with one end of the 5th resistance, second capacitance and the 6th resistance respectively, institute
The other end for stating the 6th resistance is connect with second pull-up power supply, the second output of the light-sensitive device of second photo-coupler
End is electrically connected with the other end of second capacitance.
In the utility model, by regarding the two-phase electricity of three-phase electricity as input, structure detects the circuit of mutually electric low and high level,
Three-phase electric performance test can be carried out by the temporal characteristics of each phase electricity low and high level, the detection method for solving the prior art is
Detect whether three-phase electricity has misphase, phase shortage, three ports of chip to detect the side of some cycles by three chip pins
Wave illustrates it is phase sequence mistake, needs the survey for carrying out phase if detecting three-phase signal not is changed by 120 degree of difference sequences
Examination, and there are three external interrupt pins, result in cumbersome, of high cost technical problem.
Description of the drawings
In order to illustrate the embodiment of the utility model or the technical proposal in the existing technology more clearly, below will be to embodiment
Or attached drawing needed to be used in the description of the prior art is briefly described, it should be apparent that, the accompanying drawings in the following description is only
It is some embodiments of the utility model, for those of ordinary skill in the art, before not making the creative labor property
It puts, can also be obtained according to these attached drawings other attached drawings.
Fig. 1 is a kind of structural schematic diagram of one embodiment of three-phase power detection circuit provided by the utility model；
It is description of the drawings below：
D1, the first diode；R1, first resistor；D2, the second diode；G1, the first photo-coupler；R2, second resistance；
C1, the first capacitance；R3,3rd resistor；VCC1, the first pull-up power supply；D3, third diode；R4, the 4th resistance；D4, the four or two
Pole pipe；G2, the second photo-coupler；R5, the 5th resistance；C2, the second capacitance；R6, the 6th resistance；VCC2, the second pull-up power supply.
Specific implementation mode
The utility model embodiment provides a kind of three-phase power detection circuit and method, solves the detection side of the prior art
Method is to detect whether three-phase electricity has misphase, phase shortage, three ports of chip to detect some cycles by three chip pins
Square wave, change by 120 degree of differences sequences if detecting three-phase signal not and being, illustrate it is phase sequence mistake, need progress phase
Test, and there are three external interrupt pin, result in cumbersome, of high cost technical problem.
It, below will knot to enable the purpose of utility model, feature, advantage of the utility model more apparent and understandable
The attached drawing in the utility model embodiment is closed, the technical scheme in the utility model embodiment is clearly and completely described,
Obviously, the embodiments described below are only the utility model a part of the embodiment, and not all embodiment.Based on this reality
It is obtained by those of ordinary skill in the art without making creative efforts all other with the embodiment in novel
Embodiment shall fall within the protection scope of the present invention.
Referring to Fig. 1, the utility model embodiment provides a kind of one embodiment of three-phase power detection circuit, including：
First diode D1, first resistor R1, the second diode D2, the first photo-coupler G1, second resistance R2, the first electricity
Hold C1,3rd resistor R3, the first pull-up power supply VCC1, third diode D3, the 4th resistance R4, the 4th diode D4, the second light
Coupler G2, the 5th resistance R5, the second capacitance C2, the 6th resistance and the second pull-up power supply VCC2；
First in one end and three-phase electricity of first diode D1 is electrically connected, the other end and first of the first diode D1
One end of resistance R1 is electrically connected, and the other end of first resistor R1 is electrically connected with the cathode of the second diode D2, the first photo-coupler
The luminescent device of G1 is connected in parallel on the second both ends diode D2, the first output end of the light-sensitive device of the first photo-coupler G1 respectively with
One end of second resistance R2, the first capacitance C1 and 3rd resistor R3 are electrically connected, the other end of 3rd resistor R3 and the first pull-up electricity
Source VCC1 connections, the second output terminal of the light-sensitive device of the first photo-coupler G1 are electrically connected with the other end of the first capacitance C1；
It should be noted that the first phase in three-phase electricity can be any one phase in three-phase；
Second in one end and three-phase electricity of third diode D3 is electrically connected, the other end and the 4th of third diode D3
One end of resistance R4 is electrically connected, and the other end of the 4th resistance R4 is electrically connected with the cathode of the 4th diode D4, the second photo-coupler
The luminescent device of G2 is connected in parallel on the 4th both ends diode D4, the first output end of the light-sensitive device of the second photo-coupler G2 respectively with
One end of 5th resistance R5, the second capacitance C2 and the 6th resistance are electrically connected, the other end and the second pull-up power supply of the 6th resistance
VCC2 connections, the second output terminal of the light-sensitive device of the second photo-coupler G2 are electrically connected with the other end of the second capacitance C2；
It should be noted that the second phase in three-phase electricity is any one phase in addition to the first phase in three-phase electricity；
It is understood that when PB feet are the positive part of sine wave, optocoupler G1 conductings, C Ph. detect low level,
If PB feet do not connect power supply, C Ph. detect always high level；
When PC feet are the positive part of sine wave, optocoupler G2 conductings, B Ph. detect low level, if PC feet do not have
Power supply is connect, then B Ph. detect always high level；
In the actual implementation process, L connects A phase electricity, and PB connects C phase electricity, and PC connects B phase electricity, when the low level for detecting C phase electricity
Afterwards, with t=0 and timing can be started, then detects the low level of B phase electricity, the value of t is 11.11ms (60HZ) or 13.33ms
(50HZ) thinks misphase, it is i.e. normal to exchange BC phases；
When L connects B phase electricity, PB connects A phase electricity, and PC connects C phase electricity, after detecting the low level of A phase electricity, t=0 and starts to count
When, then the low level of C phase electricity is detected, the value of t is 11.11ms (60HZ) or 13.33ms (50HZ), that is, thinks misphase, is exchanged
AC phases are i.e. normal.
When L (No. 5 terminals) connects C phases electricity, PB (No. 3 terminals) connects B phase electricity, and it is electric that PC (No. 1 terminal) connects A phases, when detecting B phases
After the low level of electricity, t=0 and start timing, then detect the low level of A phase electricity, the value of t be 11.11ms (60HZ) or
13.33ms (50HZ) thinks misphase, and it is i.e. normal to exchange AB phases.
In the utility model embodiment, pass through the first diode D1, first resistor R1, the second diode D2, the first optocoupler
Clutch G1, second resistance R2, the first capacitance C1,3rd resistor R3, the first pull-up power supply VCC1, third diode D3, the 4th electricity
Hinder R4, the 4th diode D4, the second photo-coupler G2, the 5th resistance R5, the second capacitance C2, the 6th resistance and the second pull-up power supply
VCC2；First in one end and three-phase electricity of first diode D1 is electrically connected, the other end of the first diode D1 and the first electricity
One end electrical connection of R1 is hindered, the other end of first resistor R1 is electrically connected with the cathode of the second diode D2, the first photo-coupler G1
Luminescent device be connected in parallel on the second both ends diode D2, the first output end of the light-sensitive device of the first photo-coupler G1 is respectively with
One end of two resistance R2, the first capacitance C1 and 3rd resistor R3 are electrically connected, the other end of 3rd resistor R3 and the first pull-up power supply
VCC1 connections, the second output terminal of the light-sensitive device of the first photo-coupler G1 are electrically connected with the other end of the first capacitance C1；Third
Second in one end and three-phase electricity of diode D3 is electrically connected, one end of the other end and the 4th resistance R4 of third diode D3
Electrical connection, the other end of the 4th resistance R4 are electrically connected with the cathode of the 4th diode D4, the luminescent device of the second photo-coupler G2
Be connected in parallel on the 4th both ends diode D4, the first output end of the light-sensitive device of the second photo-coupler G2 respectively with the 5th resistance R5,
One end of second capacitance C2 and the 6th resistance is electrically connected, and the other end of the 6th resistance is connect with the second pull-up power supply VCC2, and second
The second output terminal of the light-sensitive device of photo-coupler G2 is electrically connected with the other end of the second capacitance C2, by by the two-phase of three-phase electricity
For electricity as input, structure detects the circuit of mutually electric low and high level, can carry out three by the temporal characteristics of each phase electricity low and high level
Phase electric performance test, the detection method for solving the prior art be by three chip pins detect three-phase electricities whether have misphase,
Three ports of phase shortage, chip detect the square wave of some cycles, if it is by 120 degree of difference sequences to detect three-phase signal not
Variation, then explanation is phase sequence mistake, needs the test for carrying out phase, and there are three external interrupt pin, result in it is cumbersome,
Technical problem of high cost.
It is the description carried out to a kind of one embodiment of three-phase power detection circuit above, it below will be to a kind of three-phase electric-examination
Another embodiment of slowdown monitoring circuit is described in detail.
Referring to Fig.1, another embodiment of a kind of three-phase power detection circuit provided by the utility model, including：
First diode D1, first resistor R1, the second diode D2, the first photo-coupler G1, second resistance R2, the first electricity
Hold C1,3rd resistor R3, the first pull-up power supply VCC1, third diode D3, the 4th resistance R4, the 4th diode D4, the second light
Coupler G2, the 5th resistance R5, the second capacitance C2, the 6th resistance and the second pull-up power supply VCC2；
First in one end and three-phase electricity of first diode D1 is electrically connected, the other end and first of the first diode D1
One end of resistance R1 is electrically connected, and the other end of first resistor R1 is electrically connected with the cathode of the second diode D2, the first photo-coupler
The luminescent device of G1 is connected in parallel on the second both ends diode D2, the first output end of the light-sensitive device of the first photo-coupler G1 respectively with
One end of second resistance R2, the first capacitance C1 and 3rd resistor R3 are electrically connected, the other end of 3rd resistor R3 and the first pull-up electricity
Source VCC1 connections, the second output terminal of the light-sensitive device of the first photo-coupler G1 are electrically connected with the other end of the first capacitance C1；
Second in one end and three-phase electricity of third diode D3 is electrically connected, the other end and the 4th of third diode D3
One end of resistance R4 is electrically connected, and the other end of the 4th resistance R4 is electrically connected with the cathode of the 4th diode D4, the second photo-coupler
The luminescent device of G2 is connected in parallel on the 4th both ends diode D4, the first output end of the light-sensitive device of the second photo-coupler G2 respectively with
One end of 5th resistance R5, the second capacitance C2 and the 6th resistance are electrically connected, the other end and the second pull-up power supply of the 6th resistance
VCC2 connections, the second output terminal of the light-sensitive device of the second photo-coupler G2 are electrically connected with the other end of the second capacitance C2；
The second output terminal of the light-sensitive device of first photo-coupler G1 is grounded.
The second output terminal of the light-sensitive device of second photo-coupler G2 is grounded.
First pull-up power supply VCC1 is 5V.
Second pull-up power supply VCC2 is 5V.
In the utility model embodiment, pass through the first diode D1, first resistor R1, the second diode D2, the first optocoupler
Clutch G1, second resistance R2, the first capacitance C1,3rd resistor R3, the first pull-up power supply VCC1, third diode D3, the 4th electricity
Hinder R4, the 4th diode D4, the second photo-coupler G2, the 5th resistance R5, the second capacitance C2, the 6th resistance and the second pull-up power supply
VCC2；First in one end and three-phase electricity of first diode D1 is electrically connected, the other end of the first diode D1 and the first electricity
One end electrical connection of R1 is hindered, the other end of first resistor R1 is electrically connected with the cathode of the second diode D2, the first photo-coupler G1
Luminescent device be connected in parallel on the second both ends diode D2, the first output end of the light-sensitive device of the first photo-coupler G1 is respectively with
One end of two resistance R2, the first capacitance C1 and 3rd resistor R3 are electrically connected, the other end of 3rd resistor R3 and the first pull-up power supply
VCC1 connections, the second output terminal of the light-sensitive device of the first photo-coupler G1 are electrically connected with the other end of the first capacitance C1；Third
Second in one end and three-phase electricity of diode D3 is electrically connected, one end of the other end and the 4th resistance R4 of third diode D3
Electrical connection, the other end of the 4th resistance R4 are electrically connected with the cathode of the 4th diode D4, the luminescent device of the second photo-coupler G2
Be connected in parallel on the 4th both ends diode D4, the first output end of the light-sensitive device of the second photo-coupler G2 respectively with the 5th resistance R5,
One end of second capacitance C2 and the 6th resistance is electrically connected, and the other end of the 6th resistance is connect with the second pull-up power supply VCC2, and second
The second output terminal of the light-sensitive device of photo-coupler G2 is electrically connected with the other end of the second capacitance C2, the light of the first photo-coupler G1
The second output terminal of sensing device is grounded, the second output terminal ground connection of the light-sensitive device of the second photo-coupler G2；First pull-up power supply
VCC1 is 5V；Second pull-up power supply VCC2 is 5V, by regarding the two-phase electricity of three-phase electricity as input, structure detection phase electricity height electricity
Flat circuit can carry out three-phase electric performance test by the temporal characteristics of each phase electricity low and high level, solve the prior art
Detection method is to detect whether three-phase electricity has misphase, phase shortage, three ports of chip to detect one by three chip pins
The square wave of fixed cycle is changed by 120 degree of differences sequences if detecting three-phase signal not and being, illustrates it is phase sequence mistake, need into
The test of row phase, and there are three external interrupt pins, result in cumbersome, of high cost technical problem.
Specific implementation mode in the present embodiment illustrates which is not described herein again in the above-described embodiments.
It is apparent to those skilled in the art that for convenience and simplicity of description, the system of foregoing description,
The specific work process of system and module, can refer to corresponding processes in the foregoing method embodiment, and details are not described herein.
The above, above example are only to illustrate the technical solution of the utility model, rather than its limitations；Although ginseng
The utility model is described in detail according to previous embodiment, it will be understood by those of ordinary skill in the art that：It is still
Can be with technical scheme described in the above embodiments is modified, or which part technical characteristic is equally replaced
It changes；And these modifications or replacements, various embodiments of the utility model technical solution that it does not separate the essence of the corresponding technical solution
Spirit and scope.
Claims (5)
1. a kind of three-phase power detection circuit, feature are, including：
First diode, first resistor, the second diode, the first photo-coupler, second resistance, the first capacitance, 3rd resistor,
One pull-up power supply, third diode, the 4th resistance, the 4th diode, the second photo-coupler, the 5th resistance, the second capacitance, the 6th
Resistance and the second pull-up power supply；
One end of first diode is electrically connected with first in the three-phase electricity, the other end of first diode with
One end of the first resistor is electrically connected, and the other end of the first resistor is electrically connected with the cathode of second diode, institute
The luminescent device for stating the first photo-coupler is connected in parallel on second diode both ends, the light-sensitive device of first photo-coupler
First output end is electrically connected with one end of the second resistance, first capacitance and the 3rd resistor respectively, the third
The other end of resistance is connect with first pull-up power supply, the second output terminal of the light-sensitive device of first photo-coupler and institute
State the other end electrical connection of the first capacitance；
One end of the third diode is electrically connected with second in the three-phase electricity, the other end of the third diode with
One end of 4th resistance is electrically connected, and the other end of the 4th resistance is electrically connected with the cathode of the 4th diode, institute
The luminescent device for stating the second photo-coupler is connected in parallel on the 4th diode both ends, the light-sensitive device of second photo-coupler
First output end is electrically connected with one end of the 5th resistance, second capacitance and the 6th resistance respectively, and the described 6th
The other end of resistance is connect with second pull-up power supply, the second output terminal of the light-sensitive device of second photo-coupler and institute
State the other end electrical connection of the second capacitance.
2. three-phase power detection circuit according to claim 1, which is characterized in that the light-sensitive device of first photo-coupler
Second output terminal ground connection.
3. three-phase power detection circuit according to claim 2, which is characterized in that the light-sensitive device of second photo-coupler
Second output terminal ground connection.
4. three-phase power detection circuit according to claim 3, which is characterized in that first pull-up power supply is 5V.
5. three-phase power detection circuit according to claim 4, which is characterized in that second pull-up power supply is 5V.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820120658.XU CN207964957U (en) | 2018-01-24 | 2018-01-24 | A kind of three-phase power detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820120658.XU CN207964957U (en) | 2018-01-24 | 2018-01-24 | A kind of three-phase power detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207964957U true CN207964957U (en) | 2018-10-12 |
Family
ID=63734897
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820120658.XU Withdrawn - After Issue CN207964957U (en) | 2018-01-24 | 2018-01-24 | A kind of three-phase power detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207964957U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108196137A (en) * | 2018-01-24 | 2018-06-22 | 广东志高暖通设备股份有限公司 | A kind of three-phase power detection circuit and method |
-
2018
- 2018-01-24 CN CN201820120658.XU patent/CN207964957U/en not_active Withdrawn - After Issue
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108196137A (en) * | 2018-01-24 | 2018-06-22 | 广东志高暖通设备股份有限公司 | A kind of three-phase power detection circuit and method |
| CN108196137B (en) * | 2018-01-24 | 2019-12-31 | 广东志高暖通设备股份有限公司 | Three-phase electricity detection circuit and method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203178453U (en) | Automatic test system for switch power supply module | |
| CN105911417A (en) | Testing device of testing on and off and correctness of cable and method thereof | |
| CN203606449U (en) | Device used for short circuit measurement between pins of connector of electronic product | |
| CN102156273A (en) | Electric energy meter verification circuit for error test and direct current and even harmonic test | |
| CN107861015A (en) | BMS wiring testing devices and method | |
| CN106786942A (en) | A kind of charge protection device and charging system | |
| CN109283424B (en) | Testing device and method for four-port sensor signal deconcentrator with LED | |
| CN207964957U (en) | A kind of three-phase power detection circuit | |
| CN107765194A (en) | A kind of flashing light tester | |
| CN204666762U (en) | A kind of cable wire sequence detecting device | |
| CN104111402B (en) | The Wiring detection method of the cross interconnected system of a kind of power cable and device | |
| CN106019193B (en) | Integrated point inspection device of voltage-withstand-voltage and grounding impedance tester | |
| CN210119553U (en) | Detection apparatus for whether short circuit exists between each pin of DB plug | |
| CN202372603U (en) | Universal serial bus (USB) connecting wire detection device | |
| CN209357727U (en) | Electrostatic discharge protection circuit and electrostatic protection apparatus | |
| CN204807649U (en) | Tester | |
| CN108196137B (en) | Three-phase electricity detection circuit and method | |
| CN204374273U (en) | A kind of handheld digital secondary pressure plate measuring instrument | |
| CN110780238A (en) | Multi-core cable detection device | |
| CN206863157U (en) | Instrument for testing polarity of current transformer | |
| CN204498131U (en) | A kind of DC testing circuit of HW High Way connectivity port and equipment and a kind of photoelectric communication equipment | |
| CN102163357B (en) | Electric fire monitoring detector with pluggable signal acquiring card | |
| CN205333770U (en) | Line detection device and system | |
| CN104122481A (en) | Multifunction cable detection device | |
| CN107132452A (en) | Instrument for testing polarity of current transformer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20181012 Effective date of abandoning: 20191231 |
|
| AV01 | Patent right actively abandoned |