CN107942132A - One kind protection convenient measuring device of platen potential - Google Patents
One kind protection convenient measuring device of platen potential Download PDFInfo
- Publication number
- CN107942132A CN107942132A CN201711185588.2A CN201711185588A CN107942132A CN 107942132 A CN107942132 A CN 107942132A CN 201711185588 A CN201711185588 A CN 201711185588A CN 107942132 A CN107942132 A CN 107942132A
- Authority
- CN
- China
- Prior art keywords
- test
- potential
- main body
- external terminal
- circuit
- 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.)
- Pending
Links
- 230000004224 protection Effects 0.000 title claims description 49
- 238000012360 testing method Methods 0.000 claims abstract description 50
- 230000003750 conditioning effect Effects 0.000 claims abstract description 14
- 230000008859 change Effects 0.000 claims abstract description 8
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 3
- 229910052744 lithium Inorganic materials 0.000 claims description 3
- 230000006872 improvement Effects 0.000 abstract description 3
- 230000006870 function Effects 0.000 description 7
- 238000000034 method Methods 0.000 description 5
- 230000001681 protective effect Effects 0.000 description 5
- 230000005611 electricity Effects 0.000 description 4
- 238000001514 detection method Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000006399 behavior Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Resistance Or Impedance (AREA)
- Measuring Fluid Pressure (AREA)
Abstract
The invention discloses one kind to protect the convenient measuring device of platen potential, including apparatus main body, it is arranged at three anterior test external terminals of apparatus main body, one of test external terminal connects a test clip, two other test external terminal connects potential test pen respectively, apparatus main body includes two paths of signals modulate circuit, two paths of signals modulate circuit is connected with being connected with the test external terminal of potential test pen respectively, signal conditioning circuit includes the voltage change ratio switching circuit of concatenation, Sallen Key active low-pass filters and Σ Δ type high-precision adcs, two Σ Δ type high-precision adcs are commonly connected to a processor, processor connects a display screen, test external terminal of two voltage change ratio switching circuits with connecting test folder is electrically connected.Realize single operation readiness；Testing result is intuitively shown；Improvement to circuit structure, had not only maintained high-precision test, but also reduced device volume and weight, had saved device cost.
Description
Technical field
The present invention relates to a kind of power equipment measuring device, and in particular to one kind protection convenient test device of platen potential,
The both ends voltage-to-ground of protection pressing plate will be put into for detection during substation operation personnel grid switching operation.
Background technology
In the regular job of substation operation personnel, the operation of pressing plate, protection pressure are predominantly protected in secondary device operation
Plate is also commonly referred to as protected in flakes, is the important bridge and tie of protective device contact external wiring in substation, is related to protection
Work and action outlet whether normally play a role.
It is different according to the position of protection pressing plate access protective device secondary circuit, defencive function pressing plate can be divided into and outlet is pressed
Two class of plate.
Function pressing plate is mainly to realize some functions of protective device, such as main protection, distance protection, zero-sequenceprotection, vertical poor
Protection etc. input and exit, be these a certain functions " switch ".Therefore, there are voltage in both sides, send signal after connection
To protective device, start corresponding function.In order to ensure antijamming capability, present substation uses to be more the strong of 110VDC
Point function pressing plate.
It is that output clamping determines protection act as a result, different according to the object that protection act outlet acts on, jump can be divided into
Lock output clamping and startup pressing plate.Tripping output clamping directly acts on this switch or shunt tripping, and other are switched；Start pressing plate conduct
Other protections are opened into use, such as unsuccessful reason pressing plate, locking prepared auto restart pressing plate.Therefore, if both sides have before input
Voltage, input can trip.In general, there is (circuit breaker trip circuit is complete) in negative voltage always, positive voltage series connection protection
Node.In protection act, node closure, positive electricity force feed to pressing plate if pressing plate is put into, is connected positive supply by pressing plate,
Protective device trips.
During above-mentioned grid switching operation, for the purpose of safety, substation operation personnel is needed in advance to protecting pressing plate two
End above earth potential is detected, and can carry out subsequent operation.
For function pressing plate pressing plate is just put into after equivalent current potential (forceful electric power pressing plate is general, it is necessary to detect protection pressing plate both ends and have
For 110VDC).
For tripping output clamping, it is necessary to which pressure could be put into after non-dissimilar polarities current potential over the ground by measuring protection pressing plate both ends
Plate, output clamping both ends above earth potential can there are four kinds of possible situations：
Pressing plate upper end above earth potential+110VDC, bottom above earth potential+110VDC, at this time protection have outlet, trip back
Road is obstructed；
Pressing plate upper end above earth potential 0V, bottom above earth potential 0V, the broken string of trip(ping) circuit at this time are obstructed；
Pressing plate upper end above earth potential -110VDC, bottom above earth potential 0V, protects do not export at this time；
Pressing plate upper end above earth potential -110VDC, bottom above earth potential+110VDC, at this time protection have outlet.
In the prior art, substation operation personnel is generally detected the current potential for protecting pressing plate using universal meter.Because
A people is needed to manage positive and negative two pen meter of universal meter, another human hand held universal meter coordinates, simultaneously for pressing plate upper and lower end parts
Detection also needs to remember potential value twice, it is necessary to carry out respectively in implementation process, and potential value twice is contrasted.Such side
Formula there are it is obvious the drawbacks of, first, operating personnel are more；Second, operating process is inconvenient；Third, front and rear test value will rely on artificially
, inevitably there is the possibility of erroneous judgement in memory.Very high field is required for substation safety, the consequence that human error is brought is very
Seriously.
Patent of invention content
In view of this, the present invention propose it is a kind of can the convenient test device of protection platen potential completed of single single, with
Reduce the quantity of operating personnel, simplify test process, while the current potential indicating value of test protection pressing plate upper and lower end parts can be kept, can have
Effect avoids the dependence judged artificial memory output.
To realize above-mentioned target, the present invention provides following technical solution：
One kind protection convenient measuring device of platen potential, can detect protection pressing plate upper and lower ends at the same time under single single operation
Two terminal potential of current potential and pressing plate of portion over the ground, including：Apparatus main body, be arranged at three anterior test external connection ends of apparatus main body
Son, one of test external terminal connect a test clip by wire body, and the test clip is used to be connected with ground potential, described another
Outer two tests external terminal is connected to the potential test pen contacted with protection pressing plate upper and lower end parts by wire body respectively.
Apparatus main body includes two path built-ins and independent signal conditioning circuit, and signal conditioning circuit includes the electricity being sequentially connected in series
Buckling than switching circuit, Sallen-Key active low-pass filters, sigma-delta type high-precision adc, two paths of signals modulate circuit
Sigma-delta type high-precision adc is commonly connected to a processor, such as 32 ARM microcontrollers, and processor connects a display screen, two-way
A shared high-precision voltage reference source is additionally provided between the sigma-delta type high-precision adc of signal conditioning circuit.Voltage change ratio electricity
Road can guarantee that under different relative potentials, and the analog voltage of best match is reached by automatic adjusument no-load voltage ratio, low-pass filtered
Inputted after device to high-precision adc；The design feature of the conditioning front end of two-way independence is, to protecting pressing plate upper and lower end parts potential value
Optimal accuracy of detection can be kept under gamut；The design feature of one shared voltage-reference is, independent to two-way
ADC can keep identical voltage reference value, its be acted upon by temperature changes being consistent property, while save cost.Dress
Microcontroller in putting shows potential value to the screen of device after handling data, there is provided operations staff's intuitive judgment.
Further, in order to realize one man operation, above device back uses magnet, can utilize magnetism during the test
By apparatus main body absorption on the metallic object near protection pressing plate, therefore held without operating personnel.
Further, in order to realize one man operation, above-mentioned test clip is pluggable, and one end is wire body, directly and device
Main body is connected, and the other end is metallic clip point, is connected with ground potential, therefore the acquisition of ground potential is held without operating personnel.
Further, in order to realize the portability of on-the-spot test, above device is powered using built-in lithium battery, and is equipped with
The charging interface of 5VDC.
Compared with prior art, the present invention haing the following advantages and beneficial effect：1st, to hand-held and method of clamping
Improve, fully achieve one man operation；2nd, protection pressing plate upper and lower end parts need not be tested respectively, fully achieves convenient behaviour
Make；3rd, testing result is intuitively shown, is protected the upper and lower end parts current potential of pressing plate to judge without relying on memory, is avoided human error；
4th, to the improvement of circuit structure, compared with the prior art needs to be detected with two single universal meters, both maintained high-precision
Test, and realize saving components cost, reduce the advantages that device volume, alleviator weight.
Brief description of the drawings
Fig. 1 is the structure diagram of present invention protection platen potential easy device.
Fig. 2 is the internal circuit diagram of present invention protection platen potential easy device.
Each reference numeral is in figure：
10- apparatus main bodies；20- display screens；30- magnet；40- protection pressing plates bottom test pen；50- test clips；60- is protected
Protect pressing plate upper end test pen；70- charge power supply sockets；11- protection pressing plates bottom external terminal interface；Outside 12- ground potentials
Connecting terminal interface；13- protection pressing plates upper end external terminal interface；The first signal conditioning circuits of 14-；141- first via voltage becomes
Compare circuit；142- first via Sallen-Key active low-pass filters；143- first via sigma-delta type high-precision adcs；15- second
Signal conditioning circuit；The second roads of 151- voltage change ratio moding circuit；The second roads of 152- Sallen-Key active low-pass filters；153-
Second road sigma-delta type high-precision adc；16-ARM microcontrollers；17- high-precision voltage references source.
Embodiment
Present disclosure is described in further details with reference to the accompanying drawings and detailed description.
With reference to reference to Fig. 1, one kind protects the convenient measuring device of platen potential, including apparatus main body 10, apparatus main body 10
Front is provided with display screen 20, for being supplied to operating personnel intuitively to observe the current potential of the upper and lower end of protection pressing plate and ground potential
Difference.
The back side of apparatus main body 10 is equipped with four magnet 30, for the apparatus main body absorption in use is attached in protection pressing plate
On near metallic object.
The front portion of apparatus main body 10 is equipped with three external terminal interfaces：Protection pressing plate bottom external terminal interface 11,
Current potential external terminal interface 12, protection pressing plate upper end external terminal interface 13.Protect pressing plate bottom external terminal interface 11
It is used to connect protection pressing plate bottom test pen 40, ground potential external terminal interface 12 by wire body for connecting ground by wire body
Potential test folder 50, protection pressing plate upper end external terminal interface 13 are used to connect protection pressing plate upper end test pen by wire body
60.Wherein, earth testing folder 50 is clamped directly on ground potential metallic object and forms potential reference point by operating personnel during test；
Thereafter, each handheld test pen 40 of right-hand man, test pen 60, respectively contact protection pressing plate upper and lower end parts obtain its current potential.
10 afterbody of apparatus main body is equipped with a 5VDC charge power supplies socket 70, for the lithium battery built in apparatus main body 10
Charging.
Protection pressing plate bottom external terminal interface is connected to as shown in Fig. 2, being included in the internal circuit of apparatus main body 10
11 the first signal conditioning circuit 14, is connected to the secondary signal modulate circuit 15 of pressing plate upper end external terminal interface 13, the
One signal conditioning circuit 14 includes first via voltage change ratio circuit 141, the active low passes of first via Sallen-Key being sequentially connected in series
Wave filter 142, first via sigma-delta type high-precision adc 143.Secondary signal modulate circuit 15 includes the second road electricity being sequentially connected in series
Buckling than moding circuit 151, the second road Sallen-Key active low-pass filters 152, the second road sigma-delta type high-precision adc 153,
First via sigma-delta type high-precision adc 143 and the second road sigma-delta type high-precision adc 153 are commonly connected to one 32 ARM microcontrollers
16, ARM microcontrollers 16 are connected to display screen 20.
One is additionally provided between first via sigma-delta type high-precision adc 143 and the second road sigma-delta type high-precision adc 153
Shared high-precision voltage reference source 17.Shared high-precision voltage reference source 17, can keep identical to the ADC of two-way independence
Voltage reference value, its be acted upon by temperature changes being consistent property, while save cost.
First signal conditioning circuit 14 is each independent with secondary signal modulate circuit 15, can be according to respective input voltage
Value matching program adaptively adjusts no-load voltage ratio and realizes optimal measurement accuracy.
Improvement of the present apparatus on hand-held, method of clamping and circuit structure, can greatly simplify and become in the prior art
Power station needs the double universal meter that is used cooperatively to measure protection pressing plate upper and lower end parts current potential twice respectively before input protects pressing plate
The advantages of mode of operation, realizes single single operation readiness, and testing result is intuitively shown.
Expansion description is carried out to the present invention above in association with drawings and embodiments, which does not have restricted, attached drawing
The shown embodiment that also simply the present invention is formed, technical scheme are not limited thereto.The ordinary skill people of this area
For member it should be appreciated that in the case where not departing from design philosophy of the present invention, actual implementation of the invention also has some details
On change.So as long as meeting spirit of the invention, these changes are included within protection scope of the present invention.
Claims (6)
1. one kind protection convenient measuring device of platen potential, it is characterised in that：Including apparatus main body, it is arranged at apparatus main body front portion
Three test external terminals, described one of test external terminal passes through wire body and connects a test clip, and the test clip is used
In connection ground potential, two other described test external terminal is connected to connect with protection pressing plate upper and lower end parts by wire body respectively
Tactile potential test pen, described device main body include two path built-ins and independent signal conditioning circuit, the signal conditioning circuit
It is connected respectively with being connected with the test external terminal of potential test pen, the signal conditioning circuit includes the voltage change ratio being sequentially connected in series
Switching circuit, Sallen-Key active low-pass filters and sigma-delta type high-precision adc, the Σ of the two paths of signals modulate circuit-
Δ type high-precision adc is commonly connected to a processor, and the processor connects a display screen, the two paths of signals modulate circuit
Voltage change ratio switching circuit is electrically connected with being connected with the test external terminal of test clip respectively.
2. the protection convenient measuring device of platen potential according to claim 1, it is characterised in that：The two paths of signals conditioning
A shared high-precision voltage reference source is additionally provided between the sigma-delta type high-precision adc of circuit.
3. the protection convenient measuring device of platen potential according to claim 1, it is characterised in that：The processor is 1
Position ARM microcontrollers.
4. the protection convenient measuring device of platen potential according to claim 1, it is characterised in that：The test clip is to insert
Test clip is pulled out, the one end being connected with ground potential is metallic clip point.
5. the protection convenient measuring device of platen potential according to claim 1, it is characterised in that：The described device main body back side
It is provided with magnet.
6. the protection convenient measuring device of platen potential according to claim 1, it is characterised in that：Described device main body uses
Built-in lithium battery is powered, and the charging interface equipped with 5VDC.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711185588.2A CN107942132A (en) | 2017-11-23 | 2017-11-23 | One kind protection convenient measuring device of platen potential |
| PCT/CN2018/103991 WO2019100805A1 (en) | 2017-11-23 | 2018-09-04 | Device for conveniently measuring potential of protection pressure plate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711185588.2A CN107942132A (en) | 2017-11-23 | 2017-11-23 | One kind protection convenient measuring device of platen potential |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107942132A true CN107942132A (en) | 2018-04-20 |
Family
ID=61930207
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711185588.2A Pending CN107942132A (en) | 2017-11-23 | 2017-11-23 | One kind protection convenient measuring device of platen potential |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN107942132A (en) |
| WO (1) | WO2019100805A1 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108982946A (en) * | 2018-04-28 | 2018-12-11 | 深圳供电局有限公司 | Pressing plate potential change detection device based on protection action contact |
| WO2019100805A1 (en) * | 2017-11-23 | 2019-05-31 | 中国南方电网有限责任公司超高压输电公司天生桥局 | Device for conveniently measuring potential of protection pressure plate |
| CN112838560A (en) * | 2020-12-31 | 2021-05-25 | 广东电网有限责任公司佛山供电局 | Device for controlling input and exit of outlet pressure plate |
| CN113092843A (en) * | 2021-04-06 | 2021-07-09 | 广东电网有限责任公司 | Pressure plate voltage measuring device |
| CN114062727A (en) * | 2021-11-17 | 2022-02-18 | 中国南方电网有限责任公司超高压输电公司柳州局 | Protective pressing plate rapid measuring instrument and protective pressing plate voltage measuring method |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2804881Y (en) * | 2005-06-03 | 2006-08-09 | 上海欣泰通信技术有限公司 | AC, DC voltage parallel measuring circuit |
| CN201044049Y (en) * | 2007-04-20 | 2008-04-02 | 长春市奥维精密试验设备有限公司 | PCI dynamic precision measurement control system |
| CN102539889A (en) * | 2012-01-17 | 2012-07-04 | 惠州三华工业有限公司 | Multi-path high-voltage small current detecting circuit |
| CN204116430U (en) * | 2014-08-28 | 2015-01-21 | 深圳供电局有限公司 | Relay protection multi-outlet pressing plate pulse voltage detection device |
| CN204374273U (en) * | 2014-11-28 | 2015-06-03 | 广东电网有限责任公司惠州供电局 | A kind of handheld digital secondary pressure plate measuring instrument |
| CN204536469U (en) * | 2015-01-29 | 2015-08-05 | 江苏省电力公司常州供电公司 | A kind of Substation secondary circuit voltage current transformer pick-up unit |
| CN106291083A (en) * | 2016-10-08 | 2017-01-04 | 国家电网公司 | Portable protection pressing plate voltage check device |
| CN106546866A (en) * | 2016-10-21 | 2017-03-29 | 北京首都机场动力能源有限公司 | A kind of method and device of test secondary circuit pressing plate break-make |
| CN106771465A (en) * | 2016-12-29 | 2017-05-31 | 国家电网公司 | A kind of improved Portable universal meter |
| CN207662958U (en) * | 2017-11-23 | 2018-07-27 | 中国南方电网有限责任公司超高压输电公司天生桥局 | A kind of convenient measuring device of protection platen potential |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202334004U (en) * | 2011-12-06 | 2012-07-11 | 北京市电力公司 | State measurement and control device and system for protection pressing plate |
| CN102565696B (en) * | 2012-01-13 | 2014-10-01 | 广东电网公司东莞供电局 | Quick measuring device of protective pressing plate and measuring method thereof |
| CN203883551U (en) * | 2013-12-05 | 2014-10-15 | 国家电网公司 | System for monitoring throwing and withdrawing of pressing plate based on RFID |
| CN204882693U (en) * | 2015-08-27 | 2015-12-16 | 国网北京市电力公司 | Trip protections equipment and electroscope thereof |
| CN106483404B (en) * | 2016-09-30 | 2019-02-01 | 国家电网公司 | A kind of protection pressing plate state monitoring method and system based on hall sensing effect |
| CN107942132A (en) * | 2017-11-23 | 2018-04-20 | 中国南方电网有限责任公司超高压输电公司天生桥局 | One kind protection convenient measuring device of platen potential |
-
2017
- 2017-11-23 CN CN201711185588.2A patent/CN107942132A/en active Pending
-
2018
- 2018-09-04 WO PCT/CN2018/103991 patent/WO2019100805A1/en active Application Filing
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2804881Y (en) * | 2005-06-03 | 2006-08-09 | 上海欣泰通信技术有限公司 | AC, DC voltage parallel measuring circuit |
| CN201044049Y (en) * | 2007-04-20 | 2008-04-02 | 长春市奥维精密试验设备有限公司 | PCI dynamic precision measurement control system |
| CN102539889A (en) * | 2012-01-17 | 2012-07-04 | 惠州三华工业有限公司 | Multi-path high-voltage small current detecting circuit |
| CN204116430U (en) * | 2014-08-28 | 2015-01-21 | 深圳供电局有限公司 | Relay protection multi-outlet pressing plate pulse voltage detection device |
| CN204374273U (en) * | 2014-11-28 | 2015-06-03 | 广东电网有限责任公司惠州供电局 | A kind of handheld digital secondary pressure plate measuring instrument |
| CN204536469U (en) * | 2015-01-29 | 2015-08-05 | 江苏省电力公司常州供电公司 | A kind of Substation secondary circuit voltage current transformer pick-up unit |
| CN106291083A (en) * | 2016-10-08 | 2017-01-04 | 国家电网公司 | Portable protection pressing plate voltage check device |
| CN106546866A (en) * | 2016-10-21 | 2017-03-29 | 北京首都机场动力能源有限公司 | A kind of method and device of test secondary circuit pressing plate break-make |
| CN106771465A (en) * | 2016-12-29 | 2017-05-31 | 国家电网公司 | A kind of improved Portable universal meter |
| CN207662958U (en) * | 2017-11-23 | 2018-07-27 | 中国南方电网有限责任公司超高压输电公司天生桥局 | A kind of convenient measuring device of protection platen potential |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019100805A1 (en) * | 2017-11-23 | 2019-05-31 | 中国南方电网有限责任公司超高压输电公司天生桥局 | Device for conveniently measuring potential of protection pressure plate |
| CN108982946A (en) * | 2018-04-28 | 2018-12-11 | 深圳供电局有限公司 | Pressing plate potential change detection device based on protection action contact |
| CN112838560A (en) * | 2020-12-31 | 2021-05-25 | 广东电网有限责任公司佛山供电局 | Device for controlling input and exit of outlet pressure plate |
| CN113092843A (en) * | 2021-04-06 | 2021-07-09 | 广东电网有限责任公司 | Pressure plate voltage measuring device |
| CN114062727A (en) * | 2021-11-17 | 2022-02-18 | 中国南方电网有限责任公司超高压输电公司柳州局 | Protective pressing plate rapid measuring instrument and protective pressing plate voltage measuring method |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2019100805A1 (en) | 2019-05-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107942132A (en) | One kind protection convenient measuring device of platen potential | |
| CN205786876U (en) | A kind of general phase-difference type switch cabinet phasing device | |
| CN103454554A (en) | Polarity tester for current transformer | |
| CN102590609B (en) | The method of mobile terminal and measurement mobile terminal power consumption | |
| CN207662958U (en) | A kind of convenient measuring device of protection platen potential | |
| CN103176050A (en) | Design method of novel ground resistance tester | |
| CN203502565U (en) | Storage battery detector | |
| CN202886502U (en) | Leakage protector tester | |
| CN211061617U (en) | High-voltage safety detection device for electric automobile | |
| CN204374273U (en) | A kind of handheld digital secondary pressure plate measuring instrument | |
| CN110579719A (en) | Storage battery impedance measuring device | |
| CN102539870A (en) | Portable high-precision multifunctional testing instrument | |
| CN108859844A (en) | A kind of charging pile for electric vehicle maintained easily | |
| CN211043621U (en) | Storage battery impedance measuring device | |
| CN204065349U (en) | A kind of microcomputer protecting device auxiliary reclay and optocoupler operating power tester | |
| CN209626997U (en) | A kind of Domestic two accumulator | |
| CN112748272A (en) | Low-voltage electricity-stealing-prevention and metering abnormity remote online monitoring device | |
| CN220323426U (en) | Circuit insulation resistance measuring device | |
| CN201682264U (en) | Leakage protector | |
| CN108490264A (en) | A kind of digital display explosion cap tester and its operating method | |
| CN109901091A (en) | It is a kind of can remote diagnosis capacitor and inductor tester | |
| CN205941692U (en) | Portable direct current resistance, integrative device of transformation ratio test | |
| CN213341981U (en) | Control circuit integrating power adapter and multimeter | |
| CN211603525U (en) | Portable current transformer polarity detection device | |
| CN103713225A (en) | Capacity discharge tester |
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 |