CN103279057B - Analog acquisition passage protects circuit and analog collection system - Google Patents
Analog acquisition passage protects circuit and analog collection system Download PDFInfo
- Publication number
- CN103279057B CN103279057B CN201310155555.9A CN201310155555A CN103279057B CN 103279057 B CN103279057 B CN 103279057B CN 201310155555 A CN201310155555 A CN 201310155555A CN 103279057 B CN103279057 B CN 103279057B
- Authority
- CN
- China
- Prior art keywords
- analog
- terminal
- signal
- circuit
- voltage
- 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
Landscapes
- Emergency Protection Circuit Devices (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Safety Devices In Control Systems (AREA)
Abstract
The present invention relates to analog acquisition passage protection circuit and analog collection systems; the analog acquisition passage protection circuit of the present invention has used two-way clamp and current-limiting resistance; it can play a protective role in short trouble and interference signal failure; have many advantages, such as small cost, protection and it is dynamic do it is reliable; there is channel signal fault detection capability simultaneously; when short circuit phenomenon occurs for the sensor failure or signal circuit of process detection; while defencive function is run, moreover it is possible to quote the sensor loop to break down（LED indication）, and have and the output of failure contact is concentrated largely to improve the stability and reliability of control system so that control system timely responds to and plant maintenance.
Description
Technical field
The present invention relates to analog acquisition passage protection circuit and analog collection systems, are changed especially suitable for direct current transportation
Flow the sampling protection of valve water-cooling control system process detection sensor.
Background technology
Since D.C. high voltage transmission (HVDC) has many advantages, such as extra long distance and large capacity transmission, low cost, small, the mesh of loss
It is preceding to find broad application in China and other countries.Converter valve is the core equipment of direct current transportation, and high-pressure high-power thyristor
It is the core equipment component of converter valve again, carries rectification（Sending end）, inversion（Receiving end）The transmission of high-power power, converter valve exist
Transmit electric energy simultaneously, itself also will produce larger power attenuation, and calorific value is big, needs reliably to cool down equipment and is cooled down,
So that converter valve and direct current transportation can be with stable operations.The most effective type of cooling, converter valve water cooling system are cooled down as converter valve
System is also used widely with direct current transportation project, has fully achieved production domesticization at present.
Converter valve water-cooling system is the very high control system of a set of complicated, control accuracy, core equipment be CPU and
Process detection sensor.The sensor for needing many high certainty of measurement, temperature, pressure, flow, liquid level, the frequency in system
Etc. parameters be converted into low voltage signal（Such as 4-20mA current signals）, the signal send to dedicated analog input acquisition module into
Row sampling is calculated, is sent again to Centralized Monitoring unit and device by communication mode, is used for that operation and control system is reliable, stablizes
Operation, while can be in man-machine interface display parameters.
Sensor output voltage signal is easy to that, by strong voltage or surge voltage signal interference, sampled signal may be caused not
Stablize.
Sensor output constant current signal is not easy to be disturbed, and generally uses 4-20mA permanent most sensor at present
Signal is flowed as output signal, is especially used widely in the system for needing accurate control.Using the sensing of constant current output
Device and the following Fig. 1 of signal acquisition signal（a）, signal adopts followed by working power anode DC24V, I+, I- of sensor, simulation
Collect AI-, AI+ of module, arrives the negative terminal GND of working power；Fig. 1（b）Connection also makes I+, I- of sensor, analog acquisition module
AI-, AI+ forming circuit, Fig. 1（b）With Fig. 1（a）Connection all makes to form a current loop between sensor and acquisition module,
Essence is identical.（Analogue collection module hereinafter referred to as MAI）.
4-20mA analog quantity sampling processing common patterns are shown in Fig. 2（a）、（b）、（c）It is shown.For Fig. 2（a）, directly to passing
The output signal of sensor is attached, and does not increase anti-interference and safeguard measure in sampling end.Fig. 2（b）, fairly simple to adopt
Sample end increases anti-overvoltage or absorber element, degree of protection and reliability are relatively low.Fig. 2（c）, to the output signal per sensor all the way
Increase signal isolation module, the signal after isolation is sent to analogue collection module again and is sampled.It can play so certain
Interference protection measure, but cost is higher.Due to increasing signal isolation module, sensor output signal accuracy can reduce, system
Control accuracy, reliability are also a greater impact.
Three of the above mode is unable to reliably protecting in sensor fault, when sensor fault or its output signal it
Between occur insulation reduce, short circuit when（Such as Fig. 3）, the working power of sensor（Such as DC24V）It is possible to be applied directly to simulation
The signal input part for measuring acquisition module, can burn analogue collection module, may when serious to influence the stable operation of system
Cause system control entanglement and machine halt trouble.In addition, coupled such as Fig. 4, between system and the strong voltage interference signal of induction not yet
Effective protection can be obtained, the signal accuracy that process detects may be caused to reduce, amplitude dither, influences the control accuracy, steady of system
It is qualitative.
Invention content
The object of the present invention is to provide a kind of analog acquisition passage protection circuit and analog collection systems, to solve
Existing protection circuit cannot be the problem of short trouble and when interference information failure play a protective role.
To achieve the above object, the scheme of the invention is：Analog acquisition passage protects circuit, including：
A pair of sensors terminal（I+、I-）, sensor terminal is for the signal with the sensor of an output constant current signal
Output end is connected respectively；
A pair of of acquisition channel terminal（AI+、AI-）, acquisition channel terminal is for the signal with an analogue collection module
Input terminal is connected respectively；
Working power is used to form a constant current output sampling for making signal flow through sensor terminal and acquisition channel terminal
Circuit；
In constant current output sampling circuit, string is equipped with current-limiting resistance（R15）, there are one two-way for the connection of acquisition channel terminal both ends
Clamp circuit, the two-way clamp are the two-way clamp clamped using anti-paralleled diode.
Analog acquisition passage protection circuit further includes a fault alarm branch, the fault alarm branch mainly by
It triggers device and alarm appliance to constitute, triggers the triggering end of device and voltage or electric current when failure in constant current output sampling circuit
Catastrophe point is correspondingly connected with.
The triggering device includes voltage-stabiliser tube（Z1）And triode（V1）, voltage-stabiliser tube（Z1）One end is connected to sensor terminal
Negative terminal（I-）Or current-limiting resistance（R15）Anode, other end connecting triode（V1）Control pole, the output stage of triode
It is correspondingly connected with the alarm appliance；The current-limiting resistance（R15）Anode be current-limiting resistance（R15）Signal flow into end.
The present invention also provides a kind of analog collection system, including at least two analog acquisition passages, each analog quantitys
Acquisition channel is equipped with analog acquisition passage protection circuit, any one analog acquisition passage protection circuit includes：
A pair of sensors terminal（I+、I-）, sensor terminal is for the sensor with the output constant current signal of corresponding channel
Signal output end be connected respectively；
A pair of of acquisition channel terminal（AI+、AI-）, acquisition channel terminal is for the analogue collection module with corresponding channel
Signal input part be connected respectively；
Working power is used to form the perseverance of sensor terminal and acquisition channel terminal that one makes signal flow through corresponding channel
Stream output sampling circuit；
In constant current output sampling circuit, string is equipped with current-limiting resistance（R15）, there are one two-way for the connection of acquisition channel terminal both ends
Clamp circuit, the two-way clamp are the two-way clamp clamped using anti-paralleled diode.
The analog collection system further includes a fault alarm branch, and the fault alarm branch is mainly by triggering device
Constituted with alarm appliance, trigger the triggering end of device for respectively with voltage when failure in the constant current output sampling circuit in each channel
Or the catastrophe point connection of electric current.
The catastrophe point of voltage or electric current is sensor terminal when failure in the constant current output sampling circuit in each channel
Negative terminal（I-）Or current-limiting resistance（R15）Anode；The current-limiting resistance（R15）Anode be current-limiting resistance（R15）Signal
Flow into end.
The triggering device includes voltage-stabiliser tube（Z1）And triode（V1）, voltage-stabiliser tube（Z1）One end is connected to each channel
Constant current output sampling circuit in failure when voltage or electric current catastrophe point, other end connecting triode（V1）Control pole, three
The output stage of pole pipe is correspondingly connected with the alarm appliance.
In the constant current output sampling circuit in each channel when failure voltage or electric current catastrophe point and voltage-stabiliser tube（Z1）It
Between string be equipped with light emitting diode.
The analog acquisition passage protection circuit of the present invention has used two-way clamp and current-limiting resistance, in short-circuit event
Barrier and when interference signal failure, can play a protective role, and it is reliable to have many advantages, such as that small cost, protection and moving is done.
Further, the present invention also has channel signal fault detection capability, when the sensor failure of process detection
Or short circuit phenomenon occurs for signal circuit, while defencive function is run, moreover it is possible to quote the sensor loop to break down（LED
Instruction）, and have and the output of failure contact is concentrated largely to improve control so that control system timely responds to and plant maintenance
The stability and reliability of system processed.
Description of the drawings
Fig. 1（a）, Fig. 1（b）It is that 2 line sensors and 4 line sensors often use connection respectively；
Fig. 2（a）, Fig. 2（b）, Fig. 2（c）It is three kinds of common connections of process detection sensor respectively；
Fig. 3 is short circuit or short circuit failure schematic diagram；
Fig. 4 is interference signal failure schematic diagram；
Fig. 5（a）, Fig. 5（b）It is the 2 line connections and 4 line connections using circuit of the present invention respectively；
Protect circuit diagram in the eight tunnel analog input channels Tu6Shi；
Fig. 7 is the analog acquisition passage protection circuit schematic diagram of the present invention；
Defencive function principle schematic when Fig. 8 is short circuit sensor failure；
Fig. 9 is 4 line sensor loop electrical schematic diagrams.
Specific implementation mode
The present invention will be further described in detail below in conjunction with the accompanying drawings.
Analog acquisition passage protects circuit embodiments 1
Such as Fig. 5（a）Shown in Fig. 7, the sensor of 2 lines is used in the present embodiment.Analog acquisition passage protects circuit,
Including：A pair of sensors terminal（I+、I-）, sensor terminal be used for and the sensor of an output constant current signal signal export
End is connected respectively；A pair of of acquisition channel terminal（AI+、AI-）, acquisition channel terminal be used for and an analogue collection module
Signal input part be connected respectively；Working power, working power and sensor terminal, acquisition channel terminal series-shunt, form
One bars is adopted followed by the constant current output of working power anode, sensor terminal, acquisition channel terminal, working power negative terminal
Sample circuit；In constant current output sampling circuit, string is equipped with current-limiting resistance R15, and there are one two-way pincers for the connection of acquisition channel terminal both ends
Position circuit, which is the two-way clamp clamped using anti-paralleled diode.It is used in the present embodiment
Two Diode series form one way clamp all the way, and another way uses two diodes in reverse series.
Above-mentioned analog quantity sampling protection circuit, is specific to direct-current transmission converter valve water-cooling control system, is examined to process
Sensor die analog quantity signal path and 4-20mA signal analog acquisition modules are surveyed, is designed, it can be to entire signal acquisition
Circuit carries out current limliting, overvoltage protection, can effectively prevent the interference of the induced overvoltage or coupled interference voltage signal in system, can
Interference voltage is absorbed, clamps limitation.Principle analysis is as follows：
In Fig. 7, TRDU8 is process detection sensor, and MAI is 4-20mA analogue collection modules, current signal sampling
Resistance is 25 Ω, and the working power of 2 elements is DC24V.The 4-20mA current signals of sensor output flow through resistance R15, mark
The terminal signals of number AI+ are the input terminal of analogue collection module, the negative terminal AI- connection systems M of analogue collection module（GND）
End, diode D36-D39 are attempted by sampling channel both ends, constitute a two-way clamp, each diode initial turn-on electricity
Pressure is about 0.5V, and conducting voltage when 2 Diode series is about 1.0V, between guarantee analog quantity sampling end AI+ and AI- in this way
Voltage be not more than ± 1.0V amplitudes.If there is interference voltage signal or the exchange noise signal of coupling are applied to analog acquisition
The input terminal of module can absorb stronger noise signal, it is ensured that adopt since D36-D39 diodes form two-way clamp circuit
Sample channel will not be damaged by stronger interference or noise signal.
When sensor normal operation, since current output sensor maximum value is about 20mA, MAI module samples channel is most
Big voltage value is 20mA × 25 Ω=0.5V.4 clamp diode D36-D39 on sampling channel are in reverse blocking at this time
State, the leakage current for flowing through diode is A grades of electric currents of μ, can be ignored relative to 20mA grading currents, that is, does not interfere with biography
The output signal accuracy of sensor.
D36-D37 series diodes are reversely attempted by sampling channel, can effectively prevent MAI sampling channel signal wire reversal connections
The damage caused by module.It simultaneously can also be to dry by exchange, the pulsation for coupling or incuding in analogue collection module channel
Signal is disturbed to be absorbed and clamped.
Such as Fig. 8, when short trouble or its 2 signal wire short circuits occur for sensor, the upper terminal voltages of resistance R15 for+
24V, due to there is clamp diode, there are about the voltages of 23V to be applied on power resistor R15, and R15 is current-limiting resistance, thus may be used
To prevent higher voltage to be applied to the sampling end of MAI, sampling end maximum voltage is 1V, and the electric current for flowing through MAI modules is 40mA,
Remaining larger fault current switches to power supply negative terminal by clamp diode D38 and D39.MAI modules are avoided in this way
For a long time by larger fault current, will not be damaged because of overcurrent.D38 and D39 can not only be clamped, and also be played in failure
Bypass acts on.
Further, in order to be equipped with fault detect/warning function to sensor passage, a fault alarm branch is also added
Road.Fault alarm branch can choose multiple means realization, and Fig. 7 gives a kind of mode, including voltage-stabiliser tube Z1 and triode V1,
The one end voltage-stabiliser tube Z1 is connected to the negative terminal I- of sensor terminal（The anode of the anode of current-limiting resistance R15, current-limiting resistance R15 is limited
The signal of leakage resistance R15 flows into end）, the control pole of other end connecting triode V1, output stage and the alarm appliance pair of triode
It should connect.If terminal voltage value is higher on resistance R15, higher voltage if, can puncture voltage-stabiliser tube Z1, then drive NPN triode
V1 is connected, and relay K1 is made to act, outputting alarm contact.The Light-emitting diode LED 8 alerted on channel simultaneously is lighted, and is indicated
Corresponding signal path is abnormal.If no exceptions phenomenon, voltage-stabiliser tube Z1 is off, the end C, E of triode V1
In not on-state, the output of abnormality alarming contact point signal is not had, and system is in normal condition.
Analog acquisition passage protects circuit embodiments 2
Fig. 5（b）Shown in 4 lines connection type it is identical as 2 line connection type essence and principle, only plant-grid connection side
Formula difference and corresponding signal flow direction are different, and those skilled in the art are easy to be extended, as shown in figure 9, since 4 line systems pass
The operation principle of sensor and 2 line sensors and mode of connection difference, 4 line sensors need independent working power, letter
Number output（Such as 4-20mA）Accessory power supply, signal source is no longer needed to be provided by sensor device itself.Its signal exports I+, I- such as
Fruit is constant current signal（Such as 4-20mA）,, will not be right even if short circuit phenomenon occurs in sensor output channel in normal work
Sensor damages, and signal output remains a constant-current source.If sensor itself breaks down or exception, defeated
The current signal gone out may be larger, and analog acquisition passage protection circuit can equally have current protection and overvoltage protection work(
Can, it prevents and analogue collection module is avoided to damage, ensure its safe and reliable operation.
Acquisition system embodiment 1
Such as Fig. 6, acquisition system includes eight channels, and each channel is corresponding, and there are one analog acquisition passage protection electricity
The protection circuit on road, each channel has shared working power.Circuit composition repeats no more.
Acquisition system also is provided with fault alarm branch, and each channel is corresponding with light emitting diode, and eight channels share one
Alarm relay part.Each channel corresponding circuits are any respectively there are one the channel status that light emitting diode indicates to be abnormal
Sensor short circuit failure occurs for one channel, total failare output contact is had, so as to system exception alarm prompt and maintenance.After
Electric appliance alarm portion shares for eight channels, and relay is exported without source contact, can be uploaded to monitoring or PLC system, be informed system
There is sensor passage failure.
Claims (8)
1. analog acquisition passage protects circuit, including：
A pair of sensors terminal（I+、I-）, sensor terminal be used for and the sensor of an output constant current signal signal export
End is connected respectively；
A pair of of acquisition channel terminal（AI+、AI-）, acquisition channel terminal is used for and the signal of analogue collection module inputs
End is connected respectively；
Working power, being used to form one makes that signal flows through sensor terminal and the constant current output of acquisition channel terminal samples back
Road；
It is characterized in that, in constant current output sampling circuit, string is equipped with current-limiting resistance（R15）, acquisition channel terminal both ends are connected with
One two-way clamp, the two-way clamp are the two-way clamp clamped using anti-paralleled diode.
2. analog acquisition passage according to claim 1 protects circuit, which is characterized in that the analog acquisition passage
It further includes a fault alarm branch to protect circuit, which is mainly made of triggering device and alarm appliance, is touched
Send out device triggering end with the catastrophe point of voltage or electric current is correspondingly connected with when failure in constant current output sampling circuit.
3. analog acquisition passage according to claim 2 protects circuit, which is characterized in that the triggering device includes steady
Pressure pipe（Z1）And triode（V1）, voltage-stabiliser tube（Z1）One end is connected to the negative terminal of sensor terminal（I-）Or current-limiting resistance
（R15）Anode, other end connecting triode（V1）Control pole, the output stage of triode it is corresponding with the alarm appliance connect
It connects；The current-limiting resistance（R15）Anode be current-limiting resistance（R15）Signal flow into end.
4. analog collection system, which is characterized in that including at least two analog acquisition passages, each analog acquisition passage
It is equipped with analog acquisition passage protection circuit, any one analog acquisition passage protection circuit includes：
A pair of sensors terminal（I+、I-）, sensor terminal is for the letter with the sensor of the output constant current signal of corresponding channel
Number output end is connected respectively；
A pair of of acquisition channel terminal（AI+、AI-）, acquisition channel terminal is for the letter with the analogue collection module of corresponding channel
Number input terminal is connected respectively；
Working power, the constant current for being used to form sensor terminal and acquisition channel terminal that one makes signal flow through corresponding channel are defeated
Go out sampling circuit；
In constant current output sampling circuit, string is equipped with current-limiting resistance（R15）, there are one two-way clamps for the connection of acquisition channel terminal both ends
Circuit, the two-way clamp are the two-way clamp clamped using anti-paralleled diode.
5. analog collection system according to claim 4, which is characterized in that the analog collection system further includes one
A fault alarm branch, the fault alarm branch are mainly made of triggering device and alarm appliance, and the triggering end for triggering device is used
The catastrophe point of voltage or electric current is connect when failure in the constant current output sampling circuit respectively with each channel.
6. analog collection system according to claim 5, which is characterized in that the constant current output in each channel samples back
The catastrophe point of voltage or electric current is the negative terminal of sensor terminal when failure in road（I-）Or current-limiting resistance（R15）Anode；Institute
State current-limiting resistance（R15）Anode be current-limiting resistance（R15）Signal flow into end.
7. analog collection system according to claim 6, which is characterized in that the triggering device includes voltage-stabiliser tube（Z1）
And triode（V1）, voltage-stabiliser tube（Z1）Voltage or electricity when one end is connected to failure in the constant current output sampling circuit in each channel
The catastrophe point of stream, other end connecting triode（V1）Control pole, the output stage of triode is correspondingly connected with the alarm appliance.
8. analog collection system according to claim 7, which is characterized in that the constant current output in each channel samples back
In road when failure voltage or electric current catastrophe point and voltage-stabiliser tube（Z1）Between string be equipped with light emitting diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310155555.9A CN103279057B (en) | 2013-04-28 | 2013-04-28 | Analog acquisition passage protects circuit and analog collection system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310155555.9A CN103279057B (en) | 2013-04-28 | 2013-04-28 | Analog acquisition passage protects circuit and analog collection system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103279057A CN103279057A (en) | 2013-09-04 |
| CN103279057B true CN103279057B (en) | 2018-09-07 |
Family
ID=49061621
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310155555.9A Active CN103279057B (en) | 2013-04-28 | 2013-04-28 | Analog acquisition passage protects circuit and analog collection system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103279057B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106291218B (en) * | 2016-09-26 | 2023-06-02 | 深圳供电局有限公司 | Latent fault analysis device for protection analog acquisition loop |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2919333Y (en) * | 2006-06-15 | 2007-07-04 | 杭州瑞琦信息技术有限公司 | Constant flow voltage limited power source |
| CN101089771A (en) * | 2006-06-15 | 2007-12-19 | 杭州瑞琦信息技术有限公司 | Constant-current voltqage limit power supply with output protection |
| CN101527450A (en) * | 2009-04-10 | 2009-09-09 | 合肥金星机电科技发展有限公司 | Protective device for video transmission |
| CN201323590Y (en) * | 2008-09-11 | 2009-10-07 | 江苏省供电公司淮安市淮阴供电公司 | Protective device of data channel |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7312653B2 (en) * | 2005-03-10 | 2007-12-25 | Gm Global Technology Operations, Inc. | NMOS reverse battery protection |
-
2013
- 2013-04-28 CN CN201310155555.9A patent/CN103279057B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2919333Y (en) * | 2006-06-15 | 2007-07-04 | 杭州瑞琦信息技术有限公司 | Constant flow voltage limited power source |
| CN101089771A (en) * | 2006-06-15 | 2007-12-19 | 杭州瑞琦信息技术有限公司 | Constant-current voltqage limit power supply with output protection |
| CN201323590Y (en) * | 2008-09-11 | 2009-10-07 | 江苏省供电公司淮安市淮阴供电公司 | Protective device of data channel |
| CN101527450A (en) * | 2009-04-10 | 2009-09-09 | 合肥金星机电科技发展有限公司 | Protective device for video transmission |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103279057A (en) | 2013-09-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104333364A (en) | AC solid state relay and fault detecting method of load circuit of same | |
| CN106058837A (en) | Line arrester leakage current detection device without isolation component | |
| CN204231318U (en) | A kind of ac solid relay | |
| CN103344848B (en) | Open phases of three-phase power source based on multimicroprocessor judges and detection device for phase sequence and its detection method | |
| CN103227506A (en) | Triggering and monitoring unit of converter valve thyristor | |
| CN103244447A (en) | Fault detection circuit and method for accurately detecting running conditions of alternating current fan | |
| CN104155505A (en) | Earth wire live detection device, air conditioner and electrical equipment | |
| CN102288827A (en) | Circuit and methods for detecting resistance value, temperature and state of motor winding in real time | |
| CN105116270A (en) | Mutual inductor fault detection method for merging unit and protection control device | |
| CN103279057B (en) | Analog acquisition passage protects circuit and analog collection system | |
| CN203673002U (en) | Direct current system earth fault searching device | |
| CN203350348U (en) | Electrification detection device for ground wire, air-conditioner and electrical equipment | |
| CN206293878U (en) | A kind of action protecting device of Intelligent Measurement residual current | |
| CN102788925B (en) | Fault detection system of communication circuit | |
| CN209167865U (en) | A kind of On-off signal detection circuit and monitoring system | |
| CN202149937U (en) | Electric energy meter calibrating device and calibrating system | |
| CN203825172U (en) | DC power supply system alternating current mixed detection device | |
| CN206378569U (en) | A kind of voltage relay abnormal detector | |
| CN103529353B (en) | Winding displacement detection method and winding displacement detection system | |
| CN107422222A (en) | A kind of photovoltaic DC-to-AC converter judges the circuit for detecting of fuse quality | |
| CN204706883U (en) | A kind of Novel lightning-proof case | |
| CN209313808U (en) | A kind of current protective device based on semiconductor module driving | |
| CN205484714U (en) | Circuit is listened to killer switch state | |
| CN104090245A (en) | Alternating current infiltrating detector for direct current supply system | |
| CN205319796U (en) | Power system fault detection system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 461000 Xuchang City, Henan Province Economic and Technological Development Zone high-tech XJ Electric City Road Patentee after: Henan Jingrui Cooling Technology Co., Ltd Address before: 461000 Xuchang City, Henan Province Economic and Technological Development Zone high-tech XJ Electric City Road Patentee before: XUCHANG XUJI JINGRUI TECHNOLOGY Co.,Ltd. |
|
| CP01 | Change in the name or title of a patent holder |