CN208820450U - A kind of overvoltage protection - Google Patents
A kind of overvoltage protection Download PDFInfo
- Publication number
- CN208820450U CN208820450U CN201820993405.3U CN201820993405U CN208820450U CN 208820450 U CN208820450 U CN 208820450U CN 201820993405 U CN201820993405 U CN 201820993405U CN 208820450 U CN208820450 U CN 208820450U
- Authority
- CN
- China
- Prior art keywords
- voltage
- optocoupler
- flop
- overvoltage protection
- rest
- 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.)
- Expired - Fee Related
Links
- 230000001681 protective effect Effects 0.000 claims description 12
- 230000008878 coupling Effects 0.000 claims description 7
- 238000010168 coupling process Methods 0.000 claims description 7
- 238000005859 coupling reaction Methods 0.000 claims description 7
- 230000003287 optical effect Effects 0.000 claims description 7
- 230000003321 amplification Effects 0.000 claims description 5
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 5
- 230000009471 action Effects 0.000 claims description 3
- 230000005611 electricity Effects 0.000 claims description 3
- 230000002441 reversible effect Effects 0.000 claims description 2
- 230000001771 impaired effect Effects 0.000 abstract description 5
- 238000000034 method Methods 0.000 description 14
- 230000005540 biological transmission Effects 0.000 description 9
- 230000008569 process Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000004804 winding Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 230000006698 induction Effects 0.000 description 2
- 238000013024 troubleshooting Methods 0.000 description 2
- 230000004888 barrier function Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000002045 lasting effect Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
Landscapes
- Emergency Protection Circuit Devices (AREA)
Abstract
The utility model provides a kind of overvoltage protection, comprising: voltage obtains module, for obtaining the instantaneous voltage of equipment to be protected in real time；Range judgment module, for judging whether the instantaneous voltage exceeds preset range；Trip protection module controls trip(ping) circuit and cuts off the equipment to be protected if exceeding preset range for the instantaneous voltage.In the prior art; the overvoltage protection of electrical equipment mainly passes through microcomputer or electromagnetic relay is realized; it is all to judge overvoltage failure whether occurs on the related main equipment such as route by judging voltage effective value; postpone so generally requiring wave period or more to sending trip signal from the generation of overvoltage failure, this cannot quickly judge the overvoltage failure caused on the main equipments such as route.And the utility model is judged using instantaneous voltage, so that occurring from overvoltage failure to less than one voltage cycle of time interval for issuing trip signal, reduces electrical equipment because of the impaired possibility of electric fault.
Description
Technical field
The utility model relates to electic protection technical field, in particular to a kind of overvoltage protection.
Background technique
The overvoltage protection of the main electrical equipments such as route, transformer mainly passes through microcomputer at present or electromagnetic relay is real
It is existing, since both schemes are all to judge whether overvoltage occurs on the related main equipment such as route by judging voltage effective value
Failure, so both schemes occur from overvoltage failure to sending trip signal to generally require the delay of a cycle or more,
This cannot quickly judge the overvoltage failure caused on the main equipments such as route.
Therefore, how a kind of overvoltage protection scheme is provided, tripping delay when overvoltage failure occurs can be reduced, subtracted
Few electrical equipment is those skilled in the art's technical problem urgently to be resolved because of the impaired possibility of electric fault.
Utility model content
In view of this, overvoltage event can be reduced the purpose of this utility model is to provide a kind of overvoltage protection scheme
Tripping delay when barrier occurs, reduces electrical equipment because of the impaired possibility of electric fault.Its concrete scheme is as follows:
A kind of overvoltage protection, comprising:
Voltage obtains module, for obtaining the instantaneous voltage of equipment to be protected in real time；
Range judgment module, for judging whether the instantaneous voltage exceeds preset range；
Trip protection module controls trip(ping) circuit excision institute if exceeding preset range for the instantaneous voltage
State equipment to be protected.
Preferably,
The voltage obtains module, comprising: the voltage transformer that primary side is connected with equipment to be protected, input terminal and institute
State the operational amplifier of the secondary connection of voltage transformer；
The range judgment module, comprising: the first optocoupler, the second optocoupler；First optocoupler, second optocoupler are reversed
Parallel connection constitutes optocoupler assembly, and the input terminal of the optocoupler assembly is connect with the output end of the operational amplifier；The optocoupler is total
At input terminal connect with the first preset resistance ground connection；The first end and DC current source of the output end of the optocoupler assembly connect
It connects, second end is connected ground connection with the second preset resistance；
The trip protection module, comprising: rest-set flip-flop, protective device；The end S of the rest-set flip-flop and the optocoupler are total
At output end second end connection；The end Q of the rest-set flip-flop is connected to the protective device.
Preferably,
The amplification factor of the operational amplifier is critical for the cut-in voltage of the optocoupler assembly and the equipment to be protected
The ratio of the secondary side voltage value of voltage transformer when failure.
Preferably,
First optocoupler, second optocoupler are linear optical coupling.
Preferably,
The end Q of the rest-set flip-flop is also connected with warning device.
Preferably,
The voltage transformer is electromagnetic potential transformer or electronic type voltage transformer.
Preferably,
The rest-set flip-flop is the rest-set flip-flop that two nor gates are constituted.
Preferably,
The end R of the rest-set flip-flop and switch are connected in series in DC power supply；The end R of the rest-set flip-flop and third are default
Resistance series connection.
Preferably,
The switch is the normal switch-dividing with snap action current-limiting protection/protective parts.
The utility model provides a kind of overvoltage protection, comprising: voltage obtains module, to be protected for obtaining in real time
The instantaneous voltage of equipment；Range judgment module, for judging whether the instantaneous voltage exceeds preset range；Trip protection
Module controls trip(ping) circuit and cuts off the equipment to be protected if exceeding preset range for the instantaneous voltage.Existing
Have in technology, the overvoltage protection of electrical equipment mainly passes through microcomputer or electromagnetic relay is realized, all due to both schemes
It is to judge overvoltage failure whether occurs on the related main equipment such as route by judging voltage effective value, so both schemes
The delay of a wave period or more is generally required from the generation of overvoltage failure to sending trip signal, this will cause route etc. main
Overvoltage failure in equipment cannot quickly judge.And the utility model is judged using instantaneous voltage, so that from
Less than one voltage cycle of time interval to sending trip signal occurs for overvoltage failure, and then can reduce overvoltage failure
Tripping delay when generation, reduces electrical equipment because of the impaired possibility of electric fault.
Detailed description of the invention
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 the embodiments of the present invention, for those of ordinary skill in the art, without creative efforts, also
Other attached drawings can be obtained according to the attached drawing of offer.
Fig. 1 is the composition schematic diagram of overvoltage protection provided by a kind of specific embodiment of the utility model；
Fig. 2 is the flow chart of the over-voltage protection method of overvoltage protection shown in FIG. 1；
Fig. 3 is that the circuit of overvoltage protection provided by another specific embodiment of the utility model forms signal
Figure；
Fig. 4 is the operational process schematic diagram of the circuit of overvoltage protection shown in Fig. 3.
Specific embodiment
The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model
Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole
Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are without making creative work
Every other embodiment obtained, fall within the protection scope of the utility model.
Referring to FIG. 1, Fig. 1 is the composition of overvoltage protection provided by a kind of specific embodiment of the utility model
Schematic diagram；Fig. 2 is the flow chart of the over-voltage protection method of overvoltage protection shown in FIG. 1.
In a kind of having in specific embodiment for the utility model, the utility model embodiment provides a kind of overvoltage protection
Device 200, comprising:
Voltage obtains module 210, for obtaining the instantaneous voltage of equipment to be protected in real time；
Range judgment module 220, for judging whether the instantaneous voltage exceeds preset range；
Trip protection module 230 controls trip(ping) circuit excision if exceeding preset range for the instantaneous voltage
The equipment to be protected.
The voltage obtains module 210, comprising: the voltage transformer 211 that primary side is connected with equipment to be protected, it is defeated
Enter the operational amplifier 212 at end with the secondary connection of the voltage transformer；
The range judgment module 220, comprising: the first optocoupler 221, the second optocoupler 222；First optocoupler, described
Two optocoupler reverse parallel connections constitute optocoupler assembly, and the input terminal of the optocoupler assembly is connect with the output end of the operational amplifier；
The input terminal of the optocoupler assembly is connected ground connection with the first preset resistance 223；The first end of the output end of the optocoupler assembly with
DC current source connection, second end are connected ground connection with the second preset resistance 224；The trip protection module 230, comprising: RS touching
Send out device 231, protective device 232；The end S of the rest-set flip-flop is connect with the second end of the output end of the optocoupler assembly；It is described
The end Q of rest-set flip-flop is connected to the protective device 232.
Further, in order to enable it is luminous with protecting equipment optocoupler in failure that can start, the operation can be put
The amplification factor of big device mutual induction of voltage when being the cut-in voltage and the equipment to be protected critical fault of the optocoupler assembly
The ratio of the secondary side voltage value of device.In this way, voltage passes ground by voltage transformer when equipment to be protected is in failure, pass through
The amplification factor amplification of operational amplifier is to become the voltage for being suitble to optocoupler starting.
Preferably, photoelectrical coupler is divided into two kinds: one kind is non-linear optocoupler, and another kind is linear optical coupling.Nonlinear optical
The current transmission characteristic curve of coupling be it is nonlinear, this kind of optocoupler is suitable for the transmission of switching signal, be not suitable for transmission simulation
Amount.The current transmission characteristic curve of linear optical coupling is close to straight line, and better performances when small signal, can be carried out with linear characteristic every
From control.Common linear optical coupling is PC817A-C series.Therefore, in the utility model embodiment, preferentially by described
One optocoupler, second optocoupler are disposed as linear optical coupling.
Further, warning device is also connected at the end Q of the rest-set flip-flop.The warning device can be flashing LED
Lamp or buzzer.
Preferably,
The voltage transformer is electromagnetic potential transformer or electronic type voltage transformer.Voltage transformer and transformer
It is similar, it is the instrument of the voltage on conversion line.Capacitance type potential transformer: capacitance type potential transformer (CVT) be by
Series capacitor partial pressure, then be depressured and be isolated through electromagnetic transformer, a kind of mutual induction of voltage as meter, relay protection etc.
Device, capacitance type potential transformer carrier frequency can also be coupled to power transmission line be used for long distance communication, a distant place measurement, selectivity
HF protection for transmission line, remote control, telex etc..Electronic type voltage transformer is by being connected to the one of Transmission system and two times transfer device
A kind of device of a or multiple voltages or current sensor composition, to transmit the measured amount that is proportional to, supply measuring instrument,
Instrument and relay protection or control device.Therefore, electronic type voltage transformer can be used in the utility model embodiment.
When selecting rest-set flip-flop, the rest-set flip-flop can be set to the rest-set flip-flop of two nor gates composition.RS
Trigger is the element for constituting various other function triggers, also known as basic RS trigger, and structure is two
Input, the output end interconnection of a NAND gate or nor gate G1, G2.The defeated of two NAND gates or nor gate G1, G2
Enter, output end interconnection, that is, may make up basic RS trigger, for the rest-set flip-flop of two NAND gates composition.There are two defeated for it
Enter to hold R, S and two output ends Q, Q non-.Its structure is relatively simple, therefore, selects two nor gates to constitute in the present embodiment
Rest-set flip-flop.
Why selection uses rest-set flip-flop, is because subsequent protective device on startup, needs a lasting letter
Number as control signal, and in the utility model embodiment using in real time acquisition equipment to be protected instantaneous voltage by the way of,
Its judging result may be only present in a flash, or be followed by voltage value fluctuation and periodically occur, and be unfavorable for subsequent
The starting of protective device, thus here locked using rest-set flip-flop determine as a result, in order to subsequent protective device starting.
Further, in order to return to original state rest-set flip-flop, can by the end R of the rest-set flip-flop with open
It closes 232 and is connected in series in DC power supply；The end R of the rest-set flip-flop is connected ground connection with third preset resistance 225.In overvoltage
After troubleshooting, before band protection putting equipment in service, needs hand to press FA button, restore rest-set flip-flop original state.Of course, it is possible to will
The switch 232 is set as the normal switch-dividing with snap action current-limiting protection/protective parts.
The utility model embodiment provides a kind of overvoltage protection, compares in the prior art, the mistake of electrical equipment
Voltage protection mainly passes through microcomputer or electromagnetic relay and realizes, due to both schemes be all by judge voltage effective value come
Judge overvoltage failure whether occurs on the related main equipment such as route, so both schemes occur from overvoltage failure to sending
Trip signal generally requires the delay of a wave period or more, this will cause the overvoltage failure on the main equipments such as route cannot
Quickly judgement.And the utility model embodiment is judged using instantaneous voltage so that from overvoltage failure occur to
Less than one voltage cycle of time interval of trip signal is issued, and then the tripping that can be reduced when overvoltage failure occurs is prolonged
Late, electrical equipment is reduced because of the impaired possibility of electric fault.
On the basis of the utility model above-mentioned specific embodiment, the utility model embodiment, which provides, is applied to above-mentioned mistake
The over-voltage protection method of voltage protection, comprising:
S11: the instantaneous voltage of equipment to be protected is obtained in real time；
S12: judge whether the instantaneous voltage exceeds preset range；
S13: if it is, control trip(ping) circuit cuts off the equipment to be protected.
In the prior art, the overvoltage protection of electrical equipment mainly passes through microcomputer or electromagnetic relay is realized, due to
Both schemes are all to judge overvoltage failure, institute whether occurs on the related main equipment such as route by judging voltage effective value
The delay of a wave period or more is generally required from the generation of overvoltage failure to sending trip signal with both schemes, this will
Cause the overvoltage failure on the main equipments such as route that cannot quickly judge.
In the utility model embodiment, on the basis of existing technology, the voltage wink of equipment to be protected can be obtained in real time
Duration, rather than judged using voltage effective value in the prior art, it can be judged using single-chip microcontroller, using electricity
Pressure sensor is implemented to obtain the instantaneous voltage of equipment to be protected.It is of course also possible to use other hardware configurations implement this
Over-voltage protection method in utility model.
Referring to FIG. 4, Fig. 4 is the operational process schematic diagram of the circuit of overvoltage protection shown in Fig. 3.
In the following, being described further for the embodiment in Fig. 3:
Overvoltage protection includes voltage transformer (PT), the operational amplifier, optocoupler of equipment to be protected (such as route)
The basic RS that IC1, optocoupler IC2, button F A, resistance R1, resistance R2, resistance R3, DC voltage source VCC, two nor gates form
Trigger.
U indicates that the primary voltage of main equipment, U ' indicate that corresponding voltage transformer secondary voltage, that is, operation are put in figure
The input voltage of big device.Uout indicates op-amp output voltage.
The connection of the input terminal of main equipment voltage transformer (CT) secondary winding and operational amplifier.
The light emitting diode of the output end of operational amplifier optocoupler (IC1, IC2) in parallel with two reversed polarity (headtotail)
Side and resistance R1Connection.
The phototriode side of DC voltage source VCC optocoupler (IC1, IC2) in parallel with two reversed polarity (headtotail), with
And resistance R2Connection.On the other hand, DC voltage source VCC passes through button F A and resistance R3Connection.
The end basic RS filpflop R is connected in button F A and resistance R3Between.The end basic RS filpflop S is connected to two reversed polarity
Between the phototriode side and resistance R2 of (headtotail) parallel connection optocoupler (IC1, IC2).
Its working principles are as follows:
If assume: (1) voltage transformer pt secondary winding instantaneous voltage absolute value when main equipment is without overvoltage failure and
Having cut off value when overvoltage failure is uset；(2) light emitting diode cut-in voltage UTHIt has determined that.Then op-amp gain A
Meet lower relation of plane, the system of this programme design can be achieved with quick overvoltage protection.
A*uset=UTH
When main equipment operates normally, voltage transformer pt secondary winding instantaneous voltage absolute value | U (t) | it is consistently less than uset,
Then
A*|U(t)|<UTH
Light emitting diode does not shine in i.e. at this time optocoupler IC1 and IC2, phototriode cut-off.It is triggered according to basic RS
The basic principle of device is it is found that basic RS filpflop will not act at this time, that is to say, that its output end Q output is 0 (low level).
When overvoltage failure occurs for main equipment, the absolute value of voltage transformer pt secondary winding instantaneous voltage can be quick
Increase, | U (t) | it in a very short period of time can be more than cut off value uset, the voltage at light emitting diode both ends is fast in optocoupler IC1 or IC2
Speed is more than cut-in voltage UTH, light emitting diode is bright in IC1 or IC2, corresponding photosensitive triode ON, resistance R2The voltage of upper end becomes
High level, that is to say, that basic RS filpflop input terminal S gets higher level.According to the principle of basic RS filpflop it is found that it is exported
End Q can export high level signal and keep.Trigger output end Q can be connected to the trip(ping) circuit of main equipment relative breaker, allow master
Equipment trips rapidly when overvoltage failure occurs, and cuts failure quickly.Meanwhile output end Q can also be with measure and control device with cooperation
For alarming from the background, allows power grid operation personnel to know and overvoltage failure occurs.
After overvoltage troubleshooting, before main equipment puts into operation, hand is needed to press FA button, restores rest-set flip-flop original state.
The response time of above-mentioned apparatus mainly consists of three parts: the transmission delay of amplifier, the transmission delay of optocoupler, basic
The actuation time of rest-set flip-flop.The time of every each section all very littles, up to millisecond or nanosecond, total time is for electric system
For can be neglected.
Finally, it is to be noted that, herein, relational terms such as first and second and the like be used merely to by
One entity or operation are distinguished with another entity or operation, without necessarily requiring or implying these entities or operation
Between there are any actual relationship or orders.Moreover, the terms "include", "comprise" or its any other variant meaning
Covering non-exclusive inclusion, so that the process, method, article or equipment for including a series of elements not only includes that
A little elements, but also including other elements that are not explicitly listed, or further include for this process, method, article or
The intrinsic element of equipment.In the absence of more restrictions, the element limited by sentence "including a ...", is not arranged
Except there is also other identical elements in the process, method, article or apparatus that includes the element.
A kind of overvoltage protection provided by the utility model is described in detail above, it is used herein
Specific case is expounded the principles of the present invention and embodiment, and the explanation of above example is only intended to help to manage
Solve the method and its core concept of the utility model；At the same time, for those skilled in the art, according to the utility model
Thought, there will be changes in the specific implementation manner and application range, in conclusion the content of the present specification should not be construed as
Limitations of the present invention.
Claims (9)
1. a kind of overvoltage protection characterized by comprising
Voltage obtains module, for obtaining the instantaneous voltage of equipment to be protected in real time；
Range judgment module, for judging whether the instantaneous voltage exceeds preset range；
Trip protection module, if exceeding preset range for the instantaneous voltage, control trip(ping) circuit excision it is described to
Protect equipment；
The voltage obtains module, comprising: the voltage transformer that primary side is connected with equipment to be protected, input terminal and the electricity
Press the operational amplifier of the secondary connection of mutual inductor；
The range judgment module, comprising: the first optocoupler, the second optocoupler；First optocoupler, the second optocoupler reverse parallel connection
Optocoupler assembly is constituted, the input terminal of the optocoupler assembly is connect with the output end of the operational amplifier；The optocoupler assembly
Input terminal is connected ground connection with the first preset resistance；The first end of the output end of the optocoupler assembly is connect with DC current source, the
Two ends are connected ground connection with the second preset resistance；
The trip protection module, comprising: rest-set flip-flop, protective device；The end S of the rest-set flip-flop and the optocoupler assembly
The second end of output end connects；The end Q of the rest-set flip-flop is connected to the protective device.
2. overvoltage protection according to claim 1, which is characterized in that
The amplification factor of the operational amplifier is the cut-in voltage and the equipment to be protected critical fault of the optocoupler assembly
The ratio of the secondary side voltage value of Shi Suoshu voltage transformer.
3. overvoltage protection according to claim 1, which is characterized in that
First optocoupler, second optocoupler are linear optical coupling.
4. overvoltage protection according to claim 1, which is characterized in that
The end Q of the rest-set flip-flop is also connected with warning device.
5. overvoltage protection according to claim 4, which is characterized in that
The warning device is glittering LED lamp or buzzer.
6. overvoltage protection according to claim 1, which is characterized in that
The voltage transformer is electromagnetic potential transformer or electronic type voltage transformer.
7. overvoltage protection according to claim 1, which is characterized in that
The rest-set flip-flop is the rest-set flip-flop that two nor gates are constituted.
8. overvoltage protection according to any one of claims 1 to 7, which is characterized in that
The end R of the rest-set flip-flop and switch are connected in series in DC power supply；The end R of the rest-set flip-flop and the default electricity of third
Resistance series connection ground connection.
9. overvoltage protection according to claim 8, which is characterized in that
The switch is the normal switch-dividing with snap action current-limiting protection/protective parts.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820993405.3U CN208820450U (en) | 2018-06-22 | 2018-06-22 | A kind of overvoltage protection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820993405.3U CN208820450U (en) | 2018-06-22 | 2018-06-22 | A kind of overvoltage protection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN208820450U true CN208820450U (en) | 2019-05-03 |
Family
ID=66270058
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820993405.3U Expired - Fee Related CN208820450U (en) | 2018-06-22 | 2018-06-22 | A kind of overvoltage protection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN208820450U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108551154A (en) * | 2018-06-22 | 2018-09-18 | 南方电网科学研究院有限责任公司 | A kind of over-voltage protection method and device |
-
2018
- 2018-06-22 CN CN201820993405.3U patent/CN208820450U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108551154A (en) * | 2018-06-22 | 2018-09-18 | 南方电网科学研究院有限责任公司 | A kind of over-voltage protection method and device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0119187B1 (en) | Power supply system | |
| CN107069655B (en) | Voltage protection circuit | |
| CN103872658A (en) | Multifunctional self-recovery over-voltage and under-voltage protector | |
| CN208820450U (en) | A kind of overvoltage protection | |
| CN108011348B (en) | Low-voltage intelligent power distribution control protection system and control protection method thereof | |
| CN101350514B (en) | Current-limiting arc-extinguishing shunted exciter tripping type earthing short circuit protection device | |
| CN101251567A (en) | Method for rapidly seeking low line electric leakage | |
| CN103887660A (en) | Earth leakage protection plug capable of being switched between three-pole mode and two-pole mode | |
| CN108551154A (en) | A kind of over-voltage protection method and device | |
| CN110311357A (en) | A kind of Backup Protection Device for Transformer accelerated using nearly bus electric arc | |
| CN2821981Y (en) | Household leak breaker mounted with lightning protection anti-over voltage function | |
| CN213072106U (en) | Surge protector failure indication and alarm device circuit | |
| CN201750133U (en) | Automatic motor phase loss, overcurrent and leakage protection switch | |
| CN203645293U (en) | Automatic reconnecting device of intelligent breaker | |
| CN201946966U (en) | Partitioned power supply protection device of communication equipment | |
| CN210430920U (en) | Alternating current power supply lightning protection device with intelligent monitoring and protection functions | |
| CN1072294A (en) | Multi-function automatic monitor for power consumption | |
| CN211907850U (en) | Socket device capable of automatically protecting electric equipment | |
| CN2410731Y (en) | Safety power supply controller | |
| CN201048275Y (en) | Household electrical appliance protector for preventing lighting strike and overvoltage | |
| CN204905838U (en) | Simple and easy overvoltage protection trigger device | |
| CN107732862B (en) | Three-phase four-wire omnibearing multifunctional accident electric control protection switch | |
| CN1152459C (en) | High-safety power supply controller | |
| DE10017837B4 (en) | Device for mains isolation | |
| CN2261681Y (en) | Phase-loss protector for ac motor with optical coupling isolating air switch |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20190503 |