CN207215933U - A kind of break detection circuit of incremental encoder - Google Patents
A kind of break detection circuit of incremental encoder Download PDFInfo
- Publication number
- CN207215933U CN207215933U CN201720791601.8U CN201720791601U CN207215933U CN 207215933 U CN207215933 U CN 207215933U CN 201720791601 U CN201720791601 U CN 201720791601U CN 207215933 U CN207215933 U CN 207215933U
- Authority
- CN
- China
- Prior art keywords
- diode
- output end
- light emitting
- incremental encoder
- negative pole
- 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
- Optical Transform (AREA)
- Transmission And Conversion Of Sensor Element Output (AREA)
Abstract
The application provides a kind of break detection circuit of incremental encoder, is connected respectively with A, B, Z three-phase differential signal line of incremental encoder by three detection units：In each detection unit, even if before motor operating, also the signal of corresponding phase differential signal line can be passed through the comparison of diode rectification, electric resistance partial pressure and comparator to its input voltage, disconnection fault is detected by judging the voltage of detection unit output end again, solves the problems, such as that prior art must can just determine whether broken string after motor rotation.
Description
Technical field
It the utility model is related to electric and electronic technical field, more particularly to a kind of burn out detection electricity of incremental encoder
Road.
Background technology
Encoder is a kind of device for angular displacement or straight-line displacement being converted into electric signal, wherein, lower-cost increment
Formula encoder, all it is widely used in motion control and Electrified Transmission field.
Incremental encoder hardware break detection circuit of the prior art, typically use software detection or by increment
Directly connect LED light after formula encoder differential signal single-endedization；After motor gets into smooth, judge whether to receive by software
To pulse, or directly visually observe LED whether there is light and shade change, to judge incremental encoder whether there is broken string.
Above two detection mode must can just determine whether broken string after motor rotation, and for certain applications field
Close, it is necessary to be judged as whether incremental encoder wiring connects normally before operating, if can not detect the very first time to break,
Potential safety hazard will be caused.
Utility model content
In view of this, the utility model provides a kind of break detection circuit of incremental encoder, to solve existing skill
The problem of art just must can determine whether broken string after motor rotation.
To achieve these goals, the technical scheme that the utility model embodiment provides is as follows：
A kind of break detection circuit of incremental encoder, including three detection units, three detection units difference
It is connected for A, B, Z three-phase differential signal line with incremental encoder；The detection unit includes：First diode, second
Diode, the 3rd diode, the 4th diode, first resistor, second resistance, 3rd resistor and comparator；Wherein：
The positive pole of first diode is connected with the negative pole of second diode, and tie point is as the detection unit
Input anode and one in corresponding phase differential signal line be connected；
The positive pole of 3rd diode is connected with the negative pole of the 4th diode, and tie point is as the detection unit
Input cathode and another in corresponding phase differential signal line be connected；
It is one end with the first resistor of the negative pole of first diode, the negative pole of the 3rd diode, described
The in-phase input end of one end of second resistance and the comparator is connected；
The other end with the first resistor of the positive pole of second diode, the positive pole of the 4th diode, institute
State one end of 3rd resistor and the inverting input of the comparator is connected；
The other end ground connection of the second resistance；
The other end of the 3rd resistor is connected with the first power supply；The voltage of first power supply is more than or equal to the increment
The supply voltage of formula encoder；
The output end of the comparator is the output end of the detection unit.
Preferably, the comparator is open collector output type comparator.
Preferably, in addition to：
The light emitting diode that negative pole is connected with the output end of three detection units, or, negative pole and described three inspections
The output end for surveying unit corresponds three connected light emitting diodes；
Or the alarm unit that input is connected with the output end of three detection units, or, input with it is described
The output end of three detection units corresponds three connected alarm units.
Preferably, in addition to：Alarm unit and light emitting diode；Wherein：
Negative pole of the output end of three detection units with the light emitting diode is connected, and tie point is by pulling up electricity
Resistance is connected with second source；
The input of the alarm unit is connected with the positive pole of the light emitting diode；
The output end of the alarm unit is connected with controller.
Preferably, in addition to：Alarm unit and three light emitting diodes；Wherein：
The negative pole of three light emitting diodes corresponds with the output end of three detection units respectively to be connected；
The positive pole of three light emitting diodes is connected, and tie point is connected with the input of the alarm unit, and passes through
Pull-up resistor is connected with second source；
The output end of the alarm unit is connected with controller.
Preferably, in addition to：Three alarm units and three light emitting diodes；Wherein：
The negative pole of three light emitting diodes corresponds with the output end of three detection units respectively to be connected；
The positive pole of three light emitting diodes corresponds with the input of three alarm units respectively to be connected, and three
Individual tie point is connected after being connected by pull-up resistor with second source；
The output end of three alarm units is connected with controller.
Preferably, the detection unit and the controller not altogether, are provided with optocoupler or number in the alarm unit
Word isolating chip.
Preferably, the detection unit and the controller altogether, the voltage of the second source and the controller
Supply voltage is identical.
The application provides a kind of break detection circuit of incremental encoder, by three detection units respectively with increment type
A, B, Z three-phase differential signal line of encoder are connected：In each detection unit, even if before motor operating, also can be by accordingly
Phase differential signal line signal by the comparison of diode rectification, electric resistance partial pressure and comparator to its input voltage, then lead to
Cross the voltage for judging detection unit output end and then detect disconnection fault, solve prior art must motor rotation after ability
The problem of determining whether broken string.
Brief description of the drawings
, below will be to embodiment in order to illustrate more clearly of the utility model embodiment or technical scheme of the prior art
Or the required accompanying drawing used is briefly described in description of the prior art, it should be apparent that, drawings in the following description are only
It is embodiment of the present utility model, for those of ordinary skill in the art, on the premise of not paying creative work, also
Other accompanying drawings can be obtained according to the accompanying drawing of offer.
Fig. 1 is a kind of structural representation for detection unit that the embodiment of the present application provides；
Fig. 2 is the structural representation for the break detection circuit that another embodiment of the application provides；
Fig. 3 is the structural representation for the break detection circuit that another embodiment of the application provides；
Fig. 4 is the structural representation for the break detection circuit that another embodiment of the application provides.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the embodiment of the utility model is carried out
Clearly and completely describing, it is clear that described embodiment is only the utility model part of the embodiment, rather than whole
Embodiment.Based on the embodiment in the utility model, those of ordinary skill in the art are not under the premise of creative work is made
The every other embodiment obtained, belong to the scope of the utility model protection.
The utility model provides a kind of break detection circuit of incremental encoder, must be in motor to solve prior art
The problem of broken string can be just determined whether after rotation.
Specifically, the break detection circuit of the incremental encoder, including three detection units, three detection unit difference
It is connected for A, B, Z three-phase differential signal line with incremental encoder.
As shown in figure 1, detection unit includes：First diode D1, the second diode D2, the 3rd diode D3, the four or two
Pole pipe D4, first resistor R1, second resistance R2,3rd resistor R3 and comparator U1；Wherein：
First diode D1 positive pole is connected with the second diode D2 negative pole, input of the tie point as detection unit
Positive pole A+ is connected with one in corresponding phase differential signal line；
3rd diode D3 positive pole is connected with the 4th diode D4 negative pole, input of the tie point as detection unit
Negative pole A- is connected with another in corresponding phase differential signal line；
One end with first resistor R1 of first diode D1 negative pole, the 3rd diode D3 negative pole, second resistance R2
One end and comparator U1 in-phase input end be connected；
The other end of the second diode D2 positive pole, the 4th diode D4 positive pole with first resistor R1,3rd resistor
R3 one end and comparator U1 inverting input are connected；
Second resistance R2 other end ground connection；
The 3rd resistor R3 other end is connected with the first power supply；The voltage VCC of first power supply encodes more than or equal to increment type
The supply voltage VH of device；
Comparator U1 output end is the output end of detection unit.
In actual applications, the first diode D1 and the second diode D2 work(can be realized using a double diode
Can, the 3rd diode D3 and the 4th diode D4 function are realized using another double diode, or four can also be used
Individual independent diode is realized, is not specifically limited herein, can depending on it is due to environment, the protection model in the application
In enclosing.
Fig. 1 is the detection unit of the A phase signals lines in incremental encoder A, B, Z signal wire, because B, Z two-phase signal wire
Detection unit in addition to input and output, remaining is completely the same with Fig. 1, so Fig. 1 enters by taking the detection unit of A phase signals lines as an example
Row displaying.Illustrated by taking Fig. 1 as an example, the input anode A+ and incremental encoder A phase signals line of above-mentioned detection unit are just
Extremely it is connected, the input cathode A- of detection unit is connected with incremental encoder A phase signals line negative poles.
Specifically operation principle is：
Assuming that the output high level of the incremental encoder is VH, low level VL；The pressure drop of each diode is VD.
Referring to Fig. 1, under normal circumstances, namely in the case of non-broken string, input anode A+ and the detection of detection unit
Level between the input cathode A- of unit is between VH and VL, and the signal of incremental encoder output is by corresponding
After diode rectification, comparator U1 homophase input terminal voltage U+=VH-VD, anti-phase input terminal voltage U-=VL+VD are obtained,
Due to the equal VD very littles of the pressure drop of each diode, VH-VL>2VD, so U+>U-；Therefore, under non-broken string condition of work, compare
Device U1 exports high resistant all the time.
In the case of broken string, for example, detection unit input anode A+ connect signal wire broken string or detection unit input
End negative pole A- connects signal wire broken string, if the signal wire output do not broken is VH, then after corresponding diode rectification,
Obtain comparator U1 homophase input terminal voltage U+=VH-VD, anti-phase input terminal voltage U-=(Vcc-U+) × R1/ (R1+R3)+
U+；Wherein, supply voltage of the voltage vcc of the first power supply for encoder or the supply voltage more than encoder, so Vcc>VH,
And then it can obtain, U--U+=(Vcc-VH+VD) × R1/ (R1+R3)>0, namely U->U+, comparator U1 will export low level.
If the signal wire output do not broken is VL, after corresponding diode rectification, comparator U1 inverting input is obtained
Voltage U-=VD, homophase input terminal voltage U+=U- × R2/ (R1+R2), it is therefore apparent that now U->U+.
If the input anode A+ of detection unit and the input cathode A- of detection unit connect signal wire and broken,
After corresponding diode rectification, comparator U1 homophase input terminal voltage U+=Vcc × R2/ (R1+R2+R3) is obtained,
Anti-phase input terminal voltage U-=Vcc × (R1+R2)/(R1+R2+R3)；So in the case of broken string, comparator U1 anti-phase input
Terminal voltage U- is consistently greater than its homophase input terminal voltage U+, comparator U1 output low level.
In addition, in the case that power supply breaks, because the incremental encoder does not export, it is equal to above-mentioned detection unit
Input anode A+ and the input cathode A- of detection unit connect the situation that signal wire all breaks.
B, the burn out detection principle of Z two-phases signal wire is identical with the above, no longer repeats one by one herein.
The present embodiment provide the incremental encoder break detection circuit, by three detection units respectively with increment
A, B, Z three-phase differential signal line of formula encoder are connected：In each detection unit, even if before motor operating, also can be by phase
The signal for the phase differential signal line answered by the comparison of diode rectification, electric resistance partial pressure and comparator to its input voltage, then
Disconnection fault is detected by judging the voltage of detection unit output end, solving prior art must be after motor rotation
The problem of broken string can be determined whether.If also, operationally break, the hardware circuit of the present embodiment can also the very first time
Output disconnection signal sends controller (such as single-chip microcomputer) to, and its response time is faster than software detection；Simultaneously can be in certain journey
Simplify software algorithm on degree, save controller resource.In addition, the present embodiment circuit is simple, cost is relatively low, beneficial to popularization.
Preferably, comparator U1 is open collector output type comparator.
Comparator U1 can be LM393, i.e. open collector output type comparator；It is only herein a kind of example, in reality
This is not limited in use, can be regarding it particularly due to depending on environment, in the protection domain of the application.
It is different according to model according to comparator U1 in specific practical application, need to meet a level pressure between U+, U-
Poor condition can just ensure that respective comparator U1 output is stable, now can by adjust first resistor R1, second resistance R2 and
3rd resistor R3 resistance is adapted to comparator U1 requirement.Also, during the comparator U1 of a certain model of adaptation, first resistor
R1, second resistance R2 and 3rd resistor R3 resistance is not unique, and three can select arbitrarily in the section for meet condition
It is worth resistance.It is not specifically limited herein, depending on its concrete application environment, in the protection domain of the application.
Another embodiment of the utility model additionally provides the break detection circuit of another incremental encoder, above-mentioned
On embodiment basis, comparator U1 output A_FAULT can be pulled up individually in Fig. 1, connect LED and/or MCU, now can be with
Be configured according to the needs of practical application, enable the break detection circuit of the incremental encoder individually detect be A, B,
Which mutually breaks Z, as shown in Figure 4；Or also can be by A, B, Z three-phase disconnection signal line with uniformly meeting LED and MCU, only retaining
One unified broken string indication signal is as shown in Figure 2.
Specifically, referring to Fig. 2, on Fig. 1 basis, the break detection circuit of the incremental encoder also includes：Report
Alert unit and light emitting diode；Wherein：
Negative pole of the output end of three detection units with light emitting diode (LED) is connected, and tie point passes through pull-up resistor
It is connected with second source (such as+5V)；
The input of alarm unit is connected with the positive pole of light emitting diode；
The output end of alarm unit is connected with controller.
As shown in Fig. 2 the incremental encoder export A, B, Z three-phase differential signal, the three-phase signal be separately input into
Fig. 1 identicals are corresponded in break detection circuit.The output of three road comparators by same resistance pull-up realize line with.Non- disconnected
Under wire state, three comparators export high-impedance state, and light emitting diode is gone out, and optocoupler is not turned on, optical coupling secondary edges PG_FAULT signals
High level is exported to controller.When having any one phase or polyphase signa breaks, light emitting diode is bright, optocoupler conducting, and secondary is defeated
Go out low level to controller.During using this embodiment, there is broken string situation, can be shown by LED and two kinds of channels of software are true
Recognize, circuit more simplifies, and cost of implementation is low.
Or referring to Fig. 3, on Fig. 1 basis, the break detection circuit of the incremental encoder also includes：Alarm
Unit and three light emitting diodes；Wherein：
The negative pole of three light emitting diodes corresponds with the output end of three detection units respectively to be connected；
The positive pole of three light emitting diodes is connected, and tie point is connected with the input of alarm unit, and passes through pull-up resistor
It is connected with second source；
The output end of alarm unit is connected with controller.
Break detection circuit shown in Fig. 3, can be shown by LED identify A, B, Z it is specific which mutually broken.
In addition, referring to Fig. 4, on Fig. 1 basis, the break detection circuit of the incremental encoder also includes：Three
Alarm unit and three light emitting diodes；Wherein：
The negative pole of three light emitting diodes corresponds with the output end of three detection units respectively to be connected；
The positive pole of three light emitting diodes corresponds with the input of three alarm units respectively to be connected, three tie points
It is connected after being connected by pull-up resistor with second source；
The output end of three alarm units is connected with controller.
Break detection circuit shown in Fig. 4, it can be shown respectively by LED and two kinds of channels of software identify that A, B, Z are specific
Which is mutually broken.
This embodiment is only used for for example, by connecting LED and/or controller, so which specific phase of A, B, Z identified
Broken.Certainly, LED and controller are also not necessarily all necessary, only can make hardware broken string instruction by LED, or only
Connection controller does software broken string instruction.For example the break detection circuit is on Fig. 1 basis, in addition to：
The light emitting diode that negative pole is connected with the output end of three detection units, or, negative pole and three detection units
Output end corresponds three connected light emitting diodes；
Or the alarm unit that input is connected with the output end of three detection units, or, input and three detections
The output end of unit corresponds three connected alarm units.
No longer repeat one by one herein, in the protection domain of the application.
Preferably, detection unit and controller be not provided with altogether, in alarm unit optocoupler (as shown in Figures 2 to 4) or
Digital isolating chip.
In the case where the ground of encoder (COM) isolates with the ground (GND) of controller, light as shown in Figures 2 to 4 can be passed through
Coupling is isolated, and can also be realized and isolated by digital isolating chip.In Fig. 2 to 4, the supply voltage (being based on COM) of optocoupler primary side and the
Two power supplys are identical, and the supply voltage (being based on GND) of optical coupling secondary edges is identical with the supply voltage of controller.
Preferably, altogether, the voltage of second source is identical with the supply voltage of controller for detection unit and controller.
In the case of the ground of encoder and controller identical, the pull-up power supply of comparator rear end, i.e. second source, setting
Controller is may be connected directly to for controller power source.
Remaining operation principle is same as the previously described embodiments, no longer repeats one by one herein.
Each embodiment is described by the way of progressive in the utility model, what each embodiment stressed be and its
The difference of his embodiment, between each embodiment identical similar portion mutually referring to.For dress disclosed in embodiment
For putting, because it is corresponded to the method disclosed in Example, so description is fairly simple, related part is referring to method part
Explanation.
It the above is only preferred embodiment of the present utility model, make skilled artisans appreciate that or realizing this practicality
It is new.A variety of modifications to these embodiments will be apparent to one skilled in the art, defined herein
General Principle can be realized in other embodiments in the case where not departing from spirit or scope of the present utility model.Therefore,
The utility model is not intended to be limited to the embodiments shown herein, and is to fit to and principles disclosed herein and new
The consistent most wide scope of clever feature.
Claims (8)
- A kind of 1. break detection circuit of incremental encoder, it is characterised in that including three detection units, three detections Unit is respectively used to be connected with A, B, Z three-phase differential signal line of incremental encoder；The detection unit includes：One or two pole Pipe, the second diode, the 3rd diode, the 4th diode, first resistor, second resistance, 3rd resistor and comparator；Wherein：The positive pole of first diode is connected with the negative pole of second diode, and tie point is defeated as the detection unit Enter proper pole with one in corresponding phase differential signal line to be connected；The positive pole of 3rd diode is connected with the negative pole of the 4th diode, and tie point is defeated as the detection unit Enter to hold negative pole to be connected with another in corresponding phase differential signal line；One end with the first resistor of the negative pole of first diode, the negative pole of the 3rd diode, described second The in-phase input end of one end of resistance and the comparator is connected；The other end with the first resistor of the positive pole of second diode, the positive pole of the 4th diode, described The inverting input of one end of three resistance and the comparator is connected；The other end ground connection of the second resistance；The other end of the 3rd resistor is connected with the first power supply；The voltage of first power supply is compiled more than or equal to the increment type The supply voltage of code device；The output end of the comparator is the output end of the detection unit.
- 2. the break detection circuit of incremental encoder according to claim 1, it is characterised in that the comparator is collection Electrode open circuit output type comparator.
- 3. the break detection circuit of incremental encoder according to claim 1, it is characterised in that also include：The light emitting diode that negative pole is connected with the output end of three detection units, or, negative pole and described three detection lists The output end of member corresponds three connected light emitting diodes；Or the alarm unit that input is connected with the output end of three detection units, or, input and described three The output end of detection unit corresponds three connected alarm units.
- 4. the break detection circuit of incremental encoder according to claim 1, it is characterised in that also include：Alarm is single Member and light emitting diode；Wherein：Negative pole of the output end of three detection units with the light emitting diode is connected, tie point by pull-up resistor with Second source is connected；The input of the alarm unit is connected with the positive pole of the light emitting diode；The output end of the alarm unit is connected with controller.
- 5. the break detection circuit of incremental encoder according to claim 1, it is characterised in that also include：Alarm is single Member and three light emitting diodes；Wherein：The negative pole of three light emitting diodes corresponds with the output end of three detection units respectively to be connected；The positive pole of three light emitting diodes is connected, and tie point is connected with the input of the alarm unit, and passes through pull-up Resistance is connected with second source；The output end of the alarm unit is connected with controller.
- 6. the break detection circuit of incremental encoder according to claim 1, it is characterised in that also include：Three reports Alert unit and three light emitting diodes；Wherein：The negative pole of three light emitting diodes corresponds with the output end of three detection units respectively to be connected；The positive pole of three light emitting diodes corresponds with the input of three alarm units respectively to be connected, three companies Contact is connected after being connected by pull-up resistor with second source；The output end of three alarm units is connected with controller.
- 7. according to the break detection circuit of any described incremental encoder of claim 4 to 6, it is characterised in that the inspection Survey unit and the controller not altogether, optocoupler or digital isolating chip are provided with the alarm unit.
- 8. according to the break detection circuit of any described incremental encoder of claim 4 to 6, it is characterised in that the inspection Survey unit and the controller altogether, the voltage of the second source is identical with the supply voltage of the controller.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720791601.8U CN207215933U (en) | 2017-06-30 | 2017-06-30 | A kind of break detection circuit of incremental encoder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720791601.8U CN207215933U (en) | 2017-06-30 | 2017-06-30 | A kind of break detection circuit of incremental encoder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207215933U true CN207215933U (en) | 2018-04-10 |
Family
ID=61812602
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201720791601.8U Active CN207215933U (en) | 2017-06-30 | 2017-06-30 | A kind of break detection circuit of incremental encoder |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207215933U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108459234A (en) * | 2018-05-04 | 2018-08-28 | 深圳易能电气技术股份有限公司 | Incremental type encoder offline detection circuit |
| CN110161360A (en) * | 2019-05-30 | 2019-08-23 | 宁波安信数控技术有限公司 | A kind of incremental encoder broken wire detection system and method |
| CN110672957A (en) * | 2019-10-14 | 2020-01-10 | 广东博智林机器人有限公司 | Encoder signal fault detection device and method |
| CN111795714A (en) * | 2019-04-03 | 2020-10-20 | 深圳市正弦电气股份有限公司 | ABZ differential encoder detection circuit without UVW magnetic pole signal |
-
2017
- 2017-06-30 CN CN201720791601.8U patent/CN207215933U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108459234A (en) * | 2018-05-04 | 2018-08-28 | 深圳易能电气技术股份有限公司 | Incremental type encoder offline detection circuit |
| CN111795714A (en) * | 2019-04-03 | 2020-10-20 | 深圳市正弦电气股份有限公司 | ABZ differential encoder detection circuit without UVW magnetic pole signal |
| CN110161360A (en) * | 2019-05-30 | 2019-08-23 | 宁波安信数控技术有限公司 | A kind of incremental encoder broken wire detection system and method |
| CN110672957A (en) * | 2019-10-14 | 2020-01-10 | 广东博智林机器人有限公司 | Encoder signal fault detection device and method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN207215933U (en) | A kind of break detection circuit of incremental encoder | |
| CN104333364A (en) | AC solid state relay and fault detecting method of load circuit of same | |
| CN204882727U (en) | Scarce phase sequence detection circuit that reaches mutually of three -phase input voltage | |
| CN204231318U (en) | A kind of ac solid relay | |
| CN2826445Y (en) | Intelligent line-checking machine | |
| CN207232324U (en) | A kind of fault diagnosis circuit of low side driving | |
| CN106501663A (en) | A kind of detection exchange ground wire connection whether good method | |
| CN107255766B (en) | A kind of break detection circuit and its connection circuit of incremental encoder | |
| CN107703414A (en) | Detect circuit and detection method | |
| CN109283424B (en) | Testing device and method for four-port sensor signal deconcentrator with LED | |
| CN108037377A (en) | A kind of method and circuit for detecting three-phase alternating-current supply phase shortage | |
| CN208035987U (en) | Low pressure accessory power supply detection device and charging pile | |
| CN102385036B (en) | Method and circuit for detecting alternating-current fuse failure of uninterruptible power supply | |
| CN209342877U (en) | New energy car battery packet relay adhesion detection circuit and system | |
| CN105973274B (en) | A kind of signal deteching circuit and device | |
| CN104898009B (en) | Detection equipment and detection method for online sensing equipment | |
| CN110596513B (en) | Hall assembly voltage detection device and Hall assembly performance detection device | |
| CN101806871B (en) | A kind of online test method | |
| CN214173663U (en) | Testing arrangement of weeping response line | |
| CN212781164U (en) | Circuit and system capable of simultaneously detecting grounding condition and reverse connection of zero line and live line | |
| CN202565020U (en) | Failure detecting circuit of automatic change-over switch | |
| CN102253288A (en) | E1 interface impedance testing device and system | |
| CN112290519B (en) | High-reliability ground wire live detection protection circuit | |
| CN2809656Y (en) | Phase sequence detection device for three-phase alternating current power supply | |
| CN205333770U (en) | Line detection device and system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |