CN102664672B - Bidirectional relay with automatic follow-up faulty cable disconnection and recovery functions and method for controlling bidirectional relay - Google Patents
Bidirectional relay with automatic follow-up faulty cable disconnection and recovery functions and method for controlling bidirectional relay Download PDFInfo
- Publication number
- CN102664672B CN102664672B CN201210117491.9A CN201210117491A CN102664672B CN 102664672 B CN102664672 B CN 102664672B CN 201210117491 A CN201210117491 A CN 201210117491A CN 102664672 B CN102664672 B CN 102664672B
- Authority
- CN
- China
- Prior art keywords
- voltage
- cpu
- output
- repeater
- amplifier
- 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
Landscapes
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
- Monitoring And Testing Of Transmission In General (AREA)
Abstract
The invention provides a bidirectional relay with automatic follow-up faulty cable disconnection and recovery functions and method for the bidirectional relay. An electronic switch is controlled by means of continuously monitoring output voltage to judge whether a follow-up cable is in short circuit or not, the automatic follow-up cable disconnection function and the automatic recovery function are realized, fault alarm indication is driven, and an effect of weakening cable short-circuit fault is achieved. The bidirectional relay comprises an uplink amplifier, a downlink amplifier, a directional coupler I, a bidirectional coupler II, an uplink voltage stabilizer, a downlink voltage stabilizer, an output voltage sampling circuit, a CPU (central processing unit), a field-effect tube, a control circuit and a voltage stabilizer connected with the CPU, wherein the uplink voltage stabilizer is connected with the uplink amplifier, the downlink voltage stabilizer is connected with the downlink amplifier, the directional coupler I is connected with an input end of the downlink amplifier and an output end of the uplink amplifier, the directional coupler II is connected with an input end of the uplink amplifier and an output end of the downlink amplifier, and a direct-current power supply channel is arranged between an input end and an output end of the bidirectional relay.
Description
Technical field
The present invention relates to the communications field, especially relate to a kind of both-way trunk and the control method thereof that are applied to Leakage Communication System.
Background technology
Leakage Communication System is still the basic means of domestic and international mine down-hole radio communication at present.It is by the special coaxial cable of an outer conductor opening---leaky cable replaces antenna, guides electromagnetic wave into underworkings, thus realizes the ultrashort wave frequency modulation communication of ground downhole integrated, be i.e. downhole wireless intercom system.Leakage Communication System is once set up in certain mine, because it is simple and convenient, clear sound is loud and clear, without any time delay, do not have the features such as communication blind district, often become the means of communication that all departments such as underground transportation scheduling, pit shaft contact, overhaul of the equipments, safety inspection are indispensable very soon.
In Leakage Communication System, all leaky cable places of arrival, the i.e. communication coverage of this system.For making system communication that full ore deposit can be covered, need the length constantly extending leaky cable.Due to radiofrequency signal in the cable long-distance transmissions will bring loss, for making up this loss, require at a certain distance insert a relay amplifier.
The circuit composition of a basic bi-directional relaying amplifier as shown in Figure 1, comprises downstream amplifier, upstream amplifier, directional coupler I, directional coupler II and the up pressurizer of powering for amplifier and descending pressurizer.Up pressurizer is connected with upstream amplifier, and descending pressurizer is connected with downstream amplifier; Directional coupler I is connected with downstream amplifier input and upstream amplifier output, and directional coupler II and upstream amplifier input are connected with downstream amplifier output, comprises direct current supply passage between the constrained input end of both-way trunk.Wherein, downstream amplifier is for amplifying the downstream signal from base station to down-hole hand-held set, and upstream amplifier is for amplifying the upward signal from hand-held set to base station, and two directional couplers make two-way amplifying circuit work simultaneously and to be independent of each other.For ease of isolation, the operating frequency of upper and lower link has been separated by 17MHz.
Radiofrequency signal from base station enters repeater by leaky cable from A end, is coupled to downstream amplifier input through directional coupler II, is coupled to leaky cable, guides tunnel far-end into after amplification through directional coupler I from B end.Hold the upward signal come then to be coupled to upstream amplifier input through directional coupler I by B, after amplification, be sent to base station from A end by leaky cable through directional coupler II.Thus complete the function of the signal simultaneously amplifying uplink and downlink two-way different frequency.In figure, dotted portion is its direct current supply passage, by two choke inductions and communication channel mutually isolated, bold portion is radio-frequency channel.For improving the isolation of upper and lower link, up-downgoing amplifier is powered by two pressurizers respectively.
In practical operation, the short circuit of cable internal and external conductor is often caused because the reason such as blowing out in a lot of mine, because all repeaters are lost the job voltage simultaneously after short circuit, investigate thoroughly that section of cable breaks down extremely to waste time and energy, therefore maintenance department will bear very large maintenance pressure, and once systemic breakdown, production efficiency will be had a strong impact on, even cause local to be stopped work.Relay amplifier is active communication equipment, needs direct current supply.For avoid to the down-hole independent power supply station of each repeater bring loaded down with trivial details, in Leakage Communication System, relay amplifier usually all utilizes the heart yearn of cable and screen to realize DC series and powers.This supply power mode greatly reduces the cost of system, but on the other hand, and this supply power mode also brings system one place cable to be short-circuited fault, will cause the puzzlement that the whole network is paralysed because of power-off.
Summary of the invention
For solving the problem, the invention provides a kind of both-way trunk with docking and restore funcitons automatically, the whether short circuit of follow-up cable is judged by continuing to monitor output voltage, thus control electronic switch, realize automatically disconnecting follow-up cable and auto restore facility, the instruction and driving malfunction is reported to the police, to reach the effect weakening cable short trouble.The alleged docking of the present invention: be repeater and disconnect the connection of consequent malfunction cable.Operated by docking, can ensure that the repeater before fault point normally works with the network of other branches.
In order to achieve the above object, the invention provides following technical scheme:
Comprise upstream amplifier, downstream amplifier, directional coupler I, directional coupler II, the up pressurizer be connected with upstream amplifier and the descending pressurizer be connected with downstream amplifier, described directional coupler I is connected with downstream amplifier input and upstream amplifier output, described directional coupler II and upstream amplifier input are connected with downstream amplifier output, direct current supply passage is comprised between the constrained input end of both-way trunk, also comprise output voltage sample circuit, CPU, field effect transistor, control circuit and the pressurizer for CPU connection, output voltage sample circuit is connected with repeater output, described field effect transistor is arranged in the direct current channel of repeater, described CPU is connected with output voltage sample circuit, be connected by control circuit between CPU with field effect transistor.
As improvement, also comprise input voltage sample circuit, described input voltage sample circuit is connected with CPU.
As improvement, also comprise the up level sensitive circuit be connected with upstream amplifier output, and the descending level sensitive circuit be connected with downstream amplifier output, described up level sensitive circuit is connected with CPU respectively with descending level sensitive circuit.
As improvement, also comprise the LED light be connected with CPU.
As preferably, described LED light comprises malfunction indicator lamp, power supply indicator, up level indicating lamp and descending level indicator light.
As improvement, also comprise the variable attenuator be connected with directional coupler II.
There is a control method for the both-way trunk of docking and restore funcitons automatically, it is characterized in that comprising the following steps:
(1) CPU monitors output dc voltage by output sampling circuit, when output dc voltage < docks critical value, then proceeds to step (2), when output dc voltage >=disconnection critical value, then proceeds to step (5);
(2) CPU sends signal cut electronic switch, lights the malfunction indicator lamp on repeater panel;
(3) CPU monitors output voltage, when output voltage raises, proceeds to step (4), otherwise continues to perform step (3);
(4) CPU sends signal and connects electronic switch, extinguishes the malfunction indicator lamp on repeater panel;
(5) CPU monitors input direct voltage by input sampling circuit, when the minimum permission operating voltage of input voltage < repeater, power supply indicator glimmers, when the minimum permission operating voltage of input voltage >=repeater, and power supply indicator Chang Liang;
(6) CPU obtains uplink and downlink radio frequency level by uplink and downlink level sensitive circuit; When descending radio frequency level >=threshold value, the descending level indicator light on repeater panel lights; When upstream radio-frequency level >=threshold value, the up level indicating lamp on repeater panel lights.
Both-way trunk provided by the invention compared with prior art, has following beneficial effect:
1. can after cable somewhere be short-circuited, cable after automatic open failure point, ensure that front and continued repeater and other branching networks normally work, and by the LED malfunction indicator lamp lighted on repeater panel, the cable broken down is indicated; After cable repairs, automatically can also connect the cable after former fault point, recover the normal operation of whole system.
2. can monitor the supply power voltage of repeater, and by light on and off corresponding indicator light, supply power voltage situation be indicated.
3. can monitor uplink and downlink radio frequency level, and by light on and off corresponding indicator light, uplink and downlink radio frequency level situation be indicated.
4. the leaky cable length that energy flexible adaptation is different.
Accompanying drawing explanation
Fig. 1 is the structural representation of both-way trunk of the prior art;
Fig. 2 be the both-way trunk with open failure point function structural representation;
Fig. 3 is the connection layouts of two both-way trunks in Leakage Communication System;
Fig. 4 be the both-way trunk increasing monitoring input voltage function structural representation;
Fig. 5 be the both-way trunk increasing monitoring up-downgoing radio frequency level function structural representation;
Fig. 6 is the control flow chart of both-way trunk provided by the invention.
Embodiment
Below with reference to specific embodiment, technical scheme provided by the invention is described in detail, following embodiment should be understood and be only not used in for illustration of the present invention and limit the scope of the invention.
As shown in Figure 2, the both-way trunk with docking and restore funcitons automatically provided by the invention, on the basis of basic both-way trunk, adds the output voltage sample circuit and a slice control board that are connected with both-way trunk output.The core devices of control board is a slice CPU, it includes the resources such as A/D converter, analog comparator and the pressurizer that is connected with CPU, output voltage sample circuit can obtain the voltage of repeater output and send CPU to, and pressurizer is connected with upstream amplifier and is that CPU powers.In figure, solid line is communication channel, and dotted line is direct current channel.
When making cable short circuit, do not affect subsequent network, then the power supply of repeater must have short-circuit protection and self-recovering function.
Because repeater requires by the direct current of more than 1A for subsequent repeater work, usually consider to adopt relay so subsequent conditioning circuit will be cut off.The adhesive of relay needs certain energy, and the repeater of series-fed then requires that power consumption is the smaller the better.Otherwise the increase of electric current will cause direct current pressure drop on leaky cable too fast, so that rearmost repeater is because of under-voltage and cisco unity malfunction.The field effect transistor of ultralow conducting resistance solves above-mentioned contradiction: its high input impedance determines its conducting not to be needed to consume electric energy, and can not produce obvious voltage drop when its extremely low conducting resistance (being less than 20m Ω) determines its conducting.(being no more than 20mV by pressure drop during 1A electric current).Therefore the present invention is also provided with the extremely low field effect transistor of conducting resistance as electronic switch in repeater direct current channel, in this article, also can be described as docking switch.Electronic switch connects CPU by control circuit, CPU according to obtain repeater output end voltage send corresponding signal to control circuit in order to control conducting, the cut-off of field effect transistor, realize the automatic break function during short circuit of repeater follow-up cable.Control circuit is triode or other conventional simple control elements in the industry.Repeater provided by the invention continues on the basis of cable upon opening, ensures that the repeater before it normally works with the network of other branches by field effect transistor.
As preferably, repeater panel is arranged a LED malfunction indicator lamp be connected with CPU, when electronic switch ends, CPU control malfunction indicator lamp lights, and during conducting, CPU controls malfunction indicator lamp extinguishing, is used to indicate the position of fault point.
In practical application, both-way trunk in Leakage Communication System is multiple, next the process illustrate when leaky cable is short-circuited fault for two the adjacent operating states of repeater when leaky cable is short-circuited fault, repeater is disconnected by electronic switch, recovered.
As shown in Figure 3 two adjacent repeater Z1, Z2, when the systems are operating normally, the electronic switch of repeater Z1, Z2 is all in conducting state, and backbone top direct voltage is 18V, often cross a repeater, direct voltage can decrease because of the direct current pressure drop on cable.But be not less than the minimum permission operating voltage of 12V(repeater).
If the follow-up cable of repeater Z2 is when C place is short-circuited, system whole piece backbone direct voltage will be pulled to 0V.Power supply is in short-circuit protection state.Now, all repeaters such as Z1, Z2 are all de-energized, and their electronic switch all enters cut-off state.
Because power supply has self-recovering function, after the electronic switch cut-off of repeater Z1, Z2, short dot is isolated, so power supply restores electricity.
When repeater Z1 powers up, Z2 not yet powers up, the electronic switch also non-conducting of Z2.Thus the load after Z1 is equivalent to open circuit.18V voltage, close to 18V, so controlled electronic switch to connect by CPU, is delivered to repeater Z2 by the voltage that its output voltage sample circuit obtains.
When repeater Z2 powers up, because its follow-up cable A place is still in short-circuit condition, so the output voltage sample circuit acquisition of Z2 is 0V voltage, so CPU controls its electronic switch remain off state.And light its malfunction indicator lamp, the cable indicated after repeater Z2 there occurs fault.
Like this, the power-off of the network after the C of fault point and quitting work, and the repeater Z2 before C point ends, the telecommunication cable before Z1 and Z1 then still keeps normal operating conditions, achieves the reduction of cable short trouble.
After repeater Z2 is in docking guard mode, CPU is by its output voltage of continuation monitoring.Once find that voltage raises, namely short trouble is got rid of, and will connect electronic switch immediately, and recover system-wide normal work by control circuit.
As a kind of improvement project; the present invention also can connect input voltage sample circuit at the input of repeater; as shown in Figure 4; described input voltage sample circuit is also connected with CPU; to make CPU monitoring input direct-current supply power voltage normal or under-voltage, and can be indicated supply power voltage situation further by the power supply indicator be connected with CPU.
As improvement, the uplink and downlink level sensitive circuit that is connected with CPU respectively also can be increased in the repeaters for detecting uplink and downlink signals level, and by the LED light display foregoing on repeater panel.As shown in Figure 5, the up level sensitive circuit be connected to upstream amplifier output provides the direct voltage relevant with uplink signal strength for the A/D converter in CPU, when recording the threshold value that upstream radio-frequency level >=a certain sets, indicate the intensity of upstream radio-frequency signal by lighting the up level indicating lamp be connected with CPU; The descending level sensitive circuit be connected to downstream amplifier output provides the direct voltage relevant with downstream signal intensity for the A/D converter in CPU, when record downlink radio frequency level >=threshold value a certain set threshold value time, by lighting the intensity of the descending level indicator light indicating downlink radiofrequency signal be connected with CPU.
In addition, in order to make the leaky cable length that this both-way trunk energy flexible adaptation is different, also between directional coupler II and repeater input, variable attenuator is added.
During both-way trunk work provided by the invention, existing repeater basic function can be realized, radiofrequency signal from base station enters repeater by leaky cable from A end, downstream amplifier input is coupled to through directional coupler II, be coupled to leaky cable through directional coupler I from B end after amplification, guide tunnel far-end into.Hold the upward signal come then to be coupled to upstream amplifier input through directional coupler I by B, after amplification, be sent to base station from A end by leaky cable through directional coupler II.Thus complete the function of the signal simultaneously amplifying uplink and downlink two-way different frequency.In figure, dotted portion is its direct current supply passage, by two choke inductions and communication channel mutually isolated, bold portion is radio-frequency channel.
As shown in Figure 6, in this both-way trunk, the overall control process of CPU is as follows:
(1) CPU monitors output dc voltage by output sampling circuit, when output dc voltage < disconnects critical value, then proceed to step (2), when output dc voltage >=disconnection critical value, perform step (5), this example breaks critical value and is set to 9V;
(2) CPU sends signal cut electronic switch, and lights the LED malfunction indicator lamp on repeater panel;
(3) under electronic switch off-state, CPU continues monitoring output voltage, when output voltage raises, such as, when output voltage is 1V, proceeds to step (4), otherwise continues to perform step (3);
(4) CPU sends signal demand working electronic switch, extinguishes malfunction indicator lamp, recovers system-wide normal work.
(5) CPU monitors input direct voltage by input sampling circuit, as input voltage < 12V, and the power supply indicator flicker on repeater panel, as input voltage >=12V, power supply indicator Chang Liang.Wherein 12V is the minimum permission operating voltage of repeater, and this magnitude of voltage presets in CPU.
(6) CPU obtains uplink and downlink radio frequency level by uplink and downlink level sensitive circuit, and when descending radio frequency level >=threshold value, the descending level indicator light on repeater panel lights; When upstream radio-frequency level >=threshold value, the up level indicating lamp on repeater panel lights.
Claims (8)
1. one kind has the both-way trunk of docking and restore funcitons automatically, comprise upstream amplifier, downstream amplifier, directional coupler I, directional coupler II, the up pressurizer be connected with upstream amplifier and the descending pressurizer be connected with downstream amplifier, described directional coupler I is connected with downstream amplifier input and upstream amplifier output, described directional coupler II and upstream amplifier input are connected with downstream amplifier output, direct current supply passage is comprised between the constrained input end of both-way trunk, it is characterized in that: described in there is the both-way trunk of automatically docking and restore funcitons power supply there is self-recovering function, also comprise output voltage sample circuit, CPU, field effect transistor, control circuit and the pressurizer be connected with CPU, output voltage sample circuit is connected with repeater output, described field effect transistor is arranged in the direct current channel of repeater, described CPU is connected with output voltage sample circuit, be connected by control circuit between CPU with field effect transistor, described CPU monitors output dc voltage by output sampling circuit, when output dc voltage < disconnects critical value, then send signal cut electronic switch, under electronic switch off-state, CPU continues monitoring output voltage, when output voltage raises, CPU sends signal demand working electronic switch.
2. the both-way trunk with docking and restore funcitons automatically according to claim 1, it is characterized in that: also comprise input voltage sample circuit, described input voltage sample circuit is connected with CPU.
3. the both-way trunk with docking and restore funcitons automatically according to claim 1, it is characterized in that: also comprise the up level sensitive circuit be connected with upstream amplifier output, and the descending level sensitive circuit to be connected with downstream amplifier output, described up level sensitive circuit is connected with CPU respectively with descending level sensitive circuit.
4., according to the both-way trunk with docking and restore funcitons automatically in claims 1 to 3 described in any one claim, it is characterized in that: also comprise the variable attenuator be connected with directional coupler II.
5., according to the both-way trunk with docking and restore funcitons automatically in claims 1 to 3 described in any one claim, it is characterized in that: also comprise the LED light be connected with CPU.
6. the both-way trunk with docking and restore funcitons automatically according to claim 5, is characterized in that: described LED light comprises malfunction indicator lamp, power supply indicator, up level indicating lamp and descending level indicator light.
7. the control method with the both-way trunk of docking and restore funcitons automatically according to claim 5, is characterized in that comprising the following steps:
(1) CPU monitors output dc voltage by output sampling circuit, when output dc voltage < docks critical value, then proceeds to step (2), when output dc voltage >=disconnection critical value, then proceeds to step (5);
(2) CPU sends signal cut electronic switch, lights the malfunction indicator lamp on repeater panel;
(3) CPU monitors output voltage, when output voltage raises, proceeds to step (4), otherwise continues to perform step (3);
(4) CPU sends signal and connects electronic switch, extinguishes the malfunction indicator lamp on repeater panel;
(5) CPU monitors input direct voltage by input sampling circuit, when the minimum permission operating voltage of input voltage < repeater, power supply indicator glimmers, when the minimum permission operating voltage of input voltage >=repeater, and power supply indicator Chang Liang;
(6) CPU obtains uplink and downlink radio frequency level by uplink and downlink level sensitive circuit, and when descending radio frequency level >=threshold value, the descending level indicator light on repeater panel lights; When upstream radio-frequency level >=threshold value, the up level indicating lamp on repeater panel lights.
8. the control method with the both-way trunk of docking and restore funcitons automatically according to claim 6, is characterized in that comprising the following steps:
(1) CPU monitors output dc voltage by output sampling circuit, when output dc voltage < docks critical value, then proceeds to step (2), when output dc voltage >=disconnection critical value, then proceeds to step (5);
(2) CPU sends signal cut electronic switch, lights the malfunction indicator lamp on repeater panel;
(3) CPU monitors output voltage, when output voltage raises, proceeds to step (4), otherwise continues to perform step (3);
(4) CPU sends signal and connects electronic switch, extinguishes the malfunction indicator lamp on repeater panel;
(5) CPU monitors input direct voltage by input sampling circuit, when the minimum permission operating voltage of input voltage < repeater, power supply indicator glimmers, when the minimum permission operating voltage of input voltage >=repeater, and power supply indicator Chang Liang;
(6) CPU obtains uplink and downlink radio frequency level by uplink and downlink level sensitive circuit, and when descending radio frequency level >=threshold value, the descending level indicator light on repeater panel lights; When upstream radio-frequency level >=threshold value, the up level indicating lamp on repeater panel lights.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210117491.9A CN102664672B (en) | 2012-04-20 | 2012-04-20 | Bidirectional relay with automatic follow-up faulty cable disconnection and recovery functions and method for controlling bidirectional relay |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210117491.9A CN102664672B (en) | 2012-04-20 | 2012-04-20 | Bidirectional relay with automatic follow-up faulty cable disconnection and recovery functions and method for controlling bidirectional relay |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102664672A CN102664672A (en) | 2012-09-12 |
| CN102664672B true CN102664672B (en) | 2015-02-18 |
Family
ID=46774098
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210117491.9A Expired - Fee Related CN102664672B (en) | 2012-04-20 | 2012-04-20 | Bidirectional relay with automatic follow-up faulty cable disconnection and recovery functions and method for controlling bidirectional relay |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102664672B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI511473B (en) * | 2013-07-01 | 2015-12-01 | Ind Tech Res Inst | Electronic device and data control method |
| CN105187090B (en) * | 2015-10-14 | 2018-05-15 | 福建奥通迈胜电力科技有限公司 | A kind of efficient relaying radio frequency communications circuitry being used between concentrator |
| CN108957271B (en) * | 2017-05-26 | 2021-05-18 | 许继集团有限公司 | IGBT driving overcurrent fault monitoring method and device |
| CN108152648B (en) * | 2017-12-19 | 2020-04-07 | 四川九洲电器集团有限责任公司 | Cable disconnection alarm device under power on and power off conditions |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1204933A (en) * | 1997-07-04 | 1999-01-13 | 三星电子株式会社 | Alarm method and apparatus for mobile communication repeating system |
| CN101369846A (en) * | 2007-08-14 | 2009-02-18 | 华为技术有限公司 | Passive optical network signal monitoring method and electric relay reactivator |
| CN101414932A (en) * | 2007-10-15 | 2009-04-22 | 华为技术有限公司 | Method, system and apparatus managing alarm of long-distance passive optical network system |
| CN101571727A (en) * | 2009-06-11 | 2009-11-04 | 和芯微电子(四川)有限公司 | Current-type band gap reference source circuit starting circuit |
| CN202798715U (en) * | 2012-04-20 | 2013-03-13 | 南京矿通科技有限公司 | Both-way repeater possessing automatic docking and recovery functions |
-
2012
- 2012-04-20 CN CN201210117491.9A patent/CN102664672B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1204933A (en) * | 1997-07-04 | 1999-01-13 | 三星电子株式会社 | Alarm method and apparatus for mobile communication repeating system |
| CN101369846A (en) * | 2007-08-14 | 2009-02-18 | 华为技术有限公司 | Passive optical network signal monitoring method and electric relay reactivator |
| CN101414932A (en) * | 2007-10-15 | 2009-04-22 | 华为技术有限公司 | Method, system and apparatus managing alarm of long-distance passive optical network system |
| CN101571727A (en) * | 2009-06-11 | 2009-11-04 | 和芯微电子(四川)有限公司 | Current-type band gap reference source circuit starting circuit |
| CN202798715U (en) * | 2012-04-20 | 2013-03-13 | 南京矿通科技有限公司 | Both-way repeater possessing automatic docking and recovery functions |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102664672A (en) | 2012-09-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102664672B (en) | Bidirectional relay with automatic follow-up faulty cable disconnection and recovery functions and method for controlling bidirectional relay | |
| CN101895337B (en) | Double-fiber hot backup radio-frequency intelligent optical module | |
| CN202798715U (en) | Both-way repeater possessing automatic docking and recovery functions | |
| CN101282180B (en) | Optical fiber direct transport station with common/different-frequency forwarding function | |
| CN102963395A (en) | Railway semi-automatic block information system capable of monitoring in real time and working method thereof | |
| CN203275508U (en) | Power capability testing device and power amplifier unit | |
| CN100449926C (en) | System of communication power supply | |
| CN204615843U (en) | A kind of addressable fault isolation system | |
| CN114284085B (en) | Wireless remote control uninterrupted power transmission switching-on/off device and control method | |
| CN103581973B (en) | A kind of cell information source backup, Apparatus and system | |
| CN201369606Y (en) | Power supply switching device for optical fiber repeater far-end machine | |
| CN101510859A (en) | Coupler capable of switching bus | |
| CN104104144B (en) | A kind of intelligent substation prepared auto restart debugging system, method and intelligent substation | |
| CN103686160A (en) | Universal digital television emission intelligent monitoring switching system and switching method | |
| CN108418621B (en) | wireless repeater | |
| CN108987203B (en) | intelligent air switch device with automatic on-off capability | |
| CN202385111U (en) | Reflection detection link device for repeater station | |
| CN207441001U (en) | A kind of Internet of Things Transmission system based on Lora technologies | |
| CN210167799U (en) | Zero line disconnection protection device | |
| CN216490497U (en) | Leaky cable fault monitoring device | |
| CN212114788U (en) | Coal mine low-voltage power supply system with remote electric leakage test function | |
| CN205249230U (en) | A automatic spare switching circuit for among cable television light transmission system | |
| CN202750232U (en) | Cell information source backup device and system | |
| CN105827324A (en) | Optical fiber repeater | |
| CN212366834U (en) | Transformer substation 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 | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150218 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |