CN201017417Y - Power cable anti-theft alarm device - Google Patents
Power cable anti-theft alarm device Download PDFInfo
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- CN201017417Y CN201017417Y CNU2007200065340U CN200720006534U CN201017417Y CN 201017417 Y CN201017417 Y CN 201017417Y CN U2007200065340 U CNU2007200065340 U CN U2007200065340U CN 200720006534 U CN200720006534 U CN 200720006534U CN 201017417 Y CN201017417 Y CN 201017417Y
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- autotransformer
- power cable
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Abstract
The utility model relates to a anti-theft alarm device for power cables, which comprises an industrial frequency generator arranged at the remote end of the cable and an alarm device arranged at the near end of the cable, wherein, the industrial frequency generator comprises an autotransformer, a power switching circuit, an oscillation circuit, and an industrial frequency envelop generator connected in shunt with the power cable; the alarm device comprises a signal detection circuit, an monostable circuit, an alarm request counter, an decoder, and a speech alarm drive circuit connected in sequence; the decoder is connected through a delayed zero clearing circuit to a zero clearing control terminal on the alarm request counter, wherein, the monostable circuit is controlled by a biasing circuit composed of the signal detection circuit and the autotransformer. When the cable is in live state, the current transformer acquires industrial frequency signals in the cable, and the signal detection circuit monitors the signals; when the cable is not in live state, the normally closed contact of a relay will connect back the biasing circuit to the cable loop; the device can monitor and judge cable completeness on the basis of variance of the biasing resistance composed of the autotransformer.
Description
Technical field:
The present invention relates to a kind of power cable guard against theft and alarm system, be suitable for any operating mode under power transmission cable, when cable break, dial the police emergency number automatically, belong to the electric equipment products technical field.
Background technology:
Along with the continuous development that road traffic is built, steal, destroy the power cable case and constantly take place, cause serious economy loss for (at a high speed) highway operation administrative authority, have a strong impact on, threatening normal, the safe operation of (at a high speed) highway.In order fast and effeciently to prevent to steal, destroy crime, must want police strength to science and technology, utilize technological means to contain, hit and steal crime.At present, conclude on the market and get up to have detection meanss dissimilar in 3, but all have certain defective:
The 1st kind is the voice carrier detection mode that adopts spread spectrum, exists to be subjected to capacitive load restriction on the cable, and signal easily is absorbed and decays greatly, can't grow Distance Transmission, defective such as monitors on the only suitable stub cable; And voice carrier will increase the influence of higher hamonic wave to electrical network, PLC equipment etc.; Moreover voice carrier is when cable is not charged, needs by the standby power supply power supply, and power fail causes the wrong report phenomenon, also is one of defective of this kind equipment.
The 2nd kind is simple current detecting mode, and when the cable part was stolen, still there was electric current in cable, had the alert defective of not reporting, and more was not suitable for the antitheft needs of power cable under the voltage no current operating mode.
The 3rd kind of detection of electrical leakage mode is a kind of detection mode of artificial manufacturing electric leakage, has hidden danger safe in utilization.
How to provide a kind of can satisfy the needs of the long-distance cable anti-thefting monitoring under any operating mode and other equipment of electrical network not have influence anti-theft device the object studied of the present invention.
Summary of the invention:
The present invention be directed to the characteristics of power cables such as traffic (at a high speed) highway, street illumination, the detection mode that adopts loop current to combine with work frequency carrier, invent a kind of under operating mode arbitrarily the cable anti-theft alarm device of equal energy reliably working.
Technical solution of the present invention is achieved in that a kind of power cable burglar alarm, comprise the power frequency generator that is located at the cable far-end, the receiving host machine of cable near-end, it is characterized in that the power frequency generator is made up of the autotransformer and power-switching circuit, oscillatory circuit and the power frequency envelop generator that are attempted by on the power cable, autotransformer and power-switching circuit provide oscillatory circuit and power frequency envelop generator working power, and the oscillator signal that oscillatory circuit produces is in power frequency envelop generator feed-in power cable; Receiving host machine is formed by connecting by signal deteching circuit, monostable circuit, warning request counter, code translator and audio alert driving circuit successively, code translator export one the tunnel behind the time-delay clear circuit to the zero clearing control end of the request counter of reporting to the police, wherein monostable circuit is controlled by the biasing circuit of signal deteching circuit and autotransformer composition respectively, signal deteching circuit connects the power frequency component of gathering in the power cable by mutual inductor, and the relay normally closed contact of biasing circuit through being connected on the power cable that autotransformer is formed connects power cable.Owing to adopt and the work frequency carrier signal of cable current with frequency, be difficult for being absorbed by capacitive load, can reach long-distance transmissions; And when cable is not charged, automatically switch to biasing circuit work, by the autotransformer winding as biasing resistor, the integrality in monitoring cable loop.
The present invention has following characteristics: 1, the design's carrier wave is not an audio frequency, its carrier frequency is a power frequency, therefore, with length, the load characteristic of cable, have voltage not have the states such as cable, partial load fault of electric current (freeway tunnel fan blower) irrelevant, be applicable to the cable cable theft-prevention needs under any operating mode, and, when being stolen by the part, realizes by cable having the police to report to judge that the complete of cable is principle; 2, the whether charged state of the automatic appropriate cable of the Signal Terminal of cable, directly utilize the phase voltage power supply when cable is charged, automatically utilize the auto-transformer winding when not charged directly as biasing resistor, therefore Signal Terminal does not need to consider power issue, stops the wrong report phenomenon that causes because of the end cell fault; 3, take logic to confirm design, i.e. fault-tolerant technique has overcome because interference such as electromagnetic wave, surge current and false triggering alarm module.
Description of drawings:
The present invention will be further described below in conjunction with concrete legend:
Fig. 1 power cable burglar alarm theory diagram
Fig. 2 cable far-end power frequency generator circuit figure
Fig. 3 receiving host machine monostable circuit partial circuit figure
Fig. 4 receiving host machine warning partial circuit figure
Embodiment:
See figures.1.and.2, the power cable burglar alarm comprises that the power frequency generator and the cable near-end that are located at cable far-end or end also are the interior receiving host machine of main equipment room.The power frequency generator is made up of the autotransformer and power-switching circuit, oscillatory circuit and the power frequency envelop generator that are attempted by on the power cable end.
Autotransformer and power-switching circuit are made up of autotransformer T1, rectifier bridge U7, DC voltage-stabilizing pipe U8 and filter capacitor C7, C8, and DC voltage-stabilizing pipe U8 model is LM7812.Autotransformer also can adopt the double winding conventional transformer to substitute.
Oscillatory circuit is that NE555 oscillator U9, peripheral capacitor C 9, C10, resistance R 14, R15 and diode D10, D11 form by model.
The power frequency envelop generator by the solid-state relay U10 of model JGX one 10F, and resistance R 17 and capacitor C 11 form.The resistance-capacitance circuit that solid-state relay U10 output is formed through resistance R 17, capacitor C 11 is attempted by on the cable loop.
The principle of work of power frequency generator: cable is when electriferous state, and auto-transformer T1 exports 12V working power as oscillator U9 after U7, C7, the voltage stabilizing of U8 rectifying and wave-filtering.Oscillatory circuit is a custom circuit, just realizes that by resistance R 14, R15, diode D10, D11 dutycycle is 1: 120, i.e. the 3rd pin output high level width is 0.5 second, is spaced apart 60 seconds.The output of the 3rd pin is through current-limiting resistance R16 driving solid relay U10, in the 3rd pin is exported 0.5 second time, 220V realizes same frequency, same-phase electric current stack envelope by R17, C11, solid-state relay AC side, detects signal by the current transformer of host computer side.
Cable is when non-electriferous state, and oscillator quits work.At this moment, auto-transformer also is the biasing resistor of biasing circuit in the receiving host machine only as the effect of the direct current resistance of cable loop, and when cable break, bias voltage changes and triggers warning.
With reference to Fig. 1, Fig. 3 and Fig. 4, receiving host machine is successively by signal deteching circuit, monostable circuit, the warning request counter, code translator and audio alert driving circuit are formed by connecting, code translator export one the tunnel behind the time-delay clear circuit to the time-delay zero clearing control end of the request counter of reporting to the police, wherein monostable circuit is controlled by the biasing circuit of signal deteching circuit and autotransformer composition respectively, signal deteching circuit connects the power frequency component of gathering in the power cable by mutual inductor, and the relay normally closed contact of biasing circuit through being connected on the power cable that autotransformer is formed connects power cable.
Signal deteching circuit is that the operational amplifier U1A of LM324 forms by rectifier bridge U2, capacitor C 4, C5, resistance R K3, RK4, R8, diode D8, protection stabilivolt D7, envelope signal indication light emitting diode D5 and model.
The biasing circuit that autotransformer is formed is that operational amplifier U1B, resistance R 1, RK1, capacitor C 1, C2, the diode D3 of LM324, the normal indication light emitting diode D1 that setovers form by model.
Monostable circuit is that the operational amplifier U1C, resistance R 3, R4, R5, R6, RK2, capacitor C 3 of LM324, the indication light emitting diode D4 that reports to the police form by model.
The warning request counter is that 74LS393 counting circuit U4A, resistance R 12, capacitor C 5 form by model.Resistance R 12, capacitor C 5 are formed the start automatic reset circuit.
Code translator U5 is that model is the 74LS138 integrated circuit.
The audio alert driving circuit is that phase inverter U6A, resistance R 13, triode Q1, diode D9, the relay K 2 of 74LS04 formed by model.
The time-delay clear circuit is that phase inverter U6B, resistance R K5, R11, R9, R10, triode Q2, capacitor C 6 and the model of 74LS04 is that LM324 operational amplifier U3A forms by model.
The receiving host machine principle of work: from the L of switchboard bus-bar, N constitutes complete cable loop by load 1, load 2, load 3 to the power frequency generator of load N, cable far-end that power cable leads to the open air.S1 is a power-cutting switch, and the cable phase line is passed mutual inductor, and the banded cable electricity condition is extracted power supply and detected cable loop work frequency carrier signal by mutual inductor.
By the mono-stable timing circuit that U1C, R3, R4, C3, RK2 etc. form, the time is T during setting.Terminal sends the interval of signal necessary＜T, if the C3 charging finishes, U1C export high level, sending reports to the police asks.If U1A, U1B be output low level between the C3 charge period, then C3 is discharged midway, and U1C exports high level never, has both sent the request of warning never.
Cable is when electriferous state, receive the work frequency carrier signal that cable termination power frequency generator sends by mutual inductor and form the reverse input end of differentiating circuit to U1A through U2, C4 rectifying and wave-filtering, C5, R8, the U1A positive input is a reference voltage under the normality, and greater than reverse input end, when differential signal, backward end is greater than forward end, the U1A output low level, C3 is discharged midway, show that cable is intact and receive signal by cable.Otherwise send the request of warning.
Cable is when non-electriferous state, and the 12V power supply forms the loop by R1, D2, K1 normally closed contact, phase line L, Signal Terminal auto-transformer coil T1, zero line N to power cathode.This moment, the below-center offset resistance of U1B positive input was the direct current resistance of terminal auto-transformer T1.Reverse input end is a reference voltage, and is higher than positive input, and U1B output low level, monostable circuit are exported high level never.If cable break, then forward is higher than oppositely, and U1B exports high level, sends the request of warning after the C3 charging finishes.
When reporting to the police request, warning request counter U4A counting once, during waiting for request next time, code translator the 1st pin output terminal is a high level, start time-delay and remove circuit, regularly receive the request of warning if counter is very free, the then artificial N output terminal that is provided with sends the execution alarm level, drives K2 and carries out alert program.
If receive the request of once reporting to the police once in a while, regularly removing circuit after 1 minute, removing counter U4A (the 2nd pin) by U3A output high level is zero.
Claims (1)
1. power cable burglar alarm, comprise the power frequency generator that is located at the cable far-end, the receiving host machine of cable near-end, it is characterized in that the power frequency generator is made up of the autotransformer and power-switching circuit, oscillatory circuit and the power frequency envelop generator that are attempted by on the power cable, autotransformer and power-switching circuit provide oscillatory circuit and power frequency envelop generator working power, and the oscillator signal that oscillatory circuit produces is in power frequency envelop generator feed-in power cable; Receiving host machine is formed by connecting by signal deteching circuit, monostable circuit, warning request counter, code translator and audio alert driving circuit successively, code translator export one the tunnel behind the time-delay clear circuit to the zero clearing control end of the request counter of reporting to the police, wherein monostable circuit is controlled by the biasing circuit of signal deteching circuit and autotransformer composition respectively, signal deteching circuit connects the power frequency component of gathering in the power cable by mutual inductor, and the relay normally closed contact of biasing circuit through being connected on the power cable that autotransformer is formed connects power cable.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007200065340U CN201017417Y (en) | 2007-03-16 | 2007-03-16 | Power cable anti-theft alarm device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007200065340U CN201017417Y (en) | 2007-03-16 | 2007-03-16 | Power cable anti-theft alarm device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201017417Y true CN201017417Y (en) | 2008-02-06 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2007200065340U Expired - Fee Related CN201017417Y (en) | 2007-03-16 | 2007-03-16 | Power cable anti-theft alarm device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201017417Y (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101858949A (en) * | 2010-05-24 | 2010-10-13 | 山东科技大学 | Monostable circuit of automatic detection warning instrument for communication cable breakpoint |
| CN103198600A (en) * | 2013-02-28 | 2013-07-10 | 上海市电力公司 | Cable shielding layer anti-theft alarm device used for power distribution network |
| CN104700527A (en) * | 2014-08-28 | 2015-06-10 | 安徽工程大学 | Cable anti-theft device and method thereof |
| CN113852043A (en) * | 2021-11-10 | 2021-12-28 | 深圳达人高科电子有限公司 | Short-circuit protection circuit |
-
2007
- 2007-03-16 CN CNU2007200065340U patent/CN201017417Y/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101858949A (en) * | 2010-05-24 | 2010-10-13 | 山东科技大学 | Monostable circuit of automatic detection warning instrument for communication cable breakpoint |
| CN103198600A (en) * | 2013-02-28 | 2013-07-10 | 上海市电力公司 | Cable shielding layer anti-theft alarm device used for power distribution network |
| CN103198600B (en) * | 2013-02-28 | 2016-03-16 | 上海市电力公司 | A kind of cable shield burglar alarm for power distribution network |
| CN104700527A (en) * | 2014-08-28 | 2015-06-10 | 安徽工程大学 | Cable anti-theft device and method thereof |
| CN113852043A (en) * | 2021-11-10 | 2021-12-28 | 深圳达人高科电子有限公司 | Short-circuit protection circuit |
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| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20080206 |