An electric fence is a barrier that uses electric shocks to avert animals or humans from bridge a boundary. The voltage of the shock may accept furnishings alignment from uncomfortable, to aching or even lethal. Most electric angry is acclimated today for agronomical angry and added forms of beastly ascendancy purposes, admitting it is frequently acclimated to enhance aegis of acute areas, and there abide places area baleful voltages are used.
Saturday, 3 March 2012
Design and function
Electric fences are advised to actualize an electrical ambit if affected by a getting or animal. A basic alleged a ability analeptic converts ability into a abrupt top voltage pulse. One terminal of the ability analeptic releases an electrical beating forth a affiliated bald wire about already per second. Another terminal is affiliated to a metal rod built-in in the earth, alleged a arena or apple rod. A getting or beastly affecting both the wire and the apple during a beating will complete an electrical ambit and will conduct the pulse, causing an afflictive electric shock. The furnishings of the shock depend aloft the voltage, the activity of the pulse, the amount of acquaintance amid the almsman and the fence and arena and the avenue of the accepted through the body; it can ambit from almost apparent to uncomfortable, aching or for some fences even lethal.
edit Fence energizers
Early alternating accepted (AC) fence chargers acclimated a agent and a mechanically-driven about-face to accomplish the electrical pulses. The pulses were advanced and the voltage unpredictable, with no-load peaks in balance of 10,000 volts and a accelerated bead in voltage as the fence arising increased. The about-face apparatus was decumbent to failure. Later systems replaced the about-face with a solid-state circuit, with an advance in constancy but no change in beating amplitude or voltage control.
"Weed burner" fence chargers were accepted for a time and featured a longer-duration achievement beating that would abort weeds affecting the fence. These were amenable for abounding grass fires if acclimated during dry weather. Admitting still available, they accept beneath in popularity.
Modern "low impedance" fence chargers use a altered design. A capacitor is answerable by a solid-state ambit – aloft acquaintance with a ashore beastly or person, the allegation is again appear application a thyristor or agnate solid-state component. Voltage is constant due to cyberbanking achievement controls, aural the banned of achievement power. Beating amplitude is abundant narrower, generally about 10 microseconds. This architecture works for either array or mains ability sources.
Depending on the breadth to be belted and absorption of its location, fence energizers may be absorbed into a abiding electrical circuit, may be run by lead-acid or dry corpuscle batteries, or a abate array kept answerable by a solar panel. The ability burning of a fence in acceptable action is low, and so a lead-acid array powering several hundred metres of fence may endure for several weeks on a individual charge. For beneath periods dry corpuscle batteries may be used. Some energizers are able of getting powered by added than one source.
edit Angry materials
Smooth animate wire is the actual a lot of generally acclimated for electric fence, alignment from a accomplished attenuate wire acclimated as a individual band to thicker, high-tensile (HT) wire. Less often, alloyed wire or acid wire fences can be electrified, admitting such practices actualize a added chancy fence, decidedly if a getting or beastly becomes bent by the angry actual (electrified acid wire is actionable in some areas). Synthetic fiber and rope-like angry abstracts alloyed with accomplished administering affairs (usually of stainless steel) accept become accessible the endure 15 to 20 years, and are decidedly advantageous for areas acute added afterimage or as acting fencing.
The electrified fence itself have to be kept cloistral from the apple and from any abstracts that will conduct electricity and burn or abbreviate out the fence. Angry have to accordingly abstain vegetation, and cannot be absorbed anon to copse or metal posts. Typically, board or metal posts are apprenticed into the arena and artificial or ceramics insulators are absorbed to them, or artificial posts are used. The administering actual is again absorbed to the posts.
edit Fence energizers
Early alternating accepted (AC) fence chargers acclimated a agent and a mechanically-driven about-face to accomplish the electrical pulses. The pulses were advanced and the voltage unpredictable, with no-load peaks in balance of 10,000 volts and a accelerated bead in voltage as the fence arising increased. The about-face apparatus was decumbent to failure. Later systems replaced the about-face with a solid-state circuit, with an advance in constancy but no change in beating amplitude or voltage control.
"Weed burner" fence chargers were accepted for a time and featured a longer-duration achievement beating that would abort weeds affecting the fence. These were amenable for abounding grass fires if acclimated during dry weather. Admitting still available, they accept beneath in popularity.
Modern "low impedance" fence chargers use a altered design. A capacitor is answerable by a solid-state ambit – aloft acquaintance with a ashore beastly or person, the allegation is again appear application a thyristor or agnate solid-state component. Voltage is constant due to cyberbanking achievement controls, aural the banned of achievement power. Beating amplitude is abundant narrower, generally about 10 microseconds. This architecture works for either array or mains ability sources.
Depending on the breadth to be belted and absorption of its location, fence energizers may be absorbed into a abiding electrical circuit, may be run by lead-acid or dry corpuscle batteries, or a abate array kept answerable by a solar panel. The ability burning of a fence in acceptable action is low, and so a lead-acid array powering several hundred metres of fence may endure for several weeks on a individual charge. For beneath periods dry corpuscle batteries may be used. Some energizers are able of getting powered by added than one source.
edit Angry materials
Smooth animate wire is the actual a lot of generally acclimated for electric fence, alignment from a accomplished attenuate wire acclimated as a individual band to thicker, high-tensile (HT) wire. Less often, alloyed wire or acid wire fences can be electrified, admitting such practices actualize a added chancy fence, decidedly if a getting or beastly becomes bent by the angry actual (electrified acid wire is actionable in some areas). Synthetic fiber and rope-like angry abstracts alloyed with accomplished administering affairs (usually of stainless steel) accept become accessible the endure 15 to 20 years, and are decidedly advantageous for areas acute added afterimage or as acting fencing.
The electrified fence itself have to be kept cloistral from the apple and from any abstracts that will conduct electricity and burn or abbreviate out the fence. Angry have to accordingly abstain vegetation, and cannot be absorbed anon to copse or metal posts. Typically, board or metal posts are apprenticed into the arena and artificial or ceramics insulators are absorbed to them, or artificial posts are used. The administering actual is again absorbed to the posts.
History
Jules Verne's "20,000 Leagues Below the Sea", described1 the use of electrification of a anatomy as a arresting weapon, in 1870. The abstraction of the electric fence was aswell declared in Mark Twain's 1889 atypical A Connecticut Yankee in King Arthur's Court, as a arresting weapon.
David H. Wilson acquired United States Patent 343,939 in 1886, accumulation protection, an anxiety bell, and blast communications. He complete an alpha 30-mile electric fence activated by a baptize caster in Texas in 1888, but it was not successful.2
In 1905, the Russian army improvised electric fences during the Russo-Japanese War at Port Arthur. In 1915, during Apple War I, the German army electrified fences forth the bound amid Belgium and the Netherlands3 to anticipate unathorized movement of humans beyond the border. The fences covered 300 kilometres and consisted of several strands of chestnut wire, backed with acid wire, and activated to several thousand volts. An estimated 3000 animal fatalities were acquired by the fence, as able-bodied as abolition of livestock.
Electric fences were acclimated to ascendancy livestock in the United States in the aboriginal 1930s, and electric angry technology developed in both the United States and New Zealand.
An aboriginal appliance of the electric fence was developed in 1936–1937 by New Zealand artist William "Bill" Gallagher Sr. Built from a car's agitation braid and a magneto set, Gallagher acclimated the accessory to accumulate his horse from abrading itself adjoin his car. Gallagher after started a aggregation to advance and bazaar the design.4 In 1962, addition New Zealand inventor, Doug Phillips, invented the non-shortable electric fence based on capacitor discharge.5 This decidedly added the ambit an electric fence could be acclimated from a few hundred meters to 35 km (~20 miles), and bargain the amount of angry by added than 80%.citation needed The non-shortable electric fence was patented by Phillips and by 1964 was bogus by Artificial Products, a New Zealand firm, below the name "Waikato Electric Fence."citation needed This abstraction was to alter bowl with artificial insulators. A array of artificial insulators are now acclimated on farms throughout the apple today.
By 1939, accessible assurance apropos in the United States prompted Underwriters' Laboratories to broadcast a account on electric shock from electric fences, arch to the ANSI/UL accepted No. 69 for electric fence controllers.6
In 1969 Robert B. Cox, a agriculturalist in Adams County, Iowa, invented an bigger electric fence bracket and was issued United States Patent No. 3,516,643 on June 23, 1970. This bracket bigger electric fences by befitting the wire top abundant aloft the arena and far abundant abroad from the fence to admittance grass and weeds growing below the wire to be mowed. The brackets absorbed to the posts by what may be alleged a "pivot bind" or "torsion-lock." The weight of the bracket, the absorbed insulator and the electric wire absorbed to the insulator bind the bracket to the post.
Electric fences accept bigger decidedly over the years. Improvements include:
Polyethylene insulators replacing ceramics insulators, alpha in the 1960s. Polyethylene is abundant cheaper than ceramics and is beneath breakable.
Improvements in electrical architecture of the fence energizer, generally alleged a "charger" (USA) or "fencer" (UK).
Changes in laws. In some jurisdictions, assertive types of electrical outputs for fences were actionable until the 1950s or 1960s. In added areas, signage requirements and added restrictions bound usability. Many US cities abide to accept anachronous laws prohibiting electric fences to anticipate agronomical fences from entering the city. Houston, for example, afflicted their authorization that banned electric angry in 2008.7
Introduction of top compactness (HT) animate fence wire in the 1970s in New Zealand and in the 1980s in the United States
Introduction of constructed fiber and rope-like angry abstracts alloyed with accomplished administering wires.
Architecture of moveable fence components, such as Tumblewheel.
David H. Wilson acquired United States Patent 343,939 in 1886, accumulation protection, an anxiety bell, and blast communications. He complete an alpha 30-mile electric fence activated by a baptize caster in Texas in 1888, but it was not successful.2
In 1905, the Russian army improvised electric fences during the Russo-Japanese War at Port Arthur. In 1915, during Apple War I, the German army electrified fences forth the bound amid Belgium and the Netherlands3 to anticipate unathorized movement of humans beyond the border. The fences covered 300 kilometres and consisted of several strands of chestnut wire, backed with acid wire, and activated to several thousand volts. An estimated 3000 animal fatalities were acquired by the fence, as able-bodied as abolition of livestock.
Electric fences were acclimated to ascendancy livestock in the United States in the aboriginal 1930s, and electric angry technology developed in both the United States and New Zealand.
An aboriginal appliance of the electric fence was developed in 1936–1937 by New Zealand artist William "Bill" Gallagher Sr. Built from a car's agitation braid and a magneto set, Gallagher acclimated the accessory to accumulate his horse from abrading itself adjoin his car. Gallagher after started a aggregation to advance and bazaar the design.4 In 1962, addition New Zealand inventor, Doug Phillips, invented the non-shortable electric fence based on capacitor discharge.5 This decidedly added the ambit an electric fence could be acclimated from a few hundred meters to 35 km (~20 miles), and bargain the amount of angry by added than 80%.citation needed The non-shortable electric fence was patented by Phillips and by 1964 was bogus by Artificial Products, a New Zealand firm, below the name "Waikato Electric Fence."citation needed This abstraction was to alter bowl with artificial insulators. A array of artificial insulators are now acclimated on farms throughout the apple today.
By 1939, accessible assurance apropos in the United States prompted Underwriters' Laboratories to broadcast a account on electric shock from electric fences, arch to the ANSI/UL accepted No. 69 for electric fence controllers.6
In 1969 Robert B. Cox, a agriculturalist in Adams County, Iowa, invented an bigger electric fence bracket and was issued United States Patent No. 3,516,643 on June 23, 1970. This bracket bigger electric fences by befitting the wire top abundant aloft the arena and far abundant abroad from the fence to admittance grass and weeds growing below the wire to be mowed. The brackets absorbed to the posts by what may be alleged a "pivot bind" or "torsion-lock." The weight of the bracket, the absorbed insulator and the electric wire absorbed to the insulator bind the bracket to the post.
Electric fences accept bigger decidedly over the years. Improvements include:
Polyethylene insulators replacing ceramics insulators, alpha in the 1960s. Polyethylene is abundant cheaper than ceramics and is beneath breakable.
Improvements in electrical architecture of the fence energizer, generally alleged a "charger" (USA) or "fencer" (UK).
Changes in laws. In some jurisdictions, assertive types of electrical outputs for fences were actionable until the 1950s or 1960s. In added areas, signage requirements and added restrictions bound usability. Many US cities abide to accept anachronous laws prohibiting electric fences to anticipate agronomical fences from entering the city. Houston, for example, afflicted their authorization that banned electric angry in 2008.7
Introduction of top compactness (HT) animate fence wire in the 1970s in New Zealand and in the 1980s in the United States
Introduction of constructed fiber and rope-like angry abstracts alloyed with accomplished administering wires.
Architecture of moveable fence components, such as Tumblewheel.
Uses
Agriculture
Main article: Agronomical fencing
Permanent electric angry is acclimated in abounding agronomical areas, as architecture of electric fences can be abundant cheaper and faster than accepted fences (it uses apparent wire and abundant lighter construction, as the fence does not charge to physically arrest animals). The accident of abrasion to livestock (particularly horses) is lower compared to fences fabricated of acid wire or assertive types of alloyed wire with ample openings that can entangle the feet.
Its disadvantages cover the abeyant for the absolute fence to be disabled due to a breach in the administering wire, shorting out if the administering wire contacts any non-electrified that may accomplish up the blow of the fence, ability failure, or affected break due to the accident of fires starting by dry frondescence affecting an electrified wire. Added disadvantages can be abridgement of afterimage and the abeyant to shock an biting animal beholder who ability accidentally blow or besom the fence.
Many fences are fabricated absolutely of accepted bland or high-tensile wire, admitting top superior constructed angry abstracts are aswell alpha to be acclimated as allotment of abiding fences, decidedly if afterimage of the fence is a concern.
Conventional agronomical angry of any blazon may be adequate by the accession of a individual electric band army on insulators absorbed to the top or foreground of the fence. A agnate wire army abutting to the arena may be acclimated to anticipate pigs from excavating below added fencing. Substandard accepted angry can aswell be fabricated briefly accessible until able aliment are fabricated by the accession of a individual electric band set on a "stand-off" insulator.
A acting electric fence of constructed abstracts and artificial step-in posts set about 12 anxiety apart
Electric abstracts are aswell acclimated for the architecture of acting fencing, decidedly to abutment the convenance of managed accelerated agriculture (also accepted as rotational or "strip" grazing). It is aswell accepted in some places for circumscribed horses and backpack animals brief if aisle riding, hunting, or at competitions such as ability benumbed and aggressive aisle riding. Typically, one or added strands of wire, constructed band or bond are army on metal or artificial posts with stakes at the bottom, advised to be apprenticed into the arena by foot. For a hand-tightened acting fence of electrified braiding or web in a baby area, these are usually spaced at no added than 12 to 15 anxiety (about 3 metres) to anticipate the angry actual from billowing and affecting the ground. Beyond areas breadth accoutrement are acclimated to amplitude wire may be able to set step-in posts at beyond distances after accident that the angry actual will sag.
With acting electric fencing, a ample breadth can be belted off in a abbreviate aeon of time. Acting angry that is advised to be larboard in abode for several weeks or months may be accustomed added abutment by the use of animate T posts (which are bound formed in with duke accoutrement and unearthed with about affluence application a advantage device) to advice accumulate the fence upright, decidedly at corners. Livestock owners application rotational agriculture in set patterns that are agnate from one year to the next may assuredly drive a few abiding copse fence posts in cardinal locations.
Portable fence energizers are fabricated for acting fencing, powered alone by batteries, or by a array kept answerable by a baby solar panel. Rapid laying-out and abatement of multiple-strand acting electric angry over a ample breadth may be done application a set of reels army on a tractor or all-terrain vehicle.
For sheep, poultry, and added abate animals, artificial electric applique may be army on careful stakes – this is aswell able at befitting out some predators such as foxes.
In practice, already a lot of animals accept abstruse of the abhorrent after-effects of affecting the fence they tend to abstain it for ample periods even if it is inactive. However, some animals apprentice to abstain the shock, either by active beneath the fence bound amid pulses, or by blame added individuals through the fence. Animals with blubbery bristling coats (such as sheep or Highland cattle) may apprentice to advance through the fence themselves, application their coats as electrical insulation. Some animals aswell apprentice to admit the slight beat complete fabricated by some electric fences and appropriately can faculty if the fence is off.
edit Agrarian animals
Electric angry to assure a aisle adjoin wildlife. Pilanesberg Game Reserve, South Africa
Electric fences are advantageous for authoritative the movements of agrarian animals. Examples cover black deer from entering clandestine property, befitting animals off airport runways, befitting agrarian animal from raiding crops, and preventing geese from abuse areas acclimated by people. Electric angry has been abundantly acclimated in ecology situations abbreviation the battle amid elephants or added animals and bodies in Africa and Asia.8
edit Security
Electric angry at an airport
edit Non-lethal fence
Non-lethal electric fences are acclimated to anticipate breach by both clandestine and government-sector bodies. These cover bales carriers, auto auctions, accessories rental companies, auto dealers, apartment communities, bartering factories or warehouses, prisons, aggressive bases, and government buildings. Abounding of these electric fences act as monitored burglar anxiety systems in accession to causing an afflictive shock. Electric fences are occasionally active to abash suicide attempts on alpine structures, and to abate the accident of graffiti and added petty crime.
Main article: Agronomical fencing
Permanent electric angry is acclimated in abounding agronomical areas, as architecture of electric fences can be abundant cheaper and faster than accepted fences (it uses apparent wire and abundant lighter construction, as the fence does not charge to physically arrest animals). The accident of abrasion to livestock (particularly horses) is lower compared to fences fabricated of acid wire or assertive types of alloyed wire with ample openings that can entangle the feet.
Its disadvantages cover the abeyant for the absolute fence to be disabled due to a breach in the administering wire, shorting out if the administering wire contacts any non-electrified that may accomplish up the blow of the fence, ability failure, or affected break due to the accident of fires starting by dry frondescence affecting an electrified wire. Added disadvantages can be abridgement of afterimage and the abeyant to shock an biting animal beholder who ability accidentally blow or besom the fence.
Many fences are fabricated absolutely of accepted bland or high-tensile wire, admitting top superior constructed angry abstracts are aswell alpha to be acclimated as allotment of abiding fences, decidedly if afterimage of the fence is a concern.
Conventional agronomical angry of any blazon may be adequate by the accession of a individual electric band army on insulators absorbed to the top or foreground of the fence. A agnate wire army abutting to the arena may be acclimated to anticipate pigs from excavating below added fencing. Substandard accepted angry can aswell be fabricated briefly accessible until able aliment are fabricated by the accession of a individual electric band set on a "stand-off" insulator.
A acting electric fence of constructed abstracts and artificial step-in posts set about 12 anxiety apart
Electric abstracts are aswell acclimated for the architecture of acting fencing, decidedly to abutment the convenance of managed accelerated agriculture (also accepted as rotational or "strip" grazing). It is aswell accepted in some places for circumscribed horses and backpack animals brief if aisle riding, hunting, or at competitions such as ability benumbed and aggressive aisle riding. Typically, one or added strands of wire, constructed band or bond are army on metal or artificial posts with stakes at the bottom, advised to be apprenticed into the arena by foot. For a hand-tightened acting fence of electrified braiding or web in a baby area, these are usually spaced at no added than 12 to 15 anxiety (about 3 metres) to anticipate the angry actual from billowing and affecting the ground. Beyond areas breadth accoutrement are acclimated to amplitude wire may be able to set step-in posts at beyond distances after accident that the angry actual will sag.
With acting electric fencing, a ample breadth can be belted off in a abbreviate aeon of time. Acting angry that is advised to be larboard in abode for several weeks or months may be accustomed added abutment by the use of animate T posts (which are bound formed in with duke accoutrement and unearthed with about affluence application a advantage device) to advice accumulate the fence upright, decidedly at corners. Livestock owners application rotational agriculture in set patterns that are agnate from one year to the next may assuredly drive a few abiding copse fence posts in cardinal locations.
Portable fence energizers are fabricated for acting fencing, powered alone by batteries, or by a array kept answerable by a baby solar panel. Rapid laying-out and abatement of multiple-strand acting electric angry over a ample breadth may be done application a set of reels army on a tractor or all-terrain vehicle.
For sheep, poultry, and added abate animals, artificial electric applique may be army on careful stakes – this is aswell able at befitting out some predators such as foxes.
In practice, already a lot of animals accept abstruse of the abhorrent after-effects of affecting the fence they tend to abstain it for ample periods even if it is inactive. However, some animals apprentice to abstain the shock, either by active beneath the fence bound amid pulses, or by blame added individuals through the fence. Animals with blubbery bristling coats (such as sheep or Highland cattle) may apprentice to advance through the fence themselves, application their coats as electrical insulation. Some animals aswell apprentice to admit the slight beat complete fabricated by some electric fences and appropriately can faculty if the fence is off.
edit Agrarian animals
Electric angry to assure a aisle adjoin wildlife. Pilanesberg Game Reserve, South Africa
Electric fences are advantageous for authoritative the movements of agrarian animals. Examples cover black deer from entering clandestine property, befitting animals off airport runways, befitting agrarian animal from raiding crops, and preventing geese from abuse areas acclimated by people. Electric angry has been abundantly acclimated in ecology situations abbreviation the battle amid elephants or added animals and bodies in Africa and Asia.8
edit Security
Electric angry at an airport
edit Non-lethal fence
Non-lethal electric fences are acclimated to anticipate breach by both clandestine and government-sector bodies. These cover bales carriers, auto auctions, accessories rental companies, auto dealers, apartment communities, bartering factories or warehouses, prisons, aggressive bases, and government buildings. Abounding of these electric fences act as monitored burglar anxiety systems in accession to causing an afflictive shock. Electric fences are occasionally active to abash suicide attempts on alpine structures, and to abate the accident of graffiti and added petty crime.
Lethal fence
Electric fences advised to backpack potentially baleful currents can be acclimated for anti-personnel purposes.
In 1915, during World War I, the German occupiers of Belgium bankrupt off the bound with aloof Netherlands, application a 300 km electric fence active from Vaals to Scheldt. Germany aswell erected a agnate fence to abstract thirteen Alsatian villages from Switzerland.3
Electric fences were acclimated to bouncer the absorption camps of Nazi Germany during World War II, area potentially baleful voltages and currents were employed, continuously rather than in pulses. Some prisoners acclimated the electric acid wire fence to accomplish suicide.9not in commendation given
Nazi absorption camps were amidst by electric fences, like the one apparent above, which independent baleful voltages, continuously rather than in pulses
During the Algerian War the French erected the electrified Morice Line.
Sections of the close German bound were lined with a 3 m (10 ft) top electric fence to avert abeyant defectors from East Germany.10
Electric fences abide to be acclimated in agnate appearance at some high-security prisons and assertive added installations to this day. Typically a nonelectric fence is complete on either ancillary of such an installation, or the baleful accepted is agitated out of accidental ability aloft a wall.citation needed
North Korea uses electric fences to allowance off locations of its bound with South Korea.
Electric fences are acclimated in the Korean Demilitarized Zone as a agency to allowance off North Korea from South Korea. Behind the fence, there is a band of acreage which has acreage mines hidden below it.
edit Added uses
Recent innovations cover electrical fence ecology for burglar apprehension as against to accouterment an electric shock to abash entry. It can be acclimated in accession to or as acting for a host of added fence ecology systems.
Buried electric fences (also alleged "invisible fences" or "electronic fences") are sometimes acclimated to accommodate dogs or livestock. The active wire radiates a anemic radio signal, which is detected by a collar beat by the animal. The collar emits a admonishing babble abreast the wire, but if this is ignored, produces a balmy shock. Humans and added animals are blind of the active line. In a agnate system, the collar uses GPS signals to actuate adjacency to a agreed "virtual fence" after a concrete installation.
In 1915, during World War I, the German occupiers of Belgium bankrupt off the bound with aloof Netherlands, application a 300 km electric fence active from Vaals to Scheldt. Germany aswell erected a agnate fence to abstract thirteen Alsatian villages from Switzerland.3
Electric fences were acclimated to bouncer the absorption camps of Nazi Germany during World War II, area potentially baleful voltages and currents were employed, continuously rather than in pulses. Some prisoners acclimated the electric acid wire fence to accomplish suicide.9not in commendation given
Nazi absorption camps were amidst by electric fences, like the one apparent above, which independent baleful voltages, continuously rather than in pulses
During the Algerian War the French erected the electrified Morice Line.
Sections of the close German bound were lined with a 3 m (10 ft) top electric fence to avert abeyant defectors from East Germany.10
Electric fences abide to be acclimated in agnate appearance at some high-security prisons and assertive added installations to this day. Typically a nonelectric fence is complete on either ancillary of such an installation, or the baleful accepted is agitated out of accidental ability aloft a wall.citation needed
North Korea uses electric fences to allowance off locations of its bound with South Korea.
Electric fences are acclimated in the Korean Demilitarized Zone as a agency to allowance off North Korea from South Korea. Behind the fence, there is a band of acreage which has acreage mines hidden below it.
edit Added uses
Recent innovations cover electrical fence ecology for burglar apprehension as against to accouterment an electric shock to abash entry. It can be acclimated in accession to or as acting for a host of added fence ecology systems.
Buried electric fences (also alleged "invisible fences" or "electronic fences") are sometimes acclimated to accommodate dogs or livestock. The active wire radiates a anemic radio signal, which is detected by a collar beat by the animal. The collar emits a admonishing babble abreast the wire, but if this is ignored, produces a balmy shock. Humans and added animals are blind of the active line. In a agnate system, the collar uses GPS signals to actuate adjacency to a agreed "virtual fence" after a concrete installation.
Interference and unwanted effects
Poorly advised or abominably maintained electric fences can actualize acceptable electromagnetic arrest to could cause problems for adjacent telephone, radio, and television accession - and has been a accurate botheration for dial-up Internet users in some rural areas.1112
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