Electric fence security question...

[Mick Bailey]

Electric fences operate by having one side of the output connected to an efficient ground. This is usually one or more dedicated copper-clad rods driven into the ground. The fence is insulated and connected to the 'hot' energizer output. So even in a situation where you have more than one fencing strand (such as used in rabbit protection), all the strands are connected to the 'hot' side.

Animals though are very different to humans in the way they get shocked. A fencer voltage that may not appear to give too much of a shock to a person can give a fair jolt to an animal because either a) it's very small, or b) it has four legs in contact with the ground, or c) animals touch things with their noses when investigating. They don't wear rubber sneakers, either.

There used to be high output energizers (now outlawed pretty much everywhere) called 'grass burners'. They put out high voltage and a fair current, and were intended to burn any vegetation away that grew against the fence which would cause a regular fence to short out. They were responsible for many fires and would kill small animals. These were also used (illegally) for protection against human intruders due to the severity of shock.

All energizers need a safety spark gap to protect the unit against an open circuit or high-resistance output. If not the transformer will eventually fail. Also consider radio, TV and other interference.

[jjj]

[QUOTE=Thank you Mick Bailey [/QUOTE]...for the Info. As mentioned, I aim to build a harmless electric fence on top of the existing fence, using a pulsed harmless fly swatter or a pulsed gas lighter circuit as a thief deterrent, intended to deliver an unpleasant shock and thus, repel the would be (mostly young) thief.
So, in this case even the best ground earthing might be futile, because the thief will be off ground. In this case I might be better to use alternative wiring (live/ground/live/ground etc.) by placing the barbed wires about an inch apart. I think such a harmless, yet effective circuit is quite useful, because the thief does not know its true level of danger. Thank you in advance for your good advice.
(Since I'm getting on in age I also thought of building an electrified cane, locked to my wrist, to stop attackers to apply it on me. This cane would also be handy for mitigating dog attacks...) Thank you in advance for your good advice.

[g1]

So even in a situation where you have more than one fencing strand (such as used in rabbit protection), all the strands are connected to the 'hot' side.

This is not alway true, in areas where the literal ground is too dry, or poorly conducting, grounded strands will be added to the fence, usually the bottom strand, but can also be alternating. It is also used to help the "delivery" to "subjects" with high resistance hides.

I believe the electric fly swatter uses the same technique, there are isolated ground wires and the fly must come into contact with both, other wise it could just land on it like a "bird on a wire".

[J M Fahey]

(Since I'm getting on in age I also thought of building an electrified cane, locked to my wrist, to stop attackers to apply it on me. This cane would also be handy for mitigating dog attacks...)

Don't know what it would do others, but said cane would certainly electrify YOU, since electrical circuits must be closed and the path to ground would be through your body.

Unless you carry a small ground rod and a hammer with you and tell thieves and dogs: "wait a second until I safely ground this cane so I can safely repel you "

There's no such a thing as a "floating/independernt" single voltage, it must always be referenced to "something", in this case ground.

[jjj]

Yes, of course, the fly swatter has a red, made of alternative ground and active fires, woven as separate, closely placed wires.
The more important thing is the fact that it is "harmless" otherwise it could not be sold to families with children... and that's what I want to merely ward off would be thieves. In this context I find it useful as additional deterrent. So, I'm quite confident that pulsed fly swatter circuit should not land me in jail, since I will be able to vindicate its origin and harmlessness to the court's electronics expert.
Of course, for the cane I prefer applying a 3V battery PS and the circuit of a gas lighter, for if I'm physically attract by assailants or dogs, my can has to bite them, too. In such a case the court won't lament the demise of the assailant or dog.

[g1]

Well, since you already have the fly-swatter
Human Cattle Prod

** please note the disclaimer: "Not suitable to be used on Humans or animals. Actually I would suggest you don’t make this at all!"

[jjj]

Well, since you already have the fly-swatter
Human Cattle Prod

** please note the disclaimer: "Not suitable to be used on Humans or animals. Actually I would suggest you don’t make this at all!"

Cattle prods are far stronger that the fly-swatter or 1V2 battery run gaslighter. So, I think with go with on e these as an additional deterrent.

[Leo_Gnardo]

Cattle prods are far stronger that the fly-swatter or 1V2 battery run gaslighter. So, I think with go with on e these as an additional deterrent.

Oh terrific, I can see you now defending the perimeter, poking at sheepskin clad burglars with a cattle prod. That oughta work just FINE! Remember, don't bring a knife to a gunfight, and don't bother with a cattle prod either. Bring two guns, nothing less than .40 cal, and have your friends bring theirs too.* Must be some helluva neighborhood. And I thought Chile was a well sorted out buttoned down kind 'a country. If it's really that bad think about moving somewhere, nice peaceful Baltimore MD sounds good this time of year...

* Straight from the US Army & Marines guidebook "24 suggestions on how to prevail in a gunfight."

[jjj]

Oh terrific, I can see you now defending the perimeter, poking at sheepskin clad burglars with a cattle prod. That oughta work just FINE! Remember, don't bring a knife to a gunfight, and don't bother with a cattle prod either. Bring two guns, nothing less than .40 cal, and have your friends bring theirs too.* Must be some helluva neighborhood. And I thought Chile was a well sorted out buttoned down kind 'a country. If it's really that bad think about moving somewhere, nice peaceful Baltimore MD sounds good this time of year...

* Straight from the US Army & Marines guidebook "24 suggestions on how to prevail in a gunfight."

I was an army man as well. So, I know how to go about, but now I live in lousy St'go de Chile and here we got lots of burglaries etc.
So, prevention is the game I prefer to play. The same common sense I use drawing money from ATM etc. There's a lot one can do to prevent terrible things from happening. I also learn from other people's mistakes. For instance I always sit in the last seats in tour buses, because on crashing these seats are the safest. Same with trains: the last wagons are safest. Also, I fly only principal airlines; no low fare ones, because they their captains are paid less and are less experienced. See, that's what's all about...

[J M Fahey]

Well, since you already have the fly-swatter
Human Cattle Prod

** please note the disclaimer: "Not suitable to be used on Humans or animals. Actually I would suggest you don’t make this at all!"

Well, there is actually one wall climbing thief on which jjj can use his stuff legally:

[jjj]

Well, there is actually one wall climbing thief on which jjj can use his stuff legally:

Since you are so much better at advising me on caricatures/ animation than on helping me design a harmless, yet effective electric fence, I have an even more interesting project for you: Here is a link in which I wrote a script for an animation in which I whistle to music. This would be a great, novel project for a keen caricaturist. Maybe you are or know a talented caricaturist, looking for a challenging project. Please make it happen! I have many great ideas... Joh
http://www.mediafire.com/download/ob...on_Scenery.rar

[g1]

Cattle prods are far stronger that the fly-swatter or 1V2 battery run gaslighter. So, I think with go with on e these as an additional deterrent.

I'm not sure if you looked at the link I posted (post #36), it was a "human prod" built from an electric fly swatter. This is why I said "since you already have the fly swatter".

[jjj]

I'm not sure if you looked at the link I posted (post #36), it was a "human prod" built from an electric fly swatter. This is why I said "since you already have the fly swatter".

OK then, since the fly swatter is that damn weak, I suppose I don't even need to pulse it. All it needs is four alternative rows of barbed wiring.
So, I'm glad having worked myself to this only safe circuit method. In a way it was good that you all kicked me in the less lethal direction. Several heads think better than one only. So, I thank you all for your hard work and caricatures.

[J M Fahey]

Who says the fly swatter is "weak"?

That capacitor has enough energy stored to "vaporize" a fly, certainly enough to *burn* an apple seed sized chunk of human skin, which is about the same volume or mass.

Not milli or micro Ampere current involved there, I bet pulses are into the Amperes range to have such a Thermal effect.

Flies are not exactly being annoyed away but vaporized on the spot.

For a Human, probably not deadly (it depends on the current path) but definitely damaging, as harmless as a burning cigarette applied to your cheek which won't kill you either.

I suggest you open your fly swatter, pull the grill away , connect both HV wires to a couple bare wires, say 5 cm away, turn it on and touch them with your bare hand.

Or even better grab one of them with your right hand, the other with the left one.

Don't even dream of connecting that contraption to a fence unless you test it yourself.

Even better, have somebody film you doing so and post it here (or on YT).

I bet you already have the musical backing for it.

[jjj]

Who says the fly swatter is "weak"? That capacitor has enough energy stored to "vaporize" a fly, certainly enough to *burn* an apple seed sized chunk of human skin,

Yes, I agree... it would harm the thief and not allow him to climb over my fence. Frankly, I am scared to test it myself, but here are a number of tests suicidal people did for me:

Test1: This lady used to torture her husband with it. I "caricatured him"....suffering in hospital and his wife 5 years in prison.
Evidence: https://www.youtube.com/watch?v=dcwNpPEcjIQ

Test2: This suicidal chap ended up losing his finger... serious incident!
Evidence: https://www.youtube.com/watch?v=Av3oB7jgrhI

Test3: And this suicidal kid lost his tongue... even worse! He went straight into a coma... and never recovered from it.
Evidence: https://www.youtube.com/watch?v=CbOiyZ5kjE8

Test4: This keen murderer electrocuted his sister... Shocking crime!
Evidence: https://www.youtube.com/watch?v=cZ2aG7o0T2M

The list goes on... and on, all suffering horrendous consequences and one wouldn't want a thief to suffer the same.
Just imagine what it would do to the poor thief (in his best years...) keen to climb my fence, rob me and then climb back over the same fence with the loot...