Electronics Off topic: Electric fence

Most of them are movement activated though, so it wouldn't usually be annoying. All of the decent quality ones I've seen were inaudible, unless they were broken...

 

http://ww2.green-trust.org:8383/equipment.htm
look at the time machine bit, includes plans for electric fence.
Other system i have sen work on cats was an automated water gun, was fired using a pir controlling a valve.
Flibb

 

If you REALLY want to do this, get a camera flash charger, take the capacitor off and hook up the points on the board. Only thing is because the voltage is quite low (~300v) you'd need some kind of metal plate or something as a ground. They output VERY little current but they hurt like ****, don't know why (probably because of the high frequency).

 

Even better, replace the capacitor with a 0.1uF one of the right voltage.

 

The problem with caps is the high peak current, which could cause burns or fibrilation (not sure if that's spelt correctly )

 

Well this is proberly the crapyiest solution but has anyone ever been shocked by a relay? All you do is connect the relay through the normally closed contacts of itself and it will tunr off and on rapidly and will give you a shcok if you touch the relays power terminals. I have done this wiht tiny ralys and shocked frineds for fun and i ahve done these wiht huge ralys and you justr need ot touch one of the power temrinals and you get the shock anyway!

 

Cool never done that before, <runs off to find bigest relay in stock>


EDIT: Post 1234, hoow purdy, shame i missed 1337, lmao

 

Also you can easily buy electric fence kits, or steal one from a farmer! But seriously have you though about asking your neighbours to keep thier animals in at night?

 

I think this has to be the best point made so far. I live in the sticks and foxes tear everyone's bin bags apart down our Lane apart from ours. Why? Cos we don't put food in the bin. We put it in the compost bin. No food smells = no reason to try and get in the bag. That's how animals work.

Also, cats are agile. A fence wouldn't stop it if it was hungry. It would get the bin bag away from the 'electric fence' and tear it apart then.

 

...then you connect a car ignition coil to a car battery through the normally open contacts and enjoy!

This is actually one of the best ways of getting very high voltage at a respectable current, because there are no mosfets to get hot and you don't have to worry about heatsinking on the input stage.

You can do this with a house transformer too to get around 240 volts RMS (although there's peaks of around 2000 so be careful and don't use it to power anything ).

Frequency in both cases tends to be about 180 hz btw.

 

I have been zapped by a 0.1uF cap charged to 200v(in an old DMM assembled in 12-2-1981(remember those nixie tubes)).
I just got a shock, no burn.
I was repairing the meter, and the problem turns out to be a shorted DC-DC converter transistor due to thermal stress(I installed a heatsink on the new one).
Now that's an antique meter.

 

You're missing the point though. We're not talking about a human, we're talking about shocking an animal many times smaller than a human, so it would be a lot easier to seriously injure/kill the animal, especially since with an animal there will be a path through the heart, whereas you placed your finger across the terminals.

 

Get a wall wart that puts out 12v AC at 300ma or higher, and a 12.6v transformer of 300ma or higher.
Wire the output of the wall wart to the secondary of the transformer, wire one end of the transformer primary to ground, and the other end to the fence.
Plug in the wall wart, and you're done.

 

No offence, but I'm beginning to think you are retarded star882.

Your setup would provide an output of 230V at 15.6mA. It is well known that at 50Hz with a current over 10mA at 230V will result in a very serious shock for a human. Muscle paralysis can occur at 15mA, and fibrillation at below 100mA. Now for a small animal like a cat that roughly weighs 5kg, its size is approximately 13 times smaller than a human that these figures are quoted for. Such a setup delivering 10mA at 230V at 50Hz would result in almost certain death, or very severe burns.

 

Borrow a .22 and stay up all night. You'll only have to do it once.

Seriously try spraying the bag with bathroom air freshner. Use the odor eating kind, that is what dad does.

 

Add resistors in series with the transformer primary to reduce the peak current.

 

I don't want to give anyone the impression that i'd actualyl do any of the things i've suggested, I'm just speculating about how they could work. You probably will cause a lot of damage to the animal in question.

 

Has anyone seen the newspapers over the last couple of days (Daily Mail I think) , "man kills cat with home made electric fence?" hmmm.....

Seriously, don't do it

 

I think this has gone on long enough...