ferrite transformer winding

[Shax]

Hi all!

I'm building an EHT supply for a cat chaser that uses a ferrite bar transformer and several doubler stages. My question is this...

should I wind the primary directly on the ferrite, and then wind the secondary over the top, or do I wind the secondary first, and then wind the primary over that?

Primary is 15 turns 0.7mm wire
secondary is 1500 turns 0.4mm wire
ferrite is 8mm x 40mm

Or doesn't it matter too much?


tia,

 

[Sceadwian]

Shouldn't matter enough to care.

 

[chemelec]

Hi all!

I'm building an EHT supply for a cat chaser that uses a ferrite bar transformer and several doubler stages. My question is this...

should I wind the primary directly on the ferrite, and then wind the secondary over the top, or do I wind the secondary first, and then wind the primary over that?

Primary is 15 turns 0.7mm wire
secondary is 1500 turns 0.4mm wire
ferrite is 8mm x 40mm

Or doesn't it matter too much?


tia,

Personally I always wind the Primary on First.
It results in a Slighly better magnetic field and better efficiency this way.

 

[Hero999]

I would use a proper core rather than a simple piece of ferrite bar because it's more efficient and the irradiated fields can get you in trouble with the law.

 

[Shax]

I would have used a proper core, but the cores I have are too damn big!

Maybe the MK2 version will use a decent sized core..

 

[chemelec]

I would use a proper core rather than a simple piece of ferrite bar because it's more efficient and the irradiated fields can get you in trouble with the law.

Efficiency I Agree with. But I really doubt they will search
for that tiny amount of radiation.

 

[ericgibbs]

hi shax,
Have you considered going to a local car breakers yard. Pick up a ignition coil ballast resistor and circuit breaker capacitor.

Saves all that winding, a few 'D' cells in a hollow tube and a push switch should give you about 20kV.

Ive made electric fences [for animal control] this way. They are non lethal but they make you jump, try it.

Regards
EricG

PS: a more humane method for pussy cat control I have seen.
A guy used a PIR connected to a electrical water control valve, with a water pipe connected to the local supply.
Its easy to move it around the garden area and you don't have to do any chasing.

As the man said: no point in running when being chased by a lion, you will just die tired.

 

[bitem2k]

hi shax,
PS: a more humane method for pussy cat control I have seen.
A guy used a PIR connected to a water control valve, with a water pipe connected to the local supply.
Its easy to move it around the garden area and you don't have to do any chasing.

Why would you want to try and zap a defenseless animal? Perhaps you are lacking in some departments and need to feel big by inflicting pain on a tiny animal.

I agree entirely with ericgibbs, there is no need to use dangerous electricity when there are much more humane methods of dealing with your problem.

 

[Hero999]

I agree, I didn't notice the application for your high voltage circuit, don't go round zapping animals, it isn't cleaver or funny.

Also don't forget that smaller animals are more easilly severly injured or killed by electricity, take a piezo igniter for example, it can kill insects but you only feel a little static shock.

I suppose an electic fence isn't too bad, just the words cat chaser gives me pictures of a moron running around zapping cats with an ignition coil.

 

[ericgibbs]

hi hero,
Sadly electric fences for animal control are 'necessary' at this time.
Hopefully one day someone will come up with a more humane method.

Many stock farms need to control their animals for the purposes of crop
protection, grazing areas etc. On our small farm in South Africa, if an animal
was to 'wander' off, it wouldn't last very long.

Invent something to do the job, you would make a fortune.

Regards
EricG

 

[Shax]

Why would you want to try and zap a defenseless animal? Perhaps you are lacking in some departments and need to feel big by inflicting pain on a tiny animal.

I agree entirely with ericgibbs, there is no need to use dangerous electricity when there are much more humane methods of dealing with your problem.

The simple reason is I am fed up with all the cat **** in the garden!
I've tried all the so called humane ways, sprays, powders, garlic, water guns.. Nothing will deter these pests from taking a dump in my garden. Not nice when there are young kids playing in the garden.

A neighbour suggested burying broken glass in the flower beds to stop them.. Now that is inhumane.

I'm intending on running an electric fence wire along the top of the garden fence panels. Seems to be the only way left, short of shooting them. And the amount of current on the wire is low enough to render is safe.. Just enough to jolt the buggers and make them think twice...

 

[Nigel Goodwin]

I don't know about other countries?, but certainly in the UK that's likely to result in a visit from police as it's highly illegal!. Still, the jails are full, so you'll probably only get a couple of years community service!.

 

[Hero999]

Running an electric fence across the top of a fence panel is unlikely to work because the cat won't be earthed when it makes contact with it.

 

[Shax]

cats.. The other white meat!!

OK, I'll run 2 lengths of fence rope... One earthed, and one carrying the eht.. That will definately work!!!

Sorry if this thread has upset some feline lovers...

 

[bitem2k]

Electric fences for cattle (LARGE ANIMALS) i have no problems with.
However cats are very small animals, which renders them more likely to be seriously injured by your "low" current.
Suppose the cat had a weak heart? What would you do if you actually killed one? Would you go and celebrate with your barbaric neighbour?

I personally dont like children very much, and if they were jumping in my garden over my fence i wouldnt enjoy it, but theres no way i would start putting up electricfied fences to control the "pests".

These animals belong to someone, just as your children belong to you. How would you like it if someone as malicious as yourself was purposefully inflicting harm on them?

polite request to the sane people of this forum:
please could you stop giving this nutter ideas. thanks.

Cats despise water more than anything else, if you rig up somesort of spray to defend your barriers, then that would be an infinately better way.

Maybe you go rig up a sprinkler that is somehow controlled by an infrared detector, such as the ones used on security lights. That would definately make them think twice about deficating in your garden.

 

[G8RPI]

I don't know about other countries?, but certainly in the UK that's likely to result in a visit from police as it's highly illegal!. Still, the jails are full, so you'll probably only get a couple of years community service!.

Hi Nigel,
I'm not going to get into the ethics of this but electric deterents are not illegal in the UK. The important issue is that it MUST be pulsed, a short zip is much less likely to cause permanent damage. Similar ethical questions arise for the "wirless fence" dog control devices, while they are not liked by the animal charities there have not been any convictions. I think the point is that the animals have a choice, don't go near the fence, don't get shocked. The manually triggered electric training collars are another matter.

On the original question, it's normally much easier to neatly wind the primary (thicker wire) as this will give a more even surface to wind the seconadary over.

 

[Shax]

I personally dont like children very much, and if they were jumping in my garden over my fence i wouldnt enjoy it, but theres no way i would start putting up electricfied fences to control the "pests".

These animals belong to someone, just as your children belong to you. How would you like it if someone as malicious as yourself was purposefully inflicting harm on them?

polite request to the sane people of this forum:
please could you stop giving this nutter ideas. thanks.

Cats despise water more than anything else, if you rig up somesort of spray to defend your barriers, then that would be an infinately better way.

Maybe you go rig up a sprinkler that is somehow controlled by an infrared detector, such as the ones used on security lights. That would definately make them think twice about deficating in your garden.

Ahh.. you seem to be missing the point...
My kids do not take delight in ripping up flowerbeds and shitting all over someone elses garden.. Maybe I should "train them".. Would save a fortune in toilet paper!!!
And if you read my previous posts, I HAVE TRIED WATER JETS, SPRAYS, POWDERS... The staff in the local petshop even suggested the E-Fence...

Have you ever tried to set a PIR to detect a cat? The bloody things are sold as being "pet proof"... And in these days of water shortages, I do not want a hose running all night, which is when these furry vermin invade!!

And by the way, I am not a nutter, the Psych Doctor in the hospital said I was safe to be released!

 

[bitem2k]

My cat constantly sets of my security light.

 

[spuffock]

git a dog. (snigger)

 

[Shax]

git a dog. (snigger)

Nah... I think I'll stick with my original plan.... bzzz zap crackle MEOWWWW!!!