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Electric Fence Tester

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andy007

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Hi. Does anyone have a c/diagram for the above please?. Local DIY cannot get any until after N.Year so have loads of components in my workshop which I like to recycle so decided to make one, if i've got the right bits. Havnt tried it yet but any thoughts on adapting a mains voltage test screwdriver?? I also thought about putting a 'pulse light' similar to the one on the unit in the stable, in a couple of locations in the field but again would like some help with components.
Any help would be most appreciated.

Thanks

Andy007
 
I really can't think of anything at the moment but the first thing that came to mind when I read the title is touching the fence haha.
 
Hi and thanks for the reply. I want to test the fence. The field is a bout 4acres, didvided into paddocks. The supply unit is more than big enough for the area but fence tape at the outermost regions is a bit old and will be replaced. As I do it I wanted to test its effectivness. I know there are loads of testers on the market that either have a lamp on a clip on housing with a trailer lead and spike that you stick in the ground, touch the fence with the other end and so on around the fencing to find where its gone to ground etc... Other similar devices have maybe 3 or more lights to indicate intesity of the pulse. The latter I would like to make but a simpler version would do for now. I could buy one but I have so many components and old circuit boards etc.. I thought it would be a nice little project for the dark nights.
As far as the pulse lights in the fileld, just a simple neon circuit, permanatly fixed to 1 or 2 locations up the field would show me of any immediate problems such as weeds causing a short or broken tape.

Dont know if a speaker from a little radio along with a circuit could be designed eg.. the louder the click the better the circuit????

Thanks for your help

Andy007
 
Interesting question. I'm sure that a simple neon lamp, NE-51 type, would light up to show high potential when one lead is touching the hot wire. However that won't really tell you it's effectivness, just if it's hot or not.

I would think the best method would be a high voltage probe connected to a standard digital multimeter. The common lead of the meter could go to say a 6" spike that you can stick in the ground and the other lead through the high voltage probe could give you an actual measurement number that you could compare with other points along the fence and closer or farther to transformer. Do you know the voltage output of the fence tranformer? AC or DC? High voltage probes are just basically resistor divider string, however construction methods must account for the high voltage level expect to be measured.

Lefty
 
Hi. Thanks for your reply. I have in the past used my meter on 5000v with some success but its expensive and dont really want to cart it around the field. I need something simple without the need to carry probes and meters around. I was thinking of something that could mount easily on say a broom handle, spike on one end and a contact strip near the top, then just push in the ground and touch the fence. The 'other half ' isnt exactly tech minded so 'simple use' would best describe their ability. As she often moves the tapes for the grazing 1 or 2 horses have gone on a walk about because the fence wasnt live. The last purchaced tester went under a hoof 3 weeks after she got it! Could get expensive at that rate:p:eek:
 
ps.. Fencer info Power Source: 220/230v
Stored Energy: 7.5 Joules
Max Power Use: 10 Watt
Open Volts: 10,000v
 
hi andy,
Try an old AM portable radio, just tuned off a station, you should hear a click in the speaker every time the fence is pulsed.

Same as you hear lightning strikes on AM radio's.:)
 
European voltage is 250V ac, there are many brand screwdrivers with an embedded neon bulb for quick testing (finger on one end, fence on the other) , cheap as.
 
European voltage is 250V ac, there are many brand screwdrivers with an embedded neon bulb for quick testing (finger on one end, fence on the other) , cheap as.

hi Andy,
DONT try this on the fence
.!

The neon will flash blue and you will get a nasty jolt.:eek:

BTW:
Europe has been 'harmonised' to 230Vac
 
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Such outstanding advice. Must have licked the HT supply in the tele too many times ;);):D:D

I did get a pretty good jolt last summer when I was messing around in the service box outside. Think somebody called at a most inopportune time. I really hate getting shocked.
 
I suppose I could touch it with one side of my kneck bolt and ground it with the other side. Works ok with lightening:p
I'll keep an eye on this thread in the hope someone could supply a circuit for just a flash light unit for the field.
I just found one for sale on the net which looks a bit like a hand held flourecent car inspection lamp. Metal hook on the top then a clear plastic body with what looks like a tube, then a link wire to what looks like a resistor, then a tail wire and stake. A bit expensive for what it is hence the DIY route. Any ideas as to the components????

Thanks again

Andy007
 
I purchased an electric fence tester from the local Tractor Supply (a farm supply store) for just a few bucks (with 5 neon lights to show strength) which I use when building the fence but often loose track of it for day-to-day testing.

I use two methods (not counting touching the fence) to test the fence when I am too lazy to go find the tester. Near the fence charger (and at a number of other locations) I have one of those spring-loaded gate insulators. I simply unhook the gate just a little bit and look for an arc to jump the small gap. If the fence is shorted out somewhere, there will be no arc because the fence charger will not supply power into a shorted fence. The other method is to take my fencing pliers (or any metal tool with an insulated handle) and create a near-short between the fence and a metal fence post leaving a small gap. Again you will see the arc if the fence is working--a larger arc indicates more power, a small arc a little power.

Now my story... I have a 10-mile charger (quite a lot of power to drive that much fence wire). I unhooked my gate which left the fence unenergized so I would not get jolted when working on the ground near the fence. However, I was kneeling on the ground near the charger. All of a sudden, the top of my head came into contact with the wire coming from the charger to the fence and I got the full ten miles worth through the top of my head. It knocked my head into the corner post; it clenched my jaw shut and knocked me to the ground. I have a lot more respect when working near the fence now.

PS. If you think wearing leather gloves will insulate you, remember, cattle are wearing leather also. I have not been brave enough to try my theory.

Dale
 
A piece of grass is what I regularly use to check if my fences are working. When you first try start near the energiser unit where you are confident the fence is working and take a piece of grass, a fairly long stalk and touch the fence briefly, then if you feel nothing hold the grass against the fence and move you hand closer along the grass to the fence. Depending on the dryness of the grass and your own footwear you will eventually become used to checking fences this way. The grass is a high resittance and if you are wareing Wellingtons (Gum Boots) you will probably be well insulated and feel very little 'kick' but if you are wearing damp leather boots you will need a longer piece of grass and a briefer 'touch'. Don't worry about the shock, it is only a tingle and you will soon become used to it. If Rubber boots are very good insulators you might need to touch the ground with your other hand (lightly at first).
An alternative is a set of two or three minature solder in wire ended neons in series with one or more 10 Megohm resistors used as the previous poster indicated with a earth connection tail at one end and a hook to the fence on the other. The neons will strike at about seventy volts so you need a signifigant dropper to avoid blowing them up.
Greenweld (Bulbs Greenweld @ Permex Ltd) sells suitable neons at ten for a pound sterling but I'm sure similar bargains can be obtained in most countries. (I have no connection with that or any other company)
Good luck
Cavan Farmer
 
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