We had a fence charger!!! His name was Ezra and he weighed about 2000 lbs and could tear right through one. No electric fence would deter him!.

Near Weymouth is a sign by a field that says, "The farmer lets you cross for free but the bull charges"

 

I knew a farmer that used 220vacstraight from an oulet. I thought he was as idiot and criminally negligent. Fortunately nobody died.

 

This is a commercial electric fence which runs on 9V dc & draws minimal current. It uses a small HV inverter which generates 225V DC which built up in a capacitor & then dumped across another Transformer to feed the fence. The pulses are aprox 3 seconds apart, its a crude CDI type system & produces quite a reasonable spark.View attachment 132091 View attachment 132092 View attachment 132093 View attachment 132094 View attachment 132095 View attachment 132096 View attachment 132097 View attachment 132098

Great Freaking Pictures! Newbs like me find visual aids to be an immense help!

That's awfully close to what I was/am looking for, but it's physical dimensions look to be just a little too large. The secondary circuit board, perpendicular to the first one makes it too thick in that dimension. That fact that physical dimensions of my power source will not be a design consideration, because that's already considered in the existing enclosure does mean that this is a pretty small design. Of course, that means I will require mine to operate on my available 6volt, but as far as designs go, that's just some creative math, to respec some components, so that's not even a big problem.

From the looks of it, the size of the components is not the problem - it's the case and circuit board that kill it for me. Any chance you measured the device, while it was still out of it's case? That would be useful information to me.

Even if this isn't the exact answer I am looking for, seeing a working charger (inside and out) that is in the ballpark of what I need for a finish project can't do anything but help me.

Thanks

 

I knew a farmer that used 220vacstraight from an oulet. I thought he was as idiot and criminally negligent. Fortunately nobody died.

The problem with the worst criminally negligent idiots is that they are "free-range", until someone gets hurt or killed. Until then, either no one notices them, no one feels compelled to report them, or the law enforcers don't interrupt their actions in a manner that justifies taking them to task (or jail).

After the fact, everyone shakes their head, in disbelief, or disgust, and asks how such a situation was ever allowed to come to pass?

And here's the kicker: All of us have been a (non-criminal) free-range idiot at some point in our lives, if not currently. Hopefully, you either saw the error of your ways, or it was pointed out to you before someone got hurt, thus teaching you an invaluable lesson, the easy way.

Don't deny it,

I gotta get back on task - see you tomorrow...

 

Definitely not in denial here! When I think back on all the foolish chances I took - I shouldn't be alive. But fate favored this foolish one for some unknown reason. And continues to - I guess.

 

All of us have been a (non-criminal) free-range idiot at some point in our lives...

So, there is a name for whats wrong with me.

 

Ok I will add a BOM ( bill of materials) totthe schemaitic on pos #50

https://forum.allaboutcircuits.com/threads/lets-talk-aout-fence-chargers.138483/page-3

 

Ok I will add a BOM ( bill of materials) totthe schemaitic on pos #50

https://forum.allaboutcircuits.com/threads/lets-talk-aout-fence-chargers.138483/page-3

That will be extremely handy - will you add it to the image itself, append the post, or add a new post to this thread?

 

Here's my take on a simple, low-power fencer using a ignition coil for the output.
The CD4093 Schmitt trigger gates are configured as a 1Hz PWM relaxation oscillator set for a low duty-cycle
POT U5 adjusts the pulse-width which affects the stored inductive energy and thus the output voltage as determined by the fence wire load capacitance.
The coil primary peak voltage is limited by zener D4 to 100V, giving a maximum output voltage of 10kV from a standard 100:1 ignition coil.

The LTspice simulation shows that the average current drawn will vary from about 0.1Ah to 1Ah per day, depending upon the setting of U5.

 

That will be extremely handy - will you add it to the image itself, append the post, or add a new post to this thread?

I will add it to the text on the thread.

 

Crutschow is on the money as battery powered electric fences need to be very conservative with power consumption. The commercial unit I showed previously only works on, 3 second pulse intervals & its only a 30Ma draw on a 9V DC supply every 3 seconds.

 

Blank-Stare, The dimensions are 700mmX650mmX35mm. The vertical board is an audio module that chirps every pulse. It will work with out it, but its purpose is to indicate that the unit is actualy working. If there is a short circuit on the Fence it stops chirping.

 

Blank-Stare, The dimensions are 700mmX650mmX35mm. The vertical board is an audio module that chirps every pulse. It will work with out it, but its purpose is to indicate that the unit is actualy working. If there is a short circuit on the Fence it stops chirping.

Interesting feature to have a sonic indicator. Did you buy that new recently?...if so, care to share your source? I'll see if I can source one, online. If it works without that board, it might be possible to change out a couple of components, and have it work for a 6 volt power source, right?

So far, that's the closest thing to store-bought that looks like it would work for me...

Whoa, wait - are those measurements just the board? 700mm...as in 70 CM... as in roughly 28 inches... nearly two and a half feet? The pictures would seem to indicate something a lot smaller...

Something's not adding up here....

 

The 1N5378Bode i78N 12 V zener diode is probably too low voltage, since a fully charged Lead Acid battery is13.6V Magic Smoke is valuable, let us not waste it. You also show An ignition coil as a single coil do you disagree with my interpretation of a old50's ignition coil?

 

Crutschow is on the money as battery powered electric fences need to be very conservative with power consumption. The commercial unit I showed previously only works on, 3 second pulse intervals & its only a 30Ma draw on a 9V DC supply every 3 seconds.

Did you really study my design?q1 is only on for 180 ms whil Q2 is on for 1 second The current draw during this time will be 12ma
. The 7555 version will be even lower. a transformer will draw no current at all unluss there is something conducting current on the q120VAC side. such is the nature of transformers they pass power used to the other side.if no current is drawn through the secondary no current is drawn through the primary. Current config i up to 480VAC at 180ms if the switch is set for high voltage out



Parts List

 

Blank-stare, sorry about the measurements 7cm X 6.5cm x 3.5cm. That unit is quite an old one but Gallagher have a new model about the same size & battery operated at. https//www.gallagherfence.net/products/b10 at quite a reasonable price.

 

Blank-stare, sorry about the measurements 7cm X 6.5cm x 3.5cm. That unit is quite an old one but Gallagher have a new model about the same size & battery operated at. https//www.gallagherfence.net/products/b10 at quite a reasonable price.

Now those are numbers that make more sense. I assume the 3.5 cm is the height of the secondary board? How thick would you say the primary board with be, if the secondary were removed?

I have an arc to work with. The arc is 1-1/4" at it's highest, and just a hair under 5" long. If the highest point on that charger is 3/4", there is a real good chance it would fit in the case. Of course, that's assuming mods to make it comply with available power source are possible, and do not make it too large.

I just looked at that link - 85 dollars is a bit spendy for this operation, at least at the current state of my wallet. That just brings me back to building one from scratch, unless I stumble onto something store-made, that fits the project, and my wallet. I am pretty well consigned to that, based on the luck I have had looking.

Still, your participation is helpful. Seeing what's already out there usually translates into a better end product.

 

Still the same height with the secondary board removed 3.5cm.

 

Wendy, most electric fences are at least 7Kv output or higher, think you will need an ignition coil at least in your design. Short HV pulses are not likely to kill any one, especialy if theres 3 second spacing in the pulses. In that commercial one i posted the Voltage is 7Kv & rated at .06 Joules & this is only a small strip fence unit.

 

Still the same height with the secondary board removed 3.5cm.

Drats. Oh well, thanks for checking for me.

The search continues...