hi Hamlet,
Wow!, thats one heck of an application.
What other technology have you tried to keep those critters out.

E

 

High there! I hope you are doing well...
The circuit runs on 12V (batteries), making this a very portable fence energizer solution. It uses 2x 555 timers, one runs in astable mode and is used to generate the frequency interval, while the second one controls the pulse length and so the output voltage. A calculator for the 555 timers can be found here The updated circuit diagram for this version of the circuit is oavailable:

View attachment 208558
Here are the Eagle files, with both the SCH and the PCB layout: fence-4.3-orig
alternatives, such as the double timer 556, we can shrink this circuit even further, without making any compromises. Here is an improved version that I’ve just designed and tested with excellent results

View attachment 208559
The eagle files: fence-4.2
Both the designs can operate on battery and have low power consumption. https://www.pocketmagic.net/electric-fence-circuit-for-perimeter-protection/

Still trying to build this circuit, assume the primary of the ignition coil connects across C8. (Thinks it 10nf 1kv but can’t make it out) Still don’t understand the purpose of the spark gap across D1, or the neon, why have both? Is this even worth bothering with as I want to energise at least 500m of fence. Also why on earth did the designer specify a surface mount transistor mmbt2222, when everything else isn’t ? Are there any designs (without relays but using vehicle IGN coil) that are proven and can supply a useful length of fence to keep horses in?

 

Take a look at this and tell me what you think?
https://www.doityourself.com/stry/making-an-electric-fence-charger-with-an-ignition-coil

 

Still trying to build this circuit, assume the primary of the ignition coil connects across C8. (Thinks it 10nf 1kv but can’t make it out) Still don’t understand the purpose of the spark gap across D1, or the neon, why have both? Is this even worth bothering with as I want to energise at least 500m of fence. Also why on earth did the designer specify a surface mount transistor mmbt2222, when everything else isn’t ? Are there any designs (without relays but using vehicle IGN coil) that are proven and can supply a useful length of fence to keep horses in?

Go to this link, and read everything three times... at least to page 4. oztules is the designer (attached hand-drawn schematic).
https://www.anotherpower.com/board/index.php?topic=731.0

And see this, details of winding the output transformer:
https://www.anotherpower.com/board/index.php/topic,1088.0.html

"Yikes... I just build the thing and turn it on.... wait for the smoke to clear, then rebuild until it works." -oztules

The second attachment is close to the circuit I use, and is the usual topology for every modern fencer.

I use genuine BTA24-800BW Triacs, but the BT137 or Bta16-800 should also work (800v).

The TIP31 can be subbed with a TIP41 or a TIP35, (or maybe TIP3055, haven't tried it.)
Darlingtons don't seem work. Should draw about 1/2 amp when it charges the 50uF.

I build 'em manhatten-style circuit board, no etching or drilling required. Build the left side
of the circuit first, make sure it works, buzz yourself with 500v a couple times, then assemble
the right side components, making sure the diac/triac trips at 450-600v, or you'll kill your cap.

If you get it right, should kick like a mule.

 

Hello,

@Hamlet , There is a picture that does not show.
It is likely stored on the web somewhere.
Always try to upload the pictures to the forum to avoid these problems.

Bertus

 

Hello,

@Hamlet , There is a picture that does not show.
It is likely stored on the web somewhere.
Always try to upload the pictures to the forum to avoid these problems.

Bertus

fixed it

 

Take a look at this and tell me what you think?
https://www.doityourself.com/stry/making-an-electric-fence-charger-with-an-ignition-coil

Had a look but seems to be more about the actual fence than the energiser

 

hi Dp,
Reading that link, I would say the author has little or no idea about fence energisers.

I know that solid state switching ie: MOSFET's etc is preferred by some designers, but a relay will stand a lot more abuse than a semi.
If you consider that a long wire fence, on insulators, running a few feet about ground is subject to all types of 'local electrical pick up, including electrical storms etc.

The circuit I posted does work well for restricting pigs; sheep and goats with their wooly 'insulation' are more difficult to confine, a higher voltage is possible.

Try a quick build and see how effective it is with horses.?
E