Author Topic: Electric Fence Zapper  (Read 62242 times)

0 Members and 1 Guest are viewing this topic.

Offline mukptl

  • Newbie
  • *
  • Posts: 7
  • Karma: +0/-0
Re: Electric Fence Zapper
« Reply #285 on: April 03, 2016, 07:41:26 AM »
Not sure if it will start in that configuration.... If you can get it to start it should work.
It is a VFO, so not sure how it will work over the range..... try it and see.

..oztules
Thanks Oztules and all other
small transformer working well but TRIAC not  triggering
resistor im using R1m R1m R1m pot 250 k R330k amd 1uf cap after diac
the cap near diac blasted and even neon gone with 100R
type and voltage rating of cap near diac ?
use SCR or  TRIAC -part number of SCR or TRIAC ?
Mukesh


Offline oztules

  • Forum Advisors
  • Hero Member
  • ****
  • Posts: 1066
  • Karma: +89/-5
  • Village idiot
Re: Electric Fence Zapper
« Reply #286 on: April 03, 2016, 03:26:24 PM »
The 1uf should be before the diac. It provides the current to turn on the triac through the diac. 50v will work fine, as the voltage should never rise past 30v before it triggers.

The 330k to ground and the 3 meg to 700v and the cap provide the timing.
Not sure how your providing secondary feedback, so it may be interfering in this part of the circuit, and injecting voltage or a path for the hv to get into your cap line.

You must have a decent cap eg 20uf to stop the inverter driving up to very high voltage instantly, and killing the triacs
Flinders Island...... Australia

Offline mukptl

  • Newbie
  • *
  • Posts: 7
  • Karma: +0/-0
Re: Electric Fence Zapper
« Reply #287 on: April 03, 2016, 09:52:33 PM »
feedback from secondary was not working then i rewind transformer with two primary thats how its working now
for triggering traic i found one of 1m R faulty i will change it then i will update on it

........Mukesh
 

Offline mukptl

  • Newbie
  • *
  • Posts: 7
  • Karma: +0/-0
Re: Electric Fence Zapper
« Reply #288 on: April 14, 2016, 08:14:36 PM »
HV transformer starting winding in pic is that ok ?
 calculation of joules to Amp correct?
5 joules Time   0.010 seconds  = 500 watts
500watts at /10000V =0.05 Amps



Offline mukptl

  • Newbie
  • *
  • Posts: 7
  • Karma: +0/-0
Re: Electric Fence Zapper
« Reply #289 on: April 20, 2016, 05:46:03 AM »
can ferrite bar used in main transformer core ?
about 25 mm dia 90 mm long

Offline oztules

  • Forum Advisors
  • Hero Member
  • ****
  • Posts: 1066
  • Karma: +89/-5
  • Village idiot
Re: Electric Fence Zapper
« Reply #290 on: April 20, 2016, 06:28:11 AM »
It would work...not sure how well, but it would work.

The big steel ones are saturated terribly anyway, so there will be a fair bit of air coil going on anyway..... but not my first choice by a long way.

.............oztules
Flinders Island...... Australia

Offline lighthunter

  • Full Member
  • ***
  • Posts: 164
  • Karma: +8/-0
Re: Electric Fence Zapper
« Reply #291 on: May 21, 2016, 07:41:28 PM »
My neighbor just stoped over an :'(d had a zareba fence controller in back of truck. After i got through with the frustration of finding my security torx (why???) I got it apart and we found a wire burned apart on secondary of transformer. Easy fix as burn was external with enough room to reterminate. Thats rare usually the wire is burned off or shorted several turns inside core. Anyway wow are they trying to kill the animal now? This thing had a capacitor larger than a motor start cap. I didnt look at the ratings unfortunately but it wasnt electrolytic (white plastic tubular body)so I,m guessing 10+uF at 450v.(edit its 50uF 900v) :'( Thats enough to drop most things that breathe, maybe I need one to keep the coons off my solar panels

LH
LH

Offline oztules

  • Forum Advisors
  • Hero Member
  • ****
  • Posts: 1066
  • Karma: +89/-5
  • Village idiot
Re: Electric Fence Zapper
« Reply #292 on: May 21, 2016, 09:52:51 PM »
There are about 1000 joules in a mars bar, and assuming 500v storage @50uf.... we get about 6-7joules (1/2 E^2xC).... so it has stored energy  of 6 thousandths of a mars bar.... mars bar much more dangerous maybe. :(

But it is the impedance of the input winding of the power transformer that will dictate the power of the surge ( assuming perfect switching in the scr)...

This means very low impedance will give very very high voltage, as the pulse width will be very very small... so power will be huge ( hundreds of thousands of watts in fact).

If they had an inductor in series with the primary, and a capacitor ( 2uf??) across the primary, then they are both making the life of the SCR much easier, and widening the pulse, and lowering the power.

This yields two things, .... less radio noise, and better transmission characteristics ( less lossy wave, and less spiky). They need to keep within a tight time range to NOT cause electrocution... your heart pulse sending system cant see the pulse below a certain width, so cant cause heart stoppage/fibrillation etc.

Nervous system really sees it though, so it is not safe to cop too many contiguous pulses..... or some other parts of you may shut down.


So yes it will give a wallop, but the winding thickness and length, and the usual in line inductor will keep the voltage down below 10000v.
It won't kill from electrocution, but will kill an elephant if it gets trapped into a string of pulses.

Seen full sized bulls killed by these things. Don't know how long it takes... may only be minutes..... never never use barbed wire near the live wires, and it is illegal here to liven up barbed wires directly... for that reason.

 I use 50uf motor run caps for this also


...............oztules
Flinders Island...... Australia

Offline lighthunter

  • Full Member
  • ***
  • Posts: 164
  • Karma: +8/-0
Re: Electric Fence Zapper
« Reply #293 on: May 23, 2016, 03:39:19 PM »
Wow, thats deep :) I guess i didnt look at ckt enough to notice details of design you speak about. Obviously they have expanded on the design since ive had one open. Used to be just a Diode, capacitor, ujt and scr, transformer, that was it. Your comments make me think about my old man grabbing spark plug wires with engine running to check/diagnose ignition ::)

Thanks much for explaining all that. I had no idea of some of the concepts and reasons.
Regards, LH
LH

Offline oztules

  • Forum Advisors
  • Hero Member
  • ****
  • Posts: 1066
  • Karma: +89/-5
  • Village idiot
Re: Electric Fence Zapper
« Reply #294 on: May 23, 2016, 04:38:45 PM »
"Your comments make me think about my old man grabbing spark plug wires with engine running to check/diagnose ignition ::)"

The ignition coil spark system is a totally different animal, very low power, high voltage..... as the impedance of the secondary is very high ( thousands of turns of hair thick wire). In the above system, the transformer may have only a dozen or more turns of 1.8mm wire on the primary, and maybe 250 turns of 1mm wire on the secondary.... and is capable of 10000v@40amps.... multiply that out...it is a massive amount of power... there is your 100 mile fencer.

Ignition has different transformer, and no storage.. so the watts can only be the  e^2/R of the primary  so very high voltage at very low current.. eg a 2R primary would give 72watts....probably near the 20-30000v.. so current is ma... not amps.

Your ole man would not relish hanging onto a 200000watt ignition lead more than once...

"Used to be just a Diode, capacitor, ujt and scr, transformer, that was it.".... still is really... but now you can see how it works,

Although usually we use a doubler to get the 240v up to 600vdc.... then dump that into the primary. I use a diac instead of ujt , and a few resistors and cap to time the voltage rise into the storage cap..... when it hits say 550v, diac triggers... etc.


................oztules
Flinders Island...... Australia

Offline winger

  • Newbie
  • *
  • Posts: 4
  • Karma: +0/-0
Re: Electric Fence Zapper
« Reply #295 on: January 25, 2017, 02:58:36 PM »
Hi,
I want to build this kind of energizer, so I decided to do it step by step, so first I made voltage doubler and after it I made triac trigger circuit but before wind transformer I wanted to test circuit with 500 ohm 20w resisstor. Problem is that circuit do only one trigger pulse. Thats means, that my neon lamp lights down and  after lights up only when I turn off/on supply voltage (triacs trigger only one time). I guess it working like this because of triacs don't closing. I want to know if it is because I don't use real transformer or there is other reasons. This circuit what i made:

Offline oztules

  • Forum Advisors
  • Hero Member
  • ****
  • Posts: 1066
  • Karma: +89/-5
  • Village idiot
Re: Electric Fence Zapper
« Reply #296 on: January 26, 2017, 03:27:08 AM »
I think the 500r resistor is to blame. Your not turning off the triacs/scr. They are staying turned on.

Use maybe 40 turns of 1mm wire in a 3/4inch diameter coil to limit the current instead.

.......oztules
Flinders Island...... Australia

Offline winger

  • Newbie
  • *
  • Posts: 4
  • Karma: +0/-0
Re: Electric Fence Zapper
« Reply #297 on: January 26, 2017, 06:52:02 AM »
Thanks, I will tray

Offline winger

  • Newbie
  • *
  • Posts: 4
  • Karma: +0/-0
Re: Electric Fence Zapper
« Reply #298 on: April 24, 2017, 01:49:07 PM »
Hello,

I finished my 220 volt version energizer. For testing I only have fence voltage tester with, I think, neon lamps. The higher lamp is rated as 6000 volts. So if I test fence near to it connection to energizer, then all tester neon lamps is burning bright, so there is at least 6000 volts, but after approximately 500 meters, neon lamps burns only till 4000 volts ratting. I thinks problem is with fence earthening. For now I have three one meter long spikes which is placed three meters apart from each other. Maybe someone can tell how to make correct earhtening for this kind of fence. Thanks.
   

Offline David HK

  • Full Member
  • ***
  • Posts: 222
  • Karma: +20/-0
  • No Personal Text Set by User
Re: Electric Fence Zapper
« Reply #299 on: May 04, 2017, 08:40:09 PM »
I'm giving away various electronics and in this forum note I want to give away my build of the Oztules electric fence main circuit unit. Its so long since I played with it that I have no idea if it still works.

Anyway its first come first served, just PM me your name and address and I will pop it into the air mail complete with photographs circuit drawings etc.

You will have to sort out the power supply and the transformer. If it does not work bin it!



David