Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
Poor mans electric fence
1,302 views
Skip to first unread message
captainvi...@gmail.com
Jun 14, 2014, 8:51:20 AM6/14/14
to
MY friend would like me to help him build a cheap electric fence. I found lots of designs, and of course we could go solid state but the simplicity of this one really intrigues me.
I showed him the schematic and he questioned if the repeated opening and closing of the flasher points used in this application would quickly burn them out. I was thinking that in spite of the inductive component, the load of the coil would be much less than the load imposed by a lighting circuit. So I thought that combined with the correct capacitor and perhaps the addition of a small snubber circuit (a small resistor in series with the capacitor) would cut down on the sparking. Perhaps I'm way off base here. Does anyone have any opinions on this or has anyone ever done this? This uses a standard automotive ignition coil. Thanks, Lenny
https://www.google.com/search?q=homemade+electric+fence&client=firefox-a&hs=bl7&rls=org.mozilla:en-US:official&channel=sb&tbm=isch&imgil=yOopc2yqK2ynXM%253A%253Bhttps%253A%252F%252Fencrypted-tbn1.gstatic.com%252Fimages%253Fq%253Dtbn%253AANd9GcQRzvxMQITZqe7WEHdEp8RCnjTVnMaxq2Z664uOe7qoQjmgxt6oSQ%253B822%253B691%253B8wWIWeBAQcjb1M%253Bhttp%25253A%25252F%25252Fgardengalbevy.com%25252F2013%25252F01%25252F22%25252Fbasics-of-electric-fencing-informed-farmers%25252F&source=iu&usg=__p0OD-YliP1vRDusfJpFUaLuPLUw%3D&sa=X&ei=2u-aU-iLCZPOsATT4oDQBA&ved=0CCcQ9QEwAw&biw=1024&bih=615#facrc=_&imgdii=_&imgrc=yOopc2yqK2ynXM%253A%3B8wWIWeBAQcjb1M%3Bhttp%253A%252F%252Fgardengalbevy.files.wordpress.com%252F2013%252F01%252Felectric-fence.jpg%3Bhttp%253A%252F%252Fgardengalbevy.com%252F2013%252F01%252F22%252Fbasics-of-electric-fencing-informed-farmers%252F%3B822%3B691
I showed him the schematic and he questioned if the repeated opening and closing of the flasher points used in this application would quickly burn them out. I was thinking that in spite of the inductive component, the load of the coil would be much less than the load imposed by a lighting circuit. So I thought that combined with the correct capacitor and perhaps the addition of a small snubber circuit (a small resistor in series with the capacitor) would cut down on the sparking. Perhaps I'm way off base here. Does anyone have any opinions on this or has anyone ever done this? This uses a standard automotive ignition coil. Thanks, Lenny
https://www.google.com/search?q=homemade+electric+fence&client=firefox-a&hs=bl7&rls=org.mozilla:en-US:official&channel=sb&tbm=isch&imgil=yOopc2yqK2ynXM%253A%253Bhttps%253A%252F%252Fencrypted-tbn1.gstatic.com%252Fimages%253Fq%253Dtbn%253AANd9GcQRzvxMQITZqe7WEHdEp8RCnjTVnMaxq2Z664uOe7qoQjmgxt6oSQ%253B822%253B691%253B8wWIWeBAQcjb1M%253Bhttp%25253A%25252F%25252Fgardengalbevy.com%25252F2013%25252F01%25252F22%25252Fbasics-of-electric-fencing-informed-farmers%25252F&source=iu&usg=__p0OD-YliP1vRDusfJpFUaLuPLUw%3D&sa=X&ei=2u-aU-iLCZPOsATT4oDQBA&ved=0CCcQ9QEwAw&biw=1024&bih=615#facrc=_&imgdii=_&imgrc=yOopc2yqK2ynXM%253A%3B8wWIWeBAQcjb1M%3Bhttp%253A%252F%252Fgardengalbevy.files.wordpress.com%252F2013%252F01%252Felectric-fence.jpg%3Bhttp%253A%252F%252Fgardengalbevy.com%252F2013%252F01%252F22%252Fbasics-of-electric-fencing-informed-farmers%252F%3B822%3B691
dave
Jun 14, 2014, 9:26:41 AM6/14/14
to
interference.
Jeff Liebermann
Jun 14, 2014, 12:44:52 PM6/14/14
to
On Sat, 14 Jun 2014 05:51:20 -0700 (PDT), captainvi...@gmail.com
wrote:
>MY friend would like me to help him build a cheap electric fence.
Please make an effort to reduce the amount of EMI/RFI to tolerable
limits.
I like the title "poor mans electric fence". Yeah, I suspect you'll
probably become poor after the doctors treat you for electric shock.
Please remember that you have but one life to give for your
profession.
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
wrote:
>MY friend would like me to help him build a cheap electric fence.
limits.
I like the title "poor mans electric fence". Yeah, I suspect you'll
probably become poor after the doctors treat you for electric shock.
Please remember that you have but one life to give for your
profession.
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
John Robertson
Jun 14, 2014, 12:47:29 PM6/14/14
to
broadcasting without a licence, along with your local HAM radio folks,
Civil and Military Aviation folks, possibly National Guard and anyone
else (neighbours with pitchforks and burning torches) who your broadband
long wave RF noise generator annoys...
Look up "Spark Gap Transmitter Interference" on your favourite search
engine.
http://radiohax.wikispaces.com/Spark+gap+transmitter
John ;-#)#
--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
captainvi...@gmail.com
Jun 14, 2014, 6:43:35 PM6/14/14
to
David Platt
Jun 15, 2014, 12:26:05 AM6/15/14
to
In article <92bfba9b-9702-43cc...@googlegroups.com>,
I looked at a few of the schematics out there on the net, and a lot of
them seem to use a low-voltage astable multivibrator (e.g. a 555) to
trigger a triac, which dumps a pulse of chrarge from a capacitor
(e.g. a couple of hundred volts) into the primary of a step-up
coil. The coil then drives the fence wire.
This approach would (I think) result in the rising and falling edges
of the current pulse into the primary not being incredibly fast... the
rising edge would be limited by the coil inductance, and the falling
edge would result from the stored-up charge in the cap damping down -
there's be some ringing to the latter, but not the sharp edges you'd
see from a spark gap. Hence, a lower bandwidth and less (or no) RF
interference.
Commercial cow fences usually seem to pulse once a second or so - it's
not a constant buzz. It's enough to displease the cows (and probably
deer as well), but it's not continuous enough to risk that somebody
will grab the wire and find themselves unable to let go (which would
be a real risk if you just let a vibrator drive a coil and keep the
wire energized all of the time).
People *do* get in trouble with the FCC over electric-fence
chargers, if the chargers are badly designed and do result in RFI.
The fines for failing to correct such sources of interference can be
quite stiff.
<captainvi...@gmail.com> wrote:
>> If you do you will be in violation of several laws regarding harmful
>> interference.
>Well then I imagine that every rancher with an electric fence must be
>repeating Marconi's experiment as well. And what about the computers in
>the area that break the squelch on my low band radio in my truck as I
>drive past the same houses. And not to mention those infernal speed
>controlers and light dimmers that raise hell with AM radio. MJy friend
>is just trying to keep coons out of his garden. How do these guys get
>away withit. Lenny
They don't use a spark-based generator.
>> If you do you will be in violation of several laws regarding harmful
>> interference.
>Well then I imagine that every rancher with an electric fence must be
>repeating Marconi's experiment as well. And what about the computers in
>the area that break the squelch on my low band radio in my truck as I
>drive past the same houses. And not to mention those infernal speed
>controlers and light dimmers that raise hell with AM radio. MJy friend
>is just trying to keep coons out of his garden. How do these guys get
>away withit. Lenny
I looked at a few of the schematics out there on the net, and a lot of
them seem to use a low-voltage astable multivibrator (e.g. a 555) to
trigger a triac, which dumps a pulse of chrarge from a capacitor
(e.g. a couple of hundred volts) into the primary of a step-up
coil. The coil then drives the fence wire.
This approach would (I think) result in the rising and falling edges
of the current pulse into the primary not being incredibly fast... the
rising edge would be limited by the coil inductance, and the falling
edge would result from the stored-up charge in the cap damping down -
there's be some ringing to the latter, but not the sharp edges you'd
see from a spark gap. Hence, a lower bandwidth and less (or no) RF
interference.
Commercial cow fences usually seem to pulse once a second or so - it's
not a constant buzz. It's enough to displease the cows (and probably
deer as well), but it's not continuous enough to risk that somebody
will grab the wire and find themselves unable to let go (which would
be a real risk if you just let a vibrator drive a coil and keep the
wire energized all of the time).
People *do* get in trouble with the FCC over electric-fence
chargers, if the chargers are badly designed and do result in RFI.
The fines for failing to correct such sources of interference can be
quite stiff.
mike
Jun 15, 2014, 2:47:29 AM6/15/14
to
less 20 or 25% coupon.
Older I get, the more I shy away from "helping" someone do something
that may cause someone to "claim" they were harmed.
Just not worth all the legal hassles you can get into.
Paul Drahn
Jun 15, 2014, 11:12:57 AM6/15/14
to
On 6/14/2014 11:47 PM, mike wrote:
>>
>>
> Harbor Freight will sell you a solar powered fence charger for $66
> less 20 or 25% coupon.
> Older I get, the more I shy away from "helping" someone do something
> that may cause someone to "claim" they were harmed.
> Just not worth all the legal hassles you can get into.
I thought one of the HF chargers would be just the thing for a deer
>>
>>
> Harbor Freight will sell you a solar powered fence charger for $66
> less 20 or 25% coupon.
> Older I get, the more I shy away from "helping" someone do something
> that may cause someone to "claim" they were harmed.
> Just not worth all the legal hassles you can get into.
fence around the garden. Worked great till winter came. Then the amount
of daylight was not enough to recharge the battery for all night use and
eventually the whole thing became useless.
Just the solar charger and battery now work great to power the trail
camera for long term use. Disconnected the charger portion.
Paul
Maynard A. Philbrook Jr.
Jun 15, 2014, 7:15:44 PM6/15/14
to
In article <d0a77766-85c3-48c1...@googlegroups.com>,
captainvi...@gmail.com says...
Use a pulsed DC to charge the cap at a high rate so they'll be
a gap in the supply to the cap. Use a timer to trigger the
scr which shorts this cap to ground.
The pulse being in the DC to charge it up has a void of no current in
the off duty part of the pulse (Diode) and allows the SCR to turn off so
the cycle can repeat itself.
if you're doing all of this from low voltage you can use a 556 timer,
this would be the DUAL version. One timer is used as a pulse generator
to charge the cap while the other would be the long duration
pulse to supply a very short duty pulse with long off time.
Some designs use the falling edge of the charging pulse to charge up
a cap on for the trigger pulse to the scr so that it's asynchronous and
that circuit will discharge that cap for the next whack on the cattle's
body!
Have fun.
Jamie
captainvi...@gmail.com says...
>
> MY friend would like me to help him build a cheap electric fence. I found lots of designs, and of course we could go solid state but the simplicity of this one really intrigues me.
> I showed him the schematic and he questioned if the repeated opening and closing of the flasher points used in this application would quickly burn them out. I was thinking that in spite of the inductive component, the load of the coil would be much less than the load imposed by a lighting circuit. So I thought that combined with the correct capacitor and perhaps the addition of a small snubber circuit (a small resistor in series with the capacitor) would cut down on the
sparking. Perhaps I'm way off base here. Does anyone have any opinions on this or has anyone ever done this? This uses a standard automotive ignition coil. Thanks, Lenny
Make a capacitor discharge into a car coil via an scr.
> MY friend would like me to help him build a cheap electric fence. I found lots of designs, and of course we could go solid state but the simplicity of this one really intrigues me.
> I showed him the schematic and he questioned if the repeated opening and closing of the flasher points used in this application would quickly burn them out. I was thinking that in spite of the inductive component, the load of the coil would be much less than the load imposed by a lighting circuit. So I thought that combined with the correct capacitor and perhaps the addition of a small snubber circuit (a small resistor in series with the capacitor) would cut down on the
sparking. Perhaps I'm way off base here. Does anyone have any opinions on this or has anyone ever done this? This uses a standard automotive ignition coil. Thanks, Lenny
Use a pulsed DC to charge the cap at a high rate so they'll be
a gap in the supply to the cap. Use a timer to trigger the
scr which shorts this cap to ground.
The pulse being in the DC to charge it up has a void of no current in
the off duty part of the pulse (Diode) and allows the SCR to turn off so
the cycle can repeat itself.
if you're doing all of this from low voltage you can use a 556 timer,
this would be the DUAL version. One timer is used as a pulse generator
to charge the cap while the other would be the long duration
pulse to supply a very short duty pulse with long off time.
Some designs use the falling edge of the charging pulse to charge up
a cap on for the trigger pulse to the scr so that it's asynchronous and
that circuit will discharge that cap for the next whack on the cattle's
body!
Have fun.
Jamie
Dave M
Jun 15, 2014, 8:47:19 PM6/15/14
to
layouts:
http://chemelec.com/Projects/Fencer-1/Fencer-1.htm
http://chemelec.com/Projects/Fencer-2/Fencer-2.htm
Dave M
dave
Jun 16, 2014, 11:12:22 AM6/16/14
to
days? There are tiny flybacks on each sparkplug wire. Run by computers,
not distributors. More efficient. Babbling.
captainvi...@gmail.com
Jun 16, 2014, 5:23:29 PM6/16/14
to
captainvi...@gmail.com
Jun 17, 2014, 12:45:23 PM6/17/14
to
On Saturday, June 14, 2014 8:51:20 AM UTC-4, captainvi...@gmail.com wrote:
Lenny
Paul Drahn
Jun 17, 2014, 1:03:16 PM6/17/14
to
automotive turn signal interrupter. They were exposed on the front of
the box so they could be replaced.
The most reliable fence charger was one that came with the 132 acre
Dairy farm Dad purchased in 1957. It had a motor that rocked a mercury
switch back and forth to supply power to a transformer that energized
the fence. You could build a similar unit.
Paul
captainvi...@gmail.com
Jun 17, 2014, 1:40:49 PM6/17/14
to
On Saturday, June 14, 2014 8:51:20 AM UTC-4, captainvi...@gmail.com wrote:
Phoena J.
Jul 9, 2014, 10:23:47 AM7/9/14
to
On 06/14/2014 04:44 PM, Jeff Liebermann wrote:
>
> I like the title "poor mans electric fence". Yeah, I suspect you'll
> probably become poor after the doctors treat you for electric shock.
Yeah, especially if they are Jewish doctors.
>
> I like the title "poor mans electric fence". Yeah, I suspect you'll
> probably become poor after the doctors treat you for electric shock.
> Please remember that you have but one life to give for your
> profession.
>
raghead country fighting another imperialistic war for US/Israel.
0 new messages