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Mini Electric Horse Fence, or Micro-Taser?

  1. Jul 27, 2017 #1
    So.... I use automatic feeders to provide the deer with a steady supply of food, which helps keep them in the area. The problem is, that the raccoons have also discovered my feeders, and are doing a great deal of damage to them, trying to get the corn out faster than the pre-programmed rate I have the feeders set for. One feeder is now inoperable, and will cost nearly half it's original purchase price to repair.

    Let me be clear - I like Raccoons. As omnivores, I feel they serve an important function in the local ecology, and I don't want to hurt them. Alas, however, they are crafty, greedy by nature, and also destructive. I just want to teach them to leave my feeder alone. There's plenty spilled on the ground they can have, without trashing hundreds of dollars of equipment.

    There is something called a "Varmint Buster" on the market, which operates like an electric fence, or shock collar, but is the size of a deck of playing cards, and intended to protect only the vital workings on the feeder. If I understand correctly, it delivers a momentary shock, then resets. Unfortunately, it is proprietary, and no such device is available for the brand of feeders I own.

    I have dabbled in circuit design in the past, but that was all 12 volt, automotive applications. The Varmint Buster boasts a 2000 volt charge, and I THINK it is AC current, but I can not find information to verify that. It's power source IS a 6 volt DC battery. The biggest problem for me is that it does NOT say what amperage the device puts out, on any webpage I have found, so I am lacking some critical design specs. In fact, while every website selling them shows the control-pack, and 4 wires sticking out of it, I can not even find an example of it in use.

    Now, I am pretty sure that I could figure out how to design a workable 6 volt, solar recharged system, if only I had some clue what amperage I needed to target. After several hours of researching this product, dog collars, and electric fences, I am simply not finding any answers to my questions.

    So my main question is, "Does anyone know from experience or calculation how many amps, and/or which type of output current (AC vs. DC) I should be incorporating into the design?" Keep in mind that I want to surprise the Raccoons with a little sting, but not do any lasting harm.

    On the other hand, I'm probably not the first guy to consider a DIY project like this. Does anyone have a favorite website that might offer ready-made plans, that I could adopt, or modify to suit my purposes? If I don't have to reinvent the wheel, that would be just fine with me - I will get plenty of satisfaction from wiring and soldering it together from loose pieces.

    Here is something I found on Youtube, that serves a similar purpose, to keep squirrels out of bird feeders...It's kinda funny...

    Finally, please forgive me if I have used incorrect terminologies. I am entirely self-taught, and have not had any formal education in electronics. I understand the basics, and can learn what I need to accomplish a goal. Feel free to correct my errors, however. If I intend to play in your sandbox, I might just as well learn the language.

    Thank you for your patience.

    P.S. - anyone know the amperage on an electric flyswatter like the ones sold at Harbor Freight?
    Last edited: Jul 27, 2017
  2. jcsd
  3. Jul 27, 2017 #2


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    I'm not clear on what you want to do. Do you want to build some high voltage varmint shocker from scratch? With your limited experience with high voltage, that doesn't sound like a good project for you just yet. Or are you wanting to build a kit from the Internet and adapt it to your feeder somehow?

    Also, could you post some pictures of your feeder(s), and show the damage you would like to avoid by using this zapper? Thanks.
  4. Jul 27, 2017 #3
    Fair enough, I appreciate the straight talk. Let me say that I am capable of learning how to build something like this, based on what I have seen on the internet, today. Let me also say that I NEVER go off half-cocked,, and I NEVER start a project like this until I am convinced I have a sound design, and have had it reviewed by people who are experienced enough to show me where I might fall short of safety, or success - that's you guys, I hope. I'm not a kid, I'm a grandfather (almost, anyway...), and while I may not have the formal education, I have always been a well-abled tinkerer

    Simply put, I am open to all possible suggestions that involve giving them a harmless electrical jolt, to teach them to look elsewhere. I have seen hacks that involve taking apart disposal cameras, building a shocker from half a dozen electronic components, and someone even suggested I hack an electronic fly-swatter from Harbor Freight. As I am in the earliest stages, all ideas are on the table. My research into this subject indicates that there is no other practical solution, than high voltage, low amperage electrical shocks. Again, I don't want to do any permanent damage, I just want to condition a negative response in them. I just want them to leave my feeder alone.

    I didn't think to take pictures of the damage when I was there earlier this week. However, I think by looking at the general design of the feeder, and by reading my description of the damage, you can get a clear picture of what I am dealing with.

    The feeders I have can be seen at http://www.cabelas.com/product/MOUL...e.cmd?categoryId=734095080&CQ_search=moultrie If you use the zoom feature, it is very easy to see the point of interface between the funnel and the spinner plate.

    There is more to my setup than shown in that link (namely a solar panel to recharge the battery), but it does show the area of the critical parts that are being damaged, though not in great detail...for that, I will do my best to describe clearly.

    Please pardon the lengthy description...

    Hanging below the main barrel is an object about the size and shape of a one-gallon bucket. That is the housing for the spinner, motor, electronics that control the spinner and photo-voltaic timer, and the 6 volt rechargeable battery. Half an inch above the clear plastic spinner, attached to the bottom of the barrel, is a funnel with an opening of about 1-1/2 inches, that feeds corn onto the spinner plate, which was originally about 4" in diameter. When the spinner stops, the corn piles up, and stops flowing, as it is gravity fed.

    Now the annoying part. The Raccoons have managed to eat through a substantial portion of the funnel, so that the corn no longer stops flowing when the spinner stops. There is now a 75# pile of corn below the feeder. They have also eaten the plastic spinner to the point where there is only about half of the formerly round, but now oblong spinner plate remaining. Furthermore, they have (nearly) eaten away at the strap that allows the spinning housing to attach to the barrel, as well as made inroads on several portions of the barrel's lid.

    The spinner and funnel can be replaced ($20.00), but the strap can not be. I want to deny them access to the interface between the spinner housing and the barrel, as, even after I replace the spinner and funnel with metal parts, they would still be able to use those nimble hands to spill corn off the plate, for as long as they had a mind to hang there, and do so.

    What I have in mind is a chicken-wire (1" holes) cage around the area, connected to the ground side of the shock device, and wrapping a positive lead wire around the parts of the plastic housing closest to the spinner and funnel, so they can be gently (though perhaps rudely) persuaded to look elsewhere for a meal. I intend to use the battery and solar panel that are already there to power the electronics.

    Thank you for taking an interest.
  5. Jul 27, 2017 #4


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    For a temporary fix, smear the endangered parts with hot sauce from the grocery store; the strongest you can find. Reapply after a rain. The "strap" you refer to doesn't show in the available photos. Awaiting further details.
  6. Jul 27, 2017 #5
    It is posible to limit the current using a string of resistors. But the intensity of the current to use may depend on the size, the skin, if dry or wet etc....
    Best use AC.
  7. Jul 28, 2017 #6


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    I have seen a home made shocker based on a 12v battery, a small 12v DC motor and a 240/12 or 240/6 transformer used backwards. However I can't comment on the safety or danger of such a device.
  8. Jul 28, 2017 #7
    I did consider that option, but I'm pretty sure the deer would experience the same physical result that the raccoons would from the hot sauce, and I have no reason to think they are not getting "friendly" with the feeders - they are smart creatures, and no doubt understand the source of the corn. I don't want to risk them having any negative experience at the feeder, lest they not come back. (Someone else swears by super-thick axle grease all over the feeder - imagine the mess?) Besides that, the feeders are 30 minutes away, and a special trip each time it rains isn't practical.

    Anyway, the damaged feeder is completely out of commission, and the other feeder is, so far, unaffected, probably due to being an 1/8 of a mile away, on a high hill.

    The strap (or maybe bracket is more accurate?) isn't really a concern for the sake of the discussion, as it is at the top of the spinner body, making the actual connection to the barrel. (It slips over a collar on the bottom of the barrel, and you twist the entire spinner body to lock it on.) Any "cage" that I put around the spinner body will, by physical limitations determined by simplicity and the construction of the feeder (mainly distance of legs to spinner body,), be inside of the enclosure.

    I may be out there Sunday - If so, I'll try to remember to get a picture of the damage.

    In the meantime, here is a listing of the spinner body replacement part, including picture. The "strap" is the highest part, with the notches in it, designed to twist lock onto a collar on the barrel.

    You may have noticed that there is a black circular fin completely surrounding the clear plastic spinner plate. That fin is the main object I intend to wrap with the positive lead of the shocker. Use the zoom feature, for a very close look.

    The DIY shockers I have found online are all DC. I assume that using circuitry to make a sine wave is how the battery operated version will work. That's a little over my head, though. For instance, the video I linked in the OP was a modified disposable camera, where the battery was replaced by what I call a "wall wart", or AC/DC adapter, plugged into 110AC.

    The ones I have seen any specs about, list 10-20,000 volts. However, I can not find a spec that says what the (micro?) amperage is, on any of them. I assume this is for liability purposes, but what do I now?

    I would be using the on board 6 volt rechargeable lantern battery, instead of mains power. (I know that does not make it "safe", but it does make it a little safer, right?) If I design this as intended, the shock will be delivered to the raccoons' fingers at or near the spinner plate, and will travel to ground, somewhere between elbow and shoulder of the little bandit. That's maybe 2 pounds of meat fur and bones, probably less.

    Doesn't high voltage have a tendency to arc, thereby making the relative moisture on the critter less of an issue?

    Then again, maybe I could simplify this whole thought process...

    Say I were designing a gag zapper, that had 2 leads coming out of a plastic project box, and I wanted it to be unpleasant, but non-lethal, drawing power from a 6 volt battery...

    The difference is that I will be connecting the ground lead to a cage around the spinner body, and wrapping the positive lead wire around the plastic parts that the raccoons are almost certainly going to touch, while reaching through the cage, to get at the corn that lays on the spinner.

    Their arms become the switch in the circuit.

    I probably should have described it that way in the first place, but the actual design of the "trap", as it were, was not yet clear in my mind, when I started this post.

    Thanks Everyone!
  9. Jul 30, 2017 #8
    I think what I had in mind, and what folks think I mean, are two different things. I've been watching youtube videos of squirrel zappers made from disposable cameras, and tazers made from electric fly swatters. These look pretty simple, but I am not savvy enough to know if they are real, or, if they ARE real, whether or not they are safe to build/use.

    I've seen a self contained voltage step-up on ebay for 8 bucks for two pieces that claims to take a 6 volt battery to 400,000 volts. (But I have seen reviews that claim it's more like 15 or 20,000.) That looks pretty simple, if I want a steady charge on the line, which will drain the battery fast. I'm assuming a clock chip would allow 150 to 200 milliseconds per second, and still get the message across....but I'd need help figuring that out.

    I just want something that gives them a poke when they get their fingers where they don't belong, and I want the electronics to last longer than I would expect a disposable camera's circuits to. It's becoming clear to me that either this is a lot more complicated than I expected, or I don't know how to ask the question in such a way that I get a simple answer.

    More ideas and thoughts would be appreciated.
  10. Jul 30, 2017 #9
  11. Jul 30, 2017 #10
    Time out. Safety first.

    Commercial electric fences have safety features that are being ignored here. An essential one of those is that they turn off for a short period of time about every second. That allows a person who might get 'stuck' gripping the 'hot' lead, with their muscles contracted by the current, to let go.

    I don't think you can predict and design for a safe voltage for humans, that will also deter a furry (insulator) animal under all conditions(wet and dry) .

    There are probably others. Buy a commercial, approved unit that can be used with a solar panel and battery.
  12. Jul 30, 2017 #11


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    The one I saw had a battery, small DC motor and the low voltage winding of a transformer in series. The commutator of the motor did an acceptable job of producing AC which was amplified by the transformer. Perhaps not very efficient (or safe) but simple.
  13. Jul 30, 2017 #12
    I bet the 2N3055 will die soon in this circuit. There's nothing limiting the collector emiter voltage when the transistor is switched off.
    Apart of that, the circuit are all time dischanging the battery except when it sparks.
  14. Jul 30, 2017 #13


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  15. Jul 30, 2017 #14


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    On a totally different track, you need a way of discriminating between Deer and Raccoons and to exploit that difference. Deer are much heavier than raccoons so why not have a system that requires a massive animal to stand on a plate before any food becomes available. A sort of weight operated shutter. This would be separate from the dispenser, which could be in a steel enclosure, tipping the rations into the feeder below. A raccoon would not be heavy enough to raise the shutter.
    I guess it would rely on the deer being smart enough to learn how to use the system initially but animals are smart enough where food is involved.
  16. Jul 30, 2017 #15
    If I could find something that meets all of the requirements that I have enumerated above, we wouldn't even be having this discussion.
    I agree - "Safety First". As a rank amateur, that's one of the most important reasons that I'm here, asking questions.

    Not safe? - nevermind.
    But thanks for playing!

    Yeah, that would be a problem - a 6 volt lantern battery has a very low aH rating.

    LOL!!! - except my house is many, many miles from where the deer are.... but I like the way you think!

    Unfortunately, the system has to be tiny, in order to be lightweight, portable, and easy to set up. Also, the feeder needs to work at specific times, regardless of which critters are there, or aren't there, big or small. The idea is to train them to come at specific times of the day.

    Besides, raccoons are smart enough (way smarter than deer, IMO), I would expect them to show up in large numbers, to trip the shutter, long before the deer even noticed the opportunity - LOL!!!

    OK, back to the search for something safe, small, 6 volt DC, and simple enough that I can follow the schematic, and solder it together, myself.
    Last edited: Jul 30, 2017
  17. Jul 31, 2017 #16


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    Lol... I almost posted that very same thought...[COLOR=#black].[/COLOR] :cool:
    I like the way you think, also.
    Last edited: Jul 31, 2017
  18. Jul 31, 2017 #17


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    With a few modifications, that basic circuit looks pretty good. Since it uses an ignition coil driven at 700Hz, it is designed to put out a continuous few thousand volts. Try these changes to make it a fence charger:

    C2 10uF (+ side to U1-7, -side to Gnd)
    R1 150K
    R2 510Ω
    T1 12.6V filament transformer, preferably Center Tapped (low current is fine, use what you can get & fit in the space)

    This will give a short pulse about every second, plenty of time to let go if needed.
    Initially, use the full 12.6V winding on the transformer. this will make the output pulse somewhere around 75V.

    The Energy in the pulse is controlled directly by R2. Bigger R2, more energy in the output pulse, up to the transformer limit. Probably best to keep it as low as practical so you don't damage the critters too badly.

    If 75V output is insufficient, use the transformer Center Tap and one winding end for about 150V output.

    If you need still more voltage to get thru the fur, use a 6.3V center tapped transformer, full winding for 150V or center tap and one end for 300V output.

    Whatever electrifying method you use, put up a few warning signs to warn people about it!

    On another note, looking at the feeder website, some models have steel wire wrapped around the dispense mechanism as a guard. Could you add this to your model? (Probably stainless steel.)

    A combination of shocking and a barrier may be better than either one alone. Try wrapping two spirals of wire around the dispenser with one connected to each output of the charger. With close spacing, a shocking experience is guaranteed.
  19. Jul 31, 2017 #18
    I think anyone who has had even very small amounts of contact with raccoons KNOWS what little stinkers they are.
    It has to be that pesky opposable thumb, right?

    Mice and rats are a pain, but easily terminated. :oldruck:

    Squirrels are a minor annoyance, and not so easily dissuaded from bird feeders, and attics. :doh:

    Cats and dogs learn fast to stay away, and respect the "superiority" of humans. :sorry:

    Raccoons OWN this planet, and unless you are willing to get downright ornery, you will never convince them otherwise.
    By way of example, I offer electro-shock therapy.:oldsurprised:
    Last edited: Jul 31, 2017
  20. Jul 31, 2017 #19
    I'll have to absorb your technical suggestions, when I am more awake. Thank you for offering them.

    However, your astute observation about the wrappings on those spinners is spot on. In fact, the reason I have to make the device so small, is so it can fit inside the housing. I had been thinking about a chicken wire grounding cage, but the more I look at it, the more I think I may be doing something like the lacing of ground and hot wires, as seen on some of the other brands. They sell a metal cage that fits around this one - I may buy it, and use it as the ground, still lacing a SS hot wire around the plastic parts of the spinner. An adult person would have a hard time getting their hand into the cage deep enough to get a shock, but the raccoons would still be in for a surprise.

    Warning signs?...hmmm. The feeders are on private property. They are well away from the house, and the couple that live there are very well aware of what I am up to. On the rare occasion that they have guests, it is even rarer that they would entertain them more than 50 feet from the house. The feeder is almost a 1/2 mile away, and surrounded by farm fields - nary a neighbor in sight. I think it's safe to say that if someone did put their hands inside the cage, and manage to get a shock, they would be trespassing, and deserve what they got. However, as I have the attention span of a brain damaged gnat in the morning, before I get my coffee, maybe I'll put them signs up, anyways - LOL!!!

    Whatever the final design is, it will have a switch that is easily seen, but not easy operated (like a real stiff toggle), and, in addition, I will be making it a habit to discharge (direct short) any residual charge, before servicing the spinner.

  21. Jul 31, 2017 #20


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    :check: ... Yup, every thing you just said in post #18 ...
  22. Jul 31, 2017 #21


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    Did you ever consider face recognition??? :biggrin:
    Enough money could get you a bomb proof solution. You could even automatically terminate the little devils!
  23. Jul 31, 2017 #22
    1. The all look alike to me. (*wink*)
    2. Depends on the bomb in question, and the budget allocated... But I think the land-owners might object...
    3. Terminating them's easy - .22 rifle with a night scope and a cooler full of road-pops.... 'cept I like the furry little bandits.

    I am certain that re-education through periodic shock-treatment is in everyone's best interest. :wink:
  24. Jul 31, 2017 #23
    300 V? According to the sources I found, they are talking about 3,000 - 5,000 volts minimum for pets/pests/predators. As I mentioned before, gotta get through that fur on a dry day. Raccoons have a pretty thick coat.

    CATTLE 4,000 To 5,000
    PREDATORS 5,000 +
    PETS 3000 +
    GARDEN PESTS 4,000+

  25. Jul 31, 2017 #24
    Good information, thanks for the link!
  26. Jul 31, 2017 #25


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    I agree. Kilovolts are needed to get thru the fur. I also agree that I didn't make that point in my previous post.o:) Thanks for the clarification!

    Anyhow, that's why the suggestion for two spirals of closely spaced wires, so that when the critters reach thru they are forced into contact with the wires; perhaps not upon insertion but definitely on withdrawal when the fur is stroked the wrong way. For a human, once there is skin contact 50V is annoying to lethal and 90V is downright uncomfortable.

    Probably either approach will work. It comes down to how much energy you can get into the flesh.
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