How to keep raccoons away

[bill]

In article , [e-mail] says... <

[Jim Black]

Somehow I doubt it's the brevity that makes static electricity harmless. I've played around with battery-powered circuits that work by delivering pulses of electricity to the subject when the current through a circuit containing an inductor is interrupted (for example, the gag lighters that shock people work this way). Whatever current is flowing through the inductor gets sent through the subject for a short period of time. It's relatively safe because the peak amperage is controlled. If you hook up a resistor in series with the subject, the maximum current doesn't change, but the pulses get shorter. When you do this, the pain falls off, but the response from your muscles doesn't change as much. Eventually, especially if the contact area between the electrodes and the skin is large, you can produce involuntary muscle contractions with little or no pain.

Given that the heart is a muscle, I would think that a few seconds of current would be better than a few milliseconds if the goal was to produce pain without rendering any permanent harm. I could be wrong, but if I had to guess, I'd say the reason static electricity isn't harmful is because most of the voltage is across the air gap, not across your body. Also, the charge is entirely on your skin, and most is probably very close to the spot where you're about to touch something, so practically no current is going through your heart.

Surely it couldn't be very difficult to have a device of some sort in the circuit to control the maximum current. At the very least, couldn't he just put an appropriate fuse in the circuit, if there wasn't one already?

There's almost one order of magnitude between the current needed to cause pain and the current that's large enough to be dangerous. The fact that the area of contact with the wire is small, and a three-year old is larger than a racoon, ought to make the range of safety even broader.

[Advanced Priority]

Who said static electricity is harmless? Lightning is static electricity, but I don't see many people standing outside in a thunderstorm.

[rot13]

But what do I tell customer service if the cocktail holder breaks!?!? :)

"Doug Kanter" pontificated wisely that:

Kevin Miller [e-mail] (rot13)

[rot13]

Ignoramus27199 pontificated wisely that:

I hear ya, but things do sometimes change. My wife would never agree to any kind of gun around, until she chased a fox away from her hen house. Then I discovered that our state laws were such that an air rifle was the only practical solution. Kevin Miller [e-mail] (rot13)

[Jim Black]

Oops ... but you know what I meant -- static electricity at around

2000 - 4000 volts, as was being discussed. Practically everything is lethal if you get enough of it.

[paghat]

How well I remember shuffling across the carpet & pointing my finger at my sister's head, giggling until -- FLASH! -- both of us fell into fits of tears. And that's why to this day I have but nine fingers & my sister went blind & became bald for life.

-paghat the ratgirl

[JMartin]

Most fence chargers work on pulses. You get zapped, but that's all it is...a zap. You have plenty of time to let go before it sends another pulse...and you tend to let go in a hurry.

A 3 year old would be fine with the fence...just like the cows...one zap and they develop a healthy respect for it.

jena

[Susan (CobbersMom)]

Very true unless you're like me. A number of years ago I kept a horse at a neighboring property, the field surrounded by an electric fence about two feet off the ground. In a small area with a lump in the ground, I would step over the fence to take a shortcut to the barn. Once, in shorts my inner thigh caught the fence. As I danced back and forth, getting each leg, I finally jumped high enough to clear it. It hurt but more of a slap/surprise kind of hurt. I must have looked so silly dancing over that fence Sue Northern Wisconsin

[Advanced Priority]

Did your sister become a lesbian, too?

[Salty Thumb]

"Adam Russell" wrote in news: [e-mail]:

As others have said, voltage doesn't kill, current does. If you want proof, go to a children's museum with a Van de Graf generator and observe as kid after kid cheats death at the expense of hairstyling. The Van de Graf Should be putting out least 10,000 V.

That said, it exceeding more likely for current to force a path through your body as electric potential (voltage) increases. So for most intents and purposes high voltage will kill you, but it also requires sustained current running through your body, screwing with your normal electrical functions and overheating your cells. (The current does not have to be high at all.) Now don't go sticking your finger in a socket or something, thinking you'll be able to let go after a short time, because you won't.

If anything, DC is "safer" than AC, but I believe this involves transmission losses that don't occur due the electric field generated by the oscillating alternating current. But the tranmission losses should be neglible at short distances and "safe" in this sense is not relevant. (Does AC make it more diffult to remove your hand from an outlet? That could be another reason, but I'm not too sure about it).

Static electricity is a capacitive discharge (as is lightning and battery power). The only difference between that and electricity from an outlet is that there is nothing resupplying the capacitor and so the duration is short, depending on the size of the capacitor. (Just because you usually get DC power from batteries and AC power from an outlet doesn't mean they can't be the other way around. It wouldn't be efficient, but you could do it).

Running electricity through a step-up transformer will step up the voltage at the expense of (I'm not sure I remember this correctly, but what else would it be?) current. (Inside a block transformer, you may also have a rectifier that converts AC to DC). You will also have current losses from the conversion and needless to say, just because you are on a 15A line, it doesn't mean the device or transformer will draw the full 15A. The input and output ratings should be printed on the transformer block. All other things being equal, the calculation above is still missing a sqrt(2) since the source is AC (in addition to conversion losses which I am guess could be 30%.)

The term "transformer electricity" should probably be reserved for Autobots and Decepticons.

[rec.gardens]

[rot13]

Did a quick search. Your town justice had it right. Here is the URL for the applicable NY state reg, section 11-0523:

"Doug Kanter" pontificated wisely that:

Kevin Miller [e-mail] (rot13)

[tinacci]

GOTHE CHEAPY WAY

Go down to Walmart and buy yourself a few bucks worth of MOTH BALLS, yes Moth Balls. and scatter them around and all your animals will stay clear until they all evaporate in about a month then scatterer some more. If you have youngsters they might think they are candy so take that in mind.

Jack

[Richard Cline]

I am reminded of a neighbor of mine who found a couple large stray dogs in his yard. He called animal control and asked them to come and pick up the dogs. They told him that they were unable to come to his house. He replied that that was no problem, he would simply shoot the dogs. They told him that it was against the law. He explained that the stray dogs were attacking his dog and he would shoot the strays as a means of protecting his dog.

The animal control people arrived within ten minutes.

Dick

[Fay]

Richard Cline wrote in news: [e-mail]:

This reminds me of a neighbor a few years ago when he saw two kids breaking into his storage building. When he called the police he was told they didn't have a car ton send right away, but would get there when they cvould. He called them back in a couple of minutes and told them not to hurry that he just shot the two intruders. They show up in about 3 minutes and caught the two kids. The police ask why he lied about shooting the kids. He said well I got lied to by you when you said you had no car to send out.

[dps]

probably much more. The breakdown field strength for air is about 25000 volts/inch. Look at the length of the sparks the Van de Graf generates. Of course, the field strength from a sharp point (such as the end of a strand of hair) drops off as r squared, so the local field could generate a breakdown which could propagate.

As far as the current level goes, I have heard that it requires as little as 0.01 amps to kill a person. This is a very small current, and I suspect that it wouldn't kill an average person except in exceptional circumstances. I know people who have experienced up to 0.05 amps (DC) before reporting discomfort (they did survive to report no discomfort).

Small currents generally kill by inducing paralysis of various important muscles, such as those responsible for breathing or blood circulation.

Large currents can kill by damaging muscles or nerves.

The voltage isn't really important if you can get the current up. Normal skin resistance requires a fairly high voltage to overcome, but if you implant an electrode below the skin into a region where bodily electrolytes can conduct the current, you can probably electrocute someone with 40 volts (as long as the current is high enough).

As far as AC/DC is concerned, it really doesn't matter. For the relative merits of AC and/or DC, refer to the discussions between Edison (DC proponent) and Westinghouse (AC proponent). Westinghouse won, although there were sections of New York City that were supplied with DC power up until the late 20th century. The main reason that AC won out over DC was that AC could be transmitted over large distances by raising the voltage and lowering the current. The resistance of the wires is what causes the transmission losses and lowering the current reduces the voltage drop. Since the voltage is high, the voltage drop is less important, being a smaller fraction of the total. Both of these reasons make AC power transmission more efficient.

Static electricity, although of short duration, is sufficient to fry electronic chips, since the current is concentrated into a small area on the chip. In that case, the relevant parameter is amperes per square cm.

Correct. The power (product of current and voltage) remains the same (neglecting transformer heating).

I have not been following this thread, but suppose it to have been started by someone recommending an electric fence transformer for raccoon prevention. The electric fence transformer I used to have was rated 0.01 amperes output. I measured the voltage at 1500 volts. The AC voltage was continuously supplied as long as it was plugged in. Being normally forgetful, I neglected to unplug the system several times and did a little garden sparking. It was unpleasant, and not something I'd like to do frequently, but I believe it was just enough to discourage repetitions (and improve memory). Other electric fence systems are pulsed, so that a single spike of high voltage is presented every second or two. The time interval between pulses is quite enough to withdraw one's hand or other portion of the anatomy that came in contact with the wire.

[dps]

Tried it. Doesn't work well in the open, where the wind can remove the smell.

[Doug Kanter]

Sounds like Krispy Kreme syndrome.

[William W. Plummer]

Filing a false report usually has a stiff penalty. How did you avoid being charged?

Two wrongs don't make a right. You can't justify your crime this way.

[v]

Sure, if you want to do that every night until you have taught all the racoons in the neighborhood not to go in the traps. But that won't keep them out of your garden.

You sure this aint just a troll????

-v.