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Build Your Own Tesla Coil
screenbert writes "Ever wanted to keep stray dogs or neighbors from trampling your backyard, but
just couldn't find the system to really deter them? Well this
site shows how they built
a bi-polar Tesla Coil system. I've always loved the Tesla coils on C&C when
they'd zap the units as they went by.
"
I believe you are incorrect. You're talking about the Telsa "Earthquake machine" oscillator, which was a tunable steam- or electrically-powered weight. There's a book about it, IIRC it's called the "Tesla Earthquake Machine" or something like that, and includes plans to build your very own.
Tesla, upon inventing the oscillator, attached it to a bar of the finest steel he could get, and within a few minutes the oscillator had found (been set to?) the resonating frequency of the bar and shattered it. Tesla then attached it to a pillar that was driven into the earth at his laboratory [keep in mind that his lab, and several other New York buildings, were built on a patch of sand, IIRC] and turned it on. He took a crowbar to it when the buildings across the street started to shake.
Keep in mind this device was no bigger than a 2-liter pop bottle, if I rember correctly.
The Tesla Coil is a high-frequency, high-voltage transformer, and shares few parts or concepts with the "earthquake machine."
This
As somebody who has built several tesla coils, I though I might be able to provide some information on this topic. A tesla coil is basically a high frequency transformer. They come in two varieties, traditional and solid state. A schematic for a traditional tesla coil can be found here. The main for a traditional tesla coil is usually a neon sign transformer, or NST as we call them. The capacitor is often a milspec jet engine ignition capacitor or a leyden jar made out of beer bottles. Solid state tesla coils are similar, except they use a less powerfull main transformer and use a flyback transformer (found on most tv's, although flyback's from the 50's and 60's work best, as they don't have as many safety devices) as the resonator. Just be forewarned, the information on the site I linked to is about 5 years out of date.
There's no sig like SIGSEG
One hopes that the above poster is intentionally posting pseudoscientific nonsense... but a few people seem to have taken it seriously... so...
.1 Amp. That will stop someone's heart.
While these Tesla coils are probably harmless, to do damage to a human you need not 100 amps, but less than
Furthermore, let us say that you want to put 100 amps into something from 20 meters. First of all, 10,000 volts isn't anywhere close (you calculations are way off - in fact, they are sheer nonsense!) A few megavolts at a minimum would be required.
But... as far as power delivered to the load... the resistance of the air is uninteresting. Once the arc starts, the resistance drops dramatically in the plasma. Thus one could deliver 100 amps at 20 meters with a lot less power than you calculate.
The statement that electricity naturally flows to the nearest earth is likewise fallacious. Electricity flows (or tries to flow) across potential differences. If you hook one end of a potential difference to the earth, electricity from the other end will certainly try to flow there. But if the Tesla coil is insulated from the earth, the electricity will have no particular interest in flowing to the earth!
All in all... very cleverly stated nonsense.
Naughty of you (or ignorant of you).
The only good weather is bad weather.
Hm.
I'm always wary of these sites. They show all this electricity zapping round, and guys with electrofingers.
Only problem is this: Unless a tesla coil is specifically built for this purpose, the skin effect does not work on telsa coils. You actually cook your organs.
I think it's highly irresponsible to blaze things like tesla coils.
I've built one, I've used one, and had an enjoyable time, but safety must be the first priority, not pretty pictures.
For more information about the dangers of tesla coils, Here[Chip Atkinson's Safety sheets]