Re: RE Arcs off the fingers and getting killed in the process...
Subject: Re: RE Arcs off the fingers and getting killed in the process...
From: Terry Fritz <twftesla-at-uswest-dot-net>
Date: Wed, 02 Feb 2000 19:05:25 -0700
Thanks for sharing this interesting information.
Arcing through yourself to ground is just about the equivalent of
discharging a primary cap through yourself. If the primary cap is charge
to say 3 joules, that energy transfers to you and the top terminal, at
perhaps 50pF at 200kV. If you place yourself in the circuit, you are the
only power dissipating resistance. I think all the energy will discharge
in a single cycle making the current pulse basically DC. Since you are the
"high resistance", all the energy is dissipated in your body (it is sort of
odd talking to a high voltage resistor directly ;-)))
Assuming 50pF at 200kV and guessing you are about 1k ohm, The RC time
constant is 1/20millionth of a second. That is just a good powerful DC
jolt of 20000 amps!! Sort of like a medical defibrillator (I guess the
opposite actually :-O). Note that this effect is also true of a grounded
person reaching out toward a coil... The streamer resistance should add a
substatntial resistance also that may "save your bacon" but the danger is
Since negative charges arc much easier than positive charges, the arcs have
a pretty high DC component just to air. That is what you feel. Then there
is that microwave oven style heating in your body that causes the headaches
as the veins and arteries in your head get heated. The brain is pretty
sensitive to that...
I think such discussions will serve to convince everyone to be even more
carful. I think trying to hid the truth only makes things worse. I don't
know why you do this but I guess you get something (perhaps a "charge" out
of it ;-))) out of it...
I have to admit, I sure is fun watching OTHER people do it!!! ;-))
Hopefully, Jeff will get Dean Ortner's clip up soon too.
I wonder, have you noticed any heath effects from doing this? I can't
think of a similar type of electrical exposure... Brent Turner wires the
current around himself, as Bill mentions, but I think you and Dean Ortner
have carried the currents through your bodies for a substantial number of
At 07:49 PM 02/02/2000 -0500, you wrote:
>I guess it is time for me to share some of my experiences and thoughts on
>having sparks jump from your fingers. This is something that I have resisted
>doing, as Terry said "in fear of leaving something out and killing someone."
>As Terry pointed out, it is relatively easy for anyone to construct a
>potentially deadly coil and with each new coiler, there is the potential for
>someone to try and recreate this demonstration without doing the research and
>taking the proper safety precautions.
>My first introduction to Tesla coils was while working at the Memphis Museum
>in Memphis, TN. We decided to put together a high voltage show and purchased
>two Tesla coils and tons of other equipment from Resonance Research. From
>the first time that I saw the sparks, I was obsessed. Originally, the show
>was presented by Roger Van Cleef (my mentor and dear friend) and Tracy Dunlap
>(the only person I have ever trusted to set up the gear for me). Tracy was
>the first one to try the sparks from the fingers demo, after receiving
>instructions from D.C. Cox of Resonance Research. For one second, Tracy had
>beautiful sparks leaping from his fingers. At the same time, he learned that
>this HURTS!!!!! In spite of the conversations that have gone on in this
>group about high frequency currents not registering on human nerve, if you do
>this demonstration, you feel it a LOT!
>That was the first and last time that Tracy ever did the demo. While he
>continued to do the tech work on the show for the next three years, he never
>got close to the sparks again. They were ready to forget the idea when I
>stepped in. I had been trying to get my foot in the door for doing the show,
>and this was my chance. We started with the variac turned way down and only
>two inches of spark from my fingers. I was wearing thimbles with needles
>welded to them, to prevent the sparks from burning my skin. I also had a hat
>made of copper strips, with nails welded to them, again to provide a place
>for the sparks to jump. At first, the demo produced quite a bit of sensation
>and gave me bad headaches. As I tell people now, after the first 500 times,
>you hardly notice it.
>At low currents, there is not much sensation, as long as the spark is just
>going into the air. EVEN AT LOW CURRENTS, NEVER LET THE SPARK JUMP FROM YOU
>TO ANYTHING. I can tell you from experience that this really hurts, and is
>potentially fatal. The amount of sensation seems to be related to current
>density. You feel it most at the point where the current moves to and from
>your body. The larger the contact area, the less you feel it. At low
>currents, the sensation stays at the surface, but as your sparks get brighter
>and thicker, the sensation moves inwards, contracting the muscles. Arcing to
>a ground causes violent contraction of the muscles and I suspect that it
>could easily stop your heart with a moderately powerful coil.
>Even with sparks jumping into the air, at full power, I get enough muscle
>contraction in my feet and arms to leave me sore the following day. I will
>add here that I have a fairly high tolerance to pain. If you insist on
>novacaine when you get a tooth filled, you should probably steer away from
>this demo, or at least stay with very low power.
>It has taken 13 years of tinkering and experimentation to get my coil tuned
>to the point where it is small and light enough to fit into my luggage when I
>fly and still get nice sparks with the least amount of discomfort. I am VERY
>careful about safety clearance. I need triple the spark length betwen me and
>the nearest potential target for the sparks in order to feel comfortable and
>I prefer more than that.
>There are hundreds of other bits of information that I feel I should be
>mentioning, but to keep this from turning into a book, I will trust all of
>you to have enough sense to be safe and to do lots of research before trying
>anything that is potentially fatal.
>Science Education Company
>Get my Free Experiment of the Week by sending an e-mail to krampf-at-krampf-dot-com