Re: RF safety

["Steve" <Steve-at-g8cyerichmond.freeserve.co.uk> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

There are a whole range of things to take into account. First, skin effect
doesn't enter into the equation as far as I am concerned. The body is a very
non-uniform conductor, for example dry skin is a poor conductor relatively
speaking, as is fat, but blood vessels, nerves and muscles are good
conductors. The path of current through the body is unpredictable. Second,
the nervous system is unable to 'feel' current at frequencies much above
700Hz, therefore we may not feel damage being caused. Localised electrical
burns are extremely painful, and can take a very long time to heal, I speak
from personal experience here, having been burnt several times..
I have deliberately taken arcs to held metal points myself, but using low
power coils (up to 50W). However I never do it when I am alone, a trusted
and experienced person operates the controls, they are also trained in CPR.
I also stand on an insulated platform. There are a number of other
precautions that I take as well I don't plan to go into these precautions
here. I don't believe that I would ever take a strike deliberately from a
higher power coil. Even a minor mistake can hurt like hell!!!
Please don't do it.

----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, July 24, 2000 7:32 AM
Subject: Re: RF safety


> Original poster: Terry Fritz <twftesla-at-uswest-dot-net>
>
> Hi Jeff,
>
> At 09:08 PM 7/23/00 -0700, you wrote:
>
> >> I would also like to mention that the individuals that charge them
selves
> >> up directly to the output potential (obviously, not recommended for the
> >> average coiler!), like Dean Ortner and Robert Krampf, have not had any
> >> problems from perhaps 20 years of doing shows.  Their exposure is
actually
> >> "being the source"!  Robert has mentioned headaches but it is hard to
say
> >> if that is from the noise, O3 and Nx gasses, or the current going
through
> >> his head.  The fact that their exposure is far far greater than any
casual
> >> observer and they don't have problems, pretty much relives any concerns
> >"I"
> >> have.  They have sort of done the high-exposure "white mice" test for
> >us...
> >
> >The last sentence is very misleading. Ortner and Krampf use
professionally
> >manufactured low power coils. And, in some cases, use "tricks of the
trade"
> >to bypass current that would otherwise flow "over" the stunt person. To
> >quote Bill Wysock: "Skin effect goes right out the door when there is a
> >power arc involved". An errant, unplanned, "gee I didn't think it'd do
that"
> >power arc can kill even a pro. And that's with the best of coils and
> >intentions.
> >Add a hobby quality coil to the effort and you have too many variables to
> >safely control.
>
> I was referencing long term health effects from conducting RF current
> through the body from a Tesla coil.  Obviously, if one connects to a pole
> pig's currents, the short term effects can be nasty!
>
> Ortner and Krampf do not use devices to route currents away from the
chest.
>  I wish they would...
>
> >
> >RF travels over the body. When done correctly, by professionals, with
> >professional equipment in a controlled environment, the stunt can be
safe.
> >However, in my professional opinion, it is way too dangerous for anyone
> >to try even at modest power levels.
> >
>
> RF current in the 200kHz region go right inside the human body favoring
> nerves and blood vessels as low conductivity paths.  The "skin effect"
> phenomena does not apply here due to the properties on the human body and
> the frequency.  One would normally think that would "mess a person up".
> However, Ortner and Krampf seem to have survived this internal RF current
> exposure over a considerable number of years.  Considering they seem ok,
> the rest of use standing 10 feet away are probably quite safe from this
> specific concern...
>
> One does not feel balanced RF currents since the nerves cannot respond to
> them (I'll leave it up to others to explain that nerve chem-mystery
stuff).
>  However, DC components and especially the 60Hz AC are deadly.  The RF
> current can cause very sever burns before a person even knows about it.  I
> saw a person get a severe RF burn.  He only realized it when he wondered
> "what was burning".  He could not feel the current at all but he sure felt
> the damage for weeks after...
>
> >The "Lightning form the Fingertips" stunt has already proven that it can
> >kill.
>
> Henry Transtrom - Was a master of electrical and Tesla coil stunts.  If he
> can get killed, anyone can...
>
>
> The list of known Tesla coil deaths is as follows:
>
> Henry L Transtrom - Electrocuted while working on a stage and using a
> large Tesla coil.  He inadvertently allowed a power arc to go from his
body
> to some metal framing that was part of the stage backdrop.  He authored
the
> following book:
>
>  "ELECTRICITY AT HIGH PRESSURES AND FREQUENCIES"
> Henry L. Transtrom, originally published: 1913, second edition
> 1921, Joseph G. Branch Publishing, Chicago; Reprinted 1990, ISBN
> 1-55918-054-4, Lindsay Publications, Bradley, Illinois, 60915.
> Paperback, 247pp, Lindsay # 20544.
>
> 1992 - Graduate student intern working at McDonnell Douglas in St. Louis.
> A Tesla coil was being used to test aircraft parts against the effects of
> lightening.  The person got too close to the tank circuit and either
bushed
> up against it or a spark left the circuit and struck him.  He never
regained
> a heartbeat despite excellent CPR and paramedic responses.
>
> March 29,1998 - An unsupervised 14 month old boy wandered into the poorly
> made AC line wiring of a Tesla coil.  He was found some time later but
> could not be resuscitated.
>
> A master, a bystander, and a small child have been killed by Tesla coils.
> It is always a number one priority to keep that list from growing...
>
> Terry
>
> >
> >Jeff Parisse
> >www.teslacoil-dot-com
> >
> >
> >
> >
> >
>
>
>