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RE: streamer hit

As a teen, I tinkered with two or three little table top coils powered by
automobile ignition coils.  Power input was under 100 Watts.  The little
coils probably ran at rather high frequency due to the small secondary
diameter and short winding length.  They gave a bright purple brush
discharge and I often drew sparks off them up to 3 or 4 inches with a metal
object (key, metal ruler, etc.).  I repeated this act at least 100 times
over the course of a year or two with no I'll effects now or then (I'm 36).

In 1983 I was bitten by a 10 Watt UHF transceiver I was bench testing.  My
knuckle happened to brush against the shell of a coax connector on a faulty
cable while the transmitter was keyed.  It felt like a bee sting--raised a
small blister too!  This incident permanently colored my attitude about RF
shock, (and about electricity in general) and I've had little desire to be
within striking range of an operating Tesla coil ever since.

Greg

----------
From: 	Tesla List[SMTP:tesla-at-pupman-dot-com]
Sent: 	Friday, November 13, 1998 7:01 PM
To: 	tesla-at-pupman-dot-com
Subject: 	RE: streamer hit

Original Poster: "Coiler" <mycroft-at-access1-dot-net> 

Terry: I am not certain it was due to my coil.. but I wonder.
I am an apherisis donor.. so I get a hand workout every two weeks, for
90 minutes I sqeeze a ball to force the blood into the machine. When
I was fooling around taking hits from my 360VA 3.5" coil, I would have
pain in my joints during the donation. Now that I am running at 1.4KVA
(and soon to move up to 3KVA or more ) I don't go near the coil. I also
don't have the pain in my hands during my donation.
The pain was localized to the joints.
Was it the coil? Dunno. But I don't intend to be a target anymore anyway.
I have my requisite RF scar on the back of one hand to remind me. (another
story)

Michael Baumann
Coiler, Homebrewer, Nerd. mycroft-at-access1-dot-net
 

> -----Original Message-----
> From: Tesla List [mailto:tesla-at-pupman-dot-com]
> Sent: Thursday, November 12, 1998 4:44 PM
> To: tesla-at-pupman-dot-com
> Subject: Re: streamer hit
> 
> 
> Original Poster: Terry Fritz <terryf-at-verinet-dot-com>
> 
> At 10:51 PM 11/11/98 -0600, you wrote:
> >Tesla List wrote:
> >snip>
> >Terry and all,
> >
> >I've been reading the many interesting posts on this topic! Lots of
> >rather exotic methods of estimating the current distributions. However,
> >you can get a quick estimate of skin effect by using the operating
> >frequency of a typical operating Tesla Coil by using the permeability
> >and conductivity of sea water to model the EM inside of your body.
> >
> >The bottom line: 
> >===============
> >At the relatively low operating frequencies used in Tesla Coils, there's
> >virtually NO "skin effect" at work - the effective "skin depth" of your
> >body is "deeper" than you are thick! For example, the RF current from a
> >100 kHz system has a "skin depth" of about 31 inches inside your body.
> >Unlike a good conductor, the current will NOT be confined only to the
> >outer surface of you body.
> >
> >The fact that you may not "feel" the RF current (particularly from a CW
> >coil) does NOT mean that it won't do any physical damage - your nerves
> >are simply not responding to the RF current - sort of like being unable
> >to hear a damaging level of ultrasonic sound. Any current flowing
> >through your body (once it penetrates your skin), will be concentrated
> >through the best conducting portions of your body - your nervous and
> >circulatory systems. And make no mistake, excessive/prolonged current
> >flow can result in temporary or long-term nerve or organ damage. 
> >
> >Worse yet, if you happen to be grounded through an accidental flashover
> >to some other part of your body (toes, elbows or kneecaps...), the
> >discharge from a fully-charged topload and coil self-C is actually a
> >direct current capacitor discharge through your body. Taking a "hit"
> >from a multi-Joule coil will most definately "smart"... a hit from a
> >larger system can kill! Ao, don't buy into the old skin effect folklore,
> >guys - it ain't true!!
> >
> >And, SAFE coilin' to you!
> >
> >-- Bert --
> >
> >
> 
> Thanks Bert,
> 
> 	I had heard the skin effect stuff for so long I really 
> didn't question it
> till recently.  I think you pretty much hit everything right on the head.
> I never was a big fan of getting shocked or taking arcs.  The fact that
> these high frequency currents travel through ones guts and all is pretty
> important to understand.  Just like X-rays, we need to know as much about
> our risks as possible.  Large coils are pretty ominous when operating and
> not too many people run TOWARD them :-))  Smaller coils don't have the
> freight factor to keep us away and we need to be aware of what they are
> doing to those of use who like to "play" with the arcs.
> 	It would be interesting to know is anyone has noticed any long term
> affects of arcs through the body aside from the obvious burns and the
> mentioned short term tingling muscles?
> 
> 	Terry
> 
> 
> 	
> 
>