Re: electrocution experiences

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "David Sharpe by way of Terry Fritz <twftesla-at-qwest-dot-net>" <sccr4us-at-erols-dot-com>

Hi Marc!

WOW!  10 Joules is considered lethal, your combination calculated out
to just over 5.5J.  The warning on bleeder resistors can't be overstated,
however, NEVER trust (your life) on the fact that the bleeders
did discharge the capacitors, they can fail too (and have a relatively
high probability of failing since they are pulse discharging a capacitor
and dissipating power while the circuit is on).

Also as a side note, the NEC "suggests" bleeders on any capacitors
larger then 0.1uF and charged to higher then 250V.  If 250V is a
peak value, stored energy is just over 0.003 Joules.  Capacitor discharge
time (5 time constants) should be no more then 1 minute, or faster
then you can get access to circuit.  Capacitors should be checked by
discharging with a grounding rod (hot stick), before touching circuits,
or physically grounding the HV with a mechanical crowbar (this technique
is used in commercial broadcast transmitters and VT induction heating
equipment).

I've never be "zapped" by the anode of a picture tube, but if you
assume the capacitance of a 26" tube to be approximately 200pF, and
charged to 25kV, results in an available 0.06 joules.  I know of a coworker
who was thrown 5 feet by a picture tube on residual charge alone while
working in the military..

Be careful out there, and Happy New Year all...

Regards
Dave Sharpe, TCBOR
Chesterfield, VA, USA

Tesla list wrote:

> Original poster: "Metlicka Marc by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <mystuffs-at-orwell-dot-net>
>
> I once let a friend hold a 4' florescent tube while i fired a 15\60 nst
> coil, he held one end to his groin and waved the other end around while
> laughing heartily. I screamed "NO" as i reached for the plug (very early
> in my coiling) Well, the multiple 2' streamers turned into one 4.5'
> streamer and you can all guess the rest? This was very "sobering" to
> him, he learned some tc safety and i started using a magnetic contactor
> to bring in the line voltage, with off button in my hand always.
>
> Once while coiling very tired i hit the on button for my pt powered
> coil. The fan for the gap came up to speed, the timer kicked the main
> contactor came in and all i herd was a hum? I shut her down and started
> looking, I discovered that my dog had knocked one of the primary leads
> off. I started to reconnect when all of the sudden it felt like someone
> was cramming a howitzer up each arm and set both off at my heart. I
> could feel the adrenaline working against what felt like my heart
> fluttering! i really thought a trip to he hospital or instant heart
> attack was coming soon? The pain in my arms and chest was almost
> unbearable for a good five minutes, but the "fear factor" of a heart
> attack made me mostly ignore this until the heart flutters stopped five
> or so minutes later
> This was before i found this list, I had never heard of a discharge
> resistor and was too tired to remember to discharge the 25nf bucket caps
> i had built, charged too 21kv it was nasty!
> Two lessons here:
> ALWAYS USE DISCHARGE RESISTORS AND/OR DISCHARGE LEADS!
> NEVER RUN YOUR COIL WHILE TOO TIRED!
>
> Tesla list wrote:
> >
> > Original poster: "G by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <bog-at-cinci.rr-dot-com>
> >
> > While testing my first coil, I held a 4' fluorescent tube out toward
> > the 30" spark to try and get better illumination. Well, I was the one
> > who got lit up. The pulsing of each break was very evident, as was
> > the propagation of the spark up my veins and tendons!
> >
> > My only reaction was "Ow, it bit me".
> >
> > Cya,
> > Gregory