Re: Safety FAQ is here -- draft, asking for comments.

>>From sgreiner-at-mail.wwnet-dot-comTue Aug 13 15:19:09 1996
>Date: Mon, 12 Aug 1996 14:50:57 -0700
>From: Skip Greiner <sgreiner-at-mail.wwnet-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: Safety FAQ is here -- draft, asking for comments.

>Tesla List wrote:
>> >From rwstephens-at-ptbo.igs-dot-netThu Aug  8 10:57:03 1996
>> Admittedly, when the wind is a blowin', the ion cloud around the
>> toroid is not a collectin'.
>> I merely wish to say that I think more research is needed here
>> before we can really understand what is happening around the top end.
>> As for your laudable attempt to create a performance category by merely
>> observing the discharge, this may not be so easy as first imagined.
>> Standardization system or not however, I'm sure no one would object
>> to having their system performance classed as #1! ;-)
>> Even if we don't come to understand the science (although I'm sure we
>> will), just getting to the point of throwing long, white hot
>> lightning bolts is a definitely neat level to achieve.
>> Regards ,rwstephens.

> I have photographs of my 720va coil exhibiting just this phenomenon
>when operating in a very light breeze. I have never been able to tie the
>jagged sparks directly to the break rate bacause I don't know how to
>make  a measurement. I estimate the length of the "steps" in the spark
>to be 2" to 3". One thought is that the spark is actually growing in
>length from the bottom which is eminating from the toroid rather than  
>growing from the tip of the spark thru conduction of current in the
>spark itself. I would be interested in other comments on this subject.

Skip, All,

I believe that the phenomenon which is being bandied about where some 
people believe that the discharge channel is growing on itself is 
completely illusory and false.  I hereby offer my hypothesis.

If we could, through high speed eyes, observe every single 
streamer that rushes out from our toroid, as an individual spark, and 
not confuse it with the one that flashed 2.5 milliseconds earlier, or 
the next one to flash 2.5 milliseconds later (based on a break rate 
of 400 PPS), then I think we would see a streamer that exists in a short space
of time which has one fixed length during its entire duration!  

In a rotary break powered system, operating on 60 Hz, the system 
capacitor goes through a cycle where it is sometimes completely 
discharged (zero point in the 60 Hz waveform) to where it is half 
charged (45 degree points in the waveform) to where it is fully 
charged (90 degree points in the waveform), and at varying voltages 
at all points in between.  Along come the contacts of our rotary 
break, commutating at random, usually half a dozen or so places along a 60 
hz sinewave.  Some commutations will meet a fully charged capacitor 
and the result will be a single pulsed  streamer for that commutation 
which is the longest that the system can produce.  Another 
commutation will occur at less than maximum charge and the single 
output streamer driven by that commutation will be shorter.  Since 
there is a beat frequency between the mains rate (or multiples of the 
mains rate) and the break rate, the train of ouput streamers will be formed in
a repeating cycle of none, to short, to longer, to longest, to shorter, to shortest, to 
none, etc.  This is repeated at the beat frequency.  When this beat 
frequency is relatively fast compared to the response of the eye, 
like  say 10 or 20 PPS or more, and given that the eye integrates what is 
seen (movies and television could not be possible without this 
persistence of the eye), an illusion is created where a short output streamer is 
seen to grow longer in steps, aparently building upon itself.

Now, I'm not sure what the de-ionization time for the arc channel 
might be, and I suspect that the channel remains highly conductive 
after the light dies away (energy is dissipated) to make a good path for the next
pulse.  This is substantiated in the fact that a powerful streamer upon 
'finding' a good solid target will remain attached to that target for 
an extended period of time with relatively little deviation of the 
arc channel path. 

I don't see this phenomenon one of streamers building on previous 
pulses, but rather a rapid succession of individual streamers, 
occuring in sequentially increasing and decreasing lengths,  each 
with a differing length due solely and traceable to no other reason 
than to the power level that created each individual one of them.
I had meant to post this earlier but have nor had time, I've noticed 
in the meantime that the idea of employing a high speed streak camera 
by Steve Roys has been suggested.  If  my hypothesis is indeed 
correct, a fast enough camera will certainly be able to verify it.

Comments welcome as always.

Regards, rwstephens