Re: Safety FAQ-discharge classification

>>From hullr-at-whitlock-dot-comMon Aug 12 20:03:58 1996
>Date: Mon, 12 Aug 1996 10:55:35 -0700
>From: Richard Hull <hullr-at-whitlock-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: Safety FAQ-discharge classification
><boilerplate snippage>

>Robert Stephens (I) wrote:

>> Therefore, Malcolm, I approve of your classification idea and support
>> it as do-able.  The question remains, is it needed?  If needed, then
>> can it be refined and extended?
>> If I may suggest, unless there is a scientific model which is being copied from
>> another discipline at work here, I would propose calling the single streamer
>> (like real lightning channel) mode Type 1, as I believe this mode to
>> be the  superior  performance oriented goal.  The mode where there are many,
>> thin, simultaneous streamers could be Type 2 discharge.  We might extend
>> this classification scheme to the brush discharge (like seen from a
>> CW Tesla coil powered by filtered DC supply driven vacuum tube or
>> solid state oscillator) as being Type 3 which hisses and looks like a
>> gas powered torch flame (or in the case of the four footer generated
>> by Mark Barton and described as 'a welding torch from Hell!'), and finally a glow
>> discharge, with no streamers whatsoever as a Type 4 discharge. Note
>> that the output ionization phenomenon can occur in two or more of the
>> above states simultaneously.  For example, a lightning like hot
>> single streamer coming near, but not touching a grounded target
>> sometimes developes a very prominent glow discharge extending in a
>> beautiful cone from the end of the arc channel.  These glow discharge
>> cones can be of significant size.
>> If you people out there don't like my suggestions then you could give me
>> an  honorary discharge:).
>> For Watt its worth, rwstephens

Richard Hull replied:


>I reread my posts and yes, I can see where they could be misunderstood.  
>Sorry for not clarifying it out to a finer degree.  But, all seems 
>understood now as I originally meant it to be.

>I like your classification numbering and definitions very much.  I 
>suppose we all could do with a little classification standards on 
>discharges.  Since there are only 4 with a couple of sub-variants, I 
>would say they are quite acceptable.  malcolm's original concept was 
>quiet good, but I like your numbering system where the #1 and best 
>discharge for us coilers is first.

>By the way, We have seen numerous instances where the #1 discharges reach 
>to almost touch a grounded object and the ionization halo is around the 
>grounded object and not the end of the arc!  Have you ever noticed this? 
> It is quite common with some tube and solid state systems too. 
>Especially, if the grounded object has a sharp point to bleed into the 
>air.  I am sure that the ion and corona streams connect even if the arc 
>cannot.  With a delicately adjusted 25 watt disruptive system, I can 
>approach the no arcing system's toroid with a dental pick and sparks 
>actually issue from the pick well before breakout occurs from the coil's 
>top load.  It is most interesiting and beautiful to observe this 
>phenomenon.  Turn the room lights off for more thrills.  I could study it 
>for hours if it weren't for the darned ozone.

>Low power systems are fun too, eh?

>Richard Hull,TCBOR


I've meant to answer your post sooner but my life has been upside 
down for the past three weeks having just survived a very 'should 
have been dead' type head-on pickup truck to pickup truck, highway 
speed,  highway collision three weeks ago.

Thanks for the accolades on the discharge classification scheme.  
Malcolm Watts deserves half of the credit :) for putting this kinda 
idea in my head.  Thank's Malcolm!

I share your observational experience of a brush (Type 3) discharge 
from grounded pointy objects held near an operating TC running below 
the breakaway power threshold.  I tell all my visitors during such a 
demo that this is St. Elmo's Fire.  With the CW vacuum tube TC 
operating from a full wave filtered DC plate supply it is a 
perfect Type 3, hissing brush discharge with little to no internal 
streamer type artifacts.  Same experiment with a disruptive TC shows 
a brush that has more predominant little streamers embedded within it.

On your comment of a Type 4, glow discharge being seen emanating from 
a grounded target when a Type 1, streamer is near; I have seen this 
from a nearly struck grounded tin can mounted about 28 inches from 
the discharging toroid with my 900 watt disruptive coil.  

I have also seen a very rare (captured on video) Type 1, 'dart 
leader' come out off a pointed ground target about a foot long, 
coming out to meet a 10 foot long type 1, from my MTC system!  The 
next video frame shows them meld into a solid strike path to the 
target.  This is just like nature's lightning, eh?!

A phenomenon which I have yet to hear anyone talk about, and which is 
especially evident in the streamer discharge to a grounded target in 
small tabletop systems is where a portion of the thin streamer seems 
to be twice as bright as the rest (majority) of the streamer.  This 
effect is often near dead center in the length of the streamer, but 
sometimes is much closer to the target end.  I've got video showing 
this effect near the target with my MTC unit with 10-12 foot scale 
arcs.  My observations so far conclude that this brightened area is actually
an overlap area where the streamer is split into two streamers, 
following a nearly identical path shape, but separate and parallel to 
each other over this brightening distance.  Have you or anyone else seen this
effect and figured out a reasonable explanation?

Extremely grateful that someone upstairs clearly wants me to continue 
coiling, and pledging not to disappoint them, rwstephens