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Re: Voltage determination
Thanks to all who replied,
It seems kv/unit measurements work within specific perameters but would be
fruitless for a TC streamer length. For example, a spark length at a static gap
measurement will be more based on voltage than would a streamer off a toroid
which seems to be based more on power and properly sized coil for the power
processed. (I use the term processed because I think of processing "this power"
into "those streamers"). I guess transforming may be a better term.
How about a static gap? Is 35kV/cm correct at a static gap? I would bet
temperature would vary that as well.
Thanks,
Bart
PS. Scott, I have comments below:
Tesla list wrote:
>
> Original poster: Rscopper-at-aol-dot-com
>
> I just rebuilt my gaps to handle the new pig, and fired it up Saturday
> evening. Going from approx 4KW to 8.5KW only gave me about 1 foot in extra
> spark length.
You've got me wondering what the spark length is/was on this stacked coil. Was
the streamer fatter in appearance? Many have reported this when power was
boosted yet spark length only grew slightly.
>
> Some interesting observations:
>
> 1) Before, when the arc hit a ground target, all other spark from the top
> would stop, Now, there are still streamers coming from other sides of the
> toroid even when one is hitting a target.
I agree that a bigger toroid would be the next step. My coil does this as well
and I too need a bigger toroid and smoother toroid.
>
> 2)There is corona coming from everywhere! between my stacked secondaries,
> and around the output arc itself. Maybe I've reached the maximum power my
> secondaries can handle, and any extra power is wasted in corona. I'm going
> to build a new larger toroid this week to see if it helps.
What are you using for a top load? Kind of curious if part of the corona is
partially due to early breakout due to a rough surface. BTW, you gap you
"upgraded". Just what kind of upgrade did you do?
>
> In the end I had 2 stacked 8-inch secondaries wound with 23 AWG with a
> total inductance of 125mh, and the whole thing was about 9 feet tall
> including toroid.
Wow! The aspect ratio is way up there. It will be even more interesting to note
the spark length on a high inductance secondary with a 13:1 aspect ratio. Just
as interesting is how big a toroid you can throw on the stacked coils.
Thanks for sharing,
Bart
>
>
> R. Scott Coppersmith
>
> In a message dated Mon, 24 Jul 2000 2:14:13 AM Eastern Daylight Time,
> "Tesla list" <tesla-at-pupman-dot-com> writes:
>
> << Original poster: Tesla729-at-cs-dot-com
>
> In a message dated 7/23/00 8:44:19 PM Central Daylight Time, tesla-at-pupman-dot-com
>
> writes:
>
> << It may be impossible to point to one element alone (e.g.
> voltage) and say that it is resonsible for a certain length of
> spark since it won't get very far if there is no substantial
> source of charge to back it up.
> >>
>
> You know, I've read a text somewhere in regard to this subject
> that said something to the affect that a pulsed discharge from
> an induction coil may require ~300 kv for a mere 6" spark, but
> a 140 kvDC power supply may require 24" of seperation between
> the output leads or terminals to prevent a possible flashover. I
> suppose the "creeping effect" of HV over a smooth non-conduc-
> tive surface comes into play when dealing with "constant" HV
> charges. And the higher rep rates of TC discharges would make
> the charge more constant (higher duty cycle/less down time) so
> a relatively "low voltage" would arc an impressive distance. Also,
> the larger the Tesla coil, the larger the ionized "cloud" around the
> toroid, which further encourages more ionization of the surrounding
> air i.e. longer sparks.
>
> David Rieben
>
> >>