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Re: Tesla magnifying transmitter



I think the breakdown field for air is pretty constant (at a given temp and
pressure, etc.) however what is very tricky to model is the actual voltage
and charge at the end of the leader, so what is not all that reliable is
the actual field (in Volts/meter).

That said, there is a wealth of empirical data on long HV sparks for all
sorts of electrode configurations in all sorts of environments. And, there
are "rough and ready" approximate theories that fit the data (even if they
don't describe what is actually happening) to allow some sort of reasonable
guess to be made about what will happen. As long as you are happy with 10%
accuracy, life is good.  

Books like Craggs and Meek, and more recently, Bazelyan and Raizer, provide
a fairly good handle on this.

----------
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: Tesla magnifying transmitter
> Date: Saturday, January 08, 2000 4:03 AM
> 
> Original Poster: "Megavolt Nick" <tesla-at-fieldfamily.prontoserve.co.uk> 
> 
> Hi All,
>            I have heard figures in the region of 100MV quoted for
lightening
> strikes and peak current of similar magnitude.  There is a minimum
voltage
> you need to form an ionized path, then the spark growth is a matter of
> current.  The minimum voltage is not 3kV/cm or some similar brown
commonly
> used fertiliser.  The calculation, when done as a field calculation, is
> quite simple but not too reliable as the breakdown field gradient of air
is
> very variable.
> 
> Regards
> Nick Field
> 
> > Original Poster: Mike Nolley <mnolley-at-mail.slc.edu>
> >
> > > > Longest sparks were 31 feet or so, highest voltage was maybe 1/2 to
> > > > 1 million volts or so at the very most, I would think.
> >
> >     Coils like current--voltage is less important.  500,000 volts at
200ma
> > and 5 A would give you radically different spark lengths.  For example,
> > lightning strikes are rarely over a million volts (or am I wrong?) and
the
> > strike lengths are in the order of hundreds and hundreds of feet--due
to
> > huge amperages.
> >                 -Mike
> >
> >
> >
> 
>