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Re: Tesla Magnifying Transmitter

that's 30 kV/cm in uniform fields by the way (3 kV/mm, 71 kV/inch) and, of
course, it varies with humidity, temperature and pressure, as well as gas.

In a uniform field, the breakdown would be the same for AC and DC, but then,
getting a uniform field for AC (what with EM propagation delays, capacitance
effects, etc.) is quite the challenge.  A standard set of spark gap tables
will give you breakdown voltages for AC and DC and impulses (the breakdown
in a long gap is greatly affected by the pulse shape.. rise time mostly...)

You might take a look at some of my pages:
http://home.earthlink-dot-net/~jimlux/hv/sphgap.htm for sphere gaps
http://home.earthlink-dot-net/~jimlux/hv/paschen.htm for Paschen's law and
breakdowns
http://home.earthlink-dot-net/~jimlux/hv/insulgas.htm for breakdowns in gases

There are also some pages on rod gaps, Rogowski profiles, etc...


-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Tuesday, January 11, 2000 1:12 AM
Subject: Re: Tesla Magnifying Transmitter


>Original Poster: Liviu Vasiliu <teslina-at-yahoo-dot-com>
>
>   Yes Nick, you has right, the value of breakdown in
>the dry air (3 kv/cm)is calculated for uniform
>E-fields. And is not a brown common used fertiliser,
>is a yellow one. Doesn't know anyone a formula of
>breakdown voltage in AC fields or it is empirical
>found?
>
>>
>>
>On Sat, 08 Jan 2000 12:32:09 -0700, Tesla List wrote:
>
>>  Original Poster: "Jim Lux" <jimlux-at-jpl.nasa.gov>
>>
>>  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.
>Could the title and publisher of the Bazelyan and
>Raizer book be
>repeated. I
>accidently deleted that entry from mail.
>
>Also Nick states:
>   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
>I have recently produced rapid , high voltage,high
>frequency  violet
>discharges of 5 mm length  to an intervening small
>insulated water
>capacity
>from  a sort of resonant rise of voltage principle
>obtained from large
>inductance coils at 60 hz resonance and  wall voltage.
>My  amperage
>draw to
>the device was about 130 ma, but the q of the coil
>system is only
>around 30,
>supplying only a 3 to 4 thousand volt unobvious, or
>resonantly choked,
>potential to the process. To enable the higher
>voltages to be shown I
>employed a  series triple arc gap  with the large
>discharge in the
>middle
>shunted by a capacity to enable breakover or short
>discharges to
>develope by
>the rapid charging and discharging of that capacity.
>Is it safe to
>assume
>that this miniature lightening effect is  only around
>1500 volts, given
>the
>5mm length
>and the quoted 3 kv/cm arc over discharge value or
>breakdown voltage.
>Thanx for any info
>Harvey D Norris
>
>
>Binary Resonant System
>http://www.insidetheweb-dot-com/mbs.cgi/mb124201
>
>
>
>
>
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