Re: Undesired "effect" with saltwater caps

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Luc by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ludev-at-videotron.ca>

Hi Chris,

It could be resonance rise, many years ago when I start to play
with tesla coil this list did not exist even web was not
invented. Often I end up with a resonant cap with my PS, in these
years I always use OBIT ( Oil Burner Ignition Transformer ) and
most of the time salt water caps If my memory is good the reso
size cap for a typical OBIT is around .0058 uF, with your 8
bottles you could be at resonance or less this way you end up
with really high voltage ( OBIT in my experience are surprisingly
resistant to over voltage I saw one depotted in a bath of oil
arcing madly inside the oil and it still working today ).

An other thing high voltage have strange behavior, I saw some
time current arcing 3 time the distance of a spark gap at other
place in the circuit; may be because of corona opening a channel
( be aware of sharp edge ) or if transient are present some time
you could have small region of your circuit with ultra high
voltage at high frequency.

Marry Christmas,

Luc Benard   

Tesla list wrote:
> 
> Original poster: "Chris by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<chris-at-atomic-pc-dot-com>
> 
> Hi all,
> 
> I realize that many experienced coil builders frown upon salt water
> caps, but right now I'm trying to make the most of available materials.
> So I have a cardboard box set up with 8 Snapple bottles in parallel.
> Experimenting with different numbers of bottles does not significantly
> affect the problem I'm about to mention.
> 
> What's happening is, now that I've switched to a series of copper tube
> sections as my spark gap (8 tube segments in series, ca. 1 mm apart),
> I'm getting big, loud (!) sparks inside the Snapple box which appear to
> be going from one bottle cap to the neighboring outside plate of the
> next bottle (this is several inches' distance).  Close examination of
> the bottles (after disconnecting, of course :-0 ) reveals myriad
> pinhole-sized burns through the aluminum foil on the outsides of the
> bottles, although the glass is intact and they do not appear to leak.
> The secondary will throw about 6 inches of spark if I experiment with #
> of primary turns.
> 
> I'm using a 10 KV, 23 mA furnace transformer.  I've tried 3 different
> primary coil setups, including one of insulated Romex 12 ga. stranded
> wire, coupled very closely to the secondary. Maybe the coupling here is
> too close?  But the problem happens also with the copper refrigeration
> tubing that's spaced much farther from the secondary.
> 
> What could be happening here?  Another note, some of the wires I'm using
> in the primary circuit are way too thin (16 ga. wire, with alligator
> clips to connect things).  Could this be introducing too much reactance
> into the primary circuit?  (please forgive my ignorance of these
> things).
> 
> Thanks,
> Chris