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RE: Z-Machine Sparkage- Try this at home!!



Original poster: "brianb by way of Terry Fritz <teslalist-at-qwest-dot-net>" <brianb-at-antelecom-dot-net>

Sue/all,

I repeated your experiment and noticed some interesting things happening in
the gap area. Some of these observations may be of use for our Tesla Coil
gaps so I don't think this is to far off topic.

My setup used a .06uf capacitor, 12kv-at-30ma NST, .75" brass electrode, and
.25" gap between the electrode and the water.

One of the things I noticed was the physical wave created in the water each
time the gap fired. At first I assumed it was due to the shockwave from the
superheated air in the arc channel (which also made an acoustic "pop" each
time the gap fired). Upon closer examination I noticed this was only part of
what was happening. What I observed was the water under the gap being pulled
up towards the electrode due to electrostatic forces then dropped as the gap
fired (dissipating the charge). This electrostatic effect is quite
pronounced as I'm able to observe the gap distance being reduced by over
half.

I had made an assumption that the breakdown voltage was simply due to the
static distance between the electrode and the water's surface. But what I
found was a dynamic interaction between the gap voltage and the
electrostatic forces. As the voltage is increased the electrostatic forces
pulled the water up closing the gap distance until it fires. With this in
mind I realized the cap was probably firing with much less than a full
charge.

In an attempt to get pictures of this effect I added a bit of yellow food
coloring to the water and was able to capture a couple interesting images
which can be seen at
http://www.briananddebbie-dot-com/images/Backyard%20Science/Water_Arcs/water_arc
s.htm

Next Steps:

1) I need to measure the cap voltage and see how high it's getting before it
fires. My expectation is this will allow me to increase the gap setting from
.25" to around .75" thus putting more energy into arc.

2) I want to reduce the surface tension of the water and see what effect
this has. It may create a more pronounced effect on the water or maybe not.
I'm not sure.

More to come...

Regards,
Brian B.
www.briananddebbie-dot-com



-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Friday, April 11, 2003 9:38 PM
To: tesla-at-pupman-dot-com
Subject: Re: Z-Machine Sparkage- Try this at home!!


Original poster: "S Gaeta by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<sgtporky-at-prodigy-dot-net>

Hi Brian,

I agree. I would not start with the huge capacitor. Maybe you should work
your way up in 10uf increments! The biggest high voltage cap I have is only
10uf anyway. That is scary enough for me! I would work my way up in .05uf
increments :-)

The choke serves no purpose whatsoever. The brass ball gap apparatus I was
using was from one of my first tesla coils that was scrapped. I was
experimenting with DC at the time so the diodes and the choke was left over
from that project. The choke was used at the time to keep the RF from the
coil out of the diodes. That particular coil only produced 8" sparks, but
took out an answering machine in the next room. I have come a long way since
then, but I saved all the junk.

Sue

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, April 11, 2003 7:05 PM
Subject: RE: Z-Machine Sparkage- Try this at home!!


  > Original poster: "brianb by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<brianb-at-antelecom-dot-net>
  >
  > Sue,
  >
  > Stepping up to big energy would take a significant learning curve and
would
  > need to be accomplished in many smaller steps. A concern with that much
  > energy would be a steam explosion but who knows.
  >
  > I assume you are using the current limiting of the NST to keep from
blowing
  > the diodes when the arc short circuits them. One question - What is the
  > function of the choke in your setup?
  >
  > Regards,
  > Brian B.
  > www.briananddebbie-dot-com
  >
  >
  > -----Original Message-----
  > From: Tesla list [mailto:tesla-at-pupman-dot-com]
  > Sent: Thursday, April 10, 2003 7:40 PM
  > To: tesla-at-pupman-dot-com
  > Subject: Re: Z-Machine Sparkage- Try this at home!!
  >
  >
  > Original poster: "S Gaeta by way of Terry Fritz <teslalist-at-qwest-dot-net>"
  > <sgtporky-at-prodigy-dot-net>
  >
  > Hi Brian,
  > I'm not exactly sure, but something tells me that it will be rather
intense,
  > that you that you shouldn't be anywhere near it! Perhaps the first test
  > should be made with an expendable video camera, with you remotely
controling
  > it from an underground bunker! I'd be reeeal curious to see what that
would
  > do!!
  >
  > Cheers,
  > Sue
  >
  > ----- Original Message -----
  > From: "Tesla list" <tesla-at-pupman-dot-com>
  > To: <tesla-at-pupman-dot-com>
  > Sent: Wednesday, April 09, 2003 8:27 PM
  > Subject: RE: Z-Machine Sparkage- Try this at home!!
  >
  >
  >   > Original poster: "brianb by way of Terry Fritz <teslalist-at-qwest-dot-net>"
  > <brianb-at-antelecom-dot-net>
  >   >
  >   > Sue,
  >   >
  >   > Great pictures. Wonder what would happen if I used my 227uf/22kv cap?
  >   >
  >   > :-)
  >   >
  >   > Regards,
  >   > Brian B.
  >   > www.briananddebbie-dot-com
  >   >
  >