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

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

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

Brian,

Very interesting observations and great photos!
I finally got to your page after playing with the hyperlink a bit.

I noticed something similar when I worked for a high voltage power supply
manufacturer. We used to test the power supplies before they were potted by
submersing them in lexan containers filled with liquid freon (now banned).
The freon was used because it is a good insulator, and leaves no residue on
the boards. It is also very light and volitile, as it turned to gas rather
quickly. The surface tension is much less than water, so the effects were
much more pronounced. When we powered up anything in the freon, it would
cause the freon to roll. It actually gave the illusion that it was boiling.
The rolling effect was caused by the freon getting charged the high voltage
point, and then the charged liquid would migrate toward the parts of the
supply that were at the opposite potential (ground). If you didn't fill the
container up enough, and there was say, only a quarter inch or so of freon
covering the sharp high voltage points, there would be a freon stream
shooting up several inches into the air! Of course the higher the voltage,
the worse it was. This really freaked out the new people!

Do not try that one at home! I am pretty sure that this stuff is one of
those banned chemicals that is impossible to get now, but in case anyone has
any of this stuff lying around, I thought I would mention that it has caused
a lot of people to quit that job because of the dammage it caused to their
lungs. It messed me up too, but I slowly got better after I left that place.
Stick with water folks!

Sue

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, April 12, 2003 6:52 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/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