Re: Water sparks (fwd)

[Steven Roys <sroys@xxxxxxxx>]

---------- Forwarded message ----------
Date: Wed, 6 Aug 2003 14:51:18 -0400
From: B2 <bensonbd@xxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: Water sparks (fwd)

Hi Sean:

Is there any salt in the water?  I tried the same thing 30 years ago.  I
used a saturated salt solution.  The capacitor was a paper and oil Sangamo.
It was rated 1 uF and charged to 10 KV.  The resulting sound left me deaf
for about 30 minutes.  The bright flash blinded me for 5 minutes.  At the
time I had my face 6 inches from the water surface and HV electrode.  I was
studying the interesting effect that the HV electrode had on the water
surface.  The surface rose up to a dimple as the wire electrode (+) began to
produce corona and then BANG!.  I received a proper education in the use of
hearing protection and safety glasses from this experience.

If you value your HV power supply use a 1 MEG Ohm, 50 watt or greater
resistor between the power supply and capacitor.

If you value your life use a bleeder resistor of about 10 MEG Ohms at 50
watts across the capacitor.  Use a shorting stick with something like a 100
watt, 10 KOhm resistor between the brass hook and the ground braid.  Work
with a friend.

Use a shallow glass bottomed dish with some type of photographic paper
underneath to capture the discharge images.  The positive discharge is
longer and quite interesting.  A book from the library on Kirlian
Photography may help.

Cheers,

Barry

> ---------- Forwarded message ----------
> Date: Tue, 5 Aug 2003 09:35:41 -0700
> From: Sean Taylor <sean.s.taylor@xxxxxxxxxxx>
> To: High Voltage list <hvlist@xxxxxxxxxx>
> Subject: Water sparks
>
> Hi all:
>
> A while back, there were several posts on the Tesla list about creeping
arc
> discharges along water surface.  It was all started by a picture of the Z
> machine at Sandia. Anyhow - I have been trying to do this, and first I
used
> a 10 kV DC PS I had, and just depended on the filter cap for the discharge
> (bad idea, I know, but it was just a test) and it worked pretty well.  I
had
> about 1 inchor so of arcs going out from the electrode (brass drawer
pull).
> I recently just tried it again with a couple maxwell pusle caps, with
higher
> voltage and more energy storage( 0.188 uF, ~15 kV) than the DC power
supply.
> Results were quite disappointing though - only about 1/2" max creeping
> discharge, but plenty of noise.  There were more arcs across the surface,
> but not nearly the same length.  So, here's the question/my theory:  Are
the
> Maxwell pulse caps too good, and the current dies out too quickly so the
> arcs don't have time to form? Or is something else going on?
>
> Thanks for the help!
> Sean Taylor
>
>