Re: High speed Tesla spark photographs - WOW!!!

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>

Hi Peter and All,

This is wonderful!!!

I think these are the first high-speed arc propagation photos taken 
of Tesla coil streamers!!!  The quality is amazing for such a simple setup!!

This is a remarkable photo (my screen saver now):

http://tesladownunder.com/HVRotMirrorTeslabigSpark1Singel.jpg

To illustrate what it represents, consider a typical arc to ground as 
seen on an oscilloscope as in this photo from Dan.

http://drsstc.com/~piranha/PIRANHA/DansPictureGroundArc.jpg

The waveform on the top terminal builds up until the voltage arcs 
over to ground.  If I turn that picture on end and put it beside 
Peters arc photo you can see the same situations in time going from 
bottom to top.

http://drsstc.com/~piranha/PIRANHA/PetesPictureWComents.jpg

Peter is simply taking pictures of the streamers through a fast 
spinning mirror.  Thus, he is able to see each "cycle" of a bang with 
1/10,000,000 second resolution!!  Here is his setup:

http://tesladownunder.com/HVBrokenSparksRotatingMirrorMotor.jpg

http://tesladownunder.com/HVRotMirrorTeslabigSetup.jpg

Be sure to check out this:

http://tesladownunder.com/HVRotMirrorTeslabigSpark1SinglePartPowerArc.jpg

http://tesladownunder.com/HVRotMirrorTeslabigSparkPowerArcGaps.jpg

The single streamer "pulse" has "gaps" in it!!!  I would "guess" that 
the dark areas have higher conductivity due to the air being hotter 
and in avalanche more.  Not sure really...

You can see the electrode "glow" from ionized air in this picture on the right:

http://tesladownunder.com/HVRotMirrorTeslabigSparkElectrodeglowDelay.jpg

http://tesladownunder.com/HVRotMirrorTeslabigSparkElectrodeglow.jpg

The streamer seems to have an after glow too!!  And a tiny right 
direct streamer when the current peaked at the top tip of the electrode!

Wild stuff!!!  Many more questions than answers!!!

Great work Peter!!!!!!!!  This is probably the most important tool to 
study coils to come along in many years!!!


I am wildly trying to get Peter's idea going myself too:

http://drsstc.com/~piranha/PIRANHA/StreakCam-01.JPG

http://drsstc.com/~piranha/PIRANHA/StreakCam-02.JPG

http://drsstc.com/~piranha/PIRANHA/StreakCam-03.JPG

A motor will spin the aluminum block with mirrors on four sides at up 
to 20,000 RPM (probably only needs 10,000 RPM though).  Super simple 
to do!!!  Spent all morning reading the instruction on how to run the 
camera manually %:o))  Waiting on the motor and mirrors to arrive 
now...  The Lexan camera shield is in case it goofs up ;o))

Cheers,

        Terry











At 05:54 PM 9/11/2006, you wrote:
> I have been working on a setup to show high speed streak photos of 
> Tesla sparks. Setup is a 3000 RPM synchronous motor with a single 
> mirror which reflects the sparks image to my Nikon D70s with 180mm 
> lens. I can resolve the 100kHz ring down sparks readily with about 
> 1us resolution. 1 camera pixel is 100ns. Calibration is 
> geometrically and with a LED at 100kHz.
> With this running on a 6 inch spark to ground I can see detail of 
> the central channel of the initial spark, details of the 5 or so 
> ring down sparks, gaps in the spark channel, immediate and delayed 
> electrode ionisation effects and (I think) a spark hitting a dust mote.
> Photos and details here:
> http://tesladownunder.com/HighVoltage.htm#High%20speed%20Tesla%20spark%20photography
> Terry is also working on a more advanced purpose built setup.
>
> Peter
> http://tesladownunder.com