[Prev][Next][Index][Thread]

Re: Fw: Arc Impedance Study - Computer Models

Barry,

Thanks for the very interesting description - sounds like quite an
interesting streamer display indeed, and not like anything I've seen off
a distruptive coil! Any feel for what the break rate might have been?

It might be that this coil was operating at a higher frequency -
roughing out the secondary and toroid, the system may have been
operating at >400 kHz while also having a bit larger bang size (~5
Joules) than coils this size usually have. Coupling also sounds as
though it might be a bit higher. They also seemed to be getting
excellent streamer length versus coil length. Wonder if it was the
combination of the higher frequency and relatively large bang size that
accounts for the difference in appearance. Very curious, for sure! 

BTW, it must be nice getting paid to play with lightning! :^)

Thanks, and safe Marxin' to you, Barry!!

-- Bert --

Tesla List wrote:
> 
> Original Poster: "B**2" <bensonbd-at-erols-dot-com>
> 
> Hi Bert,
>     There were at most two streamers at any time.  One was growing
> while the other one was being absorbed (appearance).  Just as one
> streamer finished the second would dart out four to five feet from the
> toroid as a solid trunk with no branches like a tube coil streamer.
> Then the branches would form outward from the end like a flower
> blossoming before the eye.  The streamer branches formed slowly
> compared to the initial trunk.  It sometimes took more than a second
> to finish.  Like a Lichtenberg ballet the last little streamerlets
> filled in the end to give it the appearance of a three dimensional
> snowflake on a long pole or a loblolly pinesque quality.  Then
> immediately a long spike like streamer would form on the other side of
> the toroid and the previous streamer would quickly fade.  The sound
> was like the crack of a quick whip.
> 
>     I once tried to recreate the effect of the streamer in the lab.  I
> discharged a Marx erected to 600 kV (Cerected +AD0- 14 nF) into two 10,000
> ohm ceramic resisters (20 kOhm total circuit R).  This gave an
> overdamped waveform (single pulse) with a current peak of around 30
> amperes (L +AD0- about 4 uH).  The pulse was like an unnaturally super
> fast lightning bolt.  Rise time of a few nanoseconds, fall time to 50+ACU-
> of around 100 us.  The appearance was intensly gratifying.  An
> intensly beautiful tree like discharge.  All of the main streamers and
> streamerlets were of nearly equal brightness and distinction.  The
> sound was similar but not as intense.  The discharge was 33 inches
> long.  The surge impedance in this circuit with streamers is about 17
> ohms.  The energy in the Marx before the discharge was about 2.5 kJ.
> 
> Barry
<SNIP>