FW: More Mini Coils
From: Robert W. Stephens[SMTP:rwstephens-at-headwaters-dot-com]
Sent: Thursday, June 19, 1997 6:34 PM
To: Tesla List
Subject: Re: More Mini Coils
> From: Alfred A. Skrocki[SMTP:alfred.skrocki-at-cybernetworking-dot-com]
> Sent: Wednesday, June 18, 1997 7:29 PM
> To: Tesla List
> Subject: Re: More Mini Coils
> Wednesday, June 18, 1997 1:01 PM Edward V. Phillips
> <ed-at-alumni.caltech.edu> wrote;
> > I have a rather small coil here, running off a 12 volt
> > battery with a transistor interrupter. I get 4.5" streamers
> > when the input current is about 2 amps, so results are almost
> > identical to Malcom's.
> Could you give a more detailed description on that coils specs?
> > Interesting thing........ If I turn the coil on in the dark, there
> > is almost no discharge visible from the 2.5" toroid. As the seconds
> > go by the discharge increases until there is a beautiful purple crown
> > coming off the terminal.
> Sounds like a resonant build to me; think of the resonant circuit of
> the secondary like a swing being pushed by the primary, with each
> properly timed push the swing will go a little higher until eventualy
> it will be at full swing.
This effect is quite probably due to the time necessary to ionize a
cloud around the top terminal which can then support streamers at a
lower voltage than unionized air. This is the likely phenomenon that leads to
final breakout since the time factor has been reported by Ed to be measured
in seconds, not milliseconds. The peak voltage on the top
terminal will be approximated by the first pop of the primary gap and
will certainly be achieved in no more than several ringing
cycles. For a 60 Hz mains operated coil this can be less than 8 mS
This was discussed on the List in some detail a while ago when it was
also determined how the streamer tends to grow on the ion channel
laid down with successive pops. It seems to be very much like the stepped
leader phenomenon of full sized lightning.