Re: Spark length, SSTC vs. spark gap

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

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 2/8/01 8:14:52 PM Eastern Standard Time, tesla-at-pupman-dot-com 
writes:

> Hi Gary,
>           I think your note sums up the various conundrums about power 
>  vs spark length well. It is theoretically possible to generate 
>  extremely long sparks using a very low average power input. Your 
>  approach performs that sort of trick. It seems to me that there is a 
>  need for a list of definitions so that in discussing length/power, we 
>  can refer to a specific set of parameters. For example, huge sparks 
>  could be generated by the ringing-up approach (given a suitable 
>  topload) but for a limited power input could occur at a rate of just 
>  a few per second. Another case is a gap driven coil producing sparks 
>  at say 200BPS so that they appear continuous to the eye. Perhaps it 
>  is all a matter of perception and expectation.

Malcolm, Gary, all,

Maybe in conjunction with all this, we need to also consider what
Greg L called the coalescence of the spark.  Above a certain
break-rate, the spark was able to coalesce and form long streamers,
below that rate, it formed a great number of small streamers all
around the toroid.  His old coil coalesced at about 220 bps, but
the Electrum coil coalesced at about 110 bps.  Some of my coils
have coalesced at 60 bps.  The toroid size is also a very critical factor
in determining successful coalescence.  In one small S.G. coil I made
(the photo of the "stylish coil" I just added to my webpage), the
spark coalesced and formed a nice 9" long single spark with a
wavering tip, when using a 4.5" by 1.5" toroid.  But with a 5" by
1" toroid, just a mass of short (5") thin sparks formed all around
the toroid.  This coalescence effect seems related to, but perhaps
different from, spark growth.

John Freau