Re: On sparks

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

Original poster: "Kennan C Herrick by way of Terry Fritz <twftesla-at-uswest-dot-net>" <kcha1-at-juno-dot-com>

John (& all)-

[snipped]

> For a given power input, a low break-rate demands
> a larger "bang size" (a bigger dump of energy from the cap for
> each gap firing of a spark gap TC).  It would seem that using a 
> high break-rate to produce long sparks is similar to using a longer
> duration application of lower-power bursts like a CW coil.  In 
> constrast, 
> a low break-rate spark is formed from a powerful, fast burst of 
> energy,
> repeated at a less frequent interval.   There seems to be no
> substitute for fast powerful bursts for obtaining longest sparks
> for a given input power.   I would go as far as to 
> say that high breakrate coils are tending towards CW coils, and 
> that
> is why a high break-rate tends to be less effective at producing 
> long
> sparks for a given input power.  High break-rate sparks tend to be
> fatter, but shorter than low break-rate sparks for a given input
> power to the system.  I should say here that I define a low break
> rate as something around 120 bps.  I define a high break-rate as
> something around 240 bps and higher.  The effectiveness of the
> input power to produce long sparks seems to decline as the
> break-rate is increased beyond 120 bps or so, at least in the
> work I've done.  Of course if the break-rate is too slow, then
> the benefits of the growth of sparks due to partial ionization of
> the air, is lost, or severely diminished, and the spark length
> is reduced.

I've had no experience with spark-gap coils but what you say makes me
think this:  At the higher break-rates, I wonder if you're not
experiencing reduction in the voltage at which the gap(s) break down, due
to the residual temperature of the air, in the area of the gap, remaining
higher.  Absent that effect, I'd think that each break would produce
exactly the same spark regardless of the rate--because the impulse of
energy applied to the primary would be the same since the gap's breakdown
voltage would be the same.

Ken

[snipped]

> John Freau
________________________________________________________________
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today!  For your FREE software, visit:
http://dl.www.juno-dot-com/get/tagj.