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RE: RQ gap question
While your 2" diameter tubes will certainly work, I doubt they would do any
better than say 1" tubes, unless you were pumping an incredible amount of
power through them. Only then might they do better due to a lower
temperature rise.
The breakdown voltage of the gap is more or less proportional to the total
gap distance. The wider the gap, the higher your capacitor will charge
before the gap fires. Your coil's power throughput and performance
increases with increasing gap voltage. But the higher your gap breakdown
voltage, the more your capacitor and NST will be stressed. This issue is
well understood and this should answer your question about 0.21" vs. 0.18".
As far as six .03" gaps being the same as three .06" gaps, this is a very
complex issue. While the gap breakdown voltage will be similar for both
cases, two other things will be different.
Quenching - the point when the gap stops conducting and primary/secondary
energy exchanges cease - appears to be better when a gap is broken into
several small gaps. The more gaps, the better the quenching. This is
probably because with the individual gaps being shorter, the relatively
closer cool electrode surfaces cool the hot plasma more quickly. The faster
a gap quenches, the less energy is wasted on heat and light in the gap, so a
coil is more efficient.
However, multiple gaps also seem to exhibit higher resistive gap losses than
single gaps of the same breakdown voltage, the exact nature of these losses
is not well understood.
I've tried both types and I've found that a single gap (with mucho airflow)
gives me superior performance over a multiple cylinder gap. There may be an
optimum number of series gaps to achieve a maximum efficiency between
quenching and other losses, but no one to my knowledge has ever performed a
controlled experiment keeping Vgap constant while varying the number of
series gaps.
Regards, Gary Lau
Waltham, MA USA
-----Original Message-----
From: Tesla List [mailto:tesla-at-pupman-dot-com]
Sent: Monday, December 20, 1999 6:54 PM
To: tesla-at-pupman-dot-com
Subject: RQ gap question
Original Poster: Ted Rosenberg <TRosen1-at-Tandy-dot-com>
Got a question re RQ style static gaps:
Previously, a list member suggested the following as a good
reason to use
larger diameter copper tube/pipe in the static series gap.
====================
The "sense" of large diameter copper multi-gap cylindrical
RQ style spark
gap:
features large active and inactive surface area with large
ROC surface to
spread heat well, resulting in cooler gap for quench,
expediting more
efficient forced air cooling,
(low bulk large area loses heat easily expedited by
circulated air)
RQ gaps work well because they represent a good tradeoff
between walls being
thick enough, with a large open mass to heat slowly when
conducting, but
thin enough with a extended surface area to cool quickly
when not conducting
in the presence of forced air.
====================
All that makes sense to me. So I got some 2" diameter copper
tube/pipe. NOW
my question is what is the benefit of, say 8 tubes with .03
spacing versus 7
tubes or 6 tubes with a different spacing. In other words,
isn't 6x3 the
same as 3x6.
For example, could use 7 gaps with .03 to start with or 6
gaps with .03 to
start with. One gives me .21 and the other .18. What's the
difference?
Thanks to all.
Gappless in Ft Worth.
Ted