Re: Capacitor Help

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Christoph Bohr" <cb@xxxxxxxxxxxxxxx>

Hello Malcom

> That looks interesting.  I take it the spark gap is very important with
> regards to output.
indeed it is, but at your current power levels its may prove pretty easy
to build a good solution for a static gap, your approach sounds reasonable.
I am not sure how thick a penny is, sounds like it could be a bit too wide,
but then again, you can use less gaps and will be OK.
However, the idea is not to strain the gap, but to distribute it into many
smaller gaps wich can transport heat away better, thus helping quenching.

> Interesting you should mention that.  It came to mind and we didn't have
> anything handy right here at work to put inside the secondary so we stuffed
> some wal-mart bags in there to form a dielectric between the top and bottom.
Hm, I am not sure if this would help. Additionally, if you fill your 
secondary with
a bunch of material, this should not aid the HF-propperties. If have no idea
how many bags "some" are ;-)
At lower power you should get away without any baffles, just make sure
the inside of the tube is clean, dry, no oil, you can still sand, dry 
( not bake )
and warnish the inside of the tube if you haven't done so, yet.


> I got to thinking... what about a rotary powered spark gap?
Nice to have, I prefer the SRSG, but more for smooth operation,
not neccessarily for performance reasons. However, A-RSG may
sound cooler, but are amlost sure deadly for your NST, unless you use
high break rates...

> old spark plug distributor from a car and attach an electric motor to it?
I doubt it will work too well, after all it was not designed to handle the
power(currents). There is usually a small carbon rod that makes contact
with the center of the rotor, this is so not pulse-power-compatible.. ;-)


> With a rotary spark gap do you just set the motor to a certain speed?
With a RSG, yes, you chose the speed in a manner, that the number of
revolutions and the number of electrode-alignments gives you the desired
break rate, typicaly 100, 200, 300, 400 bps, other configurations are
possible, but the positive effect of an SRSG vanishes somewhat over 300
or 400BPS.
With async RSG's you can vary the speed and by this the breakerate over
a broad range, but there usually is a sweet spot. Usually you use ARSG
with higher bps to avoid problems with surging. To really go from zero to
"whatever it might withstand" you usually need a special supply.... 
another story...

> busy charging and the distributor lines up the terminals and discharges it?
as long as the gap is able to fire, the is at least nothing dangerous 
about that,
unless you go below 100bps. But this is usually this is not the best mode of
operation for an rsg. One advantage of an RSG can be, that you can
predetermine when exactly the gap should fire, thus being able to charge
a bigger cap ( more energy ). Optimum cap sizes for each gap type will vary.

> I don't know, maybe I'm just thinking to hard about it :)
No, the idea came to my mind when I started coiling, too. But I never
tried it. I felt it was too obvious it would not work too well.
I find myself thinking if one could modify such a thing.... surely possible
but no, that just too wierd...
C'mon anyone, proove me wrong! ;-)

You did a great job with your coil in such a short time, congratulations!

best regards

Christoph Bohr