Re: Phase controller question. Final success

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

Original poster: "Christoph Bohr" <cb-at-luebke-lands.de> 

Hello John.

 > I wonder why the gap is so loud?

I had some thought about that, too. First of all, while in a RQ sparc gap
the discharge is enlosed inside the tube and the sonic waves will probalby
follow
the path of that tube ( away from my ears ) the discharge in my rotary gap
is completely exposed. Another thing is, that the static gap fires at lower
voltage. When connected parallel to the
RSG almost all firings occour in the static gap. But why is this still
louder than my older RSG?
I believe that it might have to do with the primary inductance, whis is
lower in this system, thus increasing the peak current, but this is just
another idea.
Furthermore I noticed that the voltage at the point of discharge is a bit
higher than the supply voltage alone, maybe 15KV or so..... ( not measured,
safety gap estimation )
After all, it is bearable with a noiseguard which I'd consider advisable
anyway. In a way the sound increases the "scary" factor for the people that
come over to see the coil, even when they knew the pics there is still
something unexpected. Though even the streamers would do the job. While they
look very faint in the pics they look much brighter and very forked to the
eye.

 >  It's good it's all working now.
Thanks, I really feel the same.If this had failed itwoul have been just too
bad after all the work.

 > Maybe you need a larger capacitor value now using the rotary for
 > best results?
That is what I thought of, too. But currently I only have 2 of the 30nF caps
and this will be the only caps I can afford, at least for the next few
month.
But the bigger cap would lead to other problems. If I increase C to 90nF I
will have to tap at ca 2,5 turns which will bring the surge current up to a
point the caps will not take too long.
So I could go for a bigger topload and keep my tapping at the 4th rurn. But
when I increase C3 I need more C2 capacitance, too, which is a problem
already with 60nF C1...

Another thing is that I am not sure how much power I am really putting
through. I know I draw nearly 10 amps at 230V, 2,3KVA. (I use no PFC.)
On the other hand, from the fomula P= 0.5 x BPS x C x Vē I would get
0.5x200x(60exp10^-9)x10000^2= 600 Watt ?! Even with worst power factor 600
Watts can't generate 10Amps current draw at 230V, can they???
Something can't be right here...., maybe you have some ideas. Kurt already
pointed me to some aspects I have to take into account, but most of them are
hard or
impossible for me to measure, which makes simulation difficult.

Currently I am not too concerned about the maximum output, though I wish for
better efficinency.
Mainly I wanted to build a nice looking coil that will last longer than its
predecessor and gives me the chance to show it to people in a safer way.

OK, thats it for now, but there is still a lot more to come ;-)

Best regards

Christoph