Thank you all for the input so far!
1) Bert:
In your opinion, with a SRSG/NST setup, how often should a safety gap pop?
10% of the time, or less? Based on what you are saying, I'd say the
resonant rise symptoms match my situation. I can see the safety gap
preventing things from 'rise' escalating, but that doesn't seem like a
permanent fix? I like your previous suggestion of removing the PFC caps and
starting over...but I am guessing the BPS and capacitance are not
happy...so ultimately do I need to re-size the MMC? What do you suggest on
sizing?
2) Gary:
I am glad you brought this up. I had initially removed the MMC and swapped
in my Maxwell .06 uF cap, but no amount of fiddling could get the gap to
reliably fire, let alone produce streamers. I have seen situations like
this before, and it was always due to the tank cap being too large. I have
no idea how your 15/60 is charging and firing a .04 uF cap! For my NST
setup with 120 BPS, JavaTC suggests a .0553 uF cap. For you, it suggests a
mere .0277 uF.
To answer your question, 'I suspect that
you were unable to stop the safety gap from firing so you opened it up to
where it stopped?', the answer is YES, you are correct.
My cap options are MMC (100 caps of .068 @ 2,000 VDC) or Maxwell pulse cap,
.06 uF @ 50,000 volts)...what do you suggest I try?
3) Phil:
Thanks for digging that out of the archives! I always love reading material
from Richie. I can't wait get a real transformer one day (it WILL happen)
and then I can leave the NST's behind. I think this all confirms what
everyone is saying...my tank cap needs to be altered.
4) To anyone else still reading...
Here is a pic of coil running...I did manage to take a quick video and here
is a single frame. By scaling on the photo (secondary is 26.5" inches of
winding), the lower streamer alone is 62+" from the breakout point to the
end of the frame. It is 72" from the break out straight down to the ground,
and this streamer ALMOST hit the ground at an angle, so I'd say it was
right around the the 6 foot mark. The amp meter was showing 40 amps...4.8
kVA YIKES!
https://imgur.com/a/xQKOpbx
~Dan
Kansas City area
On Tue, Nov 20, 2018 at 4:18 PM phil <pip@xxxxxxxxxxx> wrote:
> Dan,
>
> Fusing blowing issues aside you mentioned you're hoping the performance
> to be the same. Sadly I doubt you will get the same performance unless
> Lady Luck shows her hand. A SRSG is never a straight swap for a static,
> the optimal cap size for one rarely if ever suits the other. This is the
> reason a lot of people give up with them, plus the hassle of converting
> a motor of course and controlling the phase correctly. Unfortunately the
> real benefit of a Synchronous system can only be utilised if you use an
> external ballasted transformer, NOT an NST with it's inbuilt shunts.
> Don't run ARSG (asynchronous) with a NST unless you're feeling brave and
> don't like the NST much.
>
> As for SRSG if bored sometime have a look at a very old post from Richie
> Burnett (below) but in your case with a NST as the power source, because
> of its inbuilt shunts none of it will apply, but it gives you a flavour
> of how things can work with an SRSG.
> https://www.pupman.com/listarchives/2001/June/msg00679.html
>
> Phil T
>
> On 19/11/2018 02:24, Daniel Kunkel wrote:
> > I finally got my SRSG online tonight. To my dismay I started blowing 30
> amp
> > fuses in my supply variac. I am hoping the list can help me figure out
> why
> > this is happening...we have guests coming over for Thanksgiving and they
> > are expecting a show!!! LOL
> >
> > When I was running the previous setup using a vacuum quenched single gap,
> > my NST bank (15kv @ 120ma) was only pulling 10 amps using a total of 302
> uF
> > in PFC caps. I was expecting similar performance with the rotary gap.
> >
> > Basic specs are:
> > 6.5 x 26.5" secondary with 1,057 turns or 22 awg
> > .033uF MMC
> > 1.8 kva NST's
> > Terry Filter
> > 1/2 HP, 3,600 RPM motor
> > 2 flying electrodes (1/8" tungsten, through disc design), for 120 BPS
> >
> > Thanks for any insight,
> > ~Dan
> > Kansas City area
> > _______________________________________________
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> > Tesla@xxxxxxxxxxxxxxxxxx
> > https://www.pupman.com/mailman/listinfo/tesla
>
> --
> Regards Phil www.hvtesla.com
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