[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Sudden Jump in NST Current



Original poster: "rheidlebaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rheidlebaugh-at-zialink-dot-com>

Dave; at times the load current of the TC can be fed back to the NST. That
is why some of us use a series coil or wire wound resistor in the NST feed
wire to the spark-gap. The inductive reactance isolates the transformer from
the gap current for a few microseconds to protect the NST.
  Robert  H

> From: "Tesla list" <tesla-at-pupman-dot-com>
> Date: Sun, 13 Jan 2002 22:50:08 -0700
> To: tesla-at-pupman-dot-com
> Subject: Sudden Jump in NST Current
> Resent-From: tesla-at-pupman-dot-com
> Resent-Date: Sun, 13 Jan 2002 23:16:24 -0700
> 
> Original poster: "David Kyle by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <dave-at-kyleusa-dot-com>
> 
> 
> Coil Specs:
> 
> 20 Amp Variac power controller
> 
> 3 x 15KV at 30ma Transco transformers for a total of 15KV at 90ma
> 
> 210uf PFC capacitor
> 
> Standard Terry RC neon protection circuit (less MOVs)
> 
> SRSG using .1 inch Thoriated Tungsten electrodes with a static safety gap in
> parallel
> 
> John s SRSG LC phase circuit
> 
> .03 uf at 70 KV Maxwell capacitor bank
> 
> Primary - 14 turns .25 copper tubing currently tapped at turn 10
> 
> Secondary 6.25 inch PVC with 36 inches of #22 wire
> 
> 24 inch spun aluminum toroid
> 
> 
> 
> First let me express my thanks to the participants of this list for the
> awesome
> assistance that has enabled me to exceed my goal of achieving 36 inch arcs.
> After some serious tuning I have observed greater than 36 inch streamers
and I
> am sure there is more to be had. But I am seeing significant current
> consumption that I am unable to explain.
> 
> 
> 
> I did my initial current tests with a Jacobs s ladder and saw a max of about
> 10
> Amps with the PFC caps. When tuning the coil I find that as I bring the
> voltage
> up I first get multiple dancing 18 inch streamers with a very raspy sound
from
> the SRSG. Current draw appears to be in the range of 10 to 15 Amps. Then as
> the
> input voltage reaches about 100 volts a dramatic transformation takes place.
> The sound becomes a singing 60Hz and a single very strong streamer starts to
> reach out and slowly circle the toroid. The combination of the sound and the
> bright streamer reaching out over 36 inches is impressive if not a bit
> daunting. But a look at the meter shows the current jumping to greater
than 30
> amps and after a minute or two the 20 amp fuse in the Variac blows. I also
> noted the NST protection circuit resisters get very warm suggesting a
> significant jump in NST output.
> 
> 
> 
> Might this be the NST going into some kind of saturation mode and if so am I
> running into trouble?
> 
> 
> 
> Dave
> 
> 
> 
> =========================================
> Dave Kyle
> Austin, TX USA
> Email: dave-at-kyleusa-dot-com
> 
> 
> 
> 
>