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RE: caps and JL
Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
When you run a say 15/60 into 30nF you will probably hit a point where the
power suddenly jumps way high as you turn up the input voltage. The NST
will growl from all the current and the lights may dim before the breaker
pops. We think this is do to the internal current shunts saturating and
losing their ability to bypass magnetic flux. Thus, the NST looses much of
it's current limiting ability.
Beware that the current is super high and this condition may blow the NST.
I put fuses on the inputs of my NSTs to stop them if they go into this
state. My small coil operates just on the edge of this effect. If the
rotary gap timing is off some, the current and voltage can go wild so the
fuse protects it.
I have thought of using this effect to get more power from an NST (SLTR)
but I never have found a way to control the effect enough.
At 12:44 PM 5/29/2001 -0400, you wrote:
>Here's an interesting tidbit that I've run into when placing caps in a JL
>I have a rebuilt 12/60 NST that now runs at 11850V and 184 ma. By itself,
>running a JL for testing, it could raise an arc to jump a gap of about 4"
>while drawing a full 15 amps from the 120V mains line. I started to play
>around with my 30nf 35kV Maxwell caps, first wiring one in parallel with the
>JL (machine gun, if I remember correctly), then I wired one in series with
>one of the HV leads from the rebuilt NST. I enjoyed a louder 60Hz hum,
>whiter arcs, and longer arcs. I was also now drawing between 6-9 amps from
>the wall as the arc ran up the JL. Intrigued, I wired a Maxwell cap in
>series with both HV leads from the NST. The whole setup will now arc the 7"
>gap at the top of my JL and draw a measly ~1 amp from the wall, according to
>my analog panel meter. The secondary windings in the NST (potted in
>petroleum jelly...many odd looks at the store with 8 cans of petroleum
>jelly...) still get nice an hot..hot enough to almost boil the petroleum
>Is this power correction from the secondary side? If so, has anybody
>noticed a lower amp draw from the wall in resonant charging tank circuits?
>I can't wait to use these Maxwell caps and this NST in a coil!
>wishing there was more time in the day...