RE: Heat & Rotary Gaps (success?)

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>

Running a coil without a secondary is extremely stressful on one's caps,
and would explain why your gap got so hot.  If you want to run things
without a secondary, construct a dummy load out of a string of 6 or more
(?) 150W/120V halogen bulbs and use that in place of your primary.  With
my 15/60, I used 4 lamps.  You'll need more, but I can't predict how
many.  That will safely dissipate the power and it will also allow you
to determine the best gap phase setting by noting when the lamps are
brightest.

Chokes?  Between the gap and NST for protection?  Loose them - they'll
either do no good or make matters worse, particularly it they're
air-core.  See my web page on protection networks at
http://www.laushaus.com/tesla/protection.htm for full details.  How do
you know the chokes are dampening kickback?

Regards, Gary Lau
MA, USA

> Original poster: tesla popp <teslas_lab@xxxxxxxxx>
>
> Good question.  I didn't have a secondary in it at the
> time.
>
> I now have assembeled one of the twins and I am a bit
> irritated.  It is only making 4' sparks at the ~15/120
> I am getting from the tranny.  My chokes are really
> dampering A LOT of kickback.  Now that the secondary
> is in it, my trannys safety gap is firing at 98% full
> power, which makes me leery.
>
> Thanks for getting to the point.
>
> Coiler forever: Jeremiah Popp
>
> --- Tesla list <tesla@xxxxxxxxxx> wrote:
>
>  > Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>
>  >
>  > When running an NST through a Variac, the optimal
>  > phase setting of the
>  > SRSG will vary depending on the Variac setting.
>  > Additionally, NST's are
>  > not the well-behaved linear devices that intuition
>  > and simulation models
>  > would have us think.  Ferroresonance occurs at
>  > higher mains voltages,
>  > causing an LTR cap to become mains-resonant, and
>  > draw lots of power.
>  > Very bizarre stuff and impossible to predict or
>  > model.  But it does
>  > effectively supercharge an NST power supply.
>  >
>  > Have you metered your NST primary current?  That
>  > will give a better
>  > indication of how much power is actually being
>  > processed by your gap.
>  > My 15/60 NST pulls close to 20 Amps on the
>  > input-side of my 120VAC
>  > Variac, and this is WITH PFC caps.  And as such, my
>  > propeller gap
>  > spinning rod is just moderately warm.
>  >
>  > I have to ask what may be a dumb question - do you
>  > have a secondary in
>  > place and is it properly tuned?  If no or no, then
>  > the power cannot be
>  > transferred to streamers, and will be expended as
>  > heat in the gap
>  > instead, which may be what you see.
>  >
>  > Regards, Gary Lau
>  > MA, USA
>  >
>  >
>  >
>  >  > Original poster: tesla popp
>  > <teslas_lab@xxxxxxxxx>
>  >  >
>  >  > Ok, I have a 15/120 NST.  My cap is 0.05uF
>  >  > Tungstin rod got hot enough to change color.
>  >  >
>  >  > I ran it for 30sec and it seams like it won't get
>  >  > overly hot if I have everything in phase.  Yet,
>  > if I
>  >  > run it at 70% power, it gets hot twice as fast!?
>  >  >
>  >  > Coiler Forever: Jeremiah Popp
>  >  >
>  >  >
>  >  >
>  >  > --- Tesla list <tesla@xxxxxxxxxx> wrote:
>  >  >
>  >  >  > Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>
>  >  >  >
>  >  >  > You didn't say what kind of power supply
>  > you're
>  >  >  > using?  With my 15/60
>  >  >  > NST, the rotating rod gets just moderately
>  > warm.
>  >  >  > But I'm sure if one
>  >  >  > were using a pole pig, that may be pushing
>  > one's
>  >  >  > luck.  You are using a
>  >  >  > shield in case things go bad, right?  I
>  > couldn't
>  >  >  > comment on a subjective
>  >  >  > "too hot to touch" without an actual
>  > measurement,
>  >  >  > but it is cause for
>  >  >  > concern.
>  >  >  >
>  >  >  > Regards, Gary Lau
>  >  >  > MA, USA
>  >  >  >
>  >  >  >  > Original poster: tesla popp
>  >  >  > <teslas_lab@xxxxxxxxx>
>  >  >  >  >
>  >  >  >  > Just set up one of my twin coils with a
>  > propeller
>  >  >  >  > gap...
>  >  >  >  > I found that after 10 seconds at 50% power,
>  > the
>  >  >  >  > rotating tungsten rod was far to hot to
>  > touch!
>  >  >  >  >
>  >  >  >  > Should I be worried about the "heat" VS the
>  >  >  > SRSG's
>  >  >  >  > plastic the  case /melting the high density
>  > PVC
>  >  >  > that
>  >  >  >  > holds the rotating tungsten rod?
>  >  >  >  >
>  >  >  >  > Jeez is this thing LOUD!!!
>  >  >  >  >
>  >  >  >  > Coiler Forever: Jeremiah Popp
>  >  >  >  >
>  >  >  >
>  >  >  >
>  >  >
>  >
>