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Re: Sonderman Testing



---------- Forwarded message ----------
Date: Mon, 29 Sep 1997 10:54:46 -0500
From: "DR.RESONANCE" <DR.RESONANCE-at-next-wave-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Sonderman Testing

To: Ed

Have noted some of your posts regarding cap damage & problems.  I'm
beginning to suspect the culprit may be your welding xmfr reactor.  We have
run 6 inch coils to over 11 ft. spark discharges with our reactors on pole
xmfrs and have not noticed any destructive effects.  I suspect you are
hitting a nice power supply resonance point that is causing your pole xmfr
to rise above its normal ratings.  The pole xmfr can take it but apparently
your caps can't.

DR.RESONANCE-at-next-wave-dot-net


----------
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: Sonderman Testing
> Date: Monday,September 29,1997 12:05 AM
> 
> 
> 
> ---------- Forwarded message ----------
> Date: Sun, 28 Sep 1997 16:45:17 -0700
> From: Bert Hickman <bert.hickman-at-aquila-dot-com>
> To: Tesla List <tesla-at-pupman-dot-com>
> Subject: Re: Sonderman Testing (fwd)
> 
> Ed,
> 
> Bet you didn't have any trouble hearing the cap's safety gap when it
> fired! :^) 
> 
> Seriously, you're seeing significant 60 Hz resonant rise between your
> ballast inductance and your tank cap. 
> Four giveaways: 
> 1. Your gap begins to sporadically (chaotic?) fire at about 25%. Do you
> also hear a sudden increase in the "hum" or "growling" coming from your
> pig at the 25% variac setting?
> 
> 2. The tank cap's 1" safety gap begins firing at 60% of max input. BTW,
> are this between sharp points or rounded electrodes?
> 
> 3. Gap firing performance improves without the ballast shunt resistors
> (higher ballast-tank cap Q). 
> 
> 4. Reducing the ballast inductance (increasing the current) results in
> poorer coil performance as you move above the 60 Hz resonance region.
> Your peak tank cap voltage is declining once you're off 60 Hz resonance.
> 
> The fact that your coil is in RF tune won't eliminate the effects of 60
> Hz resonant rise. Under certain particularly nasty rotary gap spacing
> and phasing conditions, your tank cap voltage can climb to 3X or 4X (or
> even more) the peak estimated peak voltage coming out of your pig. This
> phenomenon is likely what took out your previous cap, and it potentially
> (NPI) will do the same for your new one!
> 
> Your "bang" size is clearly not a problem if you are intermittently
> firing your capacitor's 1" safety gap. Based upon your earlier posts, it
> sounds like your primary wiring should be as good, or better, than what
> you had before. I'm beginning to think that one problem may be your 6"
> secondary! Although your coil was previously a very hot performer
> (especially for a 6" coil), SOMETHING is now limiting the efficiency of
> energy transfer from your primary tank circuit to your resonator:toroid. 
> 
> Some thoughts on what to look for/try next:
> 1. Change the current setting on your welder significantly so that you
> "detune" it off 60 Hz resonance and leave it there until the root cause
> of your coil's performance problem has been determined. 
> 
> 2. Reduce the cap's safety gap spacing, especially if it's arcing over
> between rounded electrodes. 
> 
> 3. Look for any signs of inter-turn shorting, internal arcing, any "hot
> spots" on the resonator, any odd burning smells, etc, any spots on the
> coil that look "strange". Shorted turns in particular can seriously
> reduce the performance of your secondary. Did you ever sustain any
> arc-overs between primary to secondary which may have damaged the
> resonator near the base?
> 
> 4. Since your coil's in tune, do an extended run (60+ seconds) to see if
> anything is getting abnormally "hot" in the primary circuit, as well as
> anywhere on the resonator. Are there any signs of excessive RF ground
> losses/heating? Remember: the energy that's not ending up in your
> discharges is being dissipated somewhere ELSE in your system! You just
> have to find out where!
> 
> 5. Have you recently made any oscilloscope measurements of the coil
> output waveform using a pickup plate or wire? Did anything look amiss?
> Could you tell where you were quenching?
> 
> 6. For a variety of reasons, it MAY be time to build a larger resonator
> more capable of handling the power levels you're at. A 10" resonator (or
> larger) WILL give you better performance. 
> 
> Good luck, Ed! I know you've been fighting this problem for some time
> now, and it must be frustrating!! Hope this helps a bit...
> 
> Safe coilin' to you!
> 
> -- Bert --
> 
> 
> 
>  
> 
>   
> 
> Tesla List wrote:
> > 
> > ---------- Forwarded message ----------
> > Date: Fri, 26 Sep 1997 18:47:25 -0400 (EDT)
> > From: Esondrmn-at-aol-dot-com
> > To: tesla-at-pupman-dot-com
> > Subject: Sonderman Testing
> > 
> > Last night I finally got my coil fired up again.  Changes since last
testing
> > were replacing all the contacts on the rotary and eliminating the
static gap
> > in series with the rotary.  The spark gap across the capacitor is set
down to
> > 5/8".  This is my 6" coil with a .025mfd C.P. cap, powered by a 14.4
kva pig.
> > 
> > The first project was to find the best tune at low power.  I had a
ground
> > wire set up maybe 3.0 feet from the toroid and a wire laying on the
edge of
> > the toroid pointing at the ground wire target.  The welder was set at
> > minimum.  It again wouldn't run worth a damn with the resistor bank in
> > parallel with the welder so I unplugged it, now using only the welder
for
> > ballasting.  I noticed immediately that I had much more consistent
firing of
> > the rotary spark gap.  It started to fire at maybe 25% of full variac
power.
> >  As I increased power, the safety gap across the cap would start
firing.  I
> > decided if the safety gap firing was due to an out of tune condition, I
> > should be able to tune the system by finding the tap on the primary
that
> > would allow the highest setting on the variac without firing the safety
gap
> > across the capacitor.  I plotted a whole range of tap positions and got
a
> > reasonable shapped bell curve, which is what you would expect.  The
best tune
> > position was between 11.75 and 12.0 turns on the primary.  This also
> > coincided with the hottest discharges from the secondary.
> > 
> > Now I opened up the safety gap across the capacitor to about 1.0".  I
was
> > very surprised to find out that I could only open up the variac to
maybe 60%
> > of full power before the safety gap across the cap started firing
again.  It
> > must be in tune, why is the safety gap firing????
> > 
> > I turned the variac down a small amount where it would run without
firing the
> > safety gap.  Increasing the primary current produces hotter sparks up
to a
> > point then at full current, the spark length falls off noticeably. 
This is
> > puzzeling.
> > 
> > Increasing the rotary gap speed causes hotter sparks for a while and
then
> > falls off past a certain point.  This is unlike my past experience
where this
> > coil was hungry for power and would continue to produce better sparks
as I
> > increased the rotor speed - as fast as I dared turn it up.
> > 
> > I could certainly use some help here.  This coil used to produce 80"
> > discharges and now I can't seem to get past about 36" to 40". 
Something is
> > not right and I can't find it.  If the primary and secondary are in
tune, why
> > can't I apply full voltage?  I have the rotary gap across the high
voltage
> > mains, should I swap it with the cap and put the cap across the mains
and let
> > the rotary act as a safety gap for the cap - and remove the existing
safety
> > gap across the cap - as Peter E. suggested the other day?  I really
can't
> > afford to blow up any more capacitors.  By the way, the main safety
gaps
> > connected near the output of the pig, with the center post grounded,
never
> > did fire in any of these tests.  It never has fired very often in the
past
> > unless I was getting secondary hits down into the primary.
> > 
> > Thanks,  Ed Sonderman
>