Re: ballasts and such...

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Gregory Hunter by way of Terry Fritz <twftesla-at-uswest-dot-net>" <ghunter31014-at-yahoo-dot-com>

Mike,

I'm using two 120V MOTs in series with their
secondaries shorted to limit my 240V/11.5kV pole pig
to 20A.  I'm not using any resistors at all.  The two
MOTs are submerged in motor oil inside a .30 cal ammo
can.  I can run indefinitely without overheating the
MOTs.  Performance is far, far better than with the
9KW of heater elements I had been using, even though
the heaters drew 37A!  As non-adjustable, low-loss,
low-cost pig ballast, MOTs rule.

Greg
www.angelfire-dot-com/ga3/tesla

--- Tesla list <tesla-at-pupman-dot-com> wrote:
> Original poster: "acmnovak by way of Terry Fritz
> <twftesla-at-uswest-dot-net>" <acmnovak-at-email.msn-dot-com>
> 
> Hi All,
> 
> On my next coil, I'll be using 2 NSTs with shunts
> completely removed. This,
> however, will require utilization of external
> ballasting to control current
> draw. I'd like to be able to use all the current
> provided by a standard
> (120v 20a) outlet, without pushing my luck. This
> leads me to a current of
> 18A.
> I was reading Richie's TC page a few days ago and
> drooled at his ballast.
> However, he spent WAY too much on it. I'm a bit of a
> "budget  oriented"
> coiler, so I've been looking for other, less costly
> alternatives.
> Seeing as MOTs work well for some people, I first
> investigated the use of
> those. I've got mixed feelings about them however.
> Some say they work
> excellent and are the best thing, while others say
> they are cheap, saturate
> easily, wimpy, lossy, and do not last long. I would
> think they should work
> just fine, within limits. I'd like to hear (only the
> experienced') opinion
> on this matter, as I really don't have any clear
> facts put togather on this
> subject.
> The next thing I pondered using, was a homebrew
> ballast. I noticed that
> Richie's ballast looks strikingly like a NST with
> only the primary. I have
> an old NST core sitting in the corner of my room
> that I want to get rid (or
> make use) of, so I though " why not just slap a
> couple of turns on it and
> it's almost exactly like Richie's...". So, I
> contacted Richie and asked him
> how one might go about constructing a ballast in
> this manner. However, he
> informed me that he had bought the unit from a
> manufacterer, specially
> designed for his specs. This proved quite
> discouraging, as I would have to
> do the math myself : ) Do any of you have the
> equations, and whatnot
> required to produce a viable ballast? My core
> measures 4"X8"X2"and is in the
> form  of a dual "E" shape. I can make accomodating
> brackets to allow for
> adjustment of inductance by means of gapping if
> needed.
> Just yesterday, I found a (suitable?) ballast
> sitting right there in the
> bottom of my closet?! This really takes the cake on
> weird shtuff I find in
> odd places... The thing measures5"X5"X1" and is
> wound with approx. 15 turns
> of #6 square wire(!!!) and it's gap is set to about
> 100 mils (.1")  The
> whole thing is coated in glyptol and bolted togather
> like it's made to take
> some abuse. And, of course, It has NO markings which
> might help me
> deetermine the usefullness of the device in
> question. How would one
> determine if it will be suitable for my needs?
> Any help would be greatly appreciated, as I'm quite
> new to this area of
> coiling...
> Thanks
> 
> -Michael
>   ______
> (_______)
>       |     |
>       |     |
>       |     |
>       |     |
>       |     |
> ooo__ooo
> ________
> 
> 
> 
> 
> 
> 
> 
> 


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