RE: Ballast ?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Rich & DJ" <rdj@xxxxxxxxxxxx>

Gerry

The transformer is all open and it is made of "E" and "I" plates, with
the windings on the center leg of the "E". It came out of a laser power
supply. I am sure it is a CCS transformer, it is well built for 1.95Kva
but I see no ballast indication. It has two secondary windings but they
are tied together in the middle with out a C/T to ground. It is just
like a standard plate transformer but a little higher in voltage. The
original set up had a bridge rectifier.

Rich

-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx]
Sent: Wednesday, June 14, 2006 8:43 AM
To: tesla@xxxxxxxxxx
Subject: Re: Ballast ?

Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi Rich,

Are you sure the transformer doesnt have any builtin ballast.  You
can verify this using a variac driving the transfomer with secondary
shorted. Start low on the output voltage of the variac and plot
current vs voltage to see if it is as expected.  If the slope is
correct then take it up to where the transformer primary current is
150ma * turns ratio.  If you get full 240Vac at this current level,
the transformer is already ballasted.  Just start out low and slow
until you feel comfortable going to a higher voltage.

Gerry R

>Original poster: "Rich & DJ" <rdj@xxxxxxxxxxxx>
>
>Hi Gerry , it is junk as a NST , I had to remove a few windings on one
>side to get continuity but the other side took half the windings to get
>a reading so its scrap unless I use the primary core for a ballast , I
>don't know all the electrical rules but here is a roll of 10ga wire
with
>an iron core , not much different from a roll of wire from home depot
>with welding rods in it.
>I need ballast on 240v, I have a transformer that requires 240v primary
>, secondary is 13Kv, no MA listing on the tag but it is 1.95Kva so that
>come in about 150ma. It should be about 8amps of 240v and all will be
>OK.
>  I need a way to control the current if I use it with a Tesla Coil. I
>don't want to run a resistor as a ballast. I did test the transformer
>with some high wattage 240v quartz bulbs as a ballast and made a Jacobs
>ladder but I read an inductive ballast is better. It is all trial and
>error at this end but I hope I only see sparks out of the coil and not
>the power supply.
>
>Rich , from the middle of Missouri
>
>Subject: Re: Ballast?
>
>Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>
>
>Hi Rich,
>
>The ballast use probably wont work on 240 since the NST was designed
>for 120 in terms of core satuation.  Two in series might work
>depending on what current you are after.  You might try to melt the
>tar in an oven.  Often this will reflow any carbon tracking and
>restore the NST (assuming that is what's wrong).  Also, you could
>remove the tar and guts, clean it up, find what's wrong with it and
>fix it, and then make a case to emerse it into oil (no more fragile
NST.
>
>Gerry R.
>
> >Original poster: "Rich & DJ" <rdj@xxxxxxxxxxxx>
> >
> >I have a Jefferson/Magnetek transformer, 15Kv 60ma, 120v primary..
> >The secondary is bad,  it has some nice 10ga wire for the primary.
> >  Would it be possible to use just the primary as a ballast on 240v
> > , with out the secondary?
> >This unit has no removable shunts for adjustment that I can see.
> >
> >Rich
> >
> >
>
>