Re: Ballasting the secondary side of transformers

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "J. Aaron Holmes" <jaholmes@xxxxxxxxxxxxxxxxxx>

But what are the costs of making a LV ballast?  I've
made two:  My first was a 30 gallon garbage can full
of water with 1/2" copper pipes immersed, one of which
had a PVC sheath I could raise or lower to adjust the
current.  Spent about $20 on that thing, including
brand new plastic garbage can from Home Depot (but I
already had the copper pipe).  The other is a ~24"
long ~5" OD piece of PVC with two layers of #6
stranded on it filled with steel ceiling wire gotten
from the local industrial surplus joint.  Steel gets a
little warm after long runs.  Big deal.  Same with the
water :-)  This latter ballast cost me $35 or so.
Granted, if you go and buy a big variac, you'll be out
$100 or more real quick!

I have a hard time believing high-side ballasting is
going to make things cheaper, and making a variable
high-side ballast (that you can vary while running!)
poses greater health risks, I think!

Regards,
Aaron, N7OE

--- Tesla list <tesla@xxxxxxxxxx> wrote:

> Original poster: "Barton B. Anderson"
> <bartb@xxxxxxxxxxxxxxxx>
>
> Can someone please tell me why we are still
> ballasting on the LV side
> of Pigs and PT's? This should be easy enough to do
> for a fixed
> current limit. The costs associated with a LV
> ballast almost demands
> we do this. The LV side is starting to appear very
> silly to me at the
> moment. Granted, there are HV concerns, but is it
> really a big deal?
> I get the feeling LV ballasting is simply
> convenient. However, it is
> also expensive (unless one builds a ferrite
> ballast).
>
> Just curious is anyone else has contemplated a high
> side ballast.
>
> Take care,
> Bart
>
> Tesla list wrote:
>
> >Original poster: "Gerry  Reynolds"
> <gerryreynolds@xxxxxxxxxxxxx>
> >
> >Hi Harvey,
> >
> >>Original poster: Harvey Norris <harvich@xxxxxxxxx>
> >>
> >>How can you even ascertain what a resonant cap
> value
> >>would be if you are not using a current limited
> >>secondary?  Can a pole pig for example have a
> current
> >>limited output measurement made by shorting out
> the
> >>secondary outputs, simply by ballasting its
> primary?
> >
> >
> >Primary ballasting current limits the same as
> secondary ballasting.
> >Only the needed value of the ballast is different.
> If ballasting on
> >the seconary, the inductance needs to be n^2 larger
> than if
> >ballasting is done on the primary, yes??
> >
> >Gerry R.
> >
> >
> >
> >
> >
> >
>
>
>
>
>