Re: Ballasting Primer (was: Help Me Prepare for a BIG Coil)

[FutureT-at-aol-dot-com (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

In a message dated 8/17/00 8:43:41 PM Pacific Daylight Time, tesla-at-pupman-dot-com 
writes:

>   I do not understand inductive ballasting at all though.  I have a small
>  portable arc welder that I could use.  I understand that I should short out
>  the secondary leads of the welder, so if I just set the welder on 80A, I
>  guess that means that the transformer only gets 80 amps max?  Furthermore,
>  I hear of people using space heaters and oven elements and all sorts of
>  stuff for ballasting.  How does their energy consumption correllate with
>  the amount of current available to the transformer? 
>   Anyway, I hope I haven't made myself sound too ignorant, but I am going to
>  make sure and know everything I need to know so I don't blow my arm off
>  and/or burn my house to the ground. :-)
>  
>   Thanks,
>      Ryan Ries

Ryan,

I do not recommend using resistive only ballasting because of the
great amount of wasted power that will burn up in the ballast.

I would try first using the welder only (no resistance) to see how
it works out.  If there's too much thumping, or the coil runs rough,
etc, you can always add some resistive ballasting.  The welder
must be connected in series with the input to the transformer,
with the secondary leads shorted as you mentioned.  The number
of amps drawn by the system will most likely bear no relation to
the amps printed on the welder dial, since it's being used in a
totally different way than a normal welder application.

As you first begin to test the coil, you'll see if it's working well as
you begin to turn up the main power variac.  You'll be doing initial
tuning at a somewhat low power, etc.  Once the coil is giving
sparks, you can find the best welder setting, etc.  It's all pretty
easy actually, just takes time to get everything working well.

Cheers,
John Freau