Re: new power transformer

To: tesla-at-pupman-dot-com
Subject: Re: new power transformer
From: Charles Brush <cfbrush-at-interport-dot-net> (by way of terryf-at-verinet-dot-com)
Date: Wed, 26 Aug 1998 18:44:53 -0600
Approved: terryf-at-verinet-dot-com

X-Envelope-From: cfbrush-at-interport-dot-net  Wed Aug 26 08:05:30 1998

>Hi All,
>
>  For the last 6 months or so I have been running my 3KW magnifier system
>with and output varying from 4-6 feet.  The problem is form marathon runs
>my power transformers overheat and start smoking after 30 min.  They are
>two 5 KV 300 ma transformers put in series.
>    I am ready to upgrade these to a potential transformer or a 5 kva pig.
>My question is are the potential transformers current limited cores? or do
>these also need ballasting to work.
>    The reason for leaning more for the potential transformer is that I
>like to keep the system portable and not everywhere I take it has 220
>available to me.  Also the pigs tend to be very heavy and hard to put on a
>truck.
>    Could anyone give me advise either way.
>
>Thanks,
>
>Dwight Duncan



Dwight,

Potential transformers are not internally current limited, so you will need
external ballast.  Still, you could set up a pretty small system.  I
recently tried using a PT with a medium sized coil and I love it.  I am
planning on getting one of those small 110v arc welders as a current
limiter, but for the time being I have been using a shorted MOT as the
limiter and it has worked wonderfully.  I think a PT and mini welder could
make a fantastic compact power supply.  At 3kW you may be above most PT's
nominal current ratings though.  PTs are very robust, but I do not know
what their really long term overload characteristics are like (someone
else?).  How long are your marathon runs?

Zap!


Charles Brush
http://www.foundrygroup-dot-com/cbrush/fun