Re: Ganging Variacs (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 17 Aug 2007 02:42:26 +0000
From: david baehr <dfb25@xxxxxxxxxxx>
To: tesla@xxxxxxxxxx
Subject: Re: Ganging Variacs (fwd)


 

Why waste a nice Variac ?,...get a cheap variable shunt  arc welder and
be done with it,

  



 

________________________________________________________________________________

      From:  "Tesla list" <tesla@xxxxxxxxxx>
      To:  tesla@xxxxxxxxxx
      Subject:  Re: Ganging Variacs (fwd)
      Date:  Thu, 16 Aug 2007 20:23:45 -0600 (MDT)
      >
      >---------- Forwarded message ----------
      >Date: Thu, 16 Aug 2007 19:08:58 -0700
      >From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
      >To: Tesla list <tesla@xxxxxxxxxx>
      >Subject: Re: Ganging Variacs (fwd)
      >
      >Hi Terry, Tim,
      >
      >I did the same with my variac. I split the core to prevent
      saturation.
      >It's been a life saver for me since I only use a single
      variac with my
      >pig. But, if I had a large enough variac or two, I wouldn't
      have done it
      >(as it does ruin the variac for any other purpose). But if
      it's solely a
      >current limiting variac, cutting the core will help prevent
      saturation
      >issues, although I have smoked the brushes on this variac
      from too much
      >current. Even though saturation is prevented, current still
      flows and
      >the components that make up the variac can still be damaged
      if high enough.
      >
      >BTW, remove the brushes at least once a year and inspect
      them. Can
      >prevent a bad situation. The smoked brushes occurred at my
      2005 4th of
      >July party. Funny, I just turned the current down and the
      smoke went
      >away. The coil kept on Rockin! The next weekend I did the
      optopsy and
      >found I was running on about 1/3 brush surface. I learned
      from that
      >experience to inspect brushes and replace when worn.
      >
      >Take care,
      >Bart
      >
      >Tesla list wrote:
      >
      > >---------- Forwarded message ----------
      > >Date: Thu, 16 Aug 2007 12:46:40 -0500
      > >From: Terry Oxandale <Toxandale@xxxxxxx>
      > >To: Tesla list <tesla@xxxxxxxxxx>
      > >Subject: RE: Ganging Variacs (fwd)
      > >
      > >There has been a great deal of discussion on this issue as
      well as the
      > >parallel aspect. My experience was saturation of the
      variac core, but
      > >this is based upon the core size and voltage/turns ratio.
      I don't have
      > >the greatest understanding of this issue, but I believe it
      is focused on
      > >the fact that only a small portion of the core is used in
      most of these
      > >applications (reduce the number of turns reduces which
      increases
      > >current, but also increases the voltage/turns ratio to a
      point of
      > >saturation.
      > >
      > >I successfully split the core of my variacs (two 1256
      variacs in
      > >parallel) to prevent this from happening and have been
      very happy with
      > >the modulated current profile as compared to the nearly
      uncontrolled
      > >profile previous to splitting the core. It was a lot of
      work though.
      > >
      > >Terry
      > >
      > >-----Original Message-----
      > >From: Tesla list [mailto:tesla@xxxxxxxxxx]
      > >Sent: Thursday, August 16, 2007 7:12 AM
      > >To: tesla@xxxxxxxxxx
      > >Subject: Ganging Variacs (fwd)
      > >
      > >
      > >---------- Forwarded message ----------
      > >Date: Thu, 16 Aug 2007 07:48:34 -0400
      > >From: timjroche@xxxxxxx
      > >To: tesla@xxxxxxxxxx
      > >Subject: Ganging Variacs
      > >
      > >I understand about using paralleling chokes when using
      variacs for
      > >voltage
      > >control, what about for ganged series variacs for current
      control or
      > >in-other-words, adjustable ballast?
      >
      >________________________________________________________________________
      > >AOL now offers free email to everyone.  Find out more
      about what's free
      > >from AOL at AOL.com.
      > >
      > >
      > >
      > >
      > >
      > >
      > >
      > >
      > >
      >
      >
      >


________________________________________________________________________________

Learn.Laugh.Share. Reallivemoms is right place!