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LOW Inductance Ballast
---------- Forwarded message ----------
Date: Fri, 3 Oct 1997 10:11:55 -0400
From: Thomas McGahee <tom_mcgahee-at-sigmais-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: LOW Inductance Ballast
>
>
> ---------- Forwarded message ----------
> Date: Thu, 2 Oct 1997 18:00:15 +0100
> From: Julian Green <julian-at-kbss.bt.co.uk>
> To: tesla-at-pupman-dot-com
> Subject: Re: Sonderman saga - Tuesday
>
>
> I dont use inductive balast either, but I do use a pole pig.
> 100meters of 1mm2 extension leed equals about 5 ohms of non
inductive balast.
>
> For high power/long runns dont forget to unwind the extension leed.
>
> Julian Green
Julian,
There is a simple method to allow you to keep the wire rolled up and
still keep the inductance near zero. The method was first used by
Nikola Tesla to fabricate wire wound resistors with low inductance.
The method is simplicity itself. Take the 100 meters of wire and
locate the center. At this point bend the wire over (and tape it if
desired). Use electrical tape to secure the half-way point to the
spool you will be winding the wire onto. As you roll the wire back
onto the spool, just keep the two wires always adjacent. When you
have the wire all back onto the reel, except for a few inches, tape
the surface down with a layer of electrical tape. The two wires that
you now have will exhibit almost zero inductance, because the current
through them is equal but of opposite direction.
I usually use this technique with much smaller reels of wire, but it
should work well at almost any scale. It is simple and very easy to
implement, and allows you to have a much more convenient high wattage
resistance. Works for any wire that has insulation.
I believe that the general principle behind this was mentioned on
this list recently, but I am posting this in case you missed it, or
missed its implications in your particular case.
Hope this helps.
Fr. Tom McGahee