RE: Aluminium aka Aluminum Wire (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 1 Oct 2007 09:46:06 -0400
From: "Lau, Gary" <Gary.Lau@xxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: RE: Aluminium aka Aluminum Wire (fwd)

Hi Bart:

I agree that the losses in short fat blocks are negligible, regardless
of the material choice.  If folks were considering using tubing or wire
made of brass for a primary conductor, then this would be a concern
(folks considering using bronze weatherstripping for a primary - take
note!).  My point was actually directed at those who suggested that
losses in RSG electrode holders made of aluminum would be unsuitable,
and that brass would be a superior choice.  Practically speaking, it
makes no difference.  But if you go through the numbers, aluminum is
better from the electrical perspective.  But yes, brass looks cooler.

Why would the secondary 1000-turn recommendation change if AL was used?
I'm not sure that resistive losses in the secondary are even terribly
important.  I think experiments with winding a bifilar secondary
(essentially keeping inductance unchanged but reducing resistance)
showed little benefit.  And I think Terry performed a Spice simulation
modeling the losses in the various parts of a coil, and the resistive
losses in the secondary were a relatively minor contributor.   Primary
losses however were critical.

Regards, Gary Lau
MA, USA

> From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: Re: Aluminium aka Aluminum Wire (fwd)
> 
> Very true Gary. But considering we use them mainly as dissipation
mass,
> they serve the purpose well. In short fat blocks like that, almost
> anything will do (even iron masses). It's when we start winding coils
> with these materials that we experience losses we can measure. I have
no
> doubt we can wind a secondary from Al magnet wire and have it perform
> well, but the design itself will be different from what we are use to
> (that thousand turn recommendation will change).
> 
> There's no doubt that RF losses will be at least 150% higher, but in
the
> tank discharge arena, it's not a factor worth discussing. If you look
at
> the losses on the total system scale, this particular loss in the
> primary circuit is extremely negligible and why the RF with aluminum
is
> interpreted as a myth hoax.
> 
> But, insert those losses to the secondary side, and then we need to
> start looking a little closer. In many cases it will not be a problem
> (many secondary geometry's can be made rather efficient with aluminum
> wire), but there are situations where it will drop output as compared
to
> a copper winding.
> 
> No matter what material we use for wire, the conductance of that
> material is just as important as the length and size of the conductor.
> We can't change physics (just do our best to understand and design
> accordingly). In some cases, aluminum will be a poor choice and copper
> will be far better. In other cases, aluminum will be just fine for the
> application. The real task is deciding when the one with lesser
> conductance is ok (and when it is not).
> 
> Take care,
> Bart
> 
> Tesla list wrote:
> 
> >---------- Forwarded message ----------
> >Date: Sun, 30 Sep 2007 21:09:28 -0400
> >From: "Lau, Gary" <Gary.Lau@xxxxxx>
> >To: Tesla list <tesla@xxxxxxxxxx>
> >Subject: RE: Aluminium aka Aluminum Wire (fwd)
> >
> >Hi Bart:
> >
> >Thanks, that's a great link.  I never looked too closely at the
relative
> >resistivities before.  In addition to the wide range of alloy
> >resistivities, I was also surprised with how poorly brass compares to
> >aluminum - TWICE the resistance!
> >
> >Regards, Gary Lau
> >MA, USA
> >
> >
> >
> >>From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
> >>To: tesla@xxxxxxxxxx
> >>Subject: Re: Aluminium aka Aluminum Wire (fwd)
> >>
> >>I goofed the link. Left out a "d" in "eddy". Here's the correct
link.
> >>http://www.eddy-current.com/condres.htm
> >>
> >>
> >
> >
> >
> >
> >
> >
> >
> >
>