Re: Oil insulated secondaries (fwd) (Aluminum plate under coil. Does it waste power? No!) (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Wed, 12 Sep 2007 21:39:55 -0700 (PDT)
From: J. Aaron Holmes <jaholmes@xxxxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Oil insulated secondaries (fwd)  (Aluminum plate under coil.  Does
    it waste power?  No!) (fwd)

Sure.  I shouldn't have used such absolute terms;
there is almost certainly some loss, however with a
good conductor it ought to be fairly small.  Mainly, I
reject "OMG, this will suck up all your power!"
predictions.  Next time a friend fires up his big
coil, I'll bring along the 16"-diameter, 3/8" thick
end cap plate and we'll sit it under the primary. 
I'll be impressed if it heats perceptibly even with
his coil pelting along at 7-10kVA.

Cheers,
Aaron, N7OE

--- Tesla list <tesla@xxxxxxxxxx> wrote:

> 
> ---------- Forwarded message ----------
> Date: Wed, 12 Sep 2007 07:13:13 -0600
> From: Gomez Addams <gomezaddams@xxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: Re: Oil insulated secondaries (fwd) 
> (Aluminum plate under coil.  Does
>     it waste power?  No!) (fwd)
> 
> 
> On Sep 10, 2007, at 7:56 AM, Tesla list wrote:
> 
> >
> > ---------- Forwarded message ----------
> > Date: Sun, 9 Sep 2007 16:33:34 -0700 (PDT)
> > From: J. Aaron Holmes
> <jaholmes@xxxxxxxxxxxxxxxxxx>
> > To: Tesla list <tesla@xxxxxxxxxx>
> > Subject: Re: Oil insulated secondaries (fwd) 
> (Aluminum plate under  
> > coil.  Does
> >     it waste power?  No!)
> >
> > Hey, Peter:
> >
> > This was discussed quite a bit on 4HV a short
> while
> > back, and almost universally contradicted (to my
> > surprise, I'll admit).  However, IIRC, it can be
> > easily explained like this:  Because copper and
> > aluminum are great conductors, it's extremely
> > difficult to induction heat them (i.e., cause them
> to
> > "waste" power).
> 
> Hang on, what happened to I-squared-R?  Sure, R may
> be
> very, very low in this case, but given that power
> dissipated
> goes as the SQUARE of the current, and given that a
> shorted
> single turn (ie; a plate intercepting a significant
> portion
> of a changing magnetic field) can have quite a lot
> of current
> flowing in it, I don't see how the idea of wasting
> power in a
> conductor is disproved at all.
> 
> However, I am thinking of current induced in it by
> the
> primary field.  If the plate intercepts only a small
> area of the primary's field, then it may not be
> worth
> mentioning.
> 
>   -  Bill "Gomez" Lemieux
> 
>
...............................................................
> Listen up George Bush, television news anchors,
> radio talk show
> hosts, and all you other illiterates: there are no
> such words
> as 'nucular', 'relator' or 'jewlery'!
> 
> 
> 
> 
>