Re: double wound secondary (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Sun, 30 Sep 2007 09:57:18 -0400
From: David Speck <dave@xxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: double wound secondary (fwd)

Scott,

A seat - of - the - pants explanation is that a double wound coil is not 
really two separate inductors. 

The inductance of a coil arises from the interaction of the magnetic 
field with the wire.  If you have two separate coils whose fields do not 
interact significantly with each other, then the inductance is, indeed 
halved.

However, with a double wound coil, the same magnetic field is 
interacting with both pieces of wire.  It's analogous to a coil having 
the same inductance if wound with stranded wire vs. solid wire of the 
same net gage.  The double windings are just like stranded wire with the 
strands a little farther apart.

my $0.02

Dave

Tesla list wrote:
> ---------- Forwarded message ----------
> Date: Sat, 29 Sep 2007 18:24:54 -0400
> From: Scott Bogard <teslas-intern@xxxxxxxxxxx>
> To: tesla@xxxxxxxxxx
> Subject: double wound secondary
>
>
> Hey everybody,
>      I know, this topic has been covered an awful lot in the archives, I
> looked; but there seems to be some disagreement, weather it is good or
> bad.  It seems lately, everybody now thinks it is not such a bad idea, as
> it decreases the resistance, therefore increasing output.  But, from what
> I know of formulas and such, two inductors (since a coil is essentially an
> inductor) in parallel decreases the inductance, which should decrease
> voltage out?  Does this situation not apply with a transformer, or does
> the resistance decrease make that much of a difference to make up for it?  
> Or, does nobody actually know why it works so well?  Just curious (and
> considering double winding my 6-in secondary). Scott Bogard.