3 Coil System Was: A photographic tutorial of Pancake Coil winding...with movies...(fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 22 Jun 2007 06:02:20 -0700
From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: 3 Coil System      Was: A photographic tutorial of Pancake Coil
    winding...with movies...(fwd)

Hi Dave,

Most magnifier systems are of the classic design with an L1:L2 driver 
situated a great distance from L3 and coupled via transmission line. L3 
is a standalone unit both in mutual inductance and the coil capacity 
itself with it's topload and ground. Those are completely different 
beast and follow different design rules which don't apply to this topic.

Very few have built 3 coil systems of helical design as my hybrid maggy. 
A few of course have with flat coils, but I'd bet in nearly every case, 
it was similar to your coil in design where the solenoid resonance was 
determined by the L1 and L2 with L3 observed only as a capacity. Trying 
to get all three resonant through trial and error would be nearly 
impossible and a program would certainly be needed. Trial and error is 
very easy with a 2 coil system but not with a 3 coil system as we are 
discussing.

You mentioned that anyone could replace the 3rd coil .... with a pipe of 
same dimensions and get the same results. That is true only if:
1) the 3rd coil is a close proximity coil as L1 and L2 are.
2) L1:L2:L3 are not designed to resonance.
3) L1 and L2 are resonant and L3 is seen as a capacity (which it is when 
2 above is not true).

But, if L1:L2:L3 "are" designed to resonance, the game changes, 
especially in a system with a flat secondary and helical solenoid.

What would be really interesting is a high coupling 3 coil maggy in 
close proximity all using flat coils! Now that, we can model (unlike 
that cone topload object which is a real pain in the butt).

Take care,
Bart

Tesla list wrote:

>---------- Forwarded message ----------
>Date: Fri, 22 Jun 2007 07:12:37 -0500
>From: David Thomson <dwt@xxxxxxxxxxxx>
>To: 'Tesla list' <tesla@xxxxxxxxxx>
>Subject: RE: A photographic tutorial of Pancake Coil winding...with
>    movies...(fwd)
>
>Hi Bart,
>
>  
>
>>>Bart just pointed out that the metal pipe you are using acts like a 
>>>waveguide, or third coil.  
>>>      
>>>
>
>  
>
>>Just the opposite. A third coil not in resonance acts more 
>>like a capacitively coupled topload object and the dimensions 
>>of the coil. The third coil is pretty much a pipe at that 
>>point. In Jeff's case, it's nothing more than a topload 
>>object. In your coil, the solenoid is acting like Jeff's pipe 
>>(just a topload object).
>>    
>>
>
>It may be an opposite perspective, but it is the same thing, either way.
>
>A third coil has no inductive coupling with the secondary and acts like a
>Helmholtz resonator.  
>
>If my understanding is correct, anybody can replace the third coil on their
>magnifier with a copper tube of the same dimensions and get the same
>results.
>
>Dave
>
>
>
>
>
>
>  
>