RE: New Primary Design 2

Hi Mike,
> Original Poster: Mike Doyle <mdoyle-at-cherrycorp-dot-com> 
> Below is an excerpt from the IEEE tesla document located on the tesla
> ring and authored by R M Craven.
> "Techniques are now employed whereby two Archimedean spiral primaries
> are stacked one on top of another. The mutual inductance M that exists
> between them is adjusted by varying the separation of the two coils.
> This removes the need for relatively lossy "tapping" connections and
> also minimizes the length of conductor needed to make up a given
> inductance. Thus the I2R or Joule losses are minimized. A further
> advantage is that there are no unused turns and this means that the
> coupling coefficient remains largely constant (less change in primary
> geometry) and there is no extra field stressing which would occur due
> to autotransformer action in the primary."
> Has anyone on the list used this method? Is it effective? How much
> available separation would you have to have to allow for tuning and
> how would moving the upper coil up and down effect coupling.
I can't quantify those last questions as it obviously depends on the 
number of turns in each layer, their spacings, how many layers 
there are and the overall shape and size of each configuration.
     The method works well and is effective. I was consulted by 
Richard for some of the information in his article so some of that 
came from me. However, others had thought of it also so I cannot 
say I was the first to think of it. I had previously discussed the idea 
with at least one other person.


"To be original in this world you have to be both lucky and quick - 
lucky to know enough at the right time to extend an idea and quick 
enough to publish before anyone else does."

- original