Re: Primary designs

[FutureT-at-aol-dot-com (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

In a message dated 7/20/00 11:29:18 AM Pacific Daylight Time, 
tesla-at-pupman-dot-com writes:

> Original poster: ANTarchimedes-at-aol-dot-com 
>  
>  
>      What different things are supposed to be achieved by the different 
>  primary designs?  By knowing this, I might be able to experiment better 
with 
> 
>  different primary designs.  Also, which primary shape did Tesla most 
>  frequesntly use?
>  
>  Nick Moor

Nick,

A cylinder type primary is capable of tighter coupling, but usually
such tight coupling is not wanted.  Unless a cylinder primary is
rather large in diameter, the secondary will probably need to be
lifted almost fully above the primary to prevent racing sparks on
the secondary. 

Cylinder primaries are most commonly used on small tube coils and
in magnifier drivers.  Small tube coils often "like" a rather tight coupling.

Flat primaries behave very similar to flattish inverted coned primaries,
but the flat primary has the advantage that the sparks from the toroid
are less likely to arc down and hit the primary.  I used to use the
15% inverted cone, but now I just use the flat primary since it's just
as good and I get fewer sparks hitting my primary.  In any case you'll
get the same spark output no matter what the primary shape is, if the 
spacings and coupling are OK, etc.

Magnifier drivers use the cylinder primary for the needed tight coupling
of the driver.

In general the shapes and proportions of TC's are not super critical,
other factors have much more effect on the spark output.

Cheers,
John Freau