[Prev][Next][Index][Thread]

Re: Conical Secondary

Hi Jason,

	I searched around my stuff and came up with zero.  Matt Behrend's page has
an inductance formula for conical "primaries" you may be able to use:

http://home.earthlink-dot-net/~electronxlc/formulas.html

As far as self capacitance or the final frequencies, I have no idea.
E-Tesla5 (my program) could be modified for the conical case but it would
not have any actual comparison testing to be sure the computer agrees with
reality.  The secondary voltage distribution is probably wrong.  However,
you may try just averaging your tube's dimensions to a standard straight
secondary.  The calculations will be off but probably be "close enough" to
give a good guess for construction and general cap sizing purposes.

Of course, if someone comes up with all the equations it will be great but
I hear a lot and this is new to me...  If you build it, measure everything
and we can go back and test to see if any of our present tools work.  A
number of older Tesla coils and Bill Wysock's reproduction coil used cones
(http://www.ttr-dot-com/Fry-coil.htm) but I don't think they had a who lot of
scientific pre-calculations before hand.  Their's were just pure skill...  

At one time (50+ years), it was felt there was an advantage to having the
secondary cone shaped.  Perhaps someone knows the why and story behind that
belief??  I notice none of them had big top terminals...  I am sure you
want to wind the wire from the small end toward the large end.  Otherwise,
it will slip forward during winding.

Of course you can wind the secondary, measure it and go from there.  In the
98 years before computer models, that seemed to work! ;-))

Hope this is of a little help at least.

Cheers,

	Terry



At 06:11 AM 03/18/2000 -0800, you wrote:
>Does any body have any calculations for a conical secondary 
>(frequency, inductance, etc.) because I've got a tube that 
>starts out -at- 2 5/8 in. and over 11 1/2 in. tapers to 1 1/8 
>in. and I thought that it would look pretty cool on one of 
>my tiny (1 7/8 x 6 3/4in) coils.
>
>Jason Johnson
>
>______________________________________________________
>Get your free web-based email at http://www.xoom-dot-com
>Birthday? Anniversary? Send FREE animated greeting
>cards for any occasion at http://greetings.xoom-dot-com
>
>