RE: Calculating secondary resonance of bipolar coils

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <free0076-at-flinders.edu.au>



On Fri, 5 Jan 2001, Tesla list wrote:

> Original poster: "sundog by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<sundog-at-timeship-dot-net>
> 
> Hi Gavin,
> 
>  Yep, Terry got that one right on!
> 
> Just calculate for 1/2 the total secondary (otherwise your Fo would be for
> driving the whole thing in a classic configuration).  Make sure you have the
> two toploads (sideloads?) as identical as possible to keep "funny" things
> from happening.  Just calc. out 1/2 the coil and 1 topload. The more turns
> you have (2x a normal coil) the less a little error in # of windings,
> topload size, etc is going to affect you when tuning.

I would have expected the two halves to be rather well magnetically 
coupled leading to a much greater inductance (looking at only half of the
coil) by nearly a factor of two. I can't see how calculating the thing
with half of the coil is going to give the correct answer. I expect that
you would get the right answer by finding the resonant frequency of the
total inductance/distributed capacitance plus the external capacitance.
The external capacitance would be the capacitance between the two
terminals and from one terminal to the ground to the other terminal.

I am assuming that the 1/4 wave theory is a myth and that the circuit acts
as a lumped inductance and capacitance, both of which are demonstrated at:

hot-streamer-dot-com/TeslaCoils/MyPapers/MyPapers.htm


Darren Freeman