Re: Calculating secondary resonance of bipolar coils

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

Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>

Hi Gavin,

        I didn't quite know what to say but since no one else did either, I'll
give you my guess anyway.  You can use E-Tesla6 to calculate half the coil
assuming the center plane of the coil is a ground plane.  Since a bipolar would
be half wave, I would guess the Fo frequency would be the same.  So, if you run
half the bipolar, I think it will give you the right Fo frequency.  I think... 


There are also supports and such that are going to mess with the external
fields a bit too but I think it will be pretty close.

http://hot-streamer-dot-com/TeslaCoils/Programs/Programs.htm

When you ask a good question like this and no one answers, you know you have
asked a good question ;-))) 

Cheers,

        Terry


At 03:24 PM 1/4/2001 +0000, you wrote: 
>
> Hi all,
> I sent a mail to the list a couple of days ago regarding secondary bipolar
> coil resonance calculations. As there has not yet been a reply, I thought I
> should elaborate on the question I originally asked. 
> Most TCs are of the up-right quarter wave resonant type, topped with a top
> load such as a torroid. I have recently wound a secondary more suited for use
> as a bipolar or half wave resonant secondary. The primary is positioned in
> the middle of this secondary coil; and the there will be no earth connection
> at the mid point of the secondary.
> Now, I know that it possible to calculate the resonant frequency of a quarter
> wave coil using medhurst and the standard LC resonance formula. It is also
> possible to treat the secondary as a Tx line by determining the wave velocity
> from the coil inductance and capacitance per unit length. Medhurst, I
> believe, was derived from empirical measurement, while the Tx-line method
> relies on modelling. Either way, it seems that these methods do not work when
> considering half-wave resonators, the frequencies tend to be much greater
> than, say, the medhurst calculation. So, has there been found a method of
> calculating the half-wave resonance of a coil? 
>  
> Thank you in advance for your help.
>  
> Gavin