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Re: Nested Secondaries

Hi Scott,

At 11:21 AM 12/26/1999 -0600, you wrote:
>Hi All...
>
>
>	I was thinking about something that I havent heard any ideas about (
>maybe its too ludicrous). I searched the archives ans still nothing on
>it, so heres the idea. 
>
>The concept is nested secondaries, one inside the other. My plans would
>consist of an 8 " dia tube with a 7" tube inside. Of course, both wound
>with 22Ga wire and both with the same amount of wire. Seeing that the 8"
>tube would hold more wire per length as the 7", the 8" form would have
>to be space wound for several inches ( havent done the exact math yet).
>Once both forms have been wound, the base of each secondary would be
>connected to each other ( and to RF grnd) while the upper leads would
>both be connected to the top load. 

I have certainly never heard of this.  I would think that the two coils
would have to have the same inductance instead of the same wire length.
There would be a lot of capacitive coupling between the two coils but that
may not hurt if they stay at the same potential along their length.  I
would worry that the two coils would be so close (less than 1/2 inch) that
there may be arcing between them but I really don't know...  The coupling
between each coil and the primary would be different but the two coils
would be so locked together by then ends and the capacitances that may be OK.

>
>Ok  heres the speculation ...   would this design allow for more power
>to be supplied to the top load ???  considering that we are dealing with
>EMF would the extra coil system use that emf and not subtract it from
>the outer coil ?

The advantage I would think you would see is that the coupling may be much
higher between the primary and secondaries.  You would almost have enough
coupling to drive two coils independently.  Hard to speculate on what would
happen but if you raise that coupling on a standard coil much above 0.2
things start to go bad really fast.

>
>some of the possible down falls that I see would be arcing between the
>secondaries BUT  ...   if they are the same ( electronically) why would
>they arc to each other ?   and what about the EMF produced by the
>secondaries themselves when the field collapses in them ?  ( not too
>bright on this subject , but trying ;)   ) 

If you arc the top to ground, there may be imbalance voltages set up in the
two secondaries causing arcing between them.  However, the power should be
low enough, in that case, that little damage should be done.

>
>
>while im here    what is the avg. length of streamers produced by a
>10KVA polepig ?  Im getting  5-6'   is there hope for more length ? 

Last year, Bart Anderson collected a ton of wonderful information from many
coilers.  See the Simulations/Graphs section at:

http://www.geocities-dot-com/CapeCanaveral/Hangar/3108/sitemap.html

Cheers,

	Terry

>
>and one more     is there anyone out there that lives in La, New Orleans
>area ( or am I the only person in this city that loves coiling ;)  ) 
>
>
>Scot D
>
References: