RE: [TCML] Secondary Coil: Wire Gauge and Number of Turns

["Phil Tuck" <phil@xxxxxxxxxxx>]

Brandon,
With only a 15/120 NST I would go up in size to AWG 22. Thicker wire, easier
to wind, and with 1000 turns still gives a winding length of 28 inches but,
taking into account your power, a lower, less lossy, 35mH.
If you're hand winding you never seem to get the number of turns you expect
anyway!  - The above recomendation and your original AWG 24 @ 1237, would
both give 2.6 thou between adjacent windings, not do-able by me now with my
eyesight, but if you're young and healthy with all your own teeth you would
manage.


Phil

-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
Of Brandon Hendershot
Sent: 02 July 2013 23:48
To: Tesla Coil Mailing List
Subject: [TCML] Secondary Coil: Wire Gauge and Number of Turns

Phil,

>Not too sure what you meant by "(... while keeping the required primary
>inductance to about 90% of the primary coil's capacity.)".

Basically I was wanting to design the secondary to require almost all of
the available primary coil when tuned properly.

>It's all about having a balance, that's why using an aspect ratio that has
>been determined as sensible by countless coilers over the years (4 / 5:1),
>combined with a turns ratio centred around 1200  (900 - 1500), means the
>both the secondary inductance and inter-turn capacitance should work out
ok.

Based on this (and other advice) I'm thinking of making it like this:
1237 Turns of 24 AWG, 28" x 6.6" (4.25:1) yielding 54.5 mH Inductance and
12.0pF Capacitance.
Based on popular opinion I believe we can all agree on this being somewhat
optimal, right?


Scott,

>I'm curious where you heard that a higher inductance is better?

The logic behind that was to maximize Vout (before accounting for losses to
resistance) and minimize losses in the Spark Gap. But now I know that that
"blatantly isn't" the case when taking into account the consequential
losses.

>With that said, to answer your question,
>what do you hope to achieve out of this coil?  Big sparks?
>Power handling capability?  Highest possible voltage?
>Aesthetically pleasing?  Wireless power?

I'm a simple man: I just want to throw the longest, brightest arcs I can ;)

>Given you are still in the design phase let me tell you how I would
>approach it, assuming you were going for maximum spark length and
>aesthetically pleasing as primary design motivators.  You know you will be
>using 1,825 watts, so we back calc for spark length and get 72 inches, so
>we pick our secondary length at 72/2.5= 28 in (a good size from a power
>handling standpoint, but optimally nice and compact (pretty) and easy to
>build.)  From there plug into Tesla map and find your wire gauge for 1200
>turns, try not to fall in love with a gauge before hand, it is just
>arbitrary, one is not better than the other except that it fits your
>design.

I've been loosely following this same advice since you gave it in another
topic of mine a few months back. Turns out I should've been following it a
bit more closely, that's increasingly similar to where my designs are
heading!


To summarize, what do you all think of the revised design mentioned above?
Are there any more factors to consider before I commit and start buying
parts??

Thanks as always everyone,

-Brandon H.
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla