Re: FW: potential gain vs. power in TC systems

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: FutureT@xxxxxxx 

In a message dated 4/8/06 1:23:05 AM Eastern Daylight Time, 
tesla@xxxxxxxxxx writes:


> Hi John,Et Al
> I too am building a 12" coil. Do you think it would be pushing the ratio to
> go 72" 6:1. 18AGW magnet wire. I was planning on going to .5" primary to get
> more diameter but I'm not sure what this does to the comparative inductance.


Jim,

My guess is that it would be OK to go to 72".  I base this on my
old research coil which used a 4" x 23" secondary which worked well.
I used 28awg wire since it was a small coil.  Using the 18awg you'll
have about 1600 or 1700 turns I guess which seems good to me.
I think your plan would be a good test of such a design which is
not often seen (tall narrow secondary on a large coil).  I don't really
see any downside to your plan.  I think the streamer length is
mostly determined by the toroid size and the secondary height,
assuming you use adequate input power.


> Is it true that a torrid is best designed at a 3:1 ratio thus 60" would seek
> a 20" minor diameter? DC if you are reading this please share how you make
> your chicken wire torrids!


I suspect that such "fat" toroids give longer sparks for a given
overall diameter.  I make my toroids close to this ratio.  Most
toroids seem to be a little flatter at 4:1 or so.  Such toroids may
give a larger number of thinner streamers, but I really haven't
done suitable comparisons.  I think Richard Hull's Nemesis toroid
was 14" x 60" and it performed well.  It would be interesting to
try the thicker 20" x 60" toroid

John


> Regards,
> Jim Mora