Re: Performance Question

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

Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com> 


Gary is correct --- a 4 times will produce even better performance.

This guy said he was a "newbie" so I was considering perhaps he didn't have
a lot of spare $$$ to spend on larger toroids.

We will be doing a bulk order for 34 x 8.5 toroid size in Oct if anyone is
interested.  Don't ask about price until we get some interest --- price goes
down as volume goes up.  Contact me off list if you are seriously
interested.

Dr. Resonance

Resonance Research Corporation
E11870 Shadylane Rd.
Baraboo   WI   53913
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, September 02, 2004 5:41 PM
Subject: RE: Performance Question


 > Original poster: "Lau, Gary" <gary.lau-at-hp-dot-com>
 >
 > On the point about top load size, it's been my experience that a larger
 > top load than suggested by Dr. R. is better.
 >
 > On my mini coil with a 1.9" x 9.5" secondary, I started with a 3" x 6"
 > toroid, and got 9"-10" streamers.  I switched to a 3.5" x 10.75" toroid
 > (5.6 times the sec diameter) and got 14" streamers.
 >
 > On my big coil with a 6.25" x 28" secondary, my best performance has
 > been with a 7" x 30" toroid (4.8 times the sec diameter).
 >
 > It's important to note that for a coil to function optimally with large
 > top loads, everything else must be "just right", or else the top load
 > will be too big and won't break out.  In particular, bang-size is
 > critical.  Unfortunately optimal top load size is something for which no
 > formula or agreed-upon guidelines exists.  One can only try something,
 > then try something else, and see which works best for you.
 >
 > And to be fair, the definition of what constitutes an optimal top load
 > is ill-defined.  My definition has been that which results in the
 > longest single streamer.  An alternate and equally valid definition
 > might be one that results in numerous smaller, simultaneous streamers
 > without using a breakout point.  A third perspective may be guided
 > purely by aesthetics.  I much prefer the look of my mini coil with the
 > 6" toroid over the 11" toroid.
 >
 > Regards, Gary Lau
 > MA, USA
 >
 >
 >
 >  > -----Original Message-----
 >  > From: Tesla list [mailto:tesla-at-pupman-dot-com]
 >  > Sent: Thursday, September 02, 2004 9:56 AM
 >  > To: tesla-at-pupman-dot-com
 >  > Subject: Re: Performance Question
 >  >
 >  > Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com>
 >  >
 >  >
 >  > No apologies necessary.  We were all newbies at one time or another.
 >  >
 >  > Yes, there will be a gain.
 >  >
 >  > Voltage is created by V = -L dI/dt  (inductance x rate change of
 > current).
 >  >
 >  > The main part of this equation, inductance (L), for a sec coil is:
 >  >
 >  > r^2 * n^2 / (9a + 10b)
 >  >
 >  > In the number part, you want to keep r (coil radius) as large as
 > practical,
 >  > and, within reason, n (number of turns) as large as practical.  There
 > are
 >  > some offsets to the value of n but for many coils 1,400 turns is
 > almost
 >  > always a good number to use.
 >  >
 >  > If you wind a new coil, keep the 4.5 to 1 height to dia ratio.  With a
 > given
 >  > coil dia. then this fixes the winding length.  Divide this winding
 > length by
 >  > 1,400 and now you have the outside dia. of the guage wire to use.
 > Select
 >  > the wire OD value from a wire chart and use 200 degree C wire for
 > excellent
 >  > high freq insulation value.
 >  >
 >  > If possible, select a toroid size of 2 to 2.5 times the dia. of your
 > sec.
 >  > coil.  Up to 4.0 is used for extreme cases.  This requires more
 > primary cap
 >  > and more power but provides nice outputs.
 >  >
 >  > This will give you spectacular performance from your new coil.
 >  >
 >  >
 >  > Dr. Resonance
 >  >
 >  > Resonance Research Corporation
 >  > E11870 Shadylane Rd.
 >  > Baraboo   WI   53913
 >  >
 >  >  >
 >  >  > Apologies to the list for the newbie type question. Without going
 > into all
 >  >  > the specifics I have a static gap TC with a 4.5" secondary (5:1
 > ratio)
 >  >  > 1.440 Kva. I am considering replacing my secondary with a 10" 3:1
 > ratio
 >  >  > secondary. Per my calculations this would not make any viable
 > change in
 >  > the
 >  >  > output power (i.e. Spark length) ...am I correct or would there be
 >  > anything
 >  >  > to gain other than the fun of winding a new secondary?
 >  >  >
 >  >  > Thanks in advance for your advice,
 >  >  >
 >  >  > Emmett
 >  >  >
 >  >  >
 >  >  >
 >  >  >
 >  >
 >
 >
 >