Re: Freau's efficiency theory=Success!

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

Original poster: "Peter Lawrence by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Peter.Lawrence-at-Sun-dot-com>


Awesome. Am I reading this right, you've got a 5"x32" toroid on a coil only
24" high? and getting 60" sparks from a coil only 24" high?

This looks like the overall shape of my next coil when I'm tired of building
12" high ones, but I'll probably only try 6"x24" toroid. You mention the
spacing and inductance of your primary, but not it's inner and outer
diameters?

-Peter Lawrence.



>
>Hi all,
>
>Over the past few months I have built a medium sized Tesla coil
>based mainly on  John Freau's efficiency theories.
>http://hometown.aol-dot-com/futuret/page3.html
> (Very good info John)! 
>
>I feel this coil is a  good performer and I wanted to share it's
>specs with everyone. (Shameless coil gloat)!
>
>Secondary:
>Material= Home Depot HDPE drain pipe. (White on the outside,
>black on the inside).
>Diameter=4.2"
>Form length=26"
>Winding length=24.5"
>Total # turns=1830, (approx).
>Wire size=28
>Inductance=56mH, (measured).
>Fres, (bare)=219.3kHz, (calculated, my Navy surplus audio signal
>generator only goes to 200kHz)!
>Fres, (loaded)=104.4kHz, (measured).
>Toroid minor dia=5"
>Toroid major dia=27", (tube center to tube center)
>Toroid capacitance=32.24pF
>I also use a 1 7/8" x 6" control toroid that just fits over the
>secondary.  The lower surface of the control toroid is even with
>the top turn of the secondary.
>
>Primary:
>21 turns of 3/16" copper tubing spaced 1/4". Tap point is 19.25
>turns, (measured 145.9uH).
>Measured Fres at this tap position is 94.7kHz, about 10kHz lower
>than the secondary Fres. (Coil tuned for maximum spark length)
>Tank cap=0.0187uF MMC, (Terry's Panasonic caps, 15 caps in each
>string, 5 parallel strings).
>Coupling, (K)=0.106
>
>Gap:
>120bps SRSG.
>
>Power transformer:
>Unmodified 12kV 60mA Magnetek/Jefferson NST, (max input 140Vac).
>VA input=3220, 23A at 140Vac. (No PFC caps).
>Actual power input=1080Watts (Measured with Wattmeter)
>Maximum spark=61"
>
>
>Any comments or questions welcomed.
>
>Jon