Certain s.s. phenomena

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

Original poster: "Kennan C Herrick by way of Terry Fritz <twftesla-at-uswest-dot-net>" <kcha1-at-juno-dot-com>

More s.s.-system results, some displeasing:

System:  "Current-ring"-primary, 12" dia x 36" high secondary space-wound
-at- 16T/inch with 22 ga. enameled wire wound over Teflon on a sonotube,
previously commented upon.

1.  I had reported that a 1-equivalent-turn primary seemed to work better
than the 2-turn one I had previously used.  Such is not the case: the
power MOSFETs get a little too hot for comfort and I now believe the
sparks to appear essentially the same.  So I am now trying a 3-turn
configuration incorporating 4 MOSFET sections and 4 "battery" sections
(see my recent postings of tcg_lp*.* at http://hot-streamer-dot-com for the
other configurations).  The 1-turn configuration employed, in effect, 2
MOSFET sections and 2 storage-capacitor ("battery") sections, doubled up.

1.1  With the 3-turn configuration, spark appearance is essentially
identical while mains current, for the same spark duty-cycle, is reduced
by ~20%.  The mains current goes into the 4 capacitor sections in
parallel; those sections' output currents now flow all-in-series into the
3 equivalent turns, via the MOSFETs, so that the loop current now = 1/4
the mains current.  Previously I had 20% more mains current going into
the same 4 capacitor sections but their output currents were flowing such
that aggregate loop current was equal to 1/2 the mains current (see the
referenced diagrams: 2 capacitor sections are within each loop that is
shown, but each section delivers 1/4 the mains current; 2 such
configurations magnetically in parallel yield 1/2 the mains current in
the overall loop).

1.2  For the same mains current, then, 3-turn aggregate loop current =
1/2 of the 1-turn loop current but the quantity of turns is increased by
a factor of 3.  Thus I would expect that the EMF driving the secondary
should have increased by a factor of 1/2 x 3 = 1.5, and perhaps even more
since transistor-drop and capacitor internal-resistance drop should now
be less.

1.3  So, how come is it that I see much the same spark?  Any comments?

2.  The displeasing news is this:  The entire T.c. assembly has heretofor
been sitting on a wood floor 4" above a concrete slab, and has been
connected to ground only via its mains-conduit ground lead.  There's
seemingly been no problem with that.  However, today I took a 4 ft x 4 ft
piece of fine-mesh screen-wire, laid it down under the assembly,
connected it to the conduit ground, and then fired up the coil.

2.1  Doing that, unless I provide a (3"-ball) break-out point on the
toroid, thus lowering the break-out voltage of the electrode, I get
sparking along the secondary coil and no breakout from the toroid itself.
 

2.3  It might thus appear that the entire primary apparatus, while
sitting only on the non-conducting floor and even though connected
more-or-less to conduit-ground, must sufficiently elevate itself in ac
potential, during the spark-voltage buildup, so as to preclude
coil-arcing.  While on the other hand, adding the 4-ft-square
counterpoise "anchors" the apparatus' potential, and thus that of the
bottom of the secondary, more closely to true ground potential, thus
allowing the voltage actually across the secondary to build up too high. 


2.4  The conclusion might be that if one wants to use a smooth 6" x 24"
toroid without a break-out point, one would definitely want a space-wound
primary, and with that spacing greater than mine--which averages ~.03"
betwen turns.  Either that or liberally slather on epoxy or the like and
hope that that substance withstands the voltage.  Is that what people do?
 I'd hesitate to do it since a breakdown within that coating could be a
pain to repair.

2.4  Any comments on that would be appreciated.

3.  Finally, a parenthetical observation of interest:  Since I can make
just 1 spark-event occur at a time if I wish, I can see that, often, more
than 1 spark will appear at the same time, i.e. during a given
pulse-burst, from the surface of the toroid.  As best I can tell by
closely watching the coil's E-field as displayed on the nearby
oscilloscope, such event is accompanied by a very sharp drop in the
E-field, at the instant of break-out and only on a negative half-cycle of
that field; never on a positive one.  Subsequent to that very sharp,
apparently negative-half-cycle, reduction, the E-field diminishes
uniformly, as expected, and is flat for the remaining duration of the
pulse-burst.  Anyone care to explain that?

Ken Herrick
________________________________________________________________
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today!  For your FREE software, visit:
http://dl.www.juno-dot-com/get/tagj.