OLTC update

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

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi All,

I took yesterday off from the OLTC thing to "recover" ;-))

But today I was back at it.  First I ran countless MicroSim and E-Tesla6
runs to tell me how to fix the tuning problem.  It was tuned 10% low before
and I could not tune to coil to the right place by moving the toroid up and
down.  I found my answer and hack sawed 5 inches off the secondary with no
fear!  I should have taken a picture of me sawing away "tuning" my coil
:o))  I guess I am getting pretty good at that stuff since it turned out
perfectly :-))  I can now tune anything again just my moving the toroid up
and down.

So I turned my attention to the fast ring up problem again.  It didn't go
away like it was supposed to.  The coil really does have very fast ring up
even at higher power levels as the no-quench yellow scope trace here shows:

http://hot-streamer-dot-com/temp/OLTC08-27-01.gif

A few minute with MicroSim gave the answer:

http://hot-streamer-dot-com/temp/OLTC08-27-02.gif

Primary circuit loss is 2.5 mOhm which is right on target at these low
power levels but the coupling REALLY IS 0.25!  I could never quite "see" or
visualize how coupling works, but I guess I did something right.  The
primary to secondary coupling in my OLTC is enormous.  I don't know if it
is the three parallel loops give very low primary inductance or what...
This 0.25 number is "with" the secondary being raised as show here (note
the shorter secondary now)!

http://hot-streamer-dot-com/temp/OLTC08-27-04.jpg

So for some reason, this coil has very high coupling.  I don't know if this
is good or bad...  I guess it is good since I can always reduce it and I
seem to be able to easily control racing arcs and primary to secondary arcs
at this level.  So I just need to find a sweet spot and adjust things for it.

I see Marco has just published an article in a prestigious scientific
journal on this very subject :-))))  I will have to read it again and try
to understand it this time :o))

The present schematic for the coil is at:

http://hot-streamer-dot-com/temp/OLTC08-27-03.gif

This model tends to have errors during runs that I fiddle with to work
around but it seems to be predicting things perfectly!  A giant help in the
case of these very odd machines...

Once I get these details worked out and the weather is nice, I will haul
all 35 pounds of it outside and let it loose!  Then I can work on pumping
it up to 4X the power running off 240VAC like it is really supposed too :-)))


BTW - Many many thanks for everyone's kind comments in all this.  It easily
could have been an embarrassing disaster!  It would have taken me almost a
whole day to get over that :o)))  But it looks like I got lucky this time
:-))  Also, many thanks for all the great ideas people have suggested that
really made this thing work!  I have been posting virtually every detail to
the list here, but I will also write it all up when the dust settles.

Cheers,

	Terry