OLTC idea...

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

Original poster: "Wells Campbell by way of Terry Fritz <twftesla-at-qwest-dot-net>" <wellscampbell-at-onebox-dot-com>

Hi Terry, all, 

I am writing with a kind of an oddball idea which I had a few years ago,
and actually made it work on my little desktop coil, and had forgotten
it completely until today as I was daydreaming...maybe it's a concept
that would have some use in the OLTC realm, who knows...

Let me first take you back to the heyday of rolled poly caps and Richard
Quick gaps, about the time when the first little blue boxy-looking phillips
caps were being soldered together and all the "high power guys" were
scoffing at the idea of an MMC being used for anything but a little coil...A
post about rolled poly caps talked about reducing inductance in the rolled
caps by using strips of foil every turn or two as a terminal, so that
the charge didn't have to travel around and around the plate to get to
the terminal. 

well, I got to thinking, what if you could make a cap that had about
the inducance of a primary, wrapped around a tube which would go around
the secondary and serve as both the primary and cap in one unit-I think
I called it a capductor or incapacitator or something, and got some copper
foil and twisted one up. The way it worked was that each plate had it's
terminal at opposing ends, so that the charge had to travel in the direction
that contributed to the magnetic field instead of cancelling it out.
I wrapped the plate/poly/plate/poly stack around a tube which fit around
my secondary with about an inch of clearance, and was about 1/3 as high
as my secondary, with about 8 turns total. The gap and supply went in
parallel to the "incapacitator", and it resonated with itself. (I know,
hurts to think about, but basically the inductive properties and the
capacitive properties produced a unit that resonated at the same frequency
as my secondary, and served as a primary and cap in one). It actually
worked! I got the values so close on the first try that I was able to
tune with 3/4 turn of  refrig. tubing, off axis. 

Anyway, my reasoning was that it would be the lowest loss arrangement
ever, because the energy wouldn't have to travel out of the capacitor,
into the primary, and back, but would just be rocking back and forth
along the plates of the incapacitator. 

I dunno, maybe you could construct a poly and copper plate cap that would
wrap around the base of the OLTC, and simply connect the IGBT "brick"
across the leads of the incapacitator? you would have to get the values
right in designing the thing, but that shouldn't be too hard, I did it
with wintesla. 

Anyway, just an idea, I thought it was a neat concept at the time, but
never got much farther than cobble-up. But it was neat seeing "noodle
theory" turn into reality :>). 

Does this sound like anything you could use?

-- 
Wells Campbell
wellscampbell-at-onebox-dot-com