Re: Magnifier conversion

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

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

Hi Antonio,

At 09:23 PM 4/29/2003 -0300, you wrote:
>Tesla list wrote:
>
> > Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>
>
> > No I forgot to try this :-(
>
> > Since I was up at 0.46 coupling, I expected problems but the plastic
> > sheeting worked very well.  The minor arcing was just due to fast sloppy
> > application of the sheeting ;-)
>
>High effective coupling can be obtained with an Oudin coil, with the
>primary and the secondary connected in series, and wound in the same
>direction. My driver can reach 0.49 with the outer end of the
>flat spiral grounded and the primary capacitor and driver connected
>to the point where the two coils are interconnected. This also
>changes the effective value of L2. The calculations can be seen at
>http://www.coe.ufrj.br/~acmq/tesla/tefp.html
>and are implemented in the Inca program too.

Neat!  Going to a high coupling flat coil would solve the corona problem 
well.  It may be a few days before I take the sawsall to the pretty 
primary, but no one said science is easy ;-))



> > >Maybe consequence of no quenching?
> >
> > Possibly.  A most odd thing.  Have to look into it more.
>
>Something weird that I noticed in my magnifier was that when I mounted
>a large half sphere as terminal, detuning the system significantly,
>I could not anymore draw arcs from the terminal to a grounded rod,
>but only lots of corona, creating a long sheet of blue light between
>the terminal and the rod.

Hmmm...  Maybe it just lowered the voltage way down.  Lots of ionization 
but no sparks.


> > I'll have to look into it more.  I think I can directly measure the
> > voltages at signal generator power to be sure is all operating as
> > expected.  also need to verify things much more.  Just didn't have much
> > time Sunday to be sure of what was going on.
>
>The waveforms that you posted days ago were close to the correct, but
>the notches could be better. A 6th-order magnifier can produce
>"second-order notches", where not only the voltages and currents are
>null at the notches, but some of their first derivatives too.
>It's also easy to check the resonance frequencies. Measurements in
>my sistem reveals that all three are withing 1.8% of the design.

I modeled the coil with a probe and signal generator setup.  Interestingly, 
my Tek5100 probe with a 220K resistor on the end is pretty close to the 
modeled streamer impedance.  This is the system model.

http://hot-streamer-dot-com/temp/NewMag/0429-02.gif

The predicted output:

http://hot-streamer-dot-com/temp/NewMag/0429-03.gif

and the real calibrated output for a 10Vp-p square wave:

http://hot-streamer-dot-com/temp/NewMag/0429-01.gif

Everything is pretty close.  I will fiddle with it a little to get the 
notches to line up better but everything is working close to what was 
predicted.  Hopefully, I can get the MOVs on the driver fixed this week and 
check notching and other real running condition things with test equipment 
present.

The MOVs on this coil were set for 120VAC, but I guess I turned it up to 
140 once too often :o)  I had to order new ones since I didn't have any 
around here.


>Regards,
>
>Antonio Carlos M. de Queiroz