Re: First light with new 12" secondary

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

Original poster: "Dr.Resonance by way of Terry Fritz <twftesla-at-qwest-dot-net>" <resonance-at-jvlnet-dot-com>


I have not noticed this effect.  If you adjust coupling either way, ie,
raising sec or moving primary outward, technically you are adjusting the
coupling to the most efficient operating point, so it should not make much
difference how it is achieved.

We have done it both ways with no overall difference in effect.  It's just
easier to start the sec winding up higher that to move the primary out which
makes the base larger.  After the prototype is finished we raise and lower
the sec coil until we get the best effect.  Then, in future coils, we just
start the winding where our experiments dictate the best performance.

Happy Holidays,

D.C. Cox



----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, December 18, 2002 8:20 PM
Subject: RE: First light with new 12" secondary


 > Original poster: "John H. Couture by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
 >
 >
 >
 > DR. Resonance, All -
 >
 > This is one of the few Tesla coil questions that has not been answered
 > before on the List. Raising the secondary will reduce the coupling but
 > doesn't this also reduce the spark output compared to obtaining the same
 > coupling by proper spacing of the primary and secondary windings when they
 > are at the same level? How is this spacing determined at the designed
stage?
 >
 > John Couture
 >
 > -------------------------
 >
 >
 > -----Original Message-----
 > From: Tesla list [mailto:tesla-at-pupman-dot-com]
 > Sent: Wednesday, December 18, 2002 5:51 PM
 > To: tesla-at-pupman-dot-com
 > Subject: Re: First light with new 12" secondary
 >
 >
 > Original poster: "Dr.Resonance by way of Terry Fritz <twftesla-at-qwest-dot-net>"
 > <resonance-at-jvlnet-dot-com>
 >
 >
 > Greg:
 >
 > You might try various elevations on the sec. coil to set the coeff. of
 > coupling.  Just use some scrap pieces of 1/2" plywood.
 >
 > I'm going to guess you will need a sec above primary elevation of around
4-5
 > inches for max output.  With our coil of 18 in. dia. we need 7.25 inch
 > elevation for max. output.
 >
 > Best regards,
 >
 > Dr. Resonance
 >
 >
 >
 >
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Wednesday, December 18, 2002 5:02 PM
 > Subject: First light with new 12" secondary
 >
 >
 >   > Original poster: "Gregory Peters by way of Terry Fritz
 > <twftesla-at-qwest-dot-net>" <s371034-at-student.uq.edu.au>
 >   >
 >   > Hello all,
 >   >
 >   > Just fired up the coil with the new 1170 turn 12" secondary and an
 >   > extra string on the MMC (now at 0.15uF). Tuned the coil roughly with
 >   > the CRO, and set the coupling pretty loose (not going to fry this
 >   > secondary as well). Fired up the coil, synced the gap at 200BPS and
 >   > recorded 11.5 foot strikes with first run. I feel the coil could do
 >   > better, but it is running nicely and reliable (ran it for 4 min
 >   > continuously), and is using all the space it has available anyway
 >   > (nice ground strikes). I haven't even tried to vary the tap point,
 >   > toroid height, coupling, etc.
 >   >
 >   > I was finally able to remove the breakout point - beautiful high
 >   > current arcs. Input was my 11kV pig. Current draw sat dead steady at
 >   > 38 amps. An absolute pleasure to run. A good night by anyone's
 >   > standards. No smoke :) Photos soon.
 >   >
 >   > I want to increase the coupling, but have noticed that racing arcs
 >   > tend to do pretty bad damage rapidly at ~10kVA. Think I will leave it
 >   > as is.
 >   >
 >   > I'm going to make a tape with all my coiling activities, including
 >   > ballasting, gaps, control cabinet, etc - not to mention spark
 >   > footage. Anyone interested? Cost is only for shipping and tape. 5USD
 >   > at a guess. Will also post some digital video to my site (if Terry
 >   > will give me some space) at some point - still got free space Terry?
 >   >
 >   > Cheers,
 >   >
 >   > Greg.
 >   >
 >   >
 >
 >