Re: Quench Improvement

From: 	Chuck Curran[SMTP:ccurran-at-execpc-dot-com]
Sent: 	Saturday, August 09, 1997 4:30 PM
To: 	Tesla List
Subject: 	Re: Quench Improvement

Tesla List wrote:
> From:   FutureT-at-aol-dot-com[SMTP:FutureT-at-aol-dot-com]
> Sent:   Saturday, August 09, 1997 7:37 AM
> To:     tesla-at-pupman-dot-com
> Subject:        Re: Quench Improvement
> In a message dated 97-08-09 09:59:04 EDT, you write:
> <<
> > O.K., my selected path was to drill and ream the original 1"
> diameter by
> > 1.25" long brass stationary electrodes (with a taper down to 3/8")
> with
> > a .125" diameter hole and added a 6-32UNF set screw at a 90 degree
> angle
> > to the axis.  Here a 1/8" diameter section of tungsten was inserted,
> > 1/2" into the brass and 3/8" extending beyond.  At the power I was
> > running I really didn't expect it to last, but it was a start.  This
> > would result in a mechanical dwell of about 88 usec.  The air gap
> was
> > .025" here and in the vacuum gap electrodes.
> > Well, I fired the system up and it ran great for 2 minutes and 40
> > seconds and then I stopped and checked out the tungsten.  (Neighbors
> > came out of the woodwork everywhere.)  It looked just like when I
> > started--it appears that the brass did do an acceptable job of heat
> > sinking the tungsten.  I ran it again and I really got the best
> sparks I
> > have ever seen on my system over the next run.  It's my opinion that
> the
> > improved quench has made a very positive change.
> Chuck,
> I'm glad to hear about the improved results of your TC system.
> It is possible that the quenching quality and time has stayed the
> same, but the gap may have been "refiring" using the wide electrodes.
> If the electrodes are too wide, the cap will have time to recharge
> partially after the gap fires, and cause the gap to fire again while
> the same electrodes are still within alignment.  "Fixing" this will
> of course help the performance by reducing current draw, and allow
> the caps more time for charging.
> > Now for the best part.  I originally was drawing 60 amps with the
> big
> > electrodes and now power comsumption dropped to 42 amps with better
> > spark!  My rotary currently has 12 rotating electrodes and runs at
> 2250
> > RPM, I may consider removing 6 electrodes and running at 4500 RPM
> for
> > better quench times yet.
> If the gap was originally "refiring" as mentioned above, then
> shortening
> the "quench-time" (actually mechanical dwell time) further might not
> help.
> The actual quench-time is often much shorter than the mechanical dwell
> time...it all depends on coupling, frequency, loading, etc.  The
> looser
> the coupling, the more likely the quench time will match the actual
> dwell time.  Also, the shorter the mechanical dwell time, the more
> likely it will match the actual quench-time.
> It is possible that you actually shortening the actual quench-time,
> but just wanted to mention the other possibility.
> John Freau
> > I've gained alot of respect for the work done by others associated
> with
> > quench times.  The impact on my systems performance was extremely
> > positive, based on one run.  I will be setting up again and trying
> to
> > see what kind of arcs I can draw, but things do appear better now!
> > Thanks to Bert Hickman for his advice, I just had to cook some
> > hamburgers and brats on the grill for all that night!
> > Chuck Curran
> > Cedarburg, WI
>   >>

Hi John:

You've suggested another real possibility here, but at this time I can
only guess at what actually is occurring.  The path visible on what
"used to be" a highly polished brass electrode  was what appears to be a
continuous path--obviously that's just an impression, I really don't
know what is actually happening at this point.  I did have the old TEk
531 connected and I attempted to monitor the picked up waveform with the
probe connected to my trusty aluminum ladder laying next to me. Hell of
an antenna.  Bert supplied various waveforms under different quench
states and it didn't appear too bad.  I will quickly admit the results
are questionable since I found I couldn't accurately monitor the coil
controls, a video camera, watch the sparks and the scope all at the same
time!  I plan to attempt to get a better scope view later this week,
I'll be on vacation for a few days starting tomorrow, so it will be
Friday or Saturday.  Thanks for your comments.

Chuck Curran