Re: Quench Improvement
Sent: Saturday, August 09, 1997 7:37 AM
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.
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.
> 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