Re: How to rise the secondary? (fwd)
---------- Forwarded message ----------
Date: Thu, 16 Jul 1998 12:26:49 EDT
Subject: Re: How to rise the secondary? (fwd)
In a message dated 98-07-16 11:22:54 EDT, you write:
> John F. -
> I was reviewing your March and April posts of 1997 and found that you have
> forgotten that some of your tests agree with what I have been saying.
> Good tuning is a prerequisite to good quenching
> At K = .11 got 1st notch quench
> At k = .16 quench moved to 2nd notch and destroyed secondary
> Sparks were longest at low K values. The JHCTES program agrees
What I meant in my recent post was that even if the tuning is correct,
you're still stuck with bad quenching when you couple up too tight.
You implied that tuning will solve the quench problem that occurs with
tight coupling...it won't (and close physical spacing between the pri and
sec is not the main problem with tight coupling either). I assumed folks
tune their coils correctly in general. After all, why run a coil mistuned?
If someone had their coil mistuned...yes it would hurt the quench, and
tuning would help, but it still wouldn't solve the main quench problem
that occurs with tight coupling. The main problem is that spark gaps
can't quench well with tight coupling, and when the quench is poor
energy is wasted, and racing sparks may occur on the secondary.
A better quenching gap would permit tighter coupling with resultant
lower losses, and longer sparks without racing sparks on the secondary.
As far as obtaining the best spark when the sec was level with the
primary, that was in just one of my coils. I mentioned many other tests
where the results were best with the secondary raised.
So I don't think I forgot anything this time, but I'm the first to admit
that I often remember a lot less than I'd like to :)
> March 30,1997
> You made 6 tests with your coil by raising the secondary. You said you
> thought that the best output was when the bottom of the secondary was almost
> level with the primary compared to the raised positions..
> John Couture
At 02:58 PM 7/14/98 -0600, you wrote:
>---------- Forwarded message ----------
>Date: Tue, 14 Jul 1998 10:42:49 EDT
>Subject: Re: How to rise the secondary? (fwd)
>In a message dated 98-07-14 00:55:08 EDT, you write:
><< snip> Quenching is
>> not changed by coupling but it may be changed by tuning and other
> > John Couture
>If only that were true.... Then we could all couple our TC's at k = .385,
>k = .6, etc, and quench them easily at the first energy transfer or notch.
>It won't happen using a spark gap (unless there's a breakthough
>in quenching). Crossed H2 thyratrons can do the job.
>Coupling affects the quench because tight coupling causes faster
>energy transfer which means there's less time available during the
>"notch" for de-ionization to occur within the gap. Also, fast energy
>transfer means less losses in the gap, so there's more energy
>available to *want* to reflect back to the pri after the first transfer.
>In other words it's more likely the gap will re-ignite after the first
>energy transfer with tight coupling.
>This has all been discussed innumerable times on this list and
>elsewhere. Fiddling with primary tuning or other adjustments does
>not solve this. Have you looked at Terry's valuable papers which
>show these effects clearly?