Re: How to rise the secondary? (fwd)
---------- Forwarded message ----------
Date: Thu, 16 Jul 1998 04:07:05 +0000
From: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: How to rise the secondary? (fwd)
John F. -
Your troubles with coupling and quenching illustrates what I mean when I
say that today's Tesla coil designers/builders should take advantage of the
experiences of what past builders have found that will work. For example, if
you follow their advice for coupling regarding a particular coil, the coil
and quenching will operate correctly because they have already determined
the proper conditions. As I have said before, I have collected this type of
information and used it to develop a TC computer program. The program will
get you in the ballpark. It is up to you to improve on the design.
I agree with you that every coiler should review, study, and understand
the wealth of information available on the Tesla List. This information
represents the experiences of many modern coilers. I have spent a lot of
time also collecting this information and sifting thru it to come up with
design criteria for creating classical Tesla coils that work.
The coupling for Tesla coils is an important parameter because if it is
too high the coil will not operate properly or at all. I agree that if the
quenching is too tight that quenching will not work as it should. This
agrees with what past coilers have found. The coupling depends on over a
dozen other TC parameters. It is a ratio of mutual inductance divided by the
sqrt of the primary inductance times the secondary inductance. It is obvious
that with these inductances that many variables are involved. These
variables must be coordinated or the Tesla coil will not operate correctly
including the quenching. With a properly designed TC the quenching will
occur at a time long after the spark leaves the toroid at the first transfer.
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?