Re: Newbie questions (fwd)

---------- Forwarded message ----------
Date: Tue, 14 Jul 1998 10:44:24 EDT
From: FutureT-at-aol-dot-com
To: tesla-at-pupman-dot-com
Subject: Re: Newbie questions (fwd)


First notch quenching refers to quenching that occurs right after the
first complete transfer of energy from the primary to the secondary.
The complete energy transfer usually takes a few cycles of RF to occur,
but the exact number of cycles depends on the value of "k" (the degree
of coupling).  As the coupling gets tighter, it gets increasingly difficult
to quench the spark at the first notch.  If the quench does not occur
at the first notch, the energy will feed back from the secondary to the
primary, then back to the secondary.  If the quench still doesn't occur
by the second notch, the energy will transfer from the secondary to the
primary again, and still more energy will be wasted, etc.  First notch,
(or first transfer) quenching is the ideal to be aimed for.  Many systems
quench at the 2nd or 3rd notch and still give acceptable results.  

Another way to look at first notch quenching is to say that all the
energy is *trapped* in the secondary at that time.  By trapping the
energy in the secondary it is forced to feed the spark output streamers,
rather than being able to transfer back into the primary to be subjected
to gap losses.

There's been long discussions on this list in the past about 1st notch
quenching, and also about the question of whether to place the spark
gap across the NST.  The consensus vote is to put the gap across
the NST.  All the arguements, pro and con, are in the list archives.

I think your questions are good ones BTW.  Building coils is fun,
understanding them is more fun.

John Freau

In a message dated 98-07-14 00:39:59 EDT, you write:

 ---------- Forwarded message ----------
> Date: Mon, 13 Jul 1998 18:27:52 -0700
> From: Terry Perdue <terryp-at-halcyon-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: Newbie questions
> Could someone explain what "first notch quenching" is? I am also trying to
> understand why it's apparently recommended that the spark gap be placed
> across the NST, and the series-connected cap and primary across that. On the
> small NST-driven coils I built as a kid (from plans I found somewhere), the
>cap and gap swapped places, and I had good results, never lost an NST, etc.
> In fact, why couldn't the NST and gap be placed in series across a primary
> tank? Dumb questions, probably, but I'm trying to learn as much as I can
> while I accumulate parts, and before I start building.
> Terry >>