Re: I'm wondering about this gap and tuning issues. Am I finally *beginning* to understand?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>

Hi Garry,

At 06:03 PM 4/11/2001 -0700, you wrote:
>I've been reading here quite a bit, and a lot of what is written here is WAY
>over my head. The hardest part I think is getting the terms straight.
>Usually, by the time my mind finally coughs up the definition of a term I am
>reading, I've forgotten what was said about it. Then by the time I am done
>reading it again, I've forgotten the definition and by the time I recall the
>definition, I've forgotten what was said again. ;-)
>
>So, I try to visualize it in my head and I was thinking about NST's. I seem
>to remember that (Reason I say this is because I don't trust my memory any
>farther than I can throw a fully loaded and operating washing machine) that
>when you have alternating current that the voltage is like a sign wave,
>going positive, then neutral at the point of reversal, and then negative.
>There are peaks and valleys in the sine wave. I will rever to them both as
>peaks.
>
>So, I was thinking about how could a cap in a tesla circuit be charged when
>the current is going negative and positive. I asked myself why it wasn't
>canceling it all out and here is what I came up with. Someone tell me if I
>am close?
>
>Are these statments true or close?
>
>The primary and the gap spacing in a tuned tesla coil is such that the gap
>fires as near the PEAK voltage (Or is this current?) so as to discharge the
>cap. The close to the peak the gap fires the better. When the charge is
>reversed, the gap fires on the reverse peak. If the gap fires early, output
>is reduced because the charge is drained before it can maximize, and if it
>fires too late, output is reduced because some of the charge has been
>canceled out by the opposite charge that is now flowing into the capacitor.
>True?

Absolutely true!

>
>The primary, acts as a kind of resistance to emf flow, halting it at the
>right time (Quenching) and delaying the discharge to the right moment. True?

The inductance value of the primary acts like a resistor to limit the
current flow.  The more inductance, the lower the current.  Quenching has
to do with the gap and a whole bunch of stuff.

Pretty close ;-)

>
>So, that's where we get the 120 breaks per minute because the gap fires on
>the peaks that are double the alternating cycle of 60 cycles per second.
>True?

Yes!

>
>Than a BPS of 60 would mean the gap discharges on the peaks of only the
>upper or lower half of the sine wave or every other peak?

Yes!  You can manage to hit it just right so you only get 60BPS.  Too large
of cap value will do that.  It misses one peak but gets sort of a spring
boost to help it hit the next one.

>
>So, rotary gaps have the advantage of better control. AC would do best with
>a sync gap and DC would work with either sync or assync?

Exactly!

>
>I recall folks speaking about voltage ringup, would that be kind of like
>where the relationship between the frequency and the inductance in the NST
>is such that the current gives a shove to the next cycle kind of like a
>person rocking back and forth on a swingset to get more swing (Amplitude).
>Wow, this last one sounds a little far fetched to me. Take this one with
>grain of salt if desired.

Almost exactly like a kid on a swing.  The primary keeps pushing at just
the right time to push the secondary voltage higher and higher.

>
>---
>
>So, after reading all your posts out there, am I finally getting some idea
>of what ye all are saying or am I still in clueless canyon?

You very close to being completely correct ;-))

>
>PS: Warning! If you reply in really technical terms. I probably won't
>understand you. ;-)

All I did was tell you that you were right seven times ;-))

Cheers,

	Terry


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