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RE: Capacitor in series with transformer or S.G ? What is right?



Original poster: "Pete Komen by way of Terry Fritz <twftesla-at-qwest-dot-net>" <pkomen-at-zianet-dot-com>

Harvey,

On an ideal cap, the current leads the voltage by 90 degrees.  Driven by an
ideal AC source, at the peak voltage, no current flows.  We do not have
ideal caps or AC sources.

For a resonant sized cap, the max voltage will be reached at the 60Hz peak,
but for an LTR cap the maximum voltage with a current-limited transformer
occurs later in the cycle.  The LTR cap makes the transformer/cap circuit
resonate at a lower frequency than 60Hz and thus the peak voltage comes
later than the 60Hz peak.  The gap firing just kind-of resets the cycle
position

Charging the cap after gap firing just means that more current will flow
through the transformer to charge the cap to the other peak.  The firing is
120 bps because when the gap fires somewhat after the 60Hz peak, the cap
cannot charge to a high enough voltage during the falling voltage part of
the half cycle to cause the gap to fire again.

In a series LC circuit at peak voltage, no current flows and the cap has all
the energy.  At zero voltage, there is maximum current flow and the inductor
has all the energy.  (while resonating anyhow).

Remember that cap and transformers don't consume energy (except losses),
they just store and release it.

I hope this helps.

Pete Komen

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Friday, February 08, 2002 4:42 PM
To: tesla-at-pupman-dot-com
Subject: Re: Capacitor in series with transformer or S.G ? What is right?

Original poster: "harvey norris by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<harvich-at-yahoo-dot-com>


> No. The static gap is triggered by voltage, so it
> tends to fire at the voltage peaks on the tank cap,
> not at zero.
Exactly agreed, but not yet resolved. Doesnt the cap
become fully charged after its source current ceases
to exist? This occurs on a cap charging in one half of
the AC cycle. Thus the actual highest voltage the cap
should have is after the current has stopped moving in
that direction, again at the point of 1/2 cycle of the
AC waveform? This then implies that it should
discharge at that point in time, and if we go by that
thinking, that would be the point in time where the
source frequency is at its zero crossing point.
However it appears that if I am dead wrong,as everyone
seems to indicate, this means the cap is firing at the
peak of the AC voltage input, then the rf burst of
short duration compared to the duration of the source
frequency means that after the rf burst (of short
duration), this still leaves another 1/4 cycle or so
for the cap to again charge up in the same polarity!?!
Using that resoning what are we trying to achieve? The
only thing I can think of by the reasonings forwarded
on this matter is that the firings must then be 240
BPS instead of the desired 120 BPS
Also, spark gaps are very fast
> switches,
> so no delay is possible. For all practical purposes,
> when the potential on the tank cap equals the
> breakdown potential of the static gap, it fires
> instantly. It does not wait for the 50/60Hz AC
> waveform to move on.
Also agreed, with the condition that the maximum
voltage on the cap has occurred after its source
current in one polarity has reached the end of its 1/2
cycle conduction.
Sincerely Harvey Norris

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