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=?iso-8859-1?Q?Re:_Okay,_cap_discharge_time_isn=B4t_really_?= valid for TC usage.
Hi Reinhard and all
If you were to use an H-Bridge gap any left over
energy would be added to the next discharge, as
the cap is pulse charged to the opposite polarity
at every presentation.
I think, though, by time the gaps open there isn't
much left. A one foot diameter gap using 1/2 inch
electrodes at 3600 RPM can't mechanically quench
in under 660 us by which time all is done if there
is any spark at all. Even with no breakout my 8"
secondary rings down in 700 us. So you are left
with whatever voltage the gap quenches at.
GL, I believe used heroic mechanical means to force
a quench at 130 us. Still a 100 kHz coil will ring up
in 50 us at the modest couplings we typically use.
LR
>Okay, I got it. I was thinking, if you didnīt have enough time to
>fully discharge the cap, you might not be using the full energy
>available. This IS true, but the energy left is indeed very small
>and wouldnīt contribute measurably to the peak spark length
>(not even in high break rate systems). If I use my cap (120nF)
>as an example and letīs say it has residual charge of 1000V
>on it, it would only be:
>
>0.5*1000^2*120*10^-9 = 0.06J
>
>A 120nF cap is a rather large cap, but even here the (high)
>residual voltage doesnīt amount to any real stored (and lost)
>energy. The reason is quite obvious, now, after looking at the
>equation: The energy goes down with square of the voltage.