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Re: AC DC Theory and Thoughts.

Hi Gary,

At 09:53 AM 03/18/2000 -0800, you wrote:
>In theory, in an AC TC circuit the capacitor should be sized correctly so it
>will reach a full charge at the peak of the AC wave cycle.  The spark gap
>should be adjusted so it will discharge at or near a full capacitor charge.
>If the cap is too large it will not reach a full charge and power output
>will be low.  If the cap is too small the discharge current will be low and
>power output will be low.

The voltage on the cap and transformer my also be very high as to blow
something due to high voltage.

>
>By using full wave DC instead of AC you no longer have to deal with the
>problem of having to be so exact in sizing the capacitor used in the
>circuit.  With DC the amount of charge in the capacitor will depend on the
>spark gap.  The spark gap can be adjusted to give maximum charge on the
>capacitor and maximum power output. The capacitor will not discharge threw
>the spark gap until it has reached a full charge.

Yes,  However, an AC system will fire at say 120 times per second where the
DC system may fire less.  I would think it would tend to fire at 1, 2, 3, 4
cycles depending on the size of the cap.  Thus the BPS would tend to be
120, 60, 40, 30...

>
>In theory the capacitor in a TC circuit could be doubled in size.  The
>charge rate of the capacitor would be longer and the output current will be
>doubled.  A coil that was producing 24" sparks from a single neon should now
>produce 48" sparks from the same neon.  As we all know doubling power will
>not exactly double discharge spark length but you get the idea.

The double value cap should charge half as fast for 60BPS.  With twice the
energy going to the discharge, the arc distance should grow 41% longer.

>
>We all know from experience if you double the power supply size, double the
>capacitor size, the coil will now produce much longer discharge sparks.  If
>you can double the cap size but don't have to double the power supply size
>because the cap charges slower and discharges twice as much current as
>before the results should be longer discharge sparks.  The cap is no longer
>required to charge at 60 Hz, it can now charge at any frequency you like.

You can actually charge "any" size cap.  Our friends who crush quarters
charge their giant 5000+joule caps with neons though rectifiers.  It may
take a minute or something to charge for each bang...  5000 joules at 20kV
gives 25uF.  So if you can live with very low rep rates you can charge any
size cap you want.  However, lower and lower BPS may hurt a coils ability
to grow streamers along the hot arc channel formed by the previous
streamers.  ""If"" one "could" tune a 25uF primary cap, the typical 5 joule
15/60 kV system's energy could be increased 100 times so the low rep rate
may not be an issue.  Assuming the square root law for streamer length, a
100X increase in energy should give a 10X increase in arc length which
would be about 500 inches.  That would be a machine of almost unimaginable
power for even the big discharge type coils.  Of course, that is easy to
"type" here on the keyboard.  Making a thing that works... ;-))  Of course,
no need to stop at just "one" 25uF cap...  The rules of the MMC still
apply. ;-))

>
>Consider this thought.  What if the capacitor were adjusted to discharge at
>a some harmonic frequency of the Tesla Coil will that affect the resonance
>rise?  

If a BIG coil ran at 30kHZ and you discharged at 120Hz, you would be at the
250th harmonic!  "I" think that is too too far away on the band to have any
effect.  ""If"" one were to make a giant ("Avalon crusher" ;-)) coil that
had a fundamental frequency of 60Hz that could be driving directly as a CW
coil off a substation transformer, GREAT fun would be had!!! ;-)))

Cheers,

	Terry

>
>This idea came to mind after reading a post about DC coils.
>
>What do you all think?  
>
>Gary Weaver
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