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Re: Fw: frequency (fwd)



> Original Poster: Hollmike-at-aol-dot-com
> 
> In a message dated 4/23/99 4:28:50 AM Mountain Daylight Time,
> tesla-at-pupman-dot-com writes:
> 
> >
> >  I bet you won't be able to catch the tail of a bang at 1000 Hz repetition
> > rate
> >  with such a small capacitor: the oscillation will die out before your 1 ms
> > is
> >  elapsed.
> >
> Marco,
> 
> That is why I am designing it to go up to 5000 Hz. My design is based on the
> assumption of 30 oscillation cycles per bang.  The TC frequency was designed
> such that I should be able to "catch the tail" at 4000Hz charging freq.  

Mike,

Interesting proposal! However, once you begin to get heavy secondary
streamers, the Q of your secondary will drop substantially, such that
you most likely will not see anything near 30 oscillations/bang.
Compounding this, under heavy streamer loading the voltage envelope's
decay tends to be more linear than exponential until the output voltage
drops below the point of streamer reignition, and exponential decay
rings down the remaining energy. I suspect you will be very hard pressed
to "catch the tail" once you start getting heavy streamer activity.
Don't let this slow you down, however - there may be some very
interesting coil-streamer interactions at these higher rep rates!

> If necessary I can use a cap up to about 7 nF(30kV) with what I have on hand,
> although the impedance match becomes important at the higher charging rates,
> if I am not mistaken.  I suppose if 5000Hz is insufficient, I could alter the
> timing circuit.  The transformers I am using would actually work better above
> 5000 Hz(originally used at 20kHz).   I could also play with the voltage a
> lot.  I plan on 10kV out from the trannies, but they will withstand up to
> 60kV. I will limit this to 30kV as more would make the corona problems
> significant(max available capacitance would be 3.5 nF at this voltage to
> ensure safety of my caps).  The  power output can be as much as 4800W(60kV -at-
> 80ma was the original output of the X-ray power suppy I removed the trannies
> from) but I plan to keep it to about 1800W at this stage.  As you can see,
> there is much flexibility in my set up.  I am just starting it and may make a
> number of changes as it progresses, but am planning to make it adaptable to
> improve the chances of success.
> Any other comments or imput welcome,
> Mike

Sounds like a very interesting tool, Mike! Please keep us posted on your
progress.

-- Bert --