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Re: Fw: frequency (fwd)



In a message dated 99-04-17 05:06:53 EDT, you write:

<< 
>   I am working with electromedical devices and am attempting to understand
> the relationship between the frequency of the incoming voltage/current
 > typically 60 cps) with regard to the charging of the capacitor and the
> breaks per second (bps) of the spark gap.  It appears that the maximum bps
> with a static gap are limited to 120.

Trent,

A static gap can fire at more than 120 bps, if the cap is small for the
amount of input power, and if the gap is narrow.  With a rotary, there's
still the need for the power supply to be capable of charging the cap
quickly enough before the gaps move into alignment. 
 
>   This limit doesn't appear to apply to a rotary gap. 

Again, this limit doesn't apply to the static gap either.

> My questions:  How
> does the use of a rotary gap effect the charging of the capacitor, the break
> down of the gap and the power transfer across the gap, when subject to the
> typical incoming frequency?  Aren't we sacrificing power by increasing the
> bps?  Is it possible, say by using a higher frequency input, to increase the
> charge to the capacitor, thereby increasing the power across the gap,
> resulting in greater effectiveness of the system?

In many ways, the cap sees the incoming AC as a  source of "DC" in 
a way, since the cap charges during a part of the incoming sine wave.
By using a rotary, we can delay the firing of the gap beyond when a
static gap might fire, but mostly we force the gap to fire on a more
regular basis.  Static gaps fire somewhat chaotically.  By using a
higher bps, we put less energy into each bang, but the total 
power can be the same.  With high bps, we depend on the spark
dynamics to increase the spark length, by adding the bangs together
"in the air".
 
>   I'm looking at the possibility of using a 400cps input in an attempt to
> realize greater efficiency from a rotary gap system; any input/feedback is
> welcomed.

It seems that at a higher input freq, a smaller cap would need to be
used, but it would fire more often.  I don't know if this would improve
the efficiency, I tend to think the efficiency would be lower?
 
John Freau
   
>Thanx and best regards,
 >                                                  Trent
  >>