Re: what BPS?

[FutureT-at-aol-dot-com (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

In a message dated 8/7/00 5:37:57 PM Pacific Daylight Time, tesla-at-pupman-dot-com 
writes:

> Original poster: "Garth van Sittert" <garth-at-mediasupplies.co.za> 
>  
>  How can someone have a spark gap running at 200/240 BPS (50/60 Hz).  A 50 
Hz
>  mains waveform only peaks in two positions in a cycle.  The crest and 
trough.
>  
>  Surely one set of electrodes will align when the wave is at zero.  

Garth,

It can be adjusted the way you say, but it can be adjusted so that
neither firing occurs at the peaks, but rather such that both firings are
equal in voltage, but both lower than the peak.  Using this method,
you process the same amount of energy, but the bang sizes are
lower.  I have found a 20% "efficiency" penalty  when running in this 
manner (the sparks are 20% shorter than when running at 120 bps,
for the same input power).

>  I have heard of guys running at 400 bps on 60 Hz.  Isn't that terribly
>  inefficient.  It would just pull down the secondary voltages when the 
> primary
>  caps are only half charged.

Well, you can simply use a smaller capacitor, then the caps can
charge up more.  Since the gap is firing more times per second,
the power throughput will be the same.  However, I've found the
sparks to be shorter nonetheless at the higher breakrates.

Still, good results can be obtained at high breakrates.

Cheers,
John Freau