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Re: Capacitor Size and BPS



Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>

Hi John,

An empirical factor could certainly be installed, but easier said than done, especially with spark gap data (as you know). I'm not optimistic that there are coilers desiring to make those measurements (but I'd like to be proved wrong).

The gap is such a factor in coil output spark lengths. The bps and power at the gap are just two appendages of very complex events. For RSG's, if adjusted for minimal gap width certainly helps. The gap will conduct if sufficient voltage is present, but RSG's will "not always" have sufficient voltage to conduct even with "plenty of charging power" as zero crossings occur (ARSG's), the gap unexpectedly conducted longer on the last event and charging just hasn't been long enough on this event (all RSG types), etc.

I need to personally experiment with high bps and track gap conduction's to presentations. I'll have to give those experiments a go this year. Peter's coil certainly shows that high bps is not a problem with spark lengths for given power input. There may be a low break rate optimum and also a point where a high enough break rate may meet or even exceed that optimum. The gap is such a lossy component in our systems that small changes (thermal, mass, size, type, etc..) is seen in the spark lengths with the naked eye for the same input power.

Take care,
Bart

Tesla list wrote:

Original poster: FutureT@xxxxxxx
In a message dated 12/27/05 2:25:01 AM Eastern Standard Time, tesla@xxxxxxxxxx writes:

Hi Bart,

Any high break rate spark gap (ARSG or SRSG)
will skip some firings near the zero crossing.  To make the
calculations more accurate, the bps figure used for the calc
could be reduced by
some estimated %, to allow for this.  A proper scoping of some
high bps SRSG rotaries could show a good ballpark % to use
for this bps reduction.  The actual reduction would depend on
factors such as gap spacing vs, voltage, calced bps, etc.
The higher the calced bps, the more firings will be skipped.
For example at 360 bps, no gap presentations might be skipped,
but at 1200 bps, two firings may be skipped on each half cycle,
giving an actual bps of 960 bps (two firings skipped x 120 half-cycles
per sec. = 240 firings skipped/ sec.   And 1200 calced bps minus
240 firings skipped = 960 bps actual).  The actual reduction could
be greater or less of course depending on various factors.  But in
any case this would have some effect on power throughput
calculations.  These low level "side" firings contribute minimally to the
overall power throughput.

In my own scope tests, I could see more firings come
on-line as I continued to crank up my input power using high bps
sync rotaries, as more gap presentations came to have sufficient voltage
to fire.

John