Re: Dwell time, etc

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Bob (R.A.) Jones" <a1accounting@xxxxxxxxxxxxx>

Hi,
----- Original Message -----
> Original poster: FutureT@xxxxxxx
snip

>Typically the gap does not quench because
> the electrodes pull apart and break the spark.  Rather the
> electrodes may still be aligned when the gap quenches.
> This is because the cap runs out of energy and the voltage
> drops until quench occurs.  A rotary gap determines when
> the gap will fire, but not when it will quench.  Quenching is
> more determined by other aspects of the Tesla coil although
> teh gap does have some effect.
snip

I agree with the above.

What I then wonder is what cause the ring of fire affect.
Is it too small a cap for the ballast? and hence recharge is so rapid that
the spark is reignited and quench is then by separation?
An other question. Some contributors suggest that dwell time can be adjusted
to produce longer sparks. If quench time is not influenced by dwell time how
can adjusting dwell effect performance.
A noticed in a crude simulator (dead short for the SG) that under certain
circumstances the charge voltage was dependent on the dwell time (period of
the short). in say going from 1/100 of a cycle dwell time to say 1/256 the
charge voltage changed by say 20%. I did not investigate this effect only to
make the dwell time as small as possible so I do not know it if was an
artifact of the simulation or a particular set of conditions that are
sensitive to the dwell time. I did consider that the longer the dwell the
greater the ballast inductor's charge voltage(hence its stored energy) under
the appropriate phase conditions.  So that when quench does occur the cap
voltage is charged to a greater voltage then if the dwell had been of
smaller duration.
Is this the reason some experimenters suggest dwell time effects
performance. I should add that its difficult to see how if the spark does
reignite why it would not be drawn out in to a ring of fire regardless of
the presentation time of the electrodes).

Robert (R. A.) Jones
A1 Accounting, Inc., Fl
407 649 6400