Bang size and break-rate


Just a clarification:

I've spoken a lot about the benefits of a low break rate with a larger 
cap size.  Other times I've mentioned the benefits of a large bang
size.  I should mention that it doesn't matter how the large bang is
created, i.e. either by using a large cap, or a higher input voltage,
the main thing is the large bang size and low break rate.  The higher
voltage might even be a little more efficient due to lower gap and
other tank losses.  The corona onset point is of course the limiting
factor for using higher input voltages.  Another reason I've generally
stressed the large cap idea rather than super-high voltages, is the 
difficulty of finding very high voltage transformers.  I've generally 
preferred to use at least 12 to 15kV xfrmers.  Nst's and PT's
are generally found most commonly up to around 15kV.  The higher
voltages will also require caps that have a suitable HV rating.  The
MMC caps will shine here, since they are easy adapted for any 
voltage.  Any resonant charging effects will have to be allowed for
also when figuring the required voltage rating.  

If you have a HV transformer of 20kV or so, by all means use it.
Also be sure to allow suitable insulation or clearances for the higher
voltages.  In some cases, X-ray transformers can be modified to
give a lower voltage output (around 20kV), by placing the HV
secondaries in parallel instead of in series, and by series-ing 
the primaries and running them on 120V instead of 240V, etc.

However, despite my above comments, lower voltage TC's of 6 to
10kV, can also give excellent performance when operated at a 
low break rate with larger caps.  

John Freau