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Re: 60 vs. 30 ma

Subject:  Re: 60 vs. 30 ma
  Date:   Wed, 11 Jun 1997 19:25:26 -0400 (EDT)
  From:   Esondrmn-at-aol-dot-com
    To:   tesla-at-pupman-dot-com


In a message dated 97-06-11 00:11:07 EDT, you write:

<< 
 >If your system is currently operating and in tune, changing from a 30
ma
 >transformer to a 60 ma transformer will require no changes to your
 >system.
 > Based on my experience, you should see about a 50% increase in
 >performance.
 > Say from 12" discharges to 18" or 20".  It probably won't double the
 >performance.
 >
 
 Are you certain? In my Tesla Coil the primary capacitor is 
 directly across the high voltage leads of the xformer. For
 most cases, in order to draw the rated current (ie 60mA) you
 need a capacitance value so that the capacitive reactance (Xc)
 is equal to your voltage (ie 12000v) divided by max current
 output (ie 60mA). Or Xc=12000/.06
 If your capacitor is matched for a certain voltage at a 
 certain current output then that will change when you use a
 different voltage or different current. For example, if you
 had a capacitor matched for 12kV and 30mA and you put a 12kV
 60mA transformer across it, it would still only draw 30mA even
 though the transformer can put out up to 60mA. This is only 
 general though, in a Tesla Coil system there are ohter things
 like spark gaps that can draw the extra power. Putting a
 higher current rated transformer in the circuit will increase
 the output, but most likely not as much as if the capacitor
 was matched. There are other things like peak amps, etc. that
 also increase with an increase in capacitance.
 
 Hope this helps,
 T.Stewart
  >>
Well, I have said this before, but will say it again.  I think folks
spend
too much time worrying about matching caps to transformers.  The
transformer
needs to be able to charge the cap up to the peak voltage (or whatever
the
gaps are set to) a few times each half cycle  -  and that's it.  Adding
higher current transformers to an existing system will increase
performance
and does not require changing the cap to match the new transformer
ratings.

Ed Sonderman