Re: cap firing voltage scope measurements question

  John -

  It certainly is a mystery. To charge the cap to 840 watts (joules?) would
require 1680 watts input! With a 1000 watt input you have over unity energy!
Or am I misreading your test?

  John Couture


At 05:07 PM 6/16/99 -0600, you wrote:
>Original Poster: FutureT-at-aol-dot-com 
> All,
> I'm seeing some strange results in my TC:
> Here are some cap voltage measurements under different conditions:
> I set my input variac at 60, and the scope indicated the output voltage
> of xfrmer was 15.2kVpeak, without the TC connected.
> At the same variac setting, but with TC connected, but with the 
> spark gap removed, the cap voltage reads 22.3kVpeak.  I suppose
> I'm getting some resonant charging here with this particular ballast
> setting.
> At the same variac and ballast setting, but with the gap firing 
> (120bps), and the TC producing sparks, the cap voltage reads
> 30.4kV.  This means I'm obtaining a 2X voltage increase during 
> ~1/2 cycle, I thought this degree of resonant build up was possible
> only when using DC charging?
> Does this seem normal?  I would have expected the voltage to be
> lower with the gap firing since there's less time for resonant voltage
> build-up.  In there a gap in my understanding?  Or is my scope
> reading wrong?  The 30.4kV makes sense from a Joule perspective,
> since it comes out to 840 cap watts or so, and the meter reads 1000
> watts, which seems about right. 
> Mystery, or insanity?
> Thanks,
> John Freau >>