Original poster: "Lee by way of Terry Fritz <twftesla-at-qwest-dot-net>" <lee-at-ics-ltd-dot-com> Should I base my capacitance calculation on the peak of my transformer or the rms value? eg. rms 15kV = 5.3nf peak 19kV = 4.2nf The transformer that I will use is 15kV/30mA So should I plug 15 or 19 into WinTesla? Thanks for your time,