Original poster: dhmccauley-at-spacecatlighting-dot-com That capacitor is way to large. You want about a 0.02uF or so for a 10kV/90mA resonant system. The 0.5uF is even too large for the largest of systems. Dan > i have a 21kv dc .5mfd for a dc tesla coil can i power it with10kv 90ma i > am having problems with building the proper reactor coil for it? anyone > have do you have any info > >