Original poster: Skip Greiner <skipg@xxxxxxxxxxxxxxx> GerryThe cap was made by High Energy Corp in 1984. I do not know what the cap was made of except that it was oil filled. I talked to High Energy about 20 years ago and they told me then that I could run it in Tesla circuits without a problem. We did discuss the charge discharge cycles, current levels and the frequency range of about 100khz to 350khz. It apparently was a foil wound cap and was used in extremely high powered lasers where multiple pulses were generated. The cap had 6 sections. Each section was independent, rated .0275mfd @ 42kv. I had wired it for approximately .035mfd. I have been using the cap for at least 20 years without mishap. I have used it on coils operating above 5kw. When it failed, it blew up the case and sprayed oil all over the place. It obviously was HOT. I do not yet know the failure mode...will be doing autopsy in the next few days. As I said, I was only up to about 65 volts input to the NST and I was adjusting the gap phasing. Also was trying to get a good handle as to what frequency it was operating at. I had gotten rid of the racing sparks and the discharges were pretty well confined to the aluminum foil ring. The safety gap was firing intermittently. Discharges were 36" to over 40" and then BLAMO!
Skip Tesla list wrote:
Original poster: "Gerry Reynolds" <gerryreynolds@xxxxxxxxxxxxx> Hi Skip,Its good you had a safety gap. This probably saved your NST. What king of cap did you have and what was its voltage rating??? You might want to autopsy the cap and see what its failure mode was (over voltage or over current).Gerry ROriginal poster: Skip Greiner <skipg@xxxxxxxxxxxxxxx>The safety gap is set to about 0.125" and the SRSG gaps are set extremely tight.