Hey Guys, I've been playing with larger arrays of fast-switching IGBTs for growing huge arcs from "tiny" coils. The idea is that hotter plasmas can be achieved at lower voltages by upping the frequency. At ~350Khz and above, its noted that the plasma tends to grow in straight segments which helps it reach further still... A dramatic demonstration of this effect is shown here with an 8" long coil with just 165 turns of wire producing maybe 100kVAC at 300khz is jumping 11 feet to the shop ceiling. https://www.flickr.com/photos/kickermagnet/15705193211/in/photostream/ More pics at: http://forcijo.smugmug.com/Events/Teslathons/Philthon-2014/45663076_MtFqHw#!i=3689589842&k=M8Crsgs For those into the specs on components and such, I'll link my 4HV.org post from earlier today: http://4hv.org/e107_plugins/forum/forum_viewtopic.php?167363 This coil is waiting for a 40kW power supply before it can sustain the 10+ foot performance at high duty cycle. For now its limited to bursts at any power level over 15kW (which can only produce about a 5-6 foot discharge at 50% "on time" or about 25% duty cycle considering its a triangular modulation signal). Maximum peak power so far is 190kW. The maximum i'd bet my power electronics can handle is 260kW peak, so i think 13-14 foot sparks may be possible from my 8" tall winding... i'll set it up with more space next time and see :-). Steve _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla