Original poster: "Vladimiro Mazzilli by way of Terry Fritz <teslalist@qwest.net>" <mazvla@iol.it> Hi all, Terry put scope photo in http://www.hot-streamer.com/temp/mazzilli referred to drain voltage(blue) vs drain current(yellow) in one IGBT with 105Vac operation and 10" brush air discharge of royerconverter. The current scale is 10mV=2A. Vladi