DRSSTC
Posted: Sat May 14, 2011 12:38 amJust an update on what I've been doing lately, as I haven't been active in the fusion side of things (since I'm at MIT and my fusor is in Washington). Just finished the third major revision of my tesla coil controller, which will be the final design for the electronics. Fired it up and got a good 5-6 feet of ground strike arc and 7-8 feet of corona. Now to make a better primary and larger top-load for more arc length. This coil is midi controllable and is optically coupled to a control computer via a SPDIF fiber cable. Controller is using a series inductor across the feedback current-detect inductor to get a phase-lead current signal (prediktor input design) so that the timings can be adjusted for zero ringing in the bridge.
Power supply is a fairly simple boost converter taking 3-phase input, with an adjustable output up to 800V. I've run the coil up to 750V on the bus so far at 8kW.
Been a great project, learned a lot about high power semiconductors (and how much of a pain they are to turn on at 60khz), precision timing of logic, all sorts of things. And learned lots of things not to do in revision 1 and 2. Hard to believe just two years ago I was barely able to get a bridge of IRFP450's going at 500 watts to power my fusor.
Power supply is a fairly simple boost converter taking 3-phase input, with an adjustable output up to 800V. I've run the coil up to 750V on the bus so far at 8kW.
Been a great project, learned a lot about high power semiconductors (and how much of a pain they are to turn on at 60khz), precision timing of logic, all sorts of things. And learned lots of things not to do in revision 1 and 2. Hard to believe just two years ago I was barely able to get a bridge of IRFP450's going at 500 watts to power my fusor.