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Hi Stefan, et all Yes you are probably right about the dummy load although it seems to me the energy not transferred into a secondary would be wasted without it. Clearly it does have to go somewhere. Much of it would go into the resonate magnetic field, though unloaded. Clearly the secondary transfers as much of the energy as we can get into it! I agree this big inductor does not lend itself well to resonance charging, however; it would still charge the tank to 24KV without breaking a sweat. I could run an external inductor as the internal inductor sits between two tallll standoffs, where the heck did you get yours? I like your break rate. This is a Raytheon charging tank or PS which is labeled -24KV on the output side of the inductor. I do not know if this is the full inductive kick for the purpose built inductance. It does imply a smaller capacitance to achieve higher break rates. I know little about quenching 130 BPS and DC gaps but have up to 24" 5/8 G10 FR4. I was thinking more along the lines of 18" to extinguish the arc. I have wanted to experiment with this truly Frankenstein-ish monster for some time. The (6) 8020 Tubes have Thoriated Tungsten filaments which will be bright white and the insulators are a bit intimidating at 12"! My original post was about a suitable rotary design. If this doesn't fly, I'll go classic Tesla with Pig Power. I have both .25" and .5 " electrodes in "W" and a fixed 9/16" 7 inch that needs to be cut. DC Cox gave me the pressing specs a long time ago for the slugs into the G10. I seem to remember there were threaded angled set screws too from the outer edge. Anybody? Best practices? I have a 12" with 1/8" electrodes I built for lower power with the help of a good machinist. Thanks, Jim Mora I took a hiatus with Tesla coiling and got into Music and repairing and building tube guitar amps. Now I have the old fever back again ;-^) Time to search the archives I suppose... -----Original Message----- From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf Of Teslalabor Sent: Sunday, June 08, 2014 1:52 AM To: tesla@xxxxxxxxxx Subject: Re: [TCML] Question on Dummyload-Testing in DC ResonantChargingcircuit, similar pursuit Hi Jim, you can not run such a circuit only with a primary in place without a secondary. The result would be extreme currents through your transformers, spark gap and capacitor, which would mean total failure of this components. So I did some calculations concerning the dummyload with the result, that the halogen dummyload testing is absolutely okay and the very best method for testing such a circuit without messing arround with sparks... ! In my case it consists of 20 halogen bulbs, each is 240V 500W. 10 of them are connected in series and 2 of this groups in parallel, giving a 10kW Dummyload. The resistance of one bulb is 100Ohm when glowing, so 10 of them in series is 1kOhm, 2 groups in parallel giving 500Ohm total of my dummyload. The dwell time of the spark gap is arround 500us, so this is enough time to empty my 50nF capacitor during each bang. Jim, I think you need another charging reactor, the Burnett-Equations will show you. This 150H inductor, built into your HVDC Supply, is not suitable. It's inductance is much to high, I think it is not possible to build a properly resonant charger with this. Also 24kV could mean some trouble, remember that the tank cap is charged to twice that voltage, in your case 48kV ! Some short facts about my coil: The system is designed (by using the Burnett-Equations) for running 7kW full power @ 400bps. I am actually testing it with my 3000rpm Schraner-Style SRSG (Hello Kurt :-) ), running @ only 300bps fixed (it is not variable in speed). The variable speed rotary is still in progress... System is 3-phase powered, with a 6-pulse rectifier, DC Charging voltage is 13,3kV. The tank cap is 2 Maxwell Caps in series, each 40kV/100nF, giving me 80kV / 50nF. My charging reactor is 12,4 Henries. The energy is fired into the 10kW dummyload, mentioned above. The performance seems to be amazing. Primary and Secondary coils will be build later... Regards, Stefan <snip> _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla