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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 aproperly 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----- Original Message ----- From: "Jim Mora" <wavetuner@xxxxxxxxx>
To: "'Tesla Coil Mailing List'" <tesla@xxxxxxxxxx> Sent: Sunday, June 08, 2014 4:18 AMSubject: Re: [TCML] Question on Dummyload-Testing in DC Resonant Chargingcircuit, similar pursuit
Hello Stefan,Why not get some heavy gauge wire and simulate the calculated turns? Now youhave introduced the inductance albeit the R is off rather than purelyresistive load which seems reasonable to me as R is so small anyway. I knowpeople have tuned traditional coils ahead of time this way. That was a Dr. Resonance trick I believe.I too am starting on a DC resonate coil. I have a huge Choke in my changingcircuit which can not reasonably be altered. I have the ability to add ade-queing diode easily enough, but there is not one in the old charger from the military. This one outputs 24KV and is full-wave 3P tube circuitry 6x GL8020's. The inductor says it is 150H ! Plugging in Richie Burnent'sequations, if I performed the math correctly, I am limited to 116 BPS with a.05UF Tank cap (I have 2 .1uf's) It drops to 82 BPS @ .1 uf. So that's not too ideal and I wonder about quenching and Tungsten size in the rotor. Anyone? The equations also reveal my max power will be 6.7KW at 116BPS which is probably fine. Comments anyone? Thanks, Jim MoraSorry to hijack your thread Stefan, we may be talking more ;-^) What size isyour coil going to be? -----Original Message----- From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf Of Teslalabor Sent: Friday, June 06, 2014 10:14 AM To: tesla@xxxxxxxxxx Subject: [TCML] Question on Dummyload-Testing in DC Resonant Charging circuit Hello all,I just finished the DC resonant charging circuit for a planned medium teslacoil project. It is 3-phase powered and today I started testing it with reduced power and a dummyload in place of the primary coil, which will beinstalled later. The dummyload consists of several 240V 500W halogen bulbs,which are glowing very nice and smoothly :-) So on the first glance, it seems to work well for testing.But the question is, how does such a dummyload with a high resistance (let'ssay 500-1000Ohms when glowing) influence the behavior of the chargingcircuit? My guess is, that the capacitor never can discharge completely intothis dummyload during each bang and still have much of its charge after eachbang... So the drawn power should be much higher, when using the real teslasetup later, instead of this dummyload? Regards, Stefan _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxhttp://www.pupman.com/mailman/listinfo/tesla
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