Hi Bert,where can I get this? Do you have a copy of it? I'm from germany and this seems to be very interesting for me:
"Pulse Generators" by Glasoe and Lebacqz (Radiation Laboratories Series, Volume 5, MIT Press, McGraw-Hill, 1948). Best Regards Stefan
I do have a current limiting ballast on the LV AC side of my control panel but I could see where the DC Res charging setup could preclude the need for this feature.Yes. However, the charging choke must have significant inductance (typically many henries), must be capable of handling significant current without significant saturation (100's of mA to amperes depending on power level), and it must be able to withstand Vsupply across terminals plus prudent design margin. If the charging inductor is too small, the rotary will fail to quench and you'll get "ring of fire" problems that can saturate the inductor, destroy the dequeing diode, or damage the gap.Also, could you share a bit more info on the capaci- tors that you use in the 2 uFd filter cap bank?The DC storage cap should be sized to ~ 10-15X the size of the tank cap. The DC storage caps be DC filter/Mylar type. Pulse capacitors can be used as DC storage caps as long as they are operated at no more than 70% of their faceplate VDC rating. Since pulse caps are designed to operate under higher internal dielectric stress, they may prematurely fail under extended DC operation at rated voltage. You don't want to make the DC storage capacitor too big since you'll make the system more dangerous (i.e., excessive high stored energy) with little/no performance benefits. Bleeder resistors are essential. I'd also recommend a shorting relay that rapidly discharges the storage cap through a beefy discharge resistor (ceramic Kanthal Globar or similar) when powered-down.David Rieben PS: That 10 kVA rated, 19.5 kV pole pig is a true treasure find for an old time ARSG coiler ;^) My pole pig is 10 kVA also, but the more standard 14.4 kV.This was a rebuilt unit from Solomon Corporation that I had them modify for 19.8 kV operation. It was 16" diameter x 34" high with beautiful Frankenstein insulators and it weighed about 450 pounds. I'm very glad to see Roger putting it to good use. My wife was elated to no longer see it lurking in the garage - I thought it was gorgeous, but she thought it was quite evil-looking... :^)http://www.capturedlightning.com/photos/HVStuff/Transformers/19.8kv10KVA-Pig.jpg Bert----- Original Message ----- From: "Roger Smith" <rwsmith@xxxxxxxxxxxxxx> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx> Sent: Sunday, July 11, 2010 7:03 PM Subject: Re: [TCML] New coil modeled after Green MonsterHi Dave, Id be happy to give you some more details of my coil. I will start with the basic parameters. Secondary Coil diameter 12.5" Secondary winding length 54" Secondary wire size 19 gage Toroud 12" x 48" Primary Coil 1/2 " OD copper wound as pan cake coil and taped on the 13th turn Primary capacitance .08 uf Max Break Rate 425 bps Max Power input so far 18 KVA Max Spark Length so far 11 feet Power Supply 10 kva , 19500 volt pole transformer which I I'm currently running at an output of 17500 volts I was running this set up with a smaller transformer and at a lower voltage but this summer I finally hooked up the bigger pole pig I got from Bert Hickman. The Output from it goes straight to a full wave rectifier and then to a 2 uf filter capacitor bank. In lieu of a big variac I have a big transformer with multiple taps that I can use to vary the voltage to the piggy. There is no Current limiting ballast on the AC side of the system at all. From the filter capacitors the current flows though the charging choke witch is many windings of # 24 gage wire wound on an "I" core for an inductance of 6 Henrys and then I have a dequing rectifier between the charging choke and the primary capacitors to prevent current from flowing back out of the primary circuit into the charging circuit. Some people have had success using solid state diodes for dequing rectifiers but I didn't have much luck with them. I ended up using a bunch of 8020 vacuum tube diodes in parallel . Under the right conditions you may not need a dequing diode but I think it reduces the risk of burning up your charging choke. One final comment, in theory it seems that the inductance of the charging choke would be kind of critical but I have played around with this a lot and it doesn't seem to be critical at all. You will run into problems if the inductance is too small but it doesn't seem possible to make it too big. There might be a sweet spot somewhere that will give you the most efferent operation but if there is I haven't found it yet. Roger ----- Original Message ----- From: "David Rieben" <drieben@xxxxxxxxxxx> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx> Sent: Sunday, July 11, 2010 9:59 AM Subject: Re: [TCML] New coil modeled after Green MonsterHi Roger, Yes, I have seen pics and some description of your coil. Very nice system you have there. Now that you have chimed in here, I would like to get a bit more de- tail on the DC resonant charging that you employ into your system. As you are probably already aware, the GM simply uses the stiff, unfiltered high voltage AC from the pole pig to power the tank circuit assembly and around 350 to 400 bps seems to be the "sweet spot". However, because of the unfiltered AC nature of the power supply and the ASRSG never being able to fully sync with the mains frequency, I do experience the surging (wah-wah) sound of the out- put through much of the ARSG sped range and it seems to me if I were to filter the HV supply to a steady DC voltage level, it would address this issue throughout the selected RPM range of the SG motor. I do try to finely tweak the RSG motor speed control to blend the surging into a more steady output but it seems to me that with a steady DC throughput to the RSG and tank circuit, there would be a larger average power throughput and conse- quently, bigger sparks and hey, bigger sparks is what it's all about, right? ;^) Feel free to contact me off-list if you feel the details would go beyond the interest of the rest of the list. David ----- Original Message ----- From: "Roger Smith" <rwsmith@xxxxxxxxxxxxxx> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx> Sent: Saturday, July 10, 2010 8:45 PM Subject: Re: [TCML] New coil modeled after Green MonsterI have built a Tesla coil that is in some ways similar to the Green Monster. The secondary is wound on a 12.5" diameter pvc sewer pipe, and it is wound with 19 gage wire. It is a DC resonant charging type Tesla coil with a break rate of 425 bps and it has worked very well. I have never built a SRSG Tesla coil but the one thing I don't like about them is that you are limited to 120 bps. That's less than a third of the break rate of my coil. That means that if you are going to run the same power level as my coil with 425 bps you need to put in over three times as much energy per break. That would be hard to do without having problems. Roger_______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla_______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla_______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla-- ******************************************************************** We specialize in UNIQUE items: coins shrunk by ultra-strong magnetic fields, Captured Lightning Lichtenberg figure sculptures, and scarce technical Books. Please visit us at http://www.capturedlightning.com ******************************************************************** _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxhttp://www.pupman.com/mailman/listinfo/tesla
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