4/27/04 I got my caps in the mail, 30 kV 780 pF doorknob type caps. These are very sturdy units. I took some 1/2" HDPE board, drilled holes down the middle, and using crimped lugs and high voltage wire, I set up the capacitor bank as 8 of these in parallel. This gives me just over the calculated ideal value of 5.8 nF. I fired up the 15 kV 30 mA NST, and the spark gap activity was not nearly as much as I would have expected. Very quickly I noticed a burning smell. The tubing I had used to protect the bottom secondary wire was arcing. So I fixed that. I fired it up again, and still nothing. I had the probe of the oscilloscope in the air, and I was seeing some of the damped sine wave stuff, and I think I was also seeing the break rate. In DSO mode, there looks to be significant artifacts at the higher sweep times. Then I heard a funny popping sound, and the spark gap quit arcing altogether. I could only get the spark gap to arc if I used only two of the copper tubes. I think I might have fried my NST :(. Right before the popping sound I heard an unusual noise a couple times. It would come and go. It almost sounded like a muffled jack hammer, but with a little bit of the locomotive rumble. I did not see any discharges or sparks. This is going to take a good bit more work, and I really should have put in a protective spark gap for the NST. 4/26/04 - Added Tesla Page You would think that in school, undergrad or grad school, they would cover Tesla coils, even if it is just for teaching the basics of LCR circuits. In 6 years of Physics education, it was only mentioned once in passing. It is a shame that this device is not a standard lab experiment for second year E#TEXTM physics students. So finally, after several years, I decided to build my own Tesla coil. All that stuff I was supposed to have learned in undergrad and grad school now makes sense and if I ever have the chance to teach physics lab again, a Tesla coil will be part of it. I doubt that any of the information I have in here would be groundbreaking or earth shattering. Most of it has already been covered in other people's web pages. My Tesla Coil is the standard 15 kv 30 mA neon sign transformer (NST) driven unit, with the standard parameters. Thanks to all the cool resources out there today, it becomes a matter of finding your transformer, and then building the rest of the design from there. |