Re: Coil Experiments in Austin
Bert Hickman wrote:
> Shazaam!! I hope you're going to take pictures and video of this for
> those of us who can't make it! :^)
Yes, I hope to get some footage if I can find a camcorder.
> Are you proposing to elevate the base of the coil to the +25 KVDC via
> the 100 KVA charging source and capacitor bank? This would leave it
> grounded "AC-wise" through the capacitor bank, but charged DC-wise to 25
> KV. 100 kJ at 25 KV implies about 320 uF - this should _certainly_ look
> like a pretty good "AC ground" to the base of the coil.
Yes, that's the plan.
> I'd think the trick would be making sure that you don't arc to something
> you don't intend to. The inductance of the coil and voltage drop in the
> arc should limit the amount of current once you've arc'ed to a good
> ground return to the other side of the caps... to maybe two or three
> thousand amps. 100 kJ is a fierce amount of energy! If I remember right,
> your secondary is wound with fairly large wire, and may be able to take
> the surge current. However, I'd also guess that 100 kJoules in this
> configuration would cause a fairly long-duration arc once struck.
The sec is 8 AWG, and should be able to take the 2 kA pk pulse, which
should be heavily damped by the resistance of the arc (3 - 6 ohms-at- 2 kA).
> Are you putting grounded metal plates around the coil to
> prevent blowing chunks out of the floor? Can your discharge
> terminal take the heat at the discharge point without melting through
> during a sustained discharge? With the large capacitor bank and the the
> substantial series inductance of your secondary, the "tank" circuit
> you'll form when this puppy discharges will probably oscillate at under
> 100 Hz! It should be... AWESOME!
In preliminary tests, it did make a pleasing audible base note, that seemed
to resonate with the chest cavity. In the show, it is going to arc to
several tall, fragile sculptures, made of neon and fluorescent tubes.
The glass tubes will most likely be damaged by the high current pulse.
A ball lightning precursor would be an added bonus.
> BTW, my brother-in-law lives in Austin - where is SRL and what show are
> you talking about? Man, I wish I lived in Texas about now!!
March 28, at the Longhorn Speedway.
> Safe Lightning-bolt generatin' to you, Greg!!
> -- Bert --