This is a recording of a hard drive platter being shot 100 feet into the air, using a 15 turn coil and a 3000uF capacitor bank charged to 1200 volts. The disk is placed onto the coil, the cap's are charged up, and the spark gap is shorted across. Instantaneous current in the coil reaches into the kiloamp level, which causes a powerful magnetic field to be formed. This magnetic field causes an induced current in the metal disk (which acts as a one-turn secondary), and results in a powerful current to circulate in the disk itself. This current causes the disk to have its OWN magnetic field...and it is in phase with that of the coil's. This causes the two objects to violently accelerate away from each other. Since the coil can't move (it's placed on concrete), the disk shoots into the air. It's the same physics that repelling magnets work on.
This is a sound clip of our homeade stacked plate capacitor being charged to 25kVDC, and discharged via a spark gap. Repetition rate is about 5Hz or so. The capacitor is charged with my 17kHz flyback supply feeding a voltage multiplier. If you listen really close, you can hear the flyback circuitry charging the capacitor before the first spark. You can't hear it after that...too much noise.
This is a recording of our 17kHz flyback supply. Turn your volume up - it's a bit hard to hear. Listen for two high-pitch squeals. The arc starts at about 1/2", and can be pulled out to 1.5" or so with 12VDC in. The output is purely AC, and is suitable for driving plasma globes and such.
This is the sound of a 12kV 120mA modified Neon Sign Transformer (NST). Aron has done the excellent work of unpotting it, and removing some of the current limiting shunts. It used to be a 12/60, but now a 12/120. It is a baaaaad transformer now. For the sound clip, it is hooked up in a jacobs ladder configuration, and the vertical wires have been coated with saltwater. This gives the characteristic orange color, and a thick crackling sound. Before the saltwater is placed on the electrodes, the arc is whitish and pale...but after it is a bright orange. How come? The arc vaporizes the sodium in the saltwater, causing the orange wavelength to be emitted. This is (almost) the exact same color as sodium streetlights...because there is sodium present in both.
What you hear here (!) is the steady discharge of a Microwave Oven Transformer (MOT). An extremely bright arc at 2500 volts, half an amp. Nothing you want to look at without welding goggles. This is a good arc to vaporize different substances and check out the different colors (wavelengths) that are emitted. Copper burns a greenish color, aluminum is bright blue, and salt is orange to name a few.
In these sound clips, Aron and I are inside our small 12x12 workshop, fooling around with a small transformer - a 5kVA pole pig to be exact. Using a spool of 14 gauge wire for current limiting, and the 240V mains...our power levels reach up into the 15kW region, and our wire spool becomes hot enough to boil water. The arc is incredible, about 2.5 inches around and almost 1.5 feet long. I'm pretty nervous about it being in the workshop with me but Aron isn't, somehow.
Ahh...the unique sound of 60Hz resonant charging. You'll have to listen close - the output sparks and spark gap noise try to cover it up, but it's definately there. The sound is most evident in the 3rd wav (tcarcs3). Using a .0106uF tank capacitor and a 15kV 60mA NST, the two components transfer power very efficiently. Even though these component values don't give the best overall coil performance, it is still *very* cool. The spark gap fires at about 10% input voltage. Thats TEN volts AC! Has a neat feel to it.
