Flying a kite on a stormy day is not the wisest thing to do, except, of course, you’re intentionally trying to catch a lightning bolt. The guys from [kreosan] replicated the famous experiment, with which Benjamin Franklin once set out to prove the electrical nature of lightning.
What do you get when you combine an arc cigarette lighter and some scrap glass and metal? [NightHawkInLight] created a simple plasma cutter project along with some hot glue and a few simple tools.
If you aren’t a smoker, an arc lighter uses a high voltage spark to light the cigarette. He essentially cannibalizes it for use as a power supply. Any similar high-voltage power supply should work just as well. He also uses the same cigarette lighter power supply for an arc pen, that we covered earlier.
Int 1777, Georg Lichtenberg found that discharging high voltage on an insulating surface covered with a powder, a fractal-like image appears, sometimes known as a lightning tree. Incidentally, this is a crude form of xerography, the principle that lets copiers and laser printers operate.
[PaulGetson] had a high voltage power source from his Jacob’s ladder experiments and decide to see if he could create Lichtenberg figures. Turns out, he could.
There was a time when making a high voltage project like a Jacob’s ladder took time to build or scrounge some kind of high voltage circuit. The neon sign transformer, Marx generator, or voltage multiplier was the hard part of the project. But nowadays you can get cheap high voltage modules that are quite inexpensive. [PaulGetson] picked up one for under $20 and turned it into a quick and easy Jacob’s ladder.
Honestly, once you have high voltage, making a Jacob’s ladder is pretty simple. [Paul] used a cheap plastic box, some coat hanger wire, and some stainless steel bolts.
We’ve seen musical Tesla coils aplenty on these pages before, and we’ll be the first to point out that [Kedar Nimbalkar]’s musical high-voltage rig doesn’t quite qualify as a Tesla coil. But it’s dirt cheap, and might make a pretty cool rainy-afternoon-with-the-kids project.
Chances are good you have the parts needed for this build lying around the house. All that’s needed is an audio power amplifier and a high-voltage source. [Kedar] used a Class D amp board and a 3V to 7kV high-voltage module sourced from eBay for a couple of bucks; if you really want to go cheap, tear down that defunct electronic fly swatter gathering dust on top of your fridge and harvest the high-voltage module inside. The output of the amp feeds the high-voltage module, the HV leads are placed close together to get an arc, and the glorious high-fidelity sound will wash over you. Or not – sounds pretty awful to us. Still, it looks like a fast, fun build.
Like many people, going through university followed an intense career building period was a dry spell in terms of making things. Of course things settled down and I finally broke that dry spell to work on what I called “non-conventional propulsion”.
I wanted to stay away from the term “anti-gravity” because I was enough of a science nut to know that such a thing was dubious. But I also suspected that there might be science principles yet to be discovered. I was willing to give it a try anyway, and did for a few years. It was also my introduction to the world of high voltage… DC. Everything came out null though, meaning that any effects could be accounted for by some form of ionization or Coulomb force. At no time did I get anything to actually fly, though there was a lot of spinning things on rotors or weight changes on scales and balances due to ion propulsion.
So when a video appeared in 2001 from a small company called Transdimensional Technologies of a triangle shaped, aluminum foil and wire thing called a lifter that actually propelled itself off the table, I immediately had to make one. I’d had enough background by then to be confident that it was flying using ion propulsion. And in fact, given my background I was able to put an enhancement in my first version that others came up with only later.
For those who’ve never seen a lifter, it’s extremely simple. Think of it as a very leaky capacitor. One electrode is an aluminum foil skirt, in the shape of a triangle. Spaced apart from that around an inch or so away, usually using 1/6″ balsa wood sticks, is a very thin bare wire (think 30AWG) also shaped as a triangle. High voltage is applied between the foil skirt and the wire. The result is that a downward jet of air is created around and through the middle of the triangle and the lifter flies up off the table. But that is just the barest explanation of how it works. We must go deeper!
Working with high voltage is like working with high pressure plumbing. You can spring a leak in your plumbing, and of course you fix it. And now that you’ve fixed that leak, you’re able to increase the pressure still more, and sometimes another leak occurs. I’ve had these same experiences but with high voltage wiring. At a high enough voltage, around 30kV or higher, the leak manifests itself as a hissing sound and a corona that appears as a bluish glow of excited ions spraying from the leak. Try to dial up the voltage and the hiss turns into a shriek.
Why do leaks occur in high voltage? I’ve found that the best way to visualize the reason is by visualizing electric fields. Electric fields exist between positive and negative charges and can be pictured as electric field lines (illustrated below on the left.) The denser the electric field lines, the stronger the electric field.
The stronger electric fields are where ionization of the air occurs. As illustrated in the “collision” example on the right above, ionization can happen by a negatively charged electron leaving the electrically conductive surface, which can be a wire or a part of the device, and colliding with a nearby neutral atom turning it into an ion. The collision can result in the electron attaching to the atom, turning the atom into a negatively charged ion, or the collision can knock another electron from the atom, turning the atom into a positively charged ion. In the “stripping off” example illustrated above, the strong electric field can affect things more directly by stripping an electron from the neutral atom, again turning it into a positive ion. And there are other effects as well such as electron avalanches and the photoelectric effect.
In either case, we wanted to keep those electrons in the electrically conductive wires or other surfaces and their loss constitutes a leak in a very real way.