jacob’s ladder

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20,000 Volt Plasma Knife Slices, Dices, And Sparks

February 9, 2024 by 5 Comments

For the most part, here at Hackaday we’re more interested in how something was made than the backstory on why an individual actually put it together. Frankly, it’s not really our business. But we’ve been around long enough to know that practicality isn’t always the driving force. Some folks build things because they want to challenge themselves, others because there’s nothing commercially available that quite meets their needs. Of course, there’s another camp that just builds things to look cool.

In the case of the plasma-infused blade [Jay Bowles] recently put together for Plasma Channel, we imagine it was a bit from each column. The basic inspiration was to create something in the style of the “Energy Sword” from Halo, but the resulting electrified blade is no mere prop. Inside the 3D printed enclosure, it packs not only the electronics necessary to produce 20,000 volts from the built-in battery pack, but a fan to help push the resulting plasma down the length of the two-piece steel blade.

As you might expect, it took a few attempts to get there. In the video after the break, [Jay] shows off the design process and some earlier incarnations of the plasma knife that didn’t quite live up to expectations. While there were always some impressive sparks, the spacing of the blades and the output power of the miniature high-voltage generator both needed fine tuning before it resulted in the band of plasma he was aiming for.

Is there a practical use for such a thing? Well the spark between the blades can apparently be used to light stuff on fire, and of course, you can cut things with it. But realistically…no, not really. It just looks cool, which is fine by us.

Should you prefer your high-voltage experimentation to have a more clearly defined goal, you might be interested in the ongoing work [Jay] has been doing with ionic propulsion and magnetohydrodynamic drives (MHDs).

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A Tiny Jacob’s Ladder You Can Build At Home

August 29, 2020 by 13 Comments

Big fizzing electrical arcs are fun, and handled properly, not too dangerous either. The Jacob’s Ladder is one such piece of arc-generating equipment, one that featured heavily in vintage sci-fi films. It remains a charming demonstration of high-voltage electrical principles, and you can easily build your own mini version at home.

The build starts with a basic high-voltage step-up kit that turns 4V DC into 15 kV at the output. At this voltage level, it’s possible to generate an arc in air. To create the Jacob’s ladder, the kit is wired up to a pair of closely-spaced electrodes that slowly get farther apart as they go up vertically. When an arc jumps from one electrode to the other, it ionises the air, and the voltage sags due to the current flow. The flowing current heats up the air, which begins to rise, taking the current path with it, causing the familiar climbing arc we all know and love. As the distance between the electrodes increases towards the top, the arc can eventually no longer be sustained. With no current flowing, the voltage rises again, and a new arc forms at the bottom of the device, repeating the process.

It’s a fun build that would make an excellent desk toy, albeit best shown under glass to avoid accidental electric shocks. You can even build a larger one out of microwave parts if you’re so inclined. Video after the break.

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Microwave Parts Become Quick And Nasty Jacob’s Ladder

February 2, 2019 by 20 Comments

The Jacob’s Ladder is an electrical device named after a biblical “ladder to Heaven”, consisting of a pair of vertically oriented conductors that spread apart vertically. These conductors are charged with high voltage, which creates the repeatedly climbing arc we’ve all come to know and love from science fiction movies of yesteryear.

[LOOK MUM NO COMPUTER] was on a scavenger hunt for electronic junk, and came across a microwave in a skip that was begging to be hacked. After kicking around a few ideas, it was decided that the microwave would donate its high voltage transformer to create a Jacob’s ladder. The transformer is first bolted down to a piece of wood, and creates some sparks on the bench when shorted. The output is then wired to a pair of copper pipes to create the classic effect.

Unfortunately, the device isn’t self starting, requiring the electrodes to be temporarily short circuited to generate the initial arc. We suspect that increasing the voltage may help things somewhat, either with another transformer in series or with a voltage multiplier.

It goes without saying that high voltage projects do bring certain risks to life and limb that should not be overlooked. If you’ve still got a thirst for danger, check out this home built X-ray machine. Video after the break.

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Pint-sized Jacob’s Ladder Packs 10,000 Volts In A Pickle Jar

November 5, 2018 by 12 Comments

File this one away for your mad scientist costume next Halloween: [bitluni]’s Pocket Jacob’s Ladder is the perfect high voltage accessory for those folks with five dollars in parts, a 3D printer, and very big pockets.

[bitluni]’s video shows you all the parts you’ll need and guides you through the very simple build process. For parts, you’ll require a cheap and readily-available high-voltage transformer, a battery holder, some silver wire for the conductors, and a few other minor bits like solder and a power switch.

Once the electronics are soldered together, they’re stuffed inside a 3d printed case that [bitluni] designed with FreeCAD. The FreeCAD and STL files are all available on Thingiverse. We’re not sure what type of jar [bitluni] used to enclose the electrodes. If your jar isn’t a match, you’ll have to get familiar with FreeCAD or start from scratch with your favorite CAD package.

Either way, we enjoy the slight nod toward electrical safety and the reuse of household objects for project enclosures.

If you’re interested in a Jacob’s Ladder with significantly higher voltage we’ve got you covered, or we’ve also written about another tiny portable Jacob’s Ladder.

The full video is embedded after the break.

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Add Some Edge To Your Blades With Blown-Arc Plasma

October 1, 2018 by 8 Comments

If you polled science fiction fans on what piece of technology portrayed by the movies that they most desire, chances are pretty good that the lightsabers from the Star Wars franchise would be near the top of the list. There’s just something about having that much power in the palm of your hand and still needing to be up close and personal to fight with it. Plus being able to melt holes in bulkheads is pretty keen, as are the cool sounds.

Sadly, the day we can shape and contain plasma in a blade-shaped field is probably pretty far off, but that didn’t stop [Alan Pan] from trying the next best thing: a handheld plasma-projecting blade. He starts with a basic Jacob’s ladder. We’ve seen many of these before, but the basic idea is to ionize the air between two parallel, vertical conductors; the hot plasma heats the air causing it to rise until it reaches the top and snuffs itself out, starting the process over again at the bottom. His twist is to force the plasma into a sheet between the electrodes with air from a leaf blower, forming a blown-arc plasma. That’s pretty cool looking by itself, but he also stretched the electrodes along razor-sharp wood planer blades, for extra danger. We have to admit that the thing looks pretty intimidating, even if the plasma doesn’t really pack bulkhead-melting thermal power. Check out the results in the video below.

We’d love to see [Alan] make good on his promise to make the whole thing self-contained with an electric ducted fan or mini jet engine. Even as it is, it’s still pretty neat. It’s not really his first lightsaber rodeo, but at least this one doesn’t need butane.

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Portable Jacob’s Ladder For When…You Know… You Need A Portable Jacob’s Ladder

June 9, 2017 by 32 Comments

When do you need a portable Jacob’s Ladder? We don’t know, but apparently [mitxela] doesn’t want to leave home (or the laboratory) without one. So he built a portable unit that works for a few minutes on a battery. In the video (see below), he says he wouldn’t presume to claim it was the smallest Jacob’s Ladder ever, but he thought it might be a contender.

The battery is a LiPo cell and although it might last up to four minutes, [mitxela] points out that the transistors probably wouldn’t survive that much on time, despite the heat sinks he put in place. The whole device is 45mm square and 17mm thick. Of course, the wires add some height (about 150mm total).

We were hoping to see more of the insides, but we presume this uses one of the cheap high voltage modules you can procure from the usual Far East sources–or, at least–it could. The rest is just laser cutting and workmanship.

If you haven’t encountered them before (outside of old monster movies), a Jacob’s Ladder lets high voltage ionize the air down at the bottom of the narrow gap. The ionized air is hot and rises, and the current flows through it, despite the electrodes getting further apart. Of course, that means you shouldn’t put on in your zero-gee space station.

You might think a portable Jacob’s ladders is unique. Turns out, it isn’t. If you want something easy (and perhaps not as portable), you can’t get much easier than this one.

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A Portable Jacob´s Ladder

January 8, 2017 by 16 Comments

A Jacob´s ladder is a favorite project of high voltage enthusiasts. It makes a visually attractive and fun display of a high voltage electrical arc climbing a pair of electrodes. [Keystone Science] shows us how to make a Jacob´s ladder that runs on 9 V batteries.

The ladder itself is pretty easy to make. It is nothing more than a pair of stiff wires in a V shape, connected to a high voltage power supply. The more difficult part is the HV power supply. [Keystone Science] explains how to build one using a flyback transformer from an old CRT tv and a few other components. It is a pretty simple circuit and can be powered by a 9 V battery. The ladder works because, when HV is applied to the electrodes, an arc is established at the bottom, where they are nearest each other. The arc is at high temperature so the air rises, and the arc starts to climb the ladder. Since the electrodes are further away from each other as the arc rises, at a certain point the distance is too large to sustain the arc and the process repeats.

This is a nice weekend project if you want to try it. In case you don´t want to make your own HV power supply, you can try another ladder project that uses a commercial one.