Low-End Parts Make Tesla Coil with a High-End Look

We all know the saying: cheap, fast, or good — pick any two. That rule seems to apply across the spectrum of hackerdom, from software projects to hardware builds. But this DIY Tesla coil build might just manage to deliver on all three.

Cheap? [Jay Bowles]’ Tesla coil is based on a handheld bug zapper that you can find for a couple of bucks, or borrow from the top of the fridge in the relatively bug-free winter months. The spark gap is just a couple of screws set into scraps of nylon cutting board — nothing fancy there. Fast? Almost everything needed to build this is stuff lying around the house, and depending on the state of your junk bin you may not even have to order the polypropylene caps [Jay] recommends. Good? That’s a relative term, of course, and if you define it as a coil capable of putting out pumpkin-slaying lightning bolts or playing “Yakkity Sax”, you’ll likely be disappointed. But there’s no denying that this Tesla coil looks good, from its Lexan base to the door-pull top load. And running off a couple of AA batteries, it’s safe to use too.

[Jay] put a lot of care into winding and dressing the secondary coil neatly, and the whole thing would look great as a desktop toy. Not into the winding part? You can always etch a PCB Tesla coil instead.

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PCB Tesla Coil Is Perfect Desk Toy

A Tesla coil easily makes it to the top spot on our list of “Mad Scientist” equipment we want for the lab, second only to maybe a Jacob’s Ladder. Even then, it’s kind of unfair advantage because you know people only want a Jacob’s Ladder for that awesome sound it makes. Sound effects not withstanding, it’s Tesla coil all the way, no question.

Unfortunately, winding your own Tesla coil is kind of a hassle. Even on relatively small builds, you’ll generally need to setup some kind of winding jig just to do the secondary coil, which can be a project in itself. So when [Daniel Eindhoven] sent his no-wind Tesla coil into the tip line, it immediately got our attention.

The genius in his design is that the coils are actually etched into the PCB, completely taking the human effort out of the equation. Made up of 6 mil traces with 6 mil separation, the PCB coil manages to pack a 25 meter long, 160 turn coil into an incredibly compact package. As you might expect, such a tiny Tesla coil isn’t exactly going to be a powerhouse, and in fact [Daniel] has managed to get the entirely thing running on the 500 mA output of your standard USB 2.0 port.

In such a low-power setup, [Daniel] was also able to replace the traditional spark gap pulse generator with a PIC18F14K50 microcontroller, further simplifying the design. An advantage of using a microcontroller for the pulse generator is that it’s very easy to adjust the coil’s operating frequency, allowing for neat tricks like making the coil “sing” by bringing its frequency into the audible range.

For those looking to build their own version, [Daniel] has put the PCB schematic and firmware available for download on his site. He also mentions that, in collaboration with Elektor magazine, he will be producing a kit in the near future. Definitely something we’ll be keeping an eye out for.

Incidentally, this isn’t the first time [Daniel] has demonstrated his mastery of high voltage. He scared impressed us all the way back in 2010 with his 11,344 Joule capacitor bank, perfect for that laptop-destroying rail gun you’ve been meaning to build.

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Catching 30 kilowatts with Thor’s Hammer

Can you really catch lightning with Mjolnir, the mythical hammer of Thor? If you’re [James Hobson] you can get pretty darn close. He’s a long time writer at Hackaday who’s been building an epic following on his YouTube channel by making the digital effects of blockbuster movies into practical effects. Today he released a video showing how he channeled a jolt of lightning with hammer held high.

The lightning source for this hack is a huge Tesla coil held overhead by a telescoping lift. Humans and high voltage mix poorly, which is why you can’t actually tell this is [James]. He’s wearing a full body suit of grounded chainmail which serves as a Faraday cage, safely directing the current around him to avoid a literally heart-stopping moment. Check out the antics in the video after the break.

Longtime readers will remember [Caleb Kraft’s] take on Mjolnir, a build that placed the Tesla coil in the hammer itself. [James]’ version is undeniably more impressive, with the tradeoff that it’s wholly unportable. While we’re on the topic of mythical hammers, our other most favorite build is the delightful prank build which makes the hammer unliftable except by the recognized owner.

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Make a Tesla Coil Winding Rig with K’Nex

Instructables user [birdycrazy] built a winding rig from a PVC pipe and a bunch of K’Nex. He had recently started a Tesla coil project and needed an efficient way to wind the secondary coil. All of the designs for DIY winding rigs he found on the Internet required parts he didn’t have or simply cost a bunch of money. Then he realized he’d been building with K’nex a lot, and why not build a tool to help him?

He ended up investing only his K’nex elements and a length of 4” PVC pipe for the project. He used a K’nex 12V motor because it plugs in rather than requiring batteries. After the coil had been completely wound he set it to rotate the assembly over a period of several days while the varnish coating dried.

[birdycrazy] has several cool K’nex projects including a couple of automatic transmissions and a differential, all made with the toy. Also be sure to check out the K’nex whiteboard plotter, the Citadel monster K’nex castle, and the K’nex skeeball table we published in the past.

Little eBay Tesla Coil Gets an Upgrade

Like so many of the projects we feature, this one started with a cheap eBay module purchase. In this case, it was a little Tesla coil that made decent sized arcs but wasn’t quite good enough. The result was a super-sized solid state Tesla coil with better results and room to grow.

As [GreatScott!] discovered, the little eBay Tesla coil has a pretty neat design. The exciter is a Slayer circuit, a super simple one-transistor design. His reverse engineering revealed that the primary coil is simply a loop trace on the PCB under the secondary coil. Sadly, his attempt to replace the primary and reproduce the Slayer exciter resulted in anemic performance. What’s a hacker to do in that case except build a bigger coil? Much bigger — like “build your own winding jig” bigger. Twelve hundred secondary turns and an appropriately menacing-looking primary later, the results were — still anemic. It turns out the Slayer is just not up to the task. He turned to an inverter circuit that was previously used in a wireless energy transfer circuit, and we finally get to see a little of the Tesla coil magic. But wait! There’s more to come, as future videos will tweak the circuit and optimize the coil for better performance.

It’s no surprise that Tesla coils are a popular project around here, especially the musical kinds, from the tiny to the large. Music doesn’t seem to be on [GreatScott!]’s mind, though, and we’ll be watching with interest to see where he takes this build.

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That Sucks! Death of a Tesla Coil

[Electroboom] always has some entertaining videos. He recently tried to run his Tesla coil in a vacuum. The video shows some interesting results, along with his usual bleeped out expletives as he drills into his hand and suffers other indignities in the name of electronics.

Unfortunately, a bit of extra bolt caused the coil to arc internally, eventually leading to the impressive device shuffling off its mortal… um, well, let’s just say its untimely demise. Along the way, though, you get to see some interesting techniques for building a silicone seal for the vacuum chamber, and some neat Tesla coil tricks with a closed off syringe.

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Tesla Coil Powered Film Canister Gatling Gun

What do you get when you combine a Tesla coil, 315 film canisters and a fortune wheel? The answer is of course a film canister Gatling gun. [ScienceBob] has taken the simple film canister cannon hack to a whole new level. The idea is simple, the film canister has a lid that fits tight and allows pressure to build up, so if you fill it with alcohol vapor and ignite it with a spark gap, you get a small explosion that sends the can flying  away.

[ScienceBob] uses 21 rows of fifteen canisters each around the wheel. There is a spark gap for each canister, and all the spark gaps in the same row are in series. You need a lot of volts to turn on fifteen spark gaps, and that is why the Tesla coil is part of the game. When the outer end of the wire in one row passes near the Tesla coil, a spark jumps and fires all the spark gaps, igniting the alcohol vapor and fifteen cans are expelled from the wheel. The wheel rotates until all rows are fired.

While this nice piece of artillery is sure a lot of fun to fire, but don’t ask us to reload it! If you want more power, check this Gatling gun that fires crossbow bolts, or the Gatling water pistol.

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