Flat Transformer Gives This PCB Tesla Coil Some Kick

Arguably, the most tedious part of any Tesla coil build is winding the transformer. Getting that fine wire wound onto a suitable form, making everything neat, and making sure it’s electrically and mechanically sound can be tricky, and it’s a make-or-break proposition, both in terms of the function and the aesthetics of the final product. So this high-output printed circuit Tesla should take away some of that tedium and uncertainty.

Now, PCB coils are nothing new — we’ve seen plenty of examples used for everything from motors to speakers. We’ve even seen a few PCB Tesla coils, but as [Ray Ring] points out, these have mostly been lower-output coils that fail to bring the heat, as it were. His printed coil generates some pretty serious streamers — a foot long (30 cm) in some cases. The secondary of the coil has 6-mil traces spaced 6 mils apart, for a total of 240 turns. The primary is a single 240-mil trace on the other side of the board, and the whole thing is potted in a clear, two-part epoxy resin to prevent arcing. Driven by the non-resonant half-bridge driver living on the PCB below it, the coil can really pack a punch. A complete schematic and build info can be found in the link above, while the video below shows off just what it can do.

Honestly, for the amount of work the PCB coil saves, we’re tempted to give this a try. It might not have the classic good looks of a hand-wound coil, but it certainly gets the job done. Continue reading “Flat Transformer Gives This PCB Tesla Coil Some Kick”

Homemade EDM Machine Moves From Prototype To Production

Of all the methods of making big pieces of metal into smaller pieces of metal, perhaps none is more interesting than electrical discharge machining. EDM is also notoriously fussy, what with having to control an arc discharge while precisely positioning the tool relative to the workpiece. Still, some home gamers give it a whirl, and we love to share their successes, like this work-in-progress EDM machine. (Video, embedded below.)

We’ve linked [Andy]’s first videos below the break, and we’d expect there will be a few more before all is said and done. But really, for being fairly early in the project, [Andy] has made a lot of progress. EDM is basically using an electric arc to remove material from a workpiece, but as anyone who has unintentionally performed EDM on, say, a screwdriver by shorting it across the terminals in a live outlet box, the process needs to be controlled to be useful.

Part 1 shows the start of the build using an old tap burning machine, a 60-volt power supply, and a simple pulse generator. This was enough to experiment with the basics of both the mechanical control of electrode positioning, and the electrical aspects of getting a sustained, useful discharge. Part 2 continues with refinements that led very quickly to the first useful parts, machined quickly and cleanly from thin stock using a custom tool. We’ll admit to being impressed — many EDM builds either never get to the point of making simple holes, or stop when progressing beyond that initial success proves daunting. Of course, when [Andy] drops the fact that he made the buttons for the control panel on his homemade injection molding machine, one gets the feeling that anything is possible.

We’re looking forward to more on this build. We’ve seen a few EDM builds before, but none with this much potential.

Continue reading “Homemade EDM Machine Moves From Prototype To Production”

Fuel From Water Using Only An Arc Welder

Water, high currents, blinding balls of plasma, and a highly flammable gas that’s toxic enough to kill you in three minutes if you breathe enough of it. What’s not to love about this plasma-powered water gas generator?

In all seriousness, [NightHawkInLight] is playing with some dangerous stuff here, and he’s quite adamant about this one being firmly in the “Don’t try this at home” category. But it’s also fascinating stuff, since it uses nothing but a tank of water and an electric arc to produce useful amounts of fuel very quickly. It’s easy to jump to the conclusion that he’s talking about the electrolytic splitting of water into the hydrogen-oxygen mix HHO, but this is something else entirely.

Using a carbon electrode torch connected to his arc welder, a setup that’s similar to the one he used to make synthetic rubies, [NightHawkInLight] is able to strike an underwater arc inside a vessel that looks for all the world like a double-barreled bong. The plasma creates a mixture of carbon monoxide and hydrogen which accumulates very rapidly in the gasometer he built to collect the flammable products produced by a wood gasifier.

The water gas burns remarkably cleanly, but probably has limited practical uses. Unless you live somewhere where electricity costs practically nothing, it’ll be hard to break even on this. Still, it’s an interesting look at what’s possible when plasma and water mix.

Continue reading “Fuel From Water Using Only An Arc Welder”

Mr. Carlson Gets Zapped By Snow

As a Canadian, [Mr. Carlson] knows a thing or two about extreme winter weather. Chances are good, though, that he never thought he’d get zapped with high voltage generated by falling snow.

[Mr. Carlson]’s shocking tale began with a quiet evening in his jam-packed lab as a snowstorm raged outside. He heard a rhythmic clicking coming from the speakers of his computer, even with the power off. Other speakers in the lab were getting into the act, as was an old radio receiver he had on the bench. The radio, which was connected to an outdoor antenna by a piece of coax, was arcing from a coil to the chassis in the front end of the radio. The voltage was enough to create arcs a couple of millimeters long and bright blue-white, with enough current to give [Mr. Carlson] a good bite when he touched the coax. The discharges were also sufficient to destroy an LED light bulb in a lamp that was powered off but whose power cord was unlucky enough to cross the antenna feedline.

Strangely, the coil from which the arc sprang formed a 36-ohm shunt to the radio’s chassis, giving the current an apparently easy path to ground. But it somehow found a way around that, and still managed to do no damage to the sturdy old radio in the process. [Mr. Carlson] doesn’t offer much speculation as to the cause of the phenomenon, but the triboelectric effect seems a likely suspect. Whatever it is, he has set a trap for it, to capture better footage and take measurements should it happen again. And since it’s the Great White North, chances are good we’ll see a follow-up sometime soon.

Continue reading “Mr. Carlson Gets Zapped By Snow”

Improbably Cheap Pocket Welder Gets An ESP32 Makeover

If you move in certain shady circles, you may have noticed the crop of improbably cheap “pocket welders” popping up on the market these days. They’re all variations on a theme, most with wildly optimistic specs minimal accessories of the lowest possible quality. But their tiny size and matching price make them irresistible to the would-be welder, as well as attractive to hardware hackers.

With a 220-V outlet in the garage waiting to be filled and well-knowing the risks, [Mr. RC-Cam] purchased one of these diminutive welding machines. Its shortcomings were immediately apparent, and a complete rework of the welder was undertaken. After addressing safety issues like the lack of a ground connection, [Mr. RC-Cam] added a color-matched 3D-printed hood to house a fancy new LCD touchscreen display. Backing that up is an ESP32 with Bluetooth, which supports remote control via a key fob. He also added a current sense board that uses the welder’s current shunt to measure welding current. Expediently calibrated using a waffle iron and a milli-ohmmeter, the sensor showed that the 200A max advertised for the welder was more like 100A. He tried adding some big electrolytics to fix the current issues, but no dice. With a decent stinger and ground clamp, the modified welder is good enough for his needs, and much was learned in the process. We call that a hacking win.

As an aside, [This Old Tony] recently did a review on a similar welder if you want more details on the internals. We also covered the conversion of a buzz-box to a TIG welder recently, should that be more your style.

Continue reading “Improbably Cheap Pocket Welder Gets An ESP32 Makeover”

Prototyping PCBs With Electrical Discharge Machining

Here at Hackaday, we thought we’d seen every method of making PCBs: CNC machining, masking and etching with a variety of chemicals, laser engraving, or even the crude but effective method of scratching away the copper with a utility knife. Whatever works is fine with us, really, but there still does seem to be room for improvement in the DIY PCB field. To whit, we present rapid PCB prototyping with electrical discharge machining.

Using an electric arc to selectively ablate the copper cladding on a PCB seems like a great idea. At least that’s how it seemed to [Jake Wachlin] when he realized that the old trick of cutting a sheet of aluminum foil using a nine-volt battery and a pencil lead is really just a form of EDM, and that the layer of copper on a PCB is not a million miles different from foil. A few experiments with a bench power supply and a mechanical pencil lead showed that it’s relatively easy to blast the copper from a blank board, so [Jake] took the next logical step and rigged up an old 3D-printer to move the tool. The video below shows the setup and some early tests; it’s not perfect by a long shot, but it has a lot of promise. If he can control the arc better, this homebrew EDM looks like it could very rapidly produce prototype boards.

[Jake] posted this project in its current state in the hopes of stimulating a discussion and further experimentation. That’s commendable, and we’d really love to see this one move along rapidly. You might start your brainstorming by looking at this somewhat sketchy mains-powered EDM, or look into the whole field in a little more detail.

Continue reading “Prototyping PCBs With Electrical Discharge Machining”

Star Wars Electrostaff Effect, Done With Spinning LEDs

[Bithead] wanted to make a prop replica of an Electrostaff from Star Wars, but wasn’t sure how best to create the “crackling arcs of energy” effect at the business ends. After a few false starts, he decided to leverage the persistence of vision effect by spinning LEDs in more than one axis to create helical arcs of light and it seems that this method has some potential.

Many multi-axis persistence of vision devices use a component called a slip ring in order to maintain electrical connections across rotating parts, but [Bithead] had a simpler plan: 3D print a frame and give each axis its own battery. No centralized power source means a quicker prototype without any specialized parts, and therefore a faster proof of concept to test the idea.

[Bithead] already has improvements planned for a new version, but you can see the current prototype in action in the short video embedded after the break.

Continue reading “Star Wars Electrostaff Effect, Done With Spinning LEDs”