Multi-Stage Ion Thruster Holds Exciting Promise

September 19, 2022 by Tom Nardi 55 Comments

Anyone who’s looked into high-voltage experiments is likely familiar with ion lifters — spindly contraptions made of wire and aluminum foil that are able to float above the workbench on a column of ionized air. It’s an impressive trick that’s been around since the 1950s, but the concept has yet to show any practical application as the thrust generated isn’t nearly enough to lift a more substantial vehicle.

It’s a bit early to suggest that [Jay Bowles] of Plasma Channel has finally found the solution to this fundamental shortcoming of electrostatic propulsion, but his recently completed multi-stage ion thruster certainly represents something of a generational leap for the technology. By combining multiple pairs of electrodes and experimentally determining the optimal values for their spacing and operational voltage, he’s been able to achieve a sustained exhaust velocity of 2.3 meters per second.

Dry ice was used to visualize airflow through the thruster.

While most ion thrusters are lucky to get a piece of paper fluttering for their trouble, [Jay] demonstrates his creation blowing out candles at a distance of a meter or more. But perhaps the most impressive quality of this build is the sound — unlike most of the experimental ion thrusters we’ve seen, the air flowing through this contraption actually makes an audible roaring sound. When the 45 kilovolt supply voltage kicks in it sounds like a hair drier, except here there’s no moving parts involved.

In addition to providing graphs that show how air velocity was impacted by input voltage and the number and spacing of the electrode pairs, [Jay] also pops the thruster on a scale to show that there is indeed a measurable thrust being produced. Admittedly the 22 grams of thrust being generated isn’t much compared to the contraption’s own mass of 490 grams, but in the world of electrostatic propulsion, those are pretty impressive numbers.

[Jay] says he has some improvements in mind that he believes will significantly improve the device’s performance as he works towards his ultimate goal of actually flying an ion-propelled aircraft. We saw MIT do it back in 2018, and it would be great to see an individual experimenter pull off a similar feat. Obviously, there’s still a long way to go before this thing takes to the skies, but if anyone can pull it off, it’s [Jay Bowles].

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Sputtering Daguerreotypes, Batman!

August 15, 2022 by Elliot Williams 14 Comments

The Daguerreotype was among the earliest photographic processes, long before glass plates or film, that relied on sensitizing a thin layer of silver on top of a copper plate. The earliest Daguerreotype plates were made physically, by rolling a copper-silver plate thinner and thinner until the silver layer was just right. Good luck finding a source of Daguerreotype plates made this way in 2022. (There are electroplating methods, but they all end up with chemically contaminated silver.)

On the other hand, magnetron sputtering is a process of depositing pure metal in thin layers using plasma, high voltages, and serious magnets, and [Koji Tokura] is making his own sputtered Daguerreotype plates this way, giving him the best of both worlds: the surreal almost-holographic quality of the Daguerreotype with the most difficult film preparation procedure imaginable.

The star of the show is [Koji]’s sputtering rig, which consists of a Tupperware glass sandwich box as a vacuum chamber and a microwave oven transformer as the high voltage source. In use, he pumps the chamber down, introduces a small amount of argon, and then lights up the plasma. The high voltage accelerates the plasma ions into a sheet of silver, and the silver particles that get knocked free coat the copper plate. A strong magnet creates a local plasma, which accelerates the coating procedure, but since [Koji] only had a relatively small magnet, he scans the plate with the magnet, using a scavenged 2D pen plotter mechanism.

Check out his video on the Hackaday.io page, and his Daguerreotype gallery as well. (We don’t think that they were all made with this procedure.)

The result is a chemically pure Daguerreotype plate produced in a seriously modern way, and we’d love to see the images in person. In these days of disposable images made by the AIs in your cell phone, it’s nice to see some people taking photography in strange directions. For instance, maybe you’d like to make your own ultra-large collodion plates. Or something else? If you do, show us!

Junkbox Build Keeps Tesla Coils Perfectly Varnished

August 9, 2022 by Dan Maloney 21 Comments

Admittedly, not a lot of people have a regular need to varnish coils. It’s mainly something that Tesla coil builders and other high-voltage experimenters are concerned with. But since that group probably constitutes a not insignificant fraction of the Hackaday audience, and because there are probably more applications for this homebrew coil varnishing setup, we figured it would be a good idea to share it.

For [Mads Barnkob], coil maintenance isn’t something to take lightly. If you check out his Kaizer Power Electronics channel on YouTube, you’ll see that he has quite a collection of large, powerful Tesla coils, some of which are used for demos and shows, and others that seem to be reserved mainly for blowing stuff up. To prevent one of his coils from joining the latter group, keeping the coat of insulating varnish on the secondary coil windings in tip-top condition is essential.

The setup seen in the video below helps with that tedious chore. Built entirely from scraps and junk bin parts, the low-speed, low-precision lathe can be set up to accommodate coils of all sizes. In use, the lathe turns the coil very slowly, allowing [Mads] to apply an even coat of varnish over the coil surface, and to keep it from sagging while it dries.

[Mads]’ setup is probably not great for coil winding as it is, but for coil maintenance, it’s just the thing. If your needs are more along the lines of a coil winder, we’ve got a fully automated winder that might work for you.

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Atmospheric High-Voltage Motor Makes Useful Power

July 26, 2022 by Bryan Cockfield 23 Comments

While it almost seems like an insane fever dream from an otherwise brilliant inventor, Nikola Tesla’s plan to harvest energy straight out of the atmosphere and essentially give it away is more reality than fiction. It’s usually prohibitively difficult get that energy out of the atmosphere for several obvious reasons, although it is still possible to do as [lasersaber] shows with his most recent atmospheric motor.

To help solve some of the logistical problems of harvesting electricity from the atmosphere, [lasersaber] is using a Van de Graaff generator as a stand-in for the high voltage gradient that can be found when suspending a long wire in the air. He has been experimenting with high-voltage motors like this for a while now and has refined his designs for corona discharge motors like these to be big enough and have enough torque to drive a drill bit. The motors have a conductive rotor with a series of discharge tubes on the stator, and exposing a metal point on the wiring (where the atmospheric wire would attach) to a sufficiently high voltage will cause rotation. In this case, it’s around 30,000 volts but with an extremely low current.

There are a number of videos documenting his latest build, including this follow-up video where he drills an arbitrarily large number of holes in various materials to demonstrate its effectiveness. Even though he is using a Van de Graaff generator in these builds, he does also show them working with a wire suspended by a drone as well for proof-of-concept. He’s also become somewhat of an expert on high-efficiency and low-power motors and has a number of other interesting builds based on these concepts.

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ESP32 Powers Fresh Take On An IoT Geiger Counter

July 7, 2022 by Tom Nardi 17 Comments

Over the years we’ve covered many projects aimed at detecting elevated radiation levels, and a fair number of them have been Internet connected in some way. But as they are often built around the Soviet-era SBM-20 Geiger–Müller tube, these devices have generally adhered to a fairly conservative design. With the current situation in Europe heightening concerns over potential radiation exposure, [g3gg0] thought it was a good a time as any to revisit the idea of an Internet-connected Geiger counter using more modern components.

Now to be clear, even this modernized approach still makes use of that same SBM-20 tube. There’s such an incredible wealth of information floating around out there about how to work with them that you’d almost put yourself at a disadvantage to chose something else to base your design on. Put simply, it’s hard to go wrong with a classic.

An unfortunate bug was discovered in the HV circuit.

That said, [g3gg0] decided early on that the design would use as many SMD components as possible, a considerable departure from many of the SBM-20 counters we’ve seen. That meant coming up with a new high-voltage power supply capable of providing the tube with the necessary 400 V, which from the sound of things, took a few attempts to complete. The final result is perhaps the smallest and cleanest looking board we’ve ever seen play host to this particular tube.

To run the show, [g3gg0] selected the ESP32-PICO-D4. You certainly don’t need such a powerful microcontroller to read the impulses from the SBM-20 tube and publish them via MQTT, but to be fair, the chip has a number of other duties. It’s handling the WS2812 RGB LEDs that go off in response to detected particles, running the (apparently optional) 2.9 inch WaveShare electronic paper display, and also pulling data from a BME280 environmental sensor as well as a CCS811 VOC sensor — so it’s keeping fairly busy.

As impressive as this build is, we do hate that it had to be built. From certain world leaders dropping casual comments about the strength of their nuclear arsenal to foolhardy attempts to capture the Chernobyl power station, having access to a reliable Geiger counter isn’t an unreasonable precaution right now. For everyone’s sake, let’s hope the fancy RGB LEDs on this particular build remain as dark as possible.

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Scrambling Pocket Calculators Made Easy With EMP Box V2

June 20, 2022 by Donald Papp 47 Comments

[Rostislav Persion] has for some time been interested in making small, portable EMP devices capable of interfering with nearby electronics. In these EMP devices, high voltage is used to create a portable spark gap generator, whose operation in turn creates electromagnetic pulses capable of resetting or scrambling nearby electronics such as pocket calculators.

Bridging adjacent holes narrows the spark gap, resulting in more frequent pulses.

His original EMP box designs relied on spark gaps constructed from metal screws threaded into a clear plastic insulator, but this newest design ditches fussy screw adjustments and relies on perfboard. By cutting out a single row of plated perfboard holes and soldering the high voltage terminals to each end, the empty holes in between form the essential parts of a spark gap.

It’s even adjustable: one simply bridges adjacent holes with solder to effectively decrease the gap. As for generating the high voltage itself, a DC voltage multiplier from Amazon takes care of that. Watch the device reset some calculators in the short video below.

Looking for high-voltage experiments that aren’t so sketchy? Get yourself a Van de Graff generator, some metal balls, and a little bit of oil, and make some art.

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ElectriPop Turns Cut Mylar Into Custom 3D Structures

May 6, 2022 by Tom Nardi 14 Comments

Mylar has a lot of useful properties, and as such as see it pop up pretty often, not just in DIY projects but in our day-to-day lives. But until today, we’ve never seen a piece of Mylar jump up and try to get our attention. But that’s precisely the promise offered by ElectriPop, a fascinating project from Carnegie Mellon University’s Future Interfaces Group.

The core principle at work here is fairly simple. When electrostatically charged, a strip of Mylar can be made to lift up vertically into the air. Cut that strip down the center, and the two sides will repel each other and produce a “Y” shape. By expanding on that concept with enough carefully placed cuts, it’s possible to create surprisingly complex three dimensional shapes that pop up once a charge is applied. A certain degree of motion can even be introduced by adjusting the input power. The video after the break offers several examples of this principle in action: such as a 3D flower that either stands up tall or wilts in relation to an external source of data, or an avatar that flails its arms wildly to get the user’s attention.

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