High-Voltage Fun With An Inexpensive Power Supply

It used to be that nearly every home had at least one decent high-voltage power supply. Of course, it was dedicated to accelerating electrons and slamming them into phosphors so we could bathe ourselves in X-rays (not really) while watching Howdy Doody. These days the trusty tube has been replaced with LEDs and liquid crystals, which is a shame because there’s so much fun to be had with tens of thousands of volts at your disposal.

That’s the impetus behind this inexpensive high-voltage power supply by [Sebastian] over at Baltic Labs. The heavy lifting for this build is done by a commercially available power supply for a 50-watt CO2 laser tube, manufactured — or at least branded — by VEVOR, a company that seems intent on becoming the “Harbor Freight of everything.” It’s a bold choice given the brand’s somewhat questionable reputation for quality, but the build quality on the supply seems decent, at least from the outside. [Sebastian] mounted the supply inside a rack-mount case, as one does, and provided some basic controls, including the obligatory scary-looking toggle switch with safety cover. A pair of ammeters show current and voltage, the latter with the help of a high-voltage resistor rated at 1 gigaohm (!). The high-voltage feedthrough on the front panel is a little dodgy — a simple rubber grommet — but along with the insulation on the high-voltage output lead, it seems to be enough.

The power supply’s 30 kV output is plenty for [Sebastian]’s current needs, which from the video below appear to mainly include spark gap experiments. He does mention that 50 kV commercial supplies are available too, but it would be tough to do that for the $150 or so he spent on this one. There are other ways to go, of course — [Niklas] over at Advanced Tinkering recently shared his design for a more scratch-built high-voltage supply that’s pretty cool too. Whatever you do, though, be careful; we’ve been bitten by a 50 kV flyback supply before and it’s no joke.

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This Unique Flip-Flop Uses Chemistry And Lasers

One of the first logic circuits most of us learn about is the humble flip-flop. They’re easy enough to build with just a couple of NOR or NAND gates, and even building one up from discrete components isn’t too much of a chore. But building a flip-flop from chemicals and lasers is another thing entirely.

That’s the path [Markus Bindhammer] took for his photochromic molecular switch. We suspect this is less of an attempt at a practical optical logic component and more of a demonstration project, but either way, it’s pretty cool. Photochromism is the property by which molecules reversibly rearrange themselves and change color upon exposure to light, the most common example being glass that darkens automatically in the sun. This principle can be used to create an optical flip-flop, which [Markus] refers to as an “RS” type but we’re pretty sure he means “SR.”

The electronics for this are pretty simple, with two laser modules and their drivers, a power supply, and an Arduino to run everything. The optics are straightforward as well — a beam splitter that directs the beams from each laser onto the target, which is a glass cuvette filled with a clear epoxy resin mixed with a photochromic chemical. [Markus] chose spiropyran as the pigment, which when bathed in UV light undergoes an intramolecular carbon-oxygen bond breakage that turns it into the dark blue pigment merocyanine. Hitting the spot with a red laser or heating the cuvette causes the C-O bond to reform, fading the blue spot.

The video below shows the intensely blue dot spot developing under UV light and rapidly fading thanks to just the ambient temperature. To make the effect last longer, [Markus] cools the target with a spritz from a CO2 cartridge. We imagine other photochromic chemicals could also be employed here, as could some kind of photometric sensor to read the current state of the flip-flop. Even as it is, though, this is an interesting way to put chemistry and optics to work.

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Hackaday Links: January 14, 2024

How long does it take a team of rocket scientists to remove two screws? When the screws they’re working on are keeping a priceless sample of asteroid safe, it’s about three months. That’s how long NASA has been working on the OSIRIS-REx sample return canister, which came back to Earth from asteroid Bennu back in September. The container was crammed full of asteroid bits, thanks in part to an overly energetic impact between the sample-collecting boom and Bennu. There was so much stuff that planetary scientists were able to recover about 70 grams of material that was covering the outside of the sealed container; this must have been a boon to the engineers, who got to figure out how to open the jammed cover of the container without anyone breathing down their necks for samples to study. The problem was a pair of stuck fasteners out of the 35 holding the lid on the container; the solution was far more complicated than a spritz of WD-40 and a little bit of heating with an oxy-acetylene torch. Engineers had to design two “clamp-like tools” and test them on a mock-up to make sure they wouldn’t contaminate the sample. We’d love to know more about these tools; trust us, we’ll be looking into this closely. If we find anything, a full article will be forthcoming.

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Homemade Raman Laser Is Shaken, Not Stirred

You wouldn’t think that shaking something in just the right way would be the recipe for creating laser light, but as [Les Wright] explains in his new video, that’s pretty much how his DIY Raman laser works.

Of course, “shaking” is probably a gross oversimplification of Raman scattering, which lies at the heart of this laser. [Les] spends the first half of the video explaining Raman scattering and stimulated Raman scattering. It’s an excellent treatment of the subject matter, but at the end of the day, when certain crystals and liquids are pumped with a high-intensity laser they’ll emit coherent, monochromatic light at a lower frequency than the pumping laser. By carefully selecting the gain medium and the pumping laser wavelength, Raman lasers can emit almost any wavelength.

Most gain media for Raman lasers are somewhat exotic, but luckily some easily available materials will work just fine too. [Les] chose the common solvent dimethylsulfoxide (DMSO) for his laser, which was made from a length of aluminum hex stock. Bored out, capped with quartz windows, and fitted with a port to fill it with DMSO, the laser — or more correctly, a resonator — is placed in the path of [Les]’ high-power tattoo removal laser. Laser light at 532 nm from the pumping laser passes through a focusing lens into the DMSO where the stimulated Raman scattering takes place, and 628 nm light comes out. [Les] measured the wavelengths with his Raspberry Pi spectrometer, and found that the emitted wavelength was exactly as predicted by the Raman spectrum of DMSO.

It’s always a treat to see one of [Les]’ videos pop up in our feed; he’s got the coolest toys, and he not only knows what to do with them, but how to explain what’s going on with the physics. It’s a rare treat to watch a video and come away feeling smarter than when you started.

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Hackaday Links: December 3, 2023

Sure, it does less than originally promised, but hey — at least it’s more expensive. That about sums up Tesla fans’ feelings after the long-awaited Cybertruck reveal at the Texas Gigafactory on Thursday, where Elon Musk himself handed over the keys — or their Cyber equivalent — to a few new owners. These are expensive machines — $61,000 for the two-motor model, and just shy of $100,000 for the three-motor all-wheel-drive model with all the bells and whistles. That’s considerably more than they were expected to cost back in 2019, a fact which may be at least partially behind the drop in Tesla shares after the launch.

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Using Gravitational Lensing To Transmit Power And Detect Aliens

Most of us will have at some point have bought a long power cable to charge the bike on the deck, but [Slava G. Turyshev] has a slightly more ambitious idea. In this recent paper, he outlines how an advanced civilization could use a star or two to transmit power or send signals over an interstellar distance. And his idea is also simple enough that we could do it right now, with existing technology, or detect if someone else is doing it.

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What The Artisan 3-in-1 CNC Offers (If One Has The Table Space)

I never feel like I have enough space in my workshop. The promise of consolidating tools to make the most of limited space drew me to the Snapmaker Artisan, a plus-sized 3-in-1 tool combining 3D printer, laser engraver, and CNC machine.

Smaller than three separate tools, but still big.

Jacks of all trades may be masters of none, but it is also true that a tool does not need to be a master of its functions to be useful. For many jobs, it enough to simply be serviceable. Does a machine like the Artisan offer something useful to a workshop?

Snapmaker was kind enough to send me an Artisan that I have by now spent a fair bit of time with. While I have come to expect the occasional glitch, having access to multiple functions is great for prototyping and desktop manufacturing.

This is especially true when it allows doing a job in-house where one previously had to outsource, or simply go without. This combo machine does have something to offer, as long as one can give it generous table space in return.

What It Is

The Artisan is a large dual-extrusion 3D printer, CNC router, and diode-based laser engraver. To change functions, one physically swaps toolheads and beds. Very thankfully, there are quick-change fixtures for this.

Driving the Artisan is Snapmaker’s software Luban (GitHub respository). Named for the ancient Chinese master craftsman, it is responsible for job setup and control. For laser and CNC work, there are convenient built-in profiles for a variety of paper, plastic, leather, and wood products.

The unit is enclosed, nicely designed, and — while I have come to expect the occasional glitch — serviceable at all three of its functions. The size and stature of the machine warrants some special mention, however.

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