The Alien Energy Crisis Solved

May 14, 2024 by 34 Comments

Since the dawn of the industrial revolution, humans have been searching for more energy. Especially lately, there has been a huge interest in wind, solar, geothermal, and other ways to capture and harness power. However, we have a huge power plant just eight light minutes away: our sun. Oh sure, we toy with solar power, but the amount of sunlight hitting the Earth or even Earth orbit is a tiny fraction of Sol’s total output. But what if you could capture nearly all of the sun’s output? Scientists think that maybe — just maybe — they’ve detected 60 new extraterrestrial civilizations doing just that. At least, that’s what it could be.

[Freeman Dyson] popularized the idea of a Dyson sphere, an artificial sphere surrounding a sun to capture the maximum amount of energy, back in 1960. However, the idea is older and usually credited to [Olaf Stapledon]’s 1937 novel Star Maker. While most people think the sphere would be solid, [Dyson] himself thought it would be a swarm of disjointed collectors owing to the difficulty in creating a solid shell of the required size.

Both SETI and Fermilab have searched for what is thought to be telltale infrared radiation that scientists think would emanate from a star surrounded by spheres or swarms. Several have been located, but there is no conclusive evidence.

The new 60 were identified by analyzing data from the Gaia satellite. Again, the evidence is not conclusive, but small and dim stars that are very bright in infrared can’t be explained by conventional explanations. One way to explain at least some of the stars would be if about 16% of the star was obscured by something like a swarm of Dyson sphere collectors.

There are, of course, more jejune explanations possible. For example, the star might happen to be in front of some more distant IR source. Still, it is tantalizing to think there may be more than 60 high-tech civilizations out there either waiting to meet us or, perhaps, waiting to eat us, depending on how paranoid you are.

Supercon 2023: Building The Ultimate Apple IIe, Decades Later

May 14, 2024 by 1 Comment

The Apple II was launched in 1977, a full 47 years ago. The Apple IIe came out six years later, with a higher level of integration and a raft of new useful features. Apple eventually ended production of the whole Apple II line in 1993, but that wasn’t the end. People like [James Lewis] are still riffing on the platform to this day. Even better, he came to Supercon 2023 to tell us all about his efforts!

[James]’s talk covers the construction of the Mega IIe, a portable machine of his own design. As the name suggests, the project was based on the Mega II chip, an ASIC for which he had little documentation. He wasn’t about to let a little detail like that stop him, though.

The journey of building the Mega IIe wasn’t supposed to be long or arduous; the initial plan was to “just wire this chip up” as [James] puts it. Things are rarely so simple, but he persevered nonetheless—and learned all about the Apple II architecture along the way.

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Printable Keycaps Keep The AlphaSmart NEO Kicking

May 14, 2024 by 8 Comments

Today schools hand out Chromebooks like they’re candy, but in the early 1990s, the idea of giving each student a laptop was laughable unless your zip code happened to be 90210. That said, there was an obvious advantage to giving students electronic devices to write with, especially if the resulting text could be easily uploaded to the teacher’s computer for grading. Seeing an opportunity, a couple ex-Apple engineers created the AlphaSmart line of portable word processors.

The devices were popular enough in schools that they remained in production until 2013, and since then, they’ve gained a sort of cult following by writers who value their incredible battery life, quality keyboard, and distraction-free nature. But keeping these old machines running with limited spare parts can be difficult, so earlier this year a challenge had been put out by the community to develop 3D printable replacement keys for the AlphaSmart — a challenge which [Adam Kemp] and his son [Sam] have now answered.

In an article published on KBD.news, [Sam] documents the duo’s efforts to design the Creative Commons licensed keycaps for the popular Neo variant of the AlphaSmart. Those who’ve created printable replacement parts probably already know the gist of the write-up, but for the uninitiated, it boils down to measuring, measuring, and measuring some more.

Things were made more complicated by the fact that the keyboard on the AlphaSmart Neo uses seven distinct types of keys, each of which took their own fine tuning and tweaking to get right. The task ended up being a good candidate for parametric design, where a model can be modified by changing the variables that determine its shape and size. This was better than having to start from scratch for each key type, but the trade-off is that getting a parametric model working properly takes additional upfront effort.

A further complication was that, instead of using something relatively easy to print like the interface on an MX-style keycap, the AlphaSmart Neo keys snap onto scissor switches. This meant producing them with fused deposition modeling (FDM) was out of the question. The only way to produce such an intricate design at home was to use a resin MSLA printer. While the cost of these machines has come down considerably over the last couple of years, they’re still less than ideal for creating functional parts. [Sam] says getting their keycaps to work reliably on your own printer is likely going to involve some experimentation with different resins and curing times.

[Adam] tells us he originally saw the call for printable AlphaSmart keycaps here on Hackaday, and as we’re personally big fans of the Neo around these parts, we’re glad they took the project on. Their efforts may well help keep a few of these unique gadgets out of the landfill, and that’s always a win in our book.

Power Resistance Isn’t Futile

May 14, 2024 by 15 Comments

As [Electronoobs] points out, everything has resistance. So, how hard can it be to make a high-power resistor? In the video below, he examines a commercial power resistor and how to make your own using nichrome wire.

Sure, in theory, you can use a long piece of wire, but normally, you want to minimize the amount of space occupied. This leads to winding the wire around some substrate. If you just wind the wire, though, you get an inductor. This can cause nasty voltage spikes when there is a change in current through the resistor. You can get “noninductive” wire wound resistors that use either two opposing windings or alternate the turn direction on each turn. This causes the magnetic fields to tend to cancel out, reducing the overall inductance.

Nichrome wire has more resistance per millimeter and can dissipate more power. Modern digital meters can measure the resistance of a wire if you account for the test leads. To make a substrate, [Electronoobs] got creative since he anticipated generating a lot of heat. The final product even uses water cooling.

Why do you want a big resistor? Maybe you need a dummy load, or you want to drain some batteries. If you want to recycle nichrome wire, it is much more common than you might expect.

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GitHub Hosts Ham Radio

May 13, 2024 by 21 Comments

[Alex R2AUK] has been busy creating version two of a homebrew all-band ham radio transceiver. The unit has a number of features you don’t always see in homebrew radios. It covers the 80, 40, 30, 20, 17, 15, 12, and 10 meter bands. The receiver is a single-IF design with AGC. The transmitter provides up to 10W for CW and 5W for single sideband operations. There’s a built-in keyer, too. A lot of the documentation is in Russian (including the video below, which is part of a playlist). But translation tools are everywhere, so if you don’t speak Russian, you can still probably figure it out.

The VFO for both transmit and receive is an Si5351. The transmit chain is straightforward. The receiver reuses many of the same filters.

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The New Extremely Large Telescopes And The US’ Waning Influence In Astronomy

May 13, 2024 by 44 Comments

For many decades, the USA has been at the forefront of astronomy, whether with ground-based telescopes or space-based observatories like Hubble and the JWST. Yet this is now at risk as US astronomers are forced to choose between funding either the Giant Magellan Telescope (GMT) or the Thirty Meter Telescope (TMT) as part of the US Extremely Large Telescope (USELT) program. This rightfully has the presidents of Carnegie Science and Caltech – [Eric D. Isaacs] and [Thomas F. Rosenbaum] respectively – upset, with their opinion piece in the Los Angeles Times going over all the reasons why this funding cut is a terrible idea.

The slow death of US astronomy is perhaps best exemplified by the slow death and eventual collapse of the Arecibo radio telescope. Originally constructed as a Cold War era ICBM detector, it found grateful use by radio astronomers, but saw constant budget cuts and decommissioning threats. After Arecibo’s collapse, it’s now China with its FAST telescope that has mostly taken the limelight. In the case of optical telescopes, the EU’s own ELT is expected to be online in 2028, sited close to the GMT in the Atacama desert. The TMT would be sited in Hawai’i.

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Broken Lens Provides Deep Dive Into Camera Repair

May 13, 2024 by 18 Comments

While most of us are probably willing to pick up the tools and void the warranty on just about anything, often just to see what’s inside, many of us draw the line at camera gear. The tiny screws, the complex mechanisms, and the easily destroyed optical elements are all enough to scare off the average hacker. Not so for [Anthony Kouttron], who tore into a broken eBay Sigma lens and got it working again.

Now, to be fair, modern lenses tend to have a lot more in them that’s amenable to repair than back in the old days. And it seemed from the get-go that [Anthony]’s repair was going to be more electronic than optical or mechanical. The 45-mm lens was in fantastic shape physically, but wouldn’t respond to any controls when mounted to a camera body. Removing the lens bayonet mount exposed the main controller PCB, which is tightly packed with SMD components and connectors for the flex cables that burrow further into the lens to its many sensors and actuators. By probing traces with his multimeter, [Anthony] found a DC-DC converter on the main PCB with an unknown component nearby. This turned out to be an SMD fuse, and as luck would have it, it was open. Replacing the fuse got the lens working again, and while there’s always the nagging suspicion that whatever blew the fuse the first time could happen again, the repair seems to have worked.

Despite the simplicity of the fix, [Anthony] continued the teardown and shared a lot of tips and tricks for lens repairs, including where he would have looked next if the fuse had been good. One tip we loved was the use of double-sided tape to organize parts as they’re removed; this is particularly important with camera gear where screws or different lengths can make for a really bad day on reassembly.

Feeling the need to dive deeper into lens repair? This step-by-step repair should keep you satisfied.