What To Expect When You’re Expecting – A Trademark

July 18, 2018 by 18 Comments

A trademark represents a brand, so it can be words like “Apple”, including made up words like “Kleenex”. It can be symbols, like the Nike swoosh. It can also be colors, like UPS brown, and even scents like the flowery musk scent in Verizon stores. Filing a trademark in the United States is surprisingly easy. With a couple hundred dollars and a couple hours, you can be well on your way to having your very own registered trademark and having the right to use the ® symbol on your mark. You don’t need a lawyer, but you should know some of the hangups you might run into. The USPTO has a fantastic primer on trademarks, but we’ll TL;DR it for you. Continue reading “What To Expect When You’re Expecting – A Trademark” →

DIY Tube Oven Brings The Heat To Homebrew Semiconductor Fab

July 18, 2018 by 16 Comments

Specialized processes require specialized tools and instruments, and processes don’t get much more specialized than the making of semiconductors. There’s a huge industry devoted to making the equipment needed for semiconductor fabrication plants, but most of it is fabulously expensive and out of reach to the home gamer. Besides, where’s the fun in buying when you can build your own fab lab stuff, like this DIY tube oven?

A tube oven isn’t much more complicated than it sounds — it’s just a tube that gets hot. Really, really hot — [Nixie] is shooting for 1,200 °C. Not just any materials will do for such an oven, of course, and this one is built out of blocks of fused alumina ceramic. The cavity for the tube was machined with a hole saw and a homebrew jig that keeps everything aligned; at first we wondered why he didn’t use his lathe, but then we realized that chucking a brittle block of ceramic would probably not end well. A smaller hole saw was used to make trenches for the Kanthal heating element and the whole thing was put in a custom stainless enclosure. A second post covers the control electronics and test runs up to 1,000°C, which ends up looking a little like the Eye of Sauron.

We’ve been following [Nixie]’s home semiconductor fab buildout for a while now, starting with a sputtering rig for thin-film deposition. It’s been interesting to watch the progress, and we’re eager to see where this all leads.

How Low Can You Go? Tiny Current Generator

July 18, 2018 by 19 Comments

Current limited power supplies are a ubiquitous feature of the bench, and have no doubt helped prevent many calamities and much magic smoke being released from pieces of electronics. But for all their usefulness they are a crude tool that has a current resolution in the range of amps rather than single digit milliamps or microamps.

To address this issue, [Yann Guidon] has produced a precision current source, a device designed to reliably inject tiny currents. And in a refreshing twist, it has an extremely simple circuit in the form of a couple of PNP transistors. It has a range from 20 mA to 5 µA which is set and fine-tuned by a pair of pots, and it has a front-panel ammeter hacked from a surplus pocket multimeter, allowing the current to be monitored. Being powered by its own internal battery (and a separate battery for the ammeter) it is not tied to the same ground as the circuit into which its current is being fed.

[Yann] is a prolific builder whose work has featured here more than once. Take a look at his rubidium reference and his discrete component clocks, for example, and his portable LED flash.

The Biggest Corner Antenna We’ve Ever Seen

July 17, 2018 by 23 Comments

Radio waves are received on antennas, for which when the signal in question comes over a long distance a big reflector is needed. When the reception distance is literally astronomical, the reflector has to be pretty darn big. [The Thought Emporium] wants to pick up signals from distant satellites, the moon, and hopefully a pulsar. On the scale of home-built amateur radio, this will be a monstrous antenna. The video also follows the break.

In hacker fashion, the project is built on a budget, so all the parts are direct from a hardware store, and the tools are already in your toolbox or hackerspace. Electrical conduit, chicken wire, PVC pipes, wood blocks, and screws make up most of the structure so put away your crazy links to Chinese distributors unless you need an SDR. The form of the antenna is the crucial thing, and the shape is three perpendicular panels as seen in the image and video. The construction in the video is just a suggestion, but it doesn’t involve welding, so that opens it to even more amateurs.

Even if you are not trying to receive a pulsar’s signature, we have hacks galore for radios and antennas.

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Bomb Hoist Teardown Shows Cold-War-Era Big Iron

July 17, 2018 by 10 Comments

Buying surplus equipment lends a frisson of excitement as you eagerly await the package or crate containing your purchase. Did you buy a hidden treasure, or has some shyster succeeded in unloading a pile of garbage onto you, their mark? [Professor Churls] shelled out $49.99 for a military surplus bomb hoist which definitely falls into the former category. His teardown reveals it to be a beautifully over-engineered piece of Cold-War-era American hardware.

As the package with its extremely heavy contents is first inspected, he reminds us just what a bomb hoist does, it is clipped to an aircraft by ground crew and serves as a small but extremely powerful crane to lift up to a 6000-pound piece of ordnance onto the wing pylon of an aircraft. This particular example dates from the 1960s, and features a 28-volt DC motor coupled to a bulky gearbox assembly on a swivel mount for attachment.

His teardown is extremely detailed, but such is the engineering and complexity of the device you’ll want to read every part of it. The motor is a fairly traditional separately-excited brushed DC design such as you’d expect from that era, but with unusual features such as brushes on pivots rather than a slide. The multiple sets of gears are packed in aged and phenolic-smelling grease, and have unusual features such as stub-form teeth for high torque at low durations. There is even an entirely separate gear train for the hex drive provided so that crews could keep the bombers rolling even when the power was out.

He leaves us with the tantalising information that there is a project awaiting this device, but doesn’t tell us what that might be. We hope we’ll get to see it, whatever it is. Meanwhile it’s great to see that this kind of item can still be found from military surplus suppliers, where this is being written they have degenerated into little more than stockists of camouflage-printed camping gear. Our colleague [Brandon Dunson] lamented in 2015 on the slow decline of the electronic surplus business in his location.

Teensy Hat Controls Games

July 17, 2018 by 3 Comments

[Carson] didn’t know how to use an accelerometer until he wired one up to a Teensy and put it all in a hat. The result is a joystick that will probably cause you neck problems if you play video games for very long. You can see a video of how the device came to be and how it works, below.

We liked the approach of building up the circuit and testing it before integrating it with the hat. He used a small breadboard with half the Teensy pins hanging off. That seems to work, although we’d be worried about something shorting or floating pins causing issues. Of course, if you drove the disconnected pins as outputs or inputs with pullups that might not be a big deal.

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Beverage Holder Of Science

July 17, 2018 by 8 Comments

The folks at [K&J Magnetics] have access to precise magnetometers, a wealth of knowledge from years of experience but when it comes to playing around with a silly project like a magnetic koozie, they go right to trial and error rather than simulations and calculations. Granted, this is the opposite of mission-critical.

Once the experimentation was over, they got down to explaining their results so we can learn more than just how to hold our beer on the side of a toolbox. They describe three factors related to magnetic holding in clear terms that are the meat and bones of this experiment. The first is that anything which comes between the magnet and surface should be thin. The second factor is that it should be grippy, not slippy. The final element is to account for the leverage of the beverage being suspended. Say that three times fast.

Magnets are so cool for anything from helping visualize gas atoms, machinists’ tools, and circumventing firearm security features.

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