[lookmumnocomputer] enjoys creating synthesizers, and early last year he created one called The Fart Box. It is an entirely analog synthesizer with which, according to its creator, it is difficult to make anything that doesn’t sound gassy. It’s not quite like any other synthesizer, and while it is capable of acting like a regular analog synth it is never very far from cranking out farty sounds.
Tesla coils are incredible pieces of hardware, but they can be tricky to build. Between the spark gap, capacitors, and finely tuned coils, it’s not exactly a beginners project. Luckily, there’s hope for anyone looking for a less complex way to shoot some sparks: the Slayer Exciter. This device can be thought of as the little cousin to the Tesla coil, and can be used for many of the same high voltage experiments while being far easier to assemble.
Now [Jay Bowles] is obviously no stranger to building his own Tesla coils, but since so many of his fans wanted to see his take on this less complex option, he recently built his own Slayer Exciter. After putting on a few of his own unique touches, the end result looks very promising. It might not be able to throw sparks as far as some of the other creations featured on his YouTube channel, but it’s still impressive for something so simple.
[Jay] uses two transistors in parallel for reliabilityWhen we say simple, we mean it. Building a bare-bones Slayer Exciter takes only takes five components: the two coils, a transistor, a diode, and a resistor. For this build, power is provided by a trio of rechargeable 9 V batteries in the base of the unit which can be easily swapped out as needed.
In the video, [Jay] does a great job explaining and illustrating how this basic circuit creates exceptionally high frequency energy. In fact, the frequency is so high that the human ear can’t hear it; unfortunate news for fans of the Tesla coil’s characteristic buzz.
Generally speaking Slayer Exciters would have the same sort of vertical coils that you’d see used on a traditional Tesla coil, but in this case, [Jay] has swapped that out for a pancake coil held in the upper level of the device. This makes for a very compact unit that would be perfect for your desk, if it wasn’t for the fact that the arcs produced by this gadget are hot enough to instantly vaporize human skin. Just something to keep in mind.
This week the new coronavirus has spread like wildfire. The good news last week has been the success with which China, Taiwan, and Singapore have handled the epidemic, and that western nations are just beginning to emulate their approach of reducing person-to-person interactions as much as possible to slow the rate of infection. The bad news, however, is that countries like Italy currently have a number of cases that is overwhelming their health system, and that the disease seems to be spreading rapidly in other countries. It’s going to get a lot worse before it gets better.
Our sincerest thanks go out to all of the medical professionals who are providing care in this difficult situation. But also to those who are providing public infrastructure in less obvious ways: the cashiers who subject themselves to hundreds of contacts per day just so that you and I can buy toothpaste, for instance. The rest of us are staying at home as much as possible, washing our hands, and slowing the spread as much as possible simply by not catching or passing on the virus.
The original part, left, with its 3D-printed counterpart.
But most of us don’t have medical expertise. If you have spare CPU cycles, consider donating them to the folding@home effort to simulate the proteins in the virus. And any hack to make the lives of those stuck in voluntary quarantine more “normal” is perhaps as important in the long run. I made a simple clock to help my son who’s stuck at home and can’t yet tell time, adjust to his new daily routine. Others have made more obviously whimsical devices. We like this computer-vision face-touching alarm. If it makes people smile while slowing down one transmission vector, it’s a win.
If you have the expertise, consider helping out your local schools with telepresence and online education. While a number of colleges are already geared up for distance learning, it’s uncharted territory for primary education most everywhere. I’m sure you can also think of other ways to help out locally. If so, don’t hesitate to tell us your success stories.
For the rest: simply washing your hands, staying healthy, and not passing the virus on to others is a quietly heroic act that we think shouldn’t be overlooked. Thanks.
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[Eric Strebel] wanted a microphone to record voiceovers, and being a designer, wanted something suitably impressive for the task. Inspired by the classic Unidyne 55, he set about designing his own mic, and used some pretty fancy techniques to get it built.
The mic was built around a ribbon element, providing good dynamic response. The design was created in CAD, and was initially intended to be constructed out of three seperate pieces. However, [Eric] realized that through the use of a binder jetting 3D printer, this wouldn’t be necessary.
Binder jetting is a technique in which a nozzle squirts binder into a powder bed to create a 3D printed part. In this case, a steel powder is used, which is then post-processed in an oven with liquid bronze. The bronze wicks into the finished part, adding strength. It’s a process which creates metal parts with very few limitations; the primary concern being minimum wall thicknesses.
With access to a binder jetting printer, [Eric] was free to design the stylish geometry of the final product. Mashing up hexagons with classic 50s curves, the final result is impressive. [Eric] now uses the microphone regularly to record voiceovers, and the aptly-named Hexavox even made an appearance at NAMM.
Setting up an environment for Embedded Development was traditionally a pain and so vendors provide integrated development environments to help bridge the gap. Google has open-sourced their version of an embedded targeted environment designated as embedded-targeted libraries which they trademarked Pigweed.
The repository contains what Google is calling modules but taking a better look reveals that it a little more than that. Packaged in a Python Virtual Environment is a number of tools including an ARM compiler, the clang-format tool and Python 3.8 interpreter which runs more than a few things. The modules that come with Pigweed assist developers by running micro-automations such as the pw_watch module that monitors files for change and triggers a build, test and even flash and debug on hardware. There is also a module that allows pre-submit checks such as linting and formatting.
Google still does not consider this offering production ready though from what we have seen so far, it is a great place for many to start experimenting with for their embedded development automation needs. Anyone tried it out yet?
No doubt some purists in the audience will call this one cheating, since this Amiga 500 from 1987 isn’t technically connecting to Spotify and playing the music by itself. But we also suspect those folks might be missing the point of a site called Hackaday. With all the hoops [Daniel Arvidsson] hopped through to make this happen, what else could it be if not a hack?
This one starts, like so many projects these days, with the Raspberry Pi. Don’t worry Amiga aficionados, this classic machine hasn’t been gutted and had its internals replaced with a diminutive Linux board. But thanks to an expansion card known as the A314, you could say it’s received a penguin infusion. This clever board allows an internally mounted Raspberry Pi to communicate with the Amiga 500 through shared memory, making all sorts of trickery possible.
In this case, the Raspberry Pi is actually the one connecting to the Spotify Connect service with raspotify and decoding the stream. But thanks to a few pipes and an ALSA plugin, the audio itself is actually pushed into the Amiga’s sound hardware. In the video after the break, the process is demonstrated with tunes that are befitting a computer of this vintage.
Readers who survived the 1970s will no doubt remember the “mood ring” fad, where a liquid crystal mounted to a ring would magically reveal your current emotional state to all and sundry by changing color. This nifty thermochromic display is based on the same principle, and while it might not start a new craze, it’s still pretty mesmerizing to watch.
This isn’t [Moritz v. Sivers]’ first attempt at a thermochromic display. His earlier version was far more complicated, using separate copper plates clad with thermochromic film for each segment, with Peltier devices to cool and heat them individually. Version two is much simpler, using a printed circuit board with heating elements in the shape of seven-segment displays etched into it. The thermochromic film sits directly on the heater PCB; a control PCB below has the MCU and sensors on it. The display alternates between temperature and humidity, with the segments fading in an uneven and ghostly way that really makes this fun to watch. [Moritz] has made the build files available, and there’s a detailed Instructable as well.
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