In the days before semiconductor diodes, transistors, or even vacuum tubes, mechanical means were used for doing many of the same things. But there’s still plenty of fun to be had in using those mechanical means today, as [Manuel] did recently with his relay computer. This post is a walk through some circuits that used those mechanical solutions before the invention of the more electronic and less mechanical means came along.
This Friday at 5pm PST, [Sprite_tm] will be leading a Hack Chat talking about the ESP32.
[Sprite_tm] should require no introduction, but we’re going to do it anyway. He’s can install Linux on a hard drive. He can play video games on his keyboard. He built the world’s tiniest Game Boy, and gave the greatest talk I’ve ever seen. Right now, [Sprite] is in China working on the guts of the ESP32, the next great WiFi and Bluetooth uberchip.
[Sprite] recently packed his bags and headed over to Espressif, creators of the ESP32. He’s one of the main devs over there, and he’s up to his neck in the varied and weird peripherals contained in this chip. His job includes porting NES emulators to a WiFi-enabled microcontroller. If you want to learn about the latest and greatest microcontroller, this is the guy you want to talk to, and he’s taking all questions.
Note that we usually do these things earlier in the day but this week we start rolling at 5 PM Pacific Friday to help match up with [Sprite’s] timezone. You can figure out when this event will happen with this handy time and date converter.
Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. Log into hackaday.io, visit that page, and look for the ‘Join this Project’ Button. Once you’re part of the project, the button will change to ‘Team Messaging’, which takes you directly to the Hack Chat.
You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.
In addition to [Sprite]’s Hack Chat on Friday, we’re going to have a Tindie Chat in the Tindie Dog Park on Friday at noon, Pacific time. You can figure out when that’ll be in your local time by following this link.
In the Tindie Chat, we’re going to be talking about all the aspects of selling hardware on Tindie. This is a phenomenal community that keeps on growing, and right now there’s some really, really cool hardware being offered up from makers and creators around the world.
We have a few more Hack Chats on the books. On February 10th, we’ll be talking RF with [Jenny List]. Sparkfun will be around for a Hack Chat on February 17th. If stats are your thing, we’ll have a chat on the ins and outs of R in a few weeks.
Most of our readers are already going to be familiar with how electromagnets work — a current is induced (usually with a coil) in a ferrous core, and that current aligns the magnetic domains present in the core. Normally those domains are aligned randomly in such a way that no cumulative force is generated. But, when the electric field created by the coil aligns them a net force is created, and the core becomes a magnet.
As you’d expect, this is an extremely useful concept, and electromagnets are used in everything from electric motors, to particle accelerators, to Beats by Dre headphones. Another use that you’re probably familiar with from your high school physics class is levitation. When two magnets are oriented with the same pole towards each other, they repel instead of attract. The same principle applies to electromagnets, so that an object can be levitated using good ol’ electricity.
That, however, isn’t the only way to levitate something using magnets. As shown in the video below, permanent magnets can be used to induce a current in conductive material, which in turn exerts a magnetic field. The permanent magnets induce that current simply by moving — in this case on rotors spun by electric motors. If the conductive material is placed below the magnets (like in the video), it will push back and you’ve got levitation.
When we build an electronic project in 2016, the chances are that the active components will be integrated circuits containing an extremely large amount of functionality in a small space. Where once we might have used an op-amp or two, a 555 timer, or a logic gate, it’s ever more common to use a microcontroller or even an IC that though it presents an analog face to the world does all its internal work in the digital domain.
There was a time when active components such as tubes or transistors were likely to be significantly expensive, and integrated circuits, if they even existed, were out of the reach of most constructors. In those days people still used electronics to do a lot of the same jobs we do today, but they relied on extremely clever circuitry rather than the brute force of a do-anything super-component. It was not uncommon to see circuits with only a few transistors or tubes that exploited all the capabilities of the devices to deliver something well beyond that which you might expect.
One of the first electronic projects I worked on was just such a circuit. It came courtesy of a children’s book, one of the Ladybird series that will be familiar to British people of a Certain Age: [George Dobbs, G3RJV]’s Making A Transistor Radio. This book built the reader up through a series of steps to a fully-functional 3-transistor Medium Wave (AM) radio with a small loudspeaker.
Two of the transistors formed the project’s audio amplifier, leaving the radio part to just one device. How on earth could a single transistor form the heart of a radio receiver with enough sensitivity and selectivity to be useful, you ask? The answer lies in an extremely clever circuit: the regenerative detector. A small amount of positive feedback is applied to an amplifier that has a tuned circuit in its path, and the effect is to both increase its gain and narrow its bandwidth. It’s still not the highest performance receiver in the world, but it’s astoundingly simple and in the early years of the 20th century it offered a huge improvement over the much simpler tuned radio frequency (TRF) receivers that were the order of the day.
Continue reading “Everyone Should Build At Least One Regenerative Radio Receiver”
This may be a controversial statement, but Nixie tubes have become a little passé in our community. Along comes another clock project, and oh look! It’s got Nixie tubes instead of 7-segment displays or an LCD. There was a time when this rediscovered archaic component was cool, but face it folks, it’s been done to death. Or has it?
So given a disaffection with the ubiquity of Nixies you might think that no Nixie project could rekindle that excitement. That might have been true, until the videos below the break came our way. [Tobias Bartusch] has made his own Nixie tube, and instead of numerals it contains a 3D model of [Darth Vader], complete with moving light saber. Suddenly the world of Nixies is interesting again.
The first video below the break shows us the tube in action. We see [Vader] from all angles, and his light saber. Below that is the second video which is a detailed story of the build. Be warned though, this is one that’s rather long.
The model is made by carefully shaping and spot welding Kanthal wire into the sculpture, a process during which (as [Tobias] says) you need to think like neon plasma. It is then encased in a cage-like structure which forms its other electrode. He takes us through the process of creating the glass envelope, in which the wire assembly is placed. The result is a slightly wireframe but very recognisable [Vader], and a unique tube.
Everyone knows accordions are cool — they look fly, make neat noises, and get your romantic interests all hot and bothered. What isn’t cool is being relegated to acoustics only. How are you going to play a packed stadium or lay down a crystal clear track like that? You could go out and buy an electric accordion, but even low-end models carry a hefty price tag. But, this is Hackaday, and you know we’re going to be telling you about someone who found a better way.
That better way, shown in a build by [Brendan Vavra], was to take an acoustic accordion and convert it to MIDI. The base for his build was a decent full-size acoustic accordion purchased on eBay for just $150. Overall, it was in good mechanical condition, but some of the reeds were out of tune or not working at all. Luckily, that didn’t matter, since he wouldn’t be using them anyway. Don’t be fooled in the demo video below; it sounds like he’s playing the acoustic according but notice he’s not pumping those bellows! However, the bellows isn’t useless either since it can feed data back as a MIDI input.
[Brendan’s] build plan called for an Arduino Mega to be tied to a series of photo-interrupters that would detect button pushes and fire MIDI signals. But, first he had to take the thing apart — no small task, given the complexity of the instrument. The accordion has 120 buttons, and they’re not interchangeable, which means he had to carefully keep track of them as they were disassembled.
Continue reading “Acoustic Accordion Becomes MIDI; Oh The Complexity!”
Our Norwegian is pretty weak, so we struggled a little bit with the documentation for a big public LED art project in the lighthouse (translated) in Horten, Norway. But we do speak the universal language of blinkies, and this project has got them: 3,008 WS2812b LEDs ring the windows at the top of the lighthouse and create reactive patterns depending on the wave height and proximity of the ferry that docks there.
This seems to be an evolving project, with more features being added slowly over time. We love the idea of searching for the WiFi access point on the ferry to tell when it’s coming in to port, and the wave height sensor should also prove interesting data, with trends at the low-frequency tidal rate as well as higher frequency single waves that come in every few seconds. What other inputs are available? How many are too many?
It’s so cool that a group of tech-minded art hackers could get access to a big building like this. Great job, [Jan] and [Rasmus] and [everyone else]!
