Mr McGuire: I just want to say one word to you. Just one word.
Benjamin: Yes, sir.
Mr McGuire: Are you listening?
Benjamin: Yes, I am.
Mr McGuire: Plastics.
You may recognize the above dialog from the movie “The Graduate” starring a young [Dustin Hoffman], whose character is getting advice about what line of work he should get into after university. Maybe Mr McGuire’s advice should have been “Microlattice.”
If you take a step back for a moment and survey the state of materials, you’ll see that not much has changed in the last 50 years. We’re still building homes out of dead trees, and most cars are still made out of iron(although that is starting to change.) It’s only been just recently has there been advances in batteries technology – and that only came about with the force of a trillion-dollar mobile phone industry behind it. So we’re excited by any new advance we see, and Boeing’s new “Microlattice” tickles our fancy.
Boeing isn’t giving away the recipe just yet, but here is what we know: it’s 99.99% empty space, making it extremely light. It’s so light, that if you drop it, it floats to the ground. It’s also compressible, giving it the ability to absorb energy and spring back (you can see it in action in the after the break.) It’s made by creating a sacrificial skeletal structure the shape of the final lattice, then coating that template with nickel-phosphorus alloy. The temporary inner structure is then etched away, leaving a “microlattice” of tiny interconnected hollow rods with wall thickness of about 100 nanometers. Of course it doesn’t take a rocket surgeon to figure out why Boeing is interested in such materials, they are eye it as an extremely lightweight building material for planes and spacecraft.
Continue reading “Boeing’s New Microlattice, Now the Lightest “Metal” Ever”
[Abhimanyu Kumar] is renovating a hotel in Nainital, near the India-Nepal border, and like any self-respecting Lord of the Rings fan, he wanted to give the restaurant a Hobbit theme. He built circular windows and to top it off a gorgeous round door complete with dragon hinges.
I asked him how well the doors work, as the 50kg (over 110lbs) weight of each of the doors must put a lot of strain on the hinges. [Abhimanyu] told me, “The door opens quite smoothly.While building the hinges even I was concerned about needing support as all other commercially available hinges we tried broke down or got bent.”
However, once the dragon hinge was installed it worked better that we expected and the door stays about 0.5″ over the ground at all times. The dragon hinges (made from 1/4-inch iron) integrate the hinge pins to the wings of the dragon, making it look like they are taking off when the doors open.
He has posted plenty of pictures of the build and the final product looks incredible. The tail of the dragon is quite long and provides a lot of support for the entire door. Each hinge itself weighs about 30kg, so it should be strong enough to hold up a door for a long time without any sagging. Kudos to him for some serious engineering!
Maxim Integrated recently posted a series of application notes chronicling how there’s more going on than you’d think in even the simplest “passive” components. Nothing’s safe: capacitors, resistors, and even printed circuit boards can all behave in non-ideal ways, and that can bite you in the reflow-oven if you’re not aware of them.
You might already know that capacitors have an equivalent series resistance that limits how fast they can discharge, and an equivalent inductance that models departures from ideal behavior at higher frequencies. But did you know that ceramic capacitors can also act like voltage sources, acting piezoelectrically under physical stress?
For resistors, you’ll also have to reckon with temperature dependence as well as the same range of piezoelectric and inductance characteristics that capacitors display. Worse, resistors can display variable resistance under higher voltages, and actually produce a small amount of random noise: Johnson Noise that depends on the value of the resistance.
Finally, the third article in the series tackles the PCB, summarizing a lot of potential manufacturing defects to look out for, as well as covering the parasitic capacitance, leakage currents, and frequency dependence that the actual fiberglass layers themselves can introduce into your circuit.
If you’re having a feeling of déjà-vu, the same series of articles ran in 2013 in Electronic Design but they’re good enough that we hope you won’t mind the redundant repetition all over again. And if you’re already quibbling with exactly what they mean by “passive”, we feel your pain: they’re really talking about parasitic effects, but we’ll let that slide too. We’re in a giving mood today.
[via Dangerous Prototypes]
About four decades ago, many European truck drivers started placing electronic LED badges in their windshields. Most of them were simple; nothing more than an animated heart pierced by an arrow. It became a common distraction in the highway night panorama of that time, at least until it became illegal. Most motorists became accustomed to seeing them, and the idea of the truck drivers making a statement with electronics always stuck with me. Now I have the chance to help people make a similar statement. Conference badges are not just a way to identify those who have registered, but a fashion statement and a mark of pride for conference organizers. They’ve become an art form, and engineers always want to stretch the limits of what is possible.
Every September, we have BalCCon, an international hacker’s conference at Novi Sad, Serbia. I was asked to design a badge for the 2016 event, and this is the first (well, the second) release. It is based on the PIC18LF24K50 and consists of a circle of LEDs which randomly displays pre-defined patterns. Every badge has its own infrared transceiver (LED-receiver pair), so the fun begins when two or more badges spot each other: they go from Adagio to full on Rondo, losing their default, dull visual pattern for a more dynamic, attention grabbing one, but most importantly – they synchronize. This means that, in a group of people, all badges will play the same pattern in unison. Every badge can spread the pattern code, so the whole group, however large, soon becomes synchronized. But if one of them “gets lost” somehow, it will try to learn it back from a neighbor or it might even launch into its own, randomly generated one. Sometimes it manages to spread it further and you get to witness a battle for light show domination.
This isn’t merely a story of designing badges, but of design choices that come in on budget while achieving a look that will delight those who end up wearing the hardware.
Continue reading “Conference Badges are the Newest Form of Hardware Art”
Building your own hardware to measure AC power isn’t a simple task. There’s a number of things to measure, including voltage, current, power, and power factor. The Atmel 90E24 is a single chip solution designed for this exact purpose. Connect a few components, and all the power data is available to a microcontroller over SPI.
[hwstar] built a custom power monitoring board based on this IC. His AC-Emeter will give you all the measurements you’d want, and includes an ESP12 module for data collection and WiFi connectivity. Aside from the Atmel 90E24 device, a high power and low resistance resistor is needed for shunt sense current measurement. An external module is used to convert mains voltage down to 5V to power the board.
Of course, working with mains voltages can be a dangerous endeavour. Fortunately, [hwstar] provides some tips on how to prevent “equipment from being BLOWN UP” along with the open source hardware and firmware.
[via Embedded Lab]
Last week, Parallax released an open hackable electronic badge that will eventually be used at dozens of conferences. It’s a great idea that allows badge hacks developed during one conference to be used at a later conference.
[Mark] was at the Hackable Electronics Badge premier at the 2015 Open Hardware Summit last weekend, and he just finished up the first interactive hack for this badge. It’s the zombie apocalypse in badge form, pitting humans and zombies against each other at your next con.
The zombie survival game works with the IR transmitter and receiver on the badge normally used to exchange contact information. Upon receiving the badge, the user chooses to be either a zombie or survivor. Pressing the resistive buttons attacks, heals, or infects others over IR. The game is your standard zombie apocalypse affair: zombies infect survivors, survivors attack zombies and heal the infected, and the infected turn into zombies.
Yes, a zombie apocalypse is a simple game for a wearable with IR communications, but for the Hackable Electronics Badge, it’s a great development. There will eventually be tens of thousands of these badges floating around at cons, and having this game available on day-one of a conference will make for a lot of fun.
As electronics engineer I have a mental collection of circuits that I’ve gathered over the years, much like a mechanic collects specialized tools as they work. All engineers do this and the tools in their tool boxes usually represent their project history and breadth.
A useful circuit to have in designer’s toolbox is the “high side switch”. Like it sounds, this is a circuit that switches the “high side” or positive voltage to a load.
We usually tend to switch things to ground as seen by outputs such as an Open Collector output, the reason being that ground usually is a known entity and is usually low impedance and is at a known voltage. But there are advantages to using a high-side switch in your circuits.
Continue reading “Learn and Build a High Side Switch”