Inventing The Induction Motor

When you think of who invented the induction motor, Nikola Tesla and Galileo Ferraris should come to mind. Though that could be a case of the squeaky wheel being the one that gets the grease. Those two were the ones who fought it out just when the infrastructure for these motors was being developed. Then again, Tesla played a huge part in inventing much of the technology behind that infrastructure.

Although they claimed to have invented it independently, nothing’s ever invented in a vacuum, and there was an interesting progression of both little guys and giants that came before them; Charles Babbage was surprisingly one of those giants. So let’s start at the beginning, and work our way to Tesla and Ferraris.

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Spy Tech: Nonlinear Junction Detectors

If you ever watch a spy movie, you’ve doubtlessly seen some nameless tech character sweep a room for bugs using some kind of detector and either declare it clean or find the hidden microphone in the lamp. Of course, as a hacker, you have to start thinking about how that would work. If you had a bug that transmits all the time, that’s easy. The lamp probably shouldn’t be emitting RF energy all the time, so that’s easy to detect and a dead give away. But what if the bug were more sophisticated? Maybe it wakes up every hour and beams its data home. Or perhaps it records to memory and doesn’t transmit anything. What then?

High-end bug detectors have another technique they use that claims to be able to find active device junctions. These are called Nonlinear Junction Detectors (NLJD). Spy agencies in the United States, Russian and China have been known to use them and prisons employ them to find cell phones. Their claim to fame is the device doesn’t have to be turned on for detection to occur. You can see a video of a commercial NLJD, below

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Huge Names Confirm Their Supercon Appearances

We’re excited to announce the next batch of speakers for the 2017 Hackaday Superconference.

We are especially pleased to welcome Michael Ossmann as a speaker. He presented an RF design workshop at the 2014 Superconference which was sold out, standing room only, and still turned away dozens of people before becoming a hit on the Internet. This year he takes the stage with colleague Dominic Spill as they focus on infrared communications and the uses and abuses of such.

Dr. Christal Gordon threw down an incredible talk on biologically inspired sensors last year and we suspect she will outdo herself this year. Her talk will cover the fanciest of cutting-edge sensors and the trade-offs of selecting the new hotness for your designs. Coming out of this you will know when to go with a suite of tried and true components and when to make the leap to new tech.

Several of this year’s Hackaday Prize Judges will be on hand and presenting talks. In addition to Christal Gordon and Danielle Applestone (announced as a speaker last week), we’re thrilled to have Anouk Wipprecht — internationally known for her work in fashion and engineering, pushing the boundaries of how technology can interface with humans — as a speaker. Nadya Peek from the Center for Bits and Atoms who spoke at Supercon in 2016 with a harrowing tale of an impromptu engineering challenge in Shenzhen has confirmed that she will speak this year.

The ever-popular Sprite_TM will be at Supercon. He has a reputation for bringing the house down with fantastic presentations, be it the Tamagochi Matrix or the Tiniest Game Boy. And we are proud to present the Art Director for Hackaday — Joe Kim will be speaking about the curious connection between art and technology and how developments in one push the other forward.

Ever wonder about the air you’re breathing in the house or at work. So does Natalia Mykhaylova whose work begins to monitor and catalog that information. She will discuss the state of our HVAC systems and what it looks like to bring them into the information age.

Below you’ll find the confirmed speakers we’re announcing today. We’ll have more, as well as a list of confirmed talks next week. Get your ticket now, they will sell out.

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The Narrowing Gap Between Amateur and Professional Fabrication

The other day I saw a plastic part that was so beautiful that I had to look twice to realize it hadn’t been cast — and no, it didn’t come out of a Stratysys or anything, just a 3D printer that probably cost $1,500. It struck me that someone who had paid an artisan to make a mold and cast that part might end up spending the same amount as that 3D printer. It also struck me that the little guys are starting to catch up with the big guys.

Haz Bridgeport, Will Mill

Sometimes it’s just a matter of getting a hold of the equipment. If you need a Bridgeport mill for your project, and you don’t have one, you have to pay for someone else to make the thing — no matter how simple. You’re paying for the operator’s education and expertise, as well as helping pay for the maintenance and support of the hardware and the shop it’s housed in.

I once worked in a packaging shop, and around 2004 we got in a prototype to use in developing the product box. This prototype was 3D printed and I was told it cost $12,000 to make. For the era it was mind blowing. The part itself was simplistic and few folks on Thingiverse circa 2017 would be impressed; the print quality was roughly on par with a Makerbot Cupcake. But because the company didn’t have a 3D printer, they had to pay someone who owned one a ton of cash to make the thing they wanted.

Unparalleled Access to Formerly Professional-Only Tools

But access to high end tools has never been easier. Hackerspaces and tool libraries alone have revolutionized what it means to have access to those machines. There are four or five Bridgeports (or similar vertical mills) at my hackerspace and I believe they were all donated. For the cost of membership, plus the time to get trained in and checked out, you can mill that part for cheap. Repeat with above-average 3D printers, CNC mills, vinyl cutters, lasers. The space’s South Bend lathe (pictured) is another example of the stuff most people don’t have in their basement shops. This group ownership model may not necessarily grant you the same gear as the pros, but sometimes it’s pretty close.
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The Science Behind Lithium Cell Characteristics and Safety

To describe the constraints on developing consumer battery technology as ‘challenging’ is an enormous understatement. The ideal rechargeable battery has conflicting properties – it has to store large amounts of energy, safely release or absorb large amounts of it on demand, and must be unable to release that energy upon failure. It also has to be cheap, nontoxic, lightweight, and scalable.

As a result, consumer battery technologies represent a compromise between competing goals. Modern rechargeable lithium batteries are no exception, although overall they are a marvel of engineering. Mobile technology would not be anywhere near as good as it is today without them. We’re not saying you cannot have cellphones based on lead-acid batteries (in fact the Motorola 2600 ‘Bag Phone’ was one), but you had better have large pockets. Also a stout belt or… some type of harness? It turns out lead is heavy.

The Motorola 2600 ‘bag phone’, with a lead-acid battery. Image CC-BY-SA 3.0 source: Trent021

Rechargeable lithium cells have evolved tremendously over the years since their commercial release in 1991. Early on in their development, small grains plated with lithium metal were used, which had several disadvantages including loss of cell capacity over time, internal short circuits, and fairly high levels of heat generation. To solve these problems, there were two main approaches: the use of polymer electrolytes, and the use of graphite electrodes to contain the lithium ions rather than use lithium metal. From these two approaches, lithium-ion (Li-ion) and lithium-polymer (Li-Po) cells were developed (Vincent, 2009, p. 163). Since then, many different chemistries have been developed.

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Sneakers: a Love-Fest

“A TURNIP CURES ELVIS” begins the opening credits, an intriguing beginning to a smart and still timely film that was released around 25 years ago. If you’ve never seen the movie, I’m about to spoil the hell out of it.

Sneakers features the title characters, hackers who work the 1992 gig economy as freelance penetration testers. They work for Martin Bishop, a hippie hacker Obi Wan who works San Francisco’s gray market, doing good deeds and helping banks improve their security.

While there is a fair amount of cheese in Sneakers, a lot of the problems the characters face — physical security and cryptography come to mind — remain the problems of today. Securing our digital business? Check. Surveillance? Check? Gray operators? Absolutely. At the same time, the movie does a good job of exploring different categories of hacker. The various characters seem to offer glimpses of people I see all the time at the hackerspace. Bigger than life, certainly, but they are in a Hollywood movie, after all.

Finally, the movie is just smart. Those opening credits offer a preview: the anagrams that begin the movie (“A TURNIP KILLS ELVIS” translates to Universal Pictures) are not just some art director’s conceit for the opening credits. The anagrams end up being important later on in the film, where there is a key clue hidden but if you think about it, shuffling letters on your Scrabble tray could be taken as a metaphor for hacker thinking — taking the same information as everyone else but looking at it in a different way.

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What’s the Best Way to Learn Electronics?

What’s the best way to learn electronics? It’s a pithy question to ask a Hackaday audience, most of whom are at least conversant in the field already. Those who already have learned often have just their own perspective to draw upon—how they themselves learned. Some of you may have taught others. I want to explore what works and what doesn’t.

Hobbyists Learn Differently Than Students

One thing I can say straight off is that students learn differently than people who learn at home. Hobbyists have the advantage of actually being interested, which is a quality a student may not enjoy. People have been teaching themselves electronics since the beginning, with analog projects–Heathkit models, BEAM robots, and ham radio sets–evolving into purely digital projects.

Let’s face it, Arduinos lower the bar like nothing else. There’s a reason why the Blink sketch has become the equivalent to “Hello World”. Dirt cheap and easily configured microcontrollers combined with breakout boards make it easy for anyone to participate.

However, ask any true EE and that person will tell you that following wiring diagrams and plugging in sensor boards from Sparkfun only teaches so much. You don’t bone up on terms like hysteresis or bias by building something from uCs and breakout boards. But do you need to? If you are truly interested in electronics and learn by making those Adafruit or Sparkfun projects, sooner or later you’ll want to make your own breakout boards. You’ll learn how to design your own circuit boards and figure out why things work and why they don’t. I don’t need to tell you the Internet has all the answers a neophyte needs–but the interest has to be there in the first place.

What’s the Best Way to Learn in the Classroom?

There is a product category within robotics kits that consists of “educational rovers” designed to be purchased in group lots by teachers so that each student or small group gets one. These rovers are either pre-built or mostly built—sure, you get to screw in motor mounts, but all the circuit boards are already soldered up for you, surface mount, no less. They come pre-configured for a variety of simple tasks like line following and obstacle avoidance. The Makeblock mBot is an example.

I think it’s part of that whole “learn coding” initiative, where the idea is to minimize the assembly in order to maximize the coding time. Insofar as soldering together a kit of through-hole components teaches about electronics, these bots mostly don’t do it. By all appearances, if there is a best way to learn electronics, this an’t it. However, regardless of what kind of project the teacher puts in front of the student, it still has to generate some sort of passion. What those robots provide is a moment of coolness that ignites the firestorm of interest.

I once led a soldering class that used Blinky Grids by Wayne and Layne as the focus. This is a fantastic kit that guides you through building a small LED matrix. It’s particularly cool because it can be programmed over a computer monitor with light sensors interacting with white and black squares on the company’s web site. When my students finished their grids, they all worked and had unique messages scrolling through. Now, that is a payoff. I’m not saying that any of those folks became hardware hackers as a result of my class, but it beat the hell out of a Christmas tree, am I right?

Getting back to that rover, what must be acknowledged is that the rover itself is the payoff, and that’s only as far as it goes if everyone loses interest. However, a lot of those rovers have expansion possibilities like bolting on another sensor or changing the method of programming–for instance, the mBot has both a graphic programming interface and can also be reflashed with a regular old Arduino bootloader.

Readers, share in comments your own perspective. How did you learn? How would you teach others?