It’s no surprise that things change as we age, and that tasks that were once trivial become difficult. Case in point: my son asked for help with the cord on his gaming headset the other night. The cable had broken and we could see frayed conductors exposed. When I got it apart, I found that I could barely see the ultra-fine wires to resolder them after cutting out the bad section. I managed to do it, but just barely.
This experience got me thinking about how to deal with the inevitable. How do you stay active as a hacker once your body starts to fight you more than it helps you? I’m interested mostly in dealing with changes in vision, but also in loss of dexterity and fine motor skills, and dealing with cognitive changes. This isn’t a comprehensive list of the ravages of time, but they’re probably the big ones that impact any hacker-related hobby. I enlisted a couple of my more seasoned Hackaday colleagues, [Bil] and [Rud], for their tips and tricks to deal with these issues.
If you build electronic circuits on a regular basis the chances are you will have used capacitors many times. They are a standard component along with the resistor whose values are lifted off the shelf without a second thought. We use them for power supply smoothing and decoupling, DC blocking, timing circuits, and many more applications.
Different capacitor applications. By Elcap (Own work) [CC0], via Wikimedia CommonsA capacitor though is not simply a blob with two wires emerging from it and a couple of parameters: working voltage and capacitance. There is a huge array of capacitor technologies and materials with different properties. And while almost any capacitor with the right value can do the job in most cases, you’ll find that knowing more about these different devices can help you make something that doesn’t just do the job, but does the best possible job. If you’ve ever had to chase a thermal stability problem or seek out the source of those extra dBs of noise for example you will appreciate this.
Summer is nearly here, and with that comes the preparations for the largest gathering of security researchers on the planet. In early August, researchers, geeks, nerds, and other extremely cool people will descend upon the high desert of Las Vegas, Nevada to discuss the vulnerabilities of software, the exploits of hardware, and the questionable activities of government entities. This is Black Hat and DEF CON, when taken together it’s the largest security conference on the planet.
These conferences serve a very important purpose. Unlike academia, security professionals don’t make a name for themselves by publishing in journals. The pecking order of the security world is determined at these talks. The best talks, and the best media coverage command higher consultancy fees. It’s an economy, and of course there will always be people ready to game the system.
Like academia, these talks are peer-reviewed. Press releases given before the talks are not, and between the knowledge of security researchers and the tech press is network security theatre. In this network security theatre, you don’t really need an interesting exploit, technique, or device, you just need to convince the right people you have one.
Lasers are optical amplifiers, optical oscillators, and in a way, the most sophisticated light source ever invented. Not only are lasers extremely useful, but they are also champions of magnitude: While different laser types cover the electromagnetic spectrum from radiation (<10 nm) over the visible spectrum to far infrared light (699 μm), their individual output band can be as narrow as a few µHz. Their high temporal and spatial coherence lets them cover hundreds of meters in a tight beam of lowest divergence as a perfectly sinusoidal, electromagnetic wave. Some lasers reach peak power outputs of several exawatts, while their beams can be focused down to the smallest spot sizes in the hundreds and even tens of nanometers. Laser is the acronym for Light Amplification by Stimulated Emission Of Radiation, which suggests that it makes use of a phenomenon called stimulated emission, but well, how exactly do they do that? It’s time to look the laser in the eye (Disclaimer: don’t!).
A bunch of people who share a large workshop and meet on a regular basis to do projects and get some input. A place where kids can learn to build robots instead of becoming robots. A little community-driven factory, or just a lair for hackers. The world needs more of these spaces, and every hackerspace, makerspace or fab lab has its very own way of making it work. Nevertheless, when and if problems and challenges show up – they are always the same – almost stereotypically, so avoid some of the pitfalls and make use of the learnings from almost a decade of makerspacing to get it just right. Let’s take a look at just what it takes to get one of these spaces up and running well.
Working with high voltage is like working with high pressure plumbing. You can spring a leak in your plumbing, and of course you fix it. And now that you’ve fixed that leak, you’re able to increase the pressure still more, and sometimes another leak occurs. I’ve had these same experiences but with high voltage wiring. At a high enough voltage, around 30kV or higher, the leak manifests itself as a hissing sound and a corona that appears as a bluish glow of excited ions spraying from the leak. Try to dial up the voltage and the hiss turns into a shriek.
Why do leaks occur in high voltage? I’ve found that the best way to visualize the reason is by visualizing electric fields. Electric fields exist between positive and negative charges and can be pictured as electric field lines (illustrated below on the left.) The denser the electric field lines, the stronger the electric field.
Weak and strong electric fields
Ionization in electric fields
The stronger electric fields are where ionization of the air occurs. As illustrated in the “collision” example on the right above, ionization can happen by a negatively charged electron leaving the electrically conductive surface, which can be a wire or a part of the device, and colliding with a nearby neutral atom turning it into an ion. The collision can result in the electron attaching to the atom, turning the atom into a negatively charged ion, or the collision can knock another electron from the atom, turning the atom into a positively charged ion. In the “stripping off” example illustrated above, the strong electric field can affect things more directly by stripping an electron from the neutral atom, again turning it into a positive ion. And there are other effects as well such as electron avalanches and the photoelectric effect.
In either case, we wanted to keep those electrons in the electrically conductive wires or other surfaces and their loss constitutes a leak in a very real way.
The handheld screw driver is a wonderful tool. We’re often tempted to reach for its beefier replacement, the power drill/driver. But the manually operated screw driver has an extremely direct feedback mechanism; the only person to blame when the screw strips or is over-torqued is you. This is a near-perfect tool and when you pull the right screwdriver from the stone you will truly be the ruler of the fastener universe.
A Bit of Screw Driver History:
The kind of fun you can have with really cheap bits.
In order to buy a good set of screw drivers, it is important to understand the pros and cons of the geometry behind it. With a bit of understanding, it’s possible to look at a screw driver and tell if it was built to turn screws or if it was built to sell cheap.
Screw heads were initially all slotted. This isn’t 100 percent historically accurate, but when it comes to understanding why the set at the big box store contains the drivers it does, it helps. (There were a lot of square headed screws back in the day, we still use them, but not as much.)
Believe it or not the “Robertson” screw came out before the Phillips. Robertson just hated money and didn’t want to license his patents. So it’s only now that they’re in common use again.
Flat head screws could be made with a slitting saw, hack saw, or file. The flat-head screw, at the time, was the cheapest to make and had pretty good torque transfer capabilities. It also needed hand alignment, a careful operator, and would almost certainly strip out and destroy itself when used with a power tool.
These shortcomings along with the arrival of the industrial age brought along many inventions from necessity, the most popular being the Phillips screw head. There were a lot of simultaneous invention going on, and it’s not clear who the first to invent was, or who stole what from who. However, the Philips screw let people on assembly lines turn a screw by hand or with a power tool and succeed most of the time. It had some huge downsides, for example, it would cam out really easily. This was not an original design intent, but the Phillips company said, “to hell with it!” and marketed it as a feature to prevent over-torquing anyway.
The traditional flathead and the Phillips won over pretty much everyone everywhere. Globally, there were some variations on the concept. For example, the Japanese use JST standard or Posidriv screws instead of Philips. These do not cam out and let the user destroy a screw if they desire. Which might show a cultural difference in thinking. That aside, it means that most of the screws intended for a user to turn with a screw driver are going to be flat-headed or Philips regardless of how awful flat headed screws or Philips screws are.
![Different capacitor applications. By Elcap (Own work) [CC0], via Wikimedia Commons](https://hackaday.com/wp-content/uploads/2016/06/capacitors-overlapping-applications.png)
