The Return of the Screen Savers

If you were lucky enough to have cable TV back in 1998, you may remember a fledgling channel called “TechTV.” The crown jewel of the network was a show called “The Screen Savers.” Well, recently the TWiT Network has relaunched the show (without the partnership or permission from the old producers) as “The New Screen Savers” – and it’s almost exactly as we remembered it. The show features tech news, tip and tricks – starring the lovable [Leo Laporte] as the main host.

We’ll assume that most Hackaday readers are at a level of knowledge above what’s generally presented in the show, but we have to admit that we almost always find some little tech tip or software review that we didn’t know about. And if you know someone who is starting to take an interest in all things tech, this might be a great way for them to start learning quickly – and to gain exposure to a wide variety of topics.

If you’re looking for a bit of nostalgia, many of the co-hosts of the old show return regularly. People like [Kevin Rose], [Patrick Norton] and [Sarah Lane]. You can watch the show on the TWiT site or on YouTube. We’ve included the first episode after the break.

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Engauge Makes Graph Thieving a Cinch

We’ve seen ’em before: the charts and graphs in poorly photocopied ’80s datasheets, ancient research papers, or even our college prof’s chalkboard chicken scratch. Sadly, this marvelously plotted data is locked away in a poorly rendered png or textbook graphic. Fortunately, a team of programmers have come the rescue to give us the proper thieving tool to lift that data directly from the source itself, and that tool is Engauge.

Engauge is an open source software tool that enables to convert pictures of plots into the numerical representation of their data. While some of us might still be tracing graphs by hand, Engauge enables us to simply define reference points on the graph, and a clever image-processing algorithm extracts the curve for us automatically! Sure, there’s a little fine-tuning to determine what counts as data, but the net result is an all-in-one software tool that eats pictures and produces data–no intermediate steps required!

Engauge has been helping scientists and engineers preserve ancient data logs for years now, but it’s a tool that’s still fresh today when we’re recording from an analog o’scope or lifting those xs and ys off a textbook. In a world that’s increasingly digital, we’ve got the Engague developers to thank for arming us with the right tool for the job. All that said, If graph-thieving isn’t your thing, try spline-thieving to go from camera to CAD.

Engauge is a little lacking in the demo-video department, but we dug up a quickie on YouTube.

Thanks for the tip, [Jason]!

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Retrotechtacular: Electronic Publishing in the 1930s

We are living in the age of citizen journalism and the 24-hour news cycle. Reports about almost anything newsworthy can be had from many perspectives, both vetted and amateur. Just a few decades ago, people relied on daily newspapers, radio, and word of mouth for their news. On the brink of the television age, several radio stations in the United States participated in an experiment to broadcast news over radio waves. But this was no ordinary transmission. At the other end, a new type of receiver printed out news stories, line drawings, and pictures on a long roll of paper.

Radio facsimile newspaper technology was introduced to the public at the 1939 World’s Fair at two different booths. One belonged to an inventor named William Finch, and one to RCA. Finch had recently made a name for himself with his talking newspaper, which embedded audio into a standard newspaper in the form of wavy lines along the edges that were read by a special device.

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Finally, a Working Lightsaber!

Just in time for the movie of the decade, [Allen] from [Sufficiently Advanced] has built a real working fire-based light saber. And it’s awesome.

He started out with a replica light saber and designed his own 3D printed enclosure to house a small tank with a syringe valve that goes inside the handle. This allows him to fuel it with a mixture of methanol and acetone, using butane as a propellant. He learned how to do this from [Tesla Down Under], who has some fantastic projects — most notably, flamethrowers.

A nichrome coil provides ignition for the flame, and after he got the pressure just right, it produces a pretty awesome, albeit skinny, flame-saber.

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Neil Movva: Adding (wearable) Haptic Feedback to Your Project

[Neil Movva] is not your average college student. Rather than studying for exams or preparing to defend a dissertation, he’s working on a project that will directly help the disabled. The project is Pathfinder, a wearable haptic navigation system for the blind. Pathfinder is an ambitious project, making it all the way to the semifinals of the 2015 Hackaday Prize. Haptics, the technology of providing feedback to a user through touch, lies at the core of Pathfinder. [Neil] was kind enough to present this talk about it at the Hackaday SuperConference.

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Calculus is not Hard – The Derivative

The Calculus is made up of a few basic principles that anyone can understand. If looked at in the right way, it’s easy to apply these principles to the world around you and to see how the real world works in their terms. Of the two main ideas of The Calculus — the derivative and the integral — today we’ll focus on the derivative.

You can enjoy this article by itself, but it is also worth looking back at the previous installment in this series. We went over the history of The Calculus and saw how it arose from two paradoxes put forth by a 4th century philosopher named Zeno of Elea. These paradoxes lead to the derivative/integral ideas that revolutionized mankind’s understanding of motion.

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Let’s Blow Up an Explosive Lightning Arrestor

Lightning is some nasty stuff. Luckily, it doesn’t have a very long lifespan. [BigClive] decided to tear down an 11KV lighting arrestor used in power distribution systems. The fiberglass core has silicone rubber water-shedding disks that make the unit look sort of floppy, but inside is some serious hardware.

To protect the circuit, metal oxide varistors shunt high voltage from a lightning strike to ground as you’d expect. The interesting part is how the device deals with failure. It would be a disaster if the device shorted the 11KV power line to ground for any length of time due to a fault. To prevent that problem, a resistor heats up when struck by lightning and triggers an explosive charge that disconnects the ground wire and releases a flag to indicate the failure.

[BigClive] triggered the charge in the video below. So if you like to see things explode in a bucket of water, you’ll enjoy the video.

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