Author Archives: Steven Dufresne

Wimshurst Machines: High Voltage from the Gods

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The Wimshurst machine is one of the oldest and best known electrostatic machines, consisting of its iconic two counter rotating disks and two Leyden jars. Most often you see someone hand cranking it, producing sparks, though we’ve seen it used for much more, including for powering a smoke precipitator for cleaning up smoke and even for powering a laser.

It works through an interesting sequence of events. Most explanations attempt to cram it all into one picture, requiring some major mental gymnastics to visualize. This often means people give up, resigned to assume these work through some mythical mechanics that …read more

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3D Printing Using Holograms is Actually Printing in 3D

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It’s the year 2260 and you’re being beamed from your starship to the planet below. Being a descendant of present day 3D printers, the transporter prints you out, slowly making one layer before moving on to the next, going from the ground up. The you-that-was hopes nothing spills out before you’re done. But what if you could print every atom in your body at the same time? If those transporters are descendant’s of Daqri’s holographic 3D printing technology then that’s just what will happen.

Daqri’s process is akin to SLA (stereolithography) and SLA/DLP (digital light processing). In SLA, a laser …read more

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MicroVox Puts the 80’s Back into Your Computer’s Voice

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[Monta Elkins] got it in his mind that he wanted to try out an old-style speech synthesizer with the SC-01 (or SC-01A) chip, one that uses phonemes to produce speech. After searching online he found a MicroVox text-to-speech synthesizer from the 1980s based around the chip, and after putting together a makeshift serial cable, he connected it up to an Arduino Uno and tried it out. It has that 8-bit artificial voice that many of us remember fondly and is fairly understandable.

The SC-01, and then the SC-01A, were made by Votrax International, Inc. In addition to the MicroVox, the …read more

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How A Van De Graaff Generator Works

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What I particularly like about the Van de Graaff (or VDG) is that it’s a combination of a few discrete scientific principles and some mechanically produced current, making it an interesting study. For example, did you know that its voltage is limited mostly by the diameter and curvature of the dome? That’s why a handheld one is harmless but you want to avoid getting zapped by one with a 15″ diameter dome. What follows is a journey through the workings of this interesting high voltage generator.

The Big Picture

The big picture in terms of how a Van de Graaff …read more

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MotorMouth For Future Artificial Humans

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When our new computer overlord arrives it’ll likely give orders using an electromagnetic speaker (or more likely, by texting instead of talking). But for a merely artificial human being, shouldn’t we use an artificial mouth with vocal chords, nasal cavity, tongue,  teeth and lips? Work on such a thing is scarce these days, but [Martin Riches] developed a delightful one called MotorMouth between 1996 and 1999.

It’s delightful for its use of a Z80 processor and assembly language, things many of us remember fondly, as well as its transparent side panel, allowing us to see the workings in action. As …read more

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Using a Lecher Line To Measure High Frequency

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How do you test the oscillator circuit you just made that runs between 200MHz and 380MHz if all you have is a 100MHz oscilloscope, a few multimeters and a DC power supply? One answer is to put away the oscilloscope and use the rest along with a length of wire instead. Form the wire into a Lecher line.

That’s just what I did when I wanted to test my oscillator circuit based around the Mini-Circuits POS-400+ voltage controlled oscillator chip (PDF). I wasn’t going for precision, just verification that the chip works and that my circuit can adjust the frequency. …read more

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Faking TV Remote Control with Paper and a Lighter

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Cut slots into a piece of paper to represent the IR remote control bitstream for putting your TV into standby. Insert it between your TV’s IR receiver and the flame from a lighter, and pull the slots along to generate the coded pattern. Get it just right and you have a paper and lighter remote control. That’s just what [ViralVideoLab] did and you can see it in action in the video below.

Think of this as just the germ of an idea. Imagine how you’d automate this and extend it to include more commands. A wheel with the various bitstreams …read more

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Motion Detecting Camera Recognizes Humans Using The Cloud

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[Mark West] and his wife had a problem, they’d been getting unwanted guests in their garden. Mark’s solution was to come up with a motion activated security camera system that emails him when a human moves in the garden. That’s right, only a human. And to make things more interesting from a technical standpoint, he does much of the processing in the cloud. He sends the cloud a photo with something moving in it, and he’s sent an email only if it has a human in it.

[Mark]’s first iteration, described very well on his website, involved putting together all …read more

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Motion Detecting Camera Recognizes Humans Using The Cloud

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[Mark West] and his wife had a problem, they’d been getting unwanted guests in their garden. Mark’s solution was to come up with a motion activated security camera system that emails him when a human moves in the garden. That’s right, only a human. And to make things more interesting from a technical standpoint, he does much of the processing in the cloud. He sends the cloud a photo with something moving in it, and he’s sent an email only if it has a human in it.

[Mark]’s first iteration, described very well on his website, involved putting together all …read more

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Self-Lacing LEGO Power Shoe

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Here’s a blast from the past, or future, reminiscent of the self-lacing shoes from Back to the Future Part II. [Vimal Patel] made his own self-lacing shoe using LEGO “bolted” to the shoe’s sole. We think these are cooler than the movie version since we get to see the mechanism in action, urging it on as the motor gets loaded down pulling the laces for that last little bit of tightness.

The electronics are all LEGO’s Power Functions parts. A Dremel was used to make holes in the soles to hot glue LEGO pieces for four attachment points. The attachment …read more

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