PossessedHand controls hand with electrical stimuli

[Emi Tamaki], [Miyaki Takashi] and [Jun Rekimoto] at the University of Tokyo came up with a device called the PossessedHand that electrically stimulates muscles to train someone to play a the koto, a Japanese stringed instrument.

The PossessedHand ‘triggers’ individual fingers with precisely placed electrodes. Sixteen joints in the hand can be controlled independently by placing one electrode on the muscle that controls the joint and a ground electrode on the tendon of that muscle. Users of the PossessedHand reported no pain from the device when 30 Volts were sent though the electrodes.

The paper (PDF warning) goes into detail about the reactions of the users of the PossessedHand. While a few subjects thought the PossessedHand was scary, many enjoyed it – one subject even thought it was possible to fly a helicopter without training. While this isn’t downloading a rotary wing licence into your brain like The Matrix, the PossessedHand did prove to be a useful tool for learning the fingering for the koto. You can see a video of the PossessedHand in action in the New Scientist story.

[via New Scientist]

Electronics lessons for beginners

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Hackaday reader [grenadier] wrote in to share a series of tutorials he is working on, where he discusses the basics of electricity and electronics. The first lesson titled, What is Electricity?” has been wrapped up, and is available for free on his site.

For any of our regular readers, the lesson will seem pretty basic (and likely full of things to nitpick). However, we imagine his lessons would be quite helpful to anyone looking to expand their electronics know-how.

Now don’t get us wrong, we love the series of electronics tutorials that Jeri has been periodically releasing, but we think there’s plenty of room on the Internet for other willing teachers as well. If his first lesson is any indicator, his tutorials will be easy to understand, sprinkled with a little bit of humor, and chock full of fun videos that demonstrate the subject at hand.

Take a quick look his way if you get a chance – you or someone you know might find his tutorials and reference guides insightful.

[Image courtesy of Electronicsandyou]

Million volt guitar rocks the house…for science!

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[Bill Porter] and his friend [Dan Flisek] work together to put on a science-related educational stage show called “Science Brothers”, in which the pair try to convince school children that their field of expertise is the cooler science. While the two are competitive on stage, the main goal of the program is to get kids interested in science, no matter what the specialty.

The pair currently finance the project out of pocket, so they are always looking for ways to make things interesting while also keeping costs in check. With that in mind [Bill] came up with an awesome way to show off the Tesla coil he built a while back. His most recent educational creation is a little something he calls “Tesla Hero”.

Since he already had a solid state Tesla coil hanging around, he dug up a PS2 Guitar Hero controller and got busy getting the two acquainted. The guitar connects to the coil via a fiber optic isolator board, playing one of five notes as he strums along. A series of Arduino-driven LED strips adorn the guitar, flashing various colors while he plays, as you can see in the video below.

It’s quite a cool project, and we’re sure that his audience will be impressed!

Stick around to see a video of  Tesla Hero in action, and if you’re interested in learning more about the Science Brothers, be sure to check them out here.

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Monitor your home’s power usage on the cheap

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[Paul] was pretty sure that he and his family used a lot of electricity throughout the day. Admittedly, he enjoys his creature comforts, but was wiling to try living a little greener. The problem was, he had no idea how much electricity he was using at a given time.

While some power companies offer devices allowing homeowners to monitor their energy usage, [Paul’s] did not. After a bit of research however, he was ready to build a power monitoring system of his own. He found that his meter emits a small infrared pulse every time a watt-hour of electricity is consumed, so his system counts how many flashes occur to measure usage.

The counting circuit is pretty simple consisting of only an AVR, a resistor, a capacitor, and a phototransistor. The data is fed to a computer where the results are graphed with gnuplot.

It’s quite a useful little hack, and undoubtedly far cheaper than purchasing a whole house power monitor.

High voltage rig wipes CDs clean

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Here at Hackaday, we’re not against showing videos of gratuitous destruction just for the sake of it, though we try not to make it a habit. In this case we just couldn’t help ourselves. However, this video technically constitutes a security hack, as it does involve erasing sensitive information from CDs…

…with awesome!

This may be the coolest CD eraser we’ve seen yet. Positioned between two high-voltage transformers, the spinning CD has its data violently stripped off in just a matter of seconds. To be fair, the data isn’t erased per se, but the metallic substrate on which the data is recorded is flaked off by the aggressive application of electricity.

Having destroyed our fair share of AOL CDs in the microwave over the years, we are now a bit sad over the fact that they were disposed of in such a lackluster fashion – if only we had one of these around!

Since we’re on the topic of mindless destruction, you might as well take a few minutes and check out this thermite-roasted Thanksgiving turkey, this self-destructing hard drive, or perhaps this thermic lance built from spaghetti.

You know, for science.

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Musical Tesla concert is electrifying

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Hackaday reader [Tyler Laseter] wrote in to tell us about an event that he and his fellow Tesla Orchestra team members are hosting next month.

The “Open Spark Project” is a concert event taking place on May 14th, which melds together electricity and music in spectacular fashion. The event features two large Tesla coils which are tuned to play musical notes while shooting bolts of electricity through the air.

Musical Tesla coils are nothing new around here, but we have yet to see someone allow the general public to play music on their coils. That’s what makes this event unique – anyone is encouraged to submit their to the Tesla Orchestra team, which will then be played back via a live video stream next month. Their web site offers up all of the technical details as well as the file format requirements for submitting music for the event, so get started on your entry today!

If a passive approach is more your style, stick around for a quick video demonstrating their coils’ abilities. Sure it’s Lady Gaga, but we won’t tell anyone you watched it. Plus, it’s totally legit when the song is being played using 20,000 volts.

Continue reading “Musical Tesla concert is electrifying”

Dead motor? Think again

While hobby brush motors are pretty cheap now adays, there’s always that feeling of why replace when you can rebuild and reuse. As such [John Carr] presents how to change the brush position in motors to revive a dead motor. So long as the motor dies from natural causes commutator wear, the idea is the brushes can be moved along the axes and fixed to a new portion of commutator that’s not worn at all. [John] also goes through the details of some tricky reassembly, but we think to make this complete a guide on brush replacement and commutator replacement might be in order hint hint.