Magnetic Levitation with Arduino

Getting a magnetic field to balance on another magnetic field is about as easy as balancing a bowling ball on the tip of an ink pen. With a little help from an Arduino mega, however, [EmmaSong] was able to balance a high density neodymium magnet in midair. He pulled off this tricky project using a set of four coils he got off of Taobao (the Chinese version of eBay), a hall effect sensor, and a handful of current regulation ICs.

The coils can be made in house if necessary, with each winding getting about 800 turns of enameled wire. The rest of the circuit is straightforward. It appears he uses a potentiometer for a rough regulation of the current going to the coils, doing the fine tuning in the code which can be found here (.RAR direct download).

We’ve seen magnetic levitation here before, and this project adds to the list of successful techniques to accomplish this difficult project.

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Thor’s Hammer Build Recognizes Its Master’s Hand

electromagnetic-thors-hammerOnly those who have completely insulated themselves from modern pop culture will miss the meaning of a Mjolnir build. It is, of course, the mythical hammer wielded by Thor, and only Thor. It’s a question of being worthy; a question solved perfectly by this electromagnetic Mjolnir build.

Using an electromagnet is smart, right? Just plunk the thing down on something metal (that is itself super-heavy or well-anchored) and nobody will be able to pick it up. It starts to get more interesting when you add a fingerprint reader, allowing only Mjolnir’s Master to retrieve it from atop a manhole cover.

But for us the real genius in the build is that the hammer isn’t burning power from the four 12V batteries most of the time. All of the people in the video below could have picked up the hammer had they first nudged it off the metal plate with their foot. The build uses a capacitive touch-sensor to enable and disable the microwave over transformer used as the electromagnet. An engineering trick like this really separates the gods from the posers.

We hate to admit it, but this is probably a cooler build than the Telsa-Coil powered Mjolin that [Caleb] built a few years back. Still, his held up as the best for many years, and if you’re going to be displaced this really is a build worthy of the new title: coolest Mjolnir hack.

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Ferrofluid Clock is a Work of Art

It is not usually too difficult to separate functionality from art. Consider a clock. It’s a machine that has a clear and distinct function. It provides information. Nothing could be more different from a clock on a wall than a piece of artwork.  A painting, for instance has no clear function and provides no information. It’s just…art. It’s nice to look at. If we were to ask you to build a functioning, information providing clock that is also a piece of artwork, you would surely have your hands full. Where would you even start? If your name was [Zelf Koelma], you’d grab a bottle of ferrofluid and build us a beautiful, almost mesmerizing clock.

clock_01There’s little to no information on the details of how the clock works other than the use of ferrofluid. But it’s not hard to guess that it uses dozens of electromagnets and an Arduino. You can even pick one up for a cool $8,300 if you’re lucky enough to get a spot on the list, as he’s only making 24 of them.

Want to make one of your own? Pick up some ferrofluid and keep us updated. We’d love to hear from you in the comments on how you’d implement a build like this one. We had a fun time hearing your ideas when we covered the clock made of clocks.

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Retrotechtacular: Building Hammond Organ Tones

Here’s a short film made by the Hammond Organ Company with the intent to educate and persuade potential consumers. Right away we are assured that Hammond organs are the cream of the crop for two simple reasons: the tone generator that gives them that unique Hammond sound, and the great care taken at every step of their construction.

Hammond organs have ninety-one individual electromagnetic tone wheel assemblies. Each of these generate a specific frequency based on the waviness of a spinning disk’s edge and the speed at which it is rotated in front of an electromagnet. By using the drawbars to stack up harmonics, an organist can build lush walls of sound.

No cost is spared in Hammond’s tireless pursuit of excellence. All transformers are wound in-house and then sealed in wax to make them impervious to moisture. Each tone wheel is cut to exacting tolerances, cross-checked, and verified by an audio specialist. The assembly and fine tuning of the tone generators is so carefully performed that Hammond alleges they’ll never need tuning again.

This level of attention isn’t limited to the guts of the instrument. No, the cabinetry department is just as meticulous. Only the highest-quality lumber is carefully dried, cut, sanded, and lacquered by hand, then rubbed to a high shine. Before it leaves the shop, every Hammond organ is subject to rigorous inspection and a performance test in a soundproofed room.

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Switchable Magnet with a Simple Circuit

Magnets are awesome. Electromagnets are even cooler. But what if you could make a semi-permanent switchable magnet that acts like an electromagnet, but doesn’t use any energy to hold metal? You’re going to want to take a look at this Low-power Magnetic Hold and Release Mechanism.

It’s actually a very simple concept. It is basically an electromagnet attached to a permanent magnet — it’ll hold any metal object exactly as you’d expect — but if you run current through the inductor attached to it, the magnetic field created by the electricity will temporarily cancel out the field of the magnet — thus freeing your object being held. Since gravity is pretty fast acting, this impulse of current doesn’t need to be very long, only fractions of a second.

Now the real question is how big could you go? We covered another project a while ago called Open Grab which discusses the possibility of using technology like this in Quadcopters.

For a solution that uses no power at all take a look at switchable magnet clamps used for welding — they’re pretty cool — but patent protected of course.

[Amazing Science’s] Simple Electric Train

Making an electromagnet is as simple as wrapping some wire around a nail and taping the wire to both ends of a battery. When you’re done, you can pick up some paper clips – it demonstrates the concept well, but it could use some more oomph. [Amazing Science] has done just that, making an “electric train” (YouTube link). All that’s needed is some coiled copper wire, a battery and magnets thin enough to fit through the coils. The magnets snap onto both ends of the battery. Put the battery inside the coil and watch the fun! The electromagnetic force generated by the current moving through the coil pushes against the magnets attached to the battery, pushing the battery along the way.

[Amazing Science] plays with the setup a bit. Connect both ends of the coil together and the battery will travel in a loop until it’s drained. Add a small hill, or even another battery/magnet set to the mix, and watch them go! We may even make a version of this ourselves to take with us to family gatherings this holiday season – it’s simple, fun, and can teach the young ‘uns about science while we swig some egg nog.

[via Reddit]

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Using MIDI and Magnets to Produce Tones with Tines

Normally you’d expect the sound of a pipe organ to come from something gigantic. [Matthew Steinke] managed to squeeze all of that rich melodic depth into an acoustic device the size of a toaster (YouTube link) which uses electromagnetism to create its familiar sound.

[Matthew ’s] instrument has a series of thin vertical tines, each coupled with a small MIDI controlled electromagnet. As the magnet pulses with modulation at a specific frequency, the pull and release of the tine causes it to resonate continuously with a particular tone. The Tine Organ is capable of producing 20 chromatic notes in full polyphony starting in middle C and can be used as an attachment to a standard keyboard or a synthesizer app on a smart phone. The classic style body of the instrument is made out of mahogany and babinga and houses the soundboard as well as the mini microcontroller responsible for receiving the MIDI and regulating the software oscillators sending voltage to the magnets.

[Matthew’s] creation is as interesting to look at as it is to listen to, so I’d recommend checking out the video below to hear the awesome sound it produces:

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