electromagnets

7 Articles

Interactive Project Teaches Lessons About Electromagnets And Waves

October 4, 2024 by 3 Comments

Whether you’re a kid or a nerdy adult, you’ll probably agree that the interactive exhibitions at the museum are the best. If you happened to get down to the Oregon Science Festival in the last couple of years, you might have enjoyed “Catch The Wave!”—a public education project to teach people about electromagnets and waves. Even better, [Justin Miller] has written up how he built this exciting project.

Catch The Wave! consists of four small tabletop cabinets. Each has physical controls and a screen, and each plays its role in teaching a lesson about electromagnets and sound waves, with a context of audio recording and playback.

The first station allows the user to power up an electromagnet and interact with it using paper clips. They can also see the effect it has on a nearby compass. The second illustrates how reversing current through an electromagnet can reverse its polarity, and demonstrates this by using it to swing a pendulum. The third station then ties this to the action of a speaker, which is effectively a fancy electromagnet—and demonstrates how it creates sound waves in this way. Finally, the fourth station demonstrates the use of a microphone to record a voice, and throws in some wacky effects for good fun.

If you’ve ever tried to explain how sound is recorded and reproduced, you’d probably have loved to had tools like these to do so. We love a good educational project around these parts, too.

Both Explanation And Build For This Artwork Are Beautiful

January 15, 2019 by 19 Comments

Sometimes you encounter projects that defy description, as is the case with this one. So perhaps it’s best to start with what this project is NOT. It is not a sphere. It is not a perpetual energy device. It has neither a sloppy build nor a slapdash video. This IS a motorized rhombicuboctahedron that is a well-explained with high-quality parts and loving attention to detail by [Wolfram Glatthar]. At its heart is an exercise in building a moving device with the barest minimum of friction. Without no grinding in the mechanism, the electronics will probably wear out first. Low friction also means low power consumption, and an hour of sunlight can run the device for two-and-a-half days. Take a look at the video below the break.

Along the sides are a balancing ring with threaded screw sockets and the load-bearing magnets which suspend the bulk of the rhombicuboctahedron using repulsion. Everything is stabilized by a ceramic sphere touching a sapphire glass plate for a single point of contact between some seriously tough materials. The clear sapphire furthers the illusion that everything is floating, but genuine magnetic suspension would require much more power.

Acoustic levitation cannot be forgotten as another powered source of floating or you can cheat and use strobe light trickery.

Continue reading “Both Explanation And Build For This Artwork Are Beautiful” →

You May Have A Nixie Tube Clock, But Can Yours Levitate?

July 31, 2016 by 19 Comments

Nixie tubes, electromagnets, levitation, and microcontrollers — this project has “Hackaday” written all over it!

Time Flies: Levitating Nixie Clock comes from [Tony Adams], and uses a lot of technology we’ve seen before, but in a new and interesting way. A nixie tube clock is nothing new, but using electromagnets to levitate it above a base certainly paired with inductive coupling to transmit power using no wires make this floating nixie build a real treat.

Continue reading “You May Have A Nixie Tube Clock, But Can Yours Levitate?” →

Captain America’s Mighty Shield With 7200N Of Powerful Electromagnets!

May 13, 2016 by 57 Comments

At Hackaday, sometimes we nerd out a bit too hard over comic book movies. With Captain America: Civil War in theaters, I knew I had to do a project dedicated to the movie — so I made a ridiculously over powered electromagnet bracer. The hope? To attract a Captain America replica shield from short distances.

electromagnet bracerI had the idea for this project a while ago after watching Avengers: Age of Ultron.

If you’re not familiar, it appears Captain America gets a suit upgrade (presumably from Stark himself) that features some pretty awesome embedded electromagnets allowing him to call his shield back to him from afar.

Now unfortunately, electromagnets aren’t that strong and I knew I wouldn’t be able to achieve quite the same effect as good ol’ CGI — but I’d be darned not to try!  Continue reading “Captain America’s Mighty Shield With 7200N Of Powerful Electromagnets!” →

Choreographed Iron Dust Dances To The Beat

September 23, 2014 by 6 Comments

Up on the second level of World Maker Faire’s main hall, one could hear Technotronic’s hit “Pump up the Jam” playing again and again. We were expecting breakdancing robots, but upon investigating, what we found was something even better. [David Durlach] was showing off his Choreographed Iron Dust, a 9 x 9 grid of magnets covered in iron filings. The filings swayed and danced to the beat of the music, at times appearing more like ferrofluid than a dry material. Two LED lights shined on the filings from an oblique angle. This added even more drama to the effect as the light played on the dancing spikes and ridges.

While chatting with [David] he told us that this wasn’t a new hack. Choreographed Iron Dust made its debut at the Boston Museum of Science back in 1989. Suddenly the 80’s music made more sense! The dust’s basic control system hasn’t changed very much since the 1980’s. The magnets are actually a stack of permanent and electromagnets. The permanent magnet provides enough force to hold the filings in place. The electromagnets are switched on to make the filings actually dance.

Since it was designed in 1989, there were no Arduinos available. This project is powered by the most hacker friendly interface of the era: the PC’s parallel port. As one might imagine, [David] has been having a hard time finding PC’s equipped with parallel ports these last few years.

[David] wasn’t just showing off iron dust. Having spent so much time painstakingly animating the iron filings for various customers, he knew there had to be a better way. He’s come up with ChoreoV, a system which can take recorded video, live performances, or even capture a section of a user’s screen. The captured data can then be translated directly into light or motion on an art piece.