Showing 32 posts tagged electricity

Generate your own electricity with some wire, a magnetic field, and the relative movement between the two of them: Alom Shaha explains electromagnetic induction using this hand-powered – or perhaps more accurately, bacon-sandwich-powered – generator.

Related watching: magnetic fields, probably one of the more awe-inducing subjects on this blog.

via Science Demo.

From PBS’ Adventures in Learning, Jennifer Cooper hosts an Electric Dough playdate to make and test circuits. For this project, developed by engineering educator AnnMarie Thomas, you’ll need homemade conductive play dough and insulating play dough, a battery pack, batteries (we highly recommend these rechargeables), and light emitting diodes/LEDS. Click here for the how-to details.

Related hands-on projects: LED Origami and Sick Science! Build a Lightbulb. Bonus: Circuit Playground’s A is for Ampere.

This is the battery-powered VC200 “volocopter,” a state-of-the-art helicopter prototype by engineers at German start-up e-volo. From Smithsonian Mag

In the coming year, engineers will continue working on the prototype, which the company boasts will be lighter, safer, quieter and greener than any other helicopter in the world.

That’s because a traditional helicopter uses one rotor to provide lift and a tail rotor to prevent the aircraft from spinning in circles. It maneuvers by changing the pitch of the two rotors. The volocopter has 18 small rotors mounted in a configuration that provides lift without causing the vehicle to spin. It navigates by changing the speed of individual rotors.

e-volo also invented this previously-featured, e-powered multicopter. Related watching: more helicopters, including human-powered ones.

There are quite a few neodymium magnets falling through copper pipes on the internet, but we can still understand why this demonstration video is making the rounds: it’s just so cool looking! We’ve covered the phenomenon of magnetic damping before:

When a magnetic field moves through a conductor a current called an Eddy current is induced in the conductor due to the magnetic field’s movement. The flow of electrons in the conductor creates an opposing magnetic field to the magnet which results in damping of the magnet and causes heating inside of the conductor similar to heat buildup inside of power cords. The loss of energy used to heat up the conductor is equal to the loss of kinetic energy by the magnet.

And a note of caution if you decide to try this, these magnets are not for unsupervised children. In fact, everyone should be careful: 

Neodymium magnets larger than a half inch are very strong and should be handled with extreme care since they can be dangerous. It is best to stick with neodymium magnets of quarter inch diameter or less.

Want to know more? Look up Lenz’s Law and watch Veritasium’s Derek Muller demonstrate how this phenomenon is related to English scientist Michael Faraday and the first electric generator, created with a magnet and a coil of wire in 1831:

Physics! Another must-watch magnet-doing-magic-like-things-video comes from the Ri Channel: Levitating Superconductor on a Möbius strip

Seen at science museums, maker faires, and all over the internet, Singing Tesla Coils combine science and music in the most fantastical and memorable of ways. But how do they work? From Physics Buzz

Sound waves are vibrations of the air around us, which you can make just by clapping your hands or talking. Pitch is just the number of times the air vibrates per second. Higher frequency, higher pitch. Tesla coils are a combination of circuits that output thousands to millions of volts. That high electric field arcs up and out of the coil, filling the air with sparks and making it possible to light up fluorescent lights wirelessly. Certain types of Tesla coils, like the one used here, are putting out hundreds of sparks per second, with a rest between each spark. That’s already a lot like a sound wave. Each spark is pushing on the air and can create a sound. Change the frequency of the sparks and you get an equal frequency wave, hitting your ears like a note of music. The creators had to find a way to move seamlessly between frequencies to make the notes sound distinct, instead of just playing the whole scale.

Above, tesla coils “sing” the Inspector Gadget theme by ArcAttack, who were the first to use this technology in a live performance in late 2005. Watch more singing tesla coil videos at Know Your Meme. Related links: the tesla coil and Nikola Tesla, who invented it around 1891.

In the archives: more electricity, more instruments, and things that glow.

Thanks, @bittelmethis.