Eddy Current Braking on a Kitchen Work-Top

Kitchen-Top Science
These are all normal speed videos. For the final report graphs I sped the camera up to 240 frames per second and slid the neodymium magnets on a covering sheet of paper to avoid surface friction differences. I also used tracking software to automatically extract position data from the videos.

Listed in terms of sliding speed, fastest first: Perspex, Stainless Steel 316, Brass, Aluminium, Copper. Copper has the highest electrical conductivity. All the items appear in the list ordered by their conductivity, least conductive first.

But when you send the magnet down long-side horizontal it slides much slower than with the long side vertical!

(Don’t let very young children near neodymium super-magnets. One swallowed magnet is not good, but two swallowed magnets can lead to surgery or death.)

If you want to see the full Eddy Current Braking experiment write-up it's here

Video editing: VSDC free video editor 2.2.2.323 (which crashed, losing all unsaved work, at least 6 times)

[maurosobreira]

Nice video. By the way, if you take the time to go through your book Analog SEEKrets and disclose bits of information on design that are already there, just talking/teaching, I bet you will have a lot of viewers, but better than that, you will help a lot of people. Cheers.

[kmottershead]

Great video. I had always heard that copper was the best material for an eddy current brake. It looks from your demonstration that it is only slightly superior to aluminum.