I just received an email from my chum Rick Curl. A couple of days ago I sent Rick a link to a video showing a battery-fan/motor-switch circuit in which the fan remained stationary but the AA battery spun around its long axis in its holder.

In Rick’s message to me, he said, “You sent me down a rabbit hole on this one. While this video is obviously fake, these are not…” Rick then proceeded to send me down my own rabbit hole with the following videos.

One of the comments to the first video says: “In 5 years when my daughter informs me of her science fair 2 days prior, we’ll do this.” This caused me to immediately email the link to this video to my next door neighbor because he has three young daughters for whom this would make a perfect project.

The notes accompanying the first video confused me by saying, “Another important point is the magnet directions: NS Battery SN.” I found this counter-intuitive. I would have expected NS Battery NS or SN Battery SN. But the creator was correct. Things are much clearer in the second video, while the third video provides details on how to form the coil and other stuff.

The trick here is that the copper wire forming the coil is uninsulated and the magnets are slightly wider than the battery, thereby forming a coil-magnet-battery-magnet-coil circuit loop.

One thing I’m left wondering is what is the resistance of the magnets. And, since we are effectively short-circuiting the battery, what is the current? I’d be interested to see how hot the battery gets and how long it lasts before (a) draining to zero or (b) catching fire.

Of course, now I want to build one of these myself. How about you? Could you be tempted to dip your toes in the electric train waters?