Charge your mobile by swinging

The Dutch will never stop to impress me with their ingenuity.

Being sustainable is now trending in Europe—and in Holland in particular. So in June 2019 my client, NS, has installed a special kind of swing at the Utrecht Centraal railway station.

This new attraction was presented during the “Sustainability Week” (Duurzame Week), and it can charge your mobile phone!

The three-swing installation was initially mounted on the ground floor of the station. It has been later moved to the first floor, where you can also find it today.

How does it work?

Technically, the device is pretty straightforward. Anyone can inspect its internals through the glass cover.

The mechanical energy of swinging is spinning the generator’s shaft:

The generator is charging a bulky 1 F capacitor, which looks very much like those used in the power chain of car subwoofers.

Further down the road you’ll apparently find a 5-volt power regulator, whose output is connected to USB Type C and Lightning plugs:

As soon as the user starts swinging, the phone charger box gets lit with green light:

Nice idea, but…

The point is the charging is excruciatingly slow. After five minutes of eager swinging we didn’t even manage to get the phone juiced up a single percent. Perhaps we needed to swing even more eagerly but that would turn it into a slightly different attraction.

Apart from its low energy output, I’m a bit confused by the thought you’ll never find out what’s on the other side of the charging cable. Can it be some obscure device that installs a backdoor on your mobile? Or, say, a USB Killer? The latter is really a piece of cake in such a setup.

By the way, there’s a sticker inside the box saying “Use it at your own risk”.

Anyway, I believe it’s a valid idea. We for one could harvest a few kilowatt-hours a day from our little daughter, we just need to find a way to turn her endless supply of energy into electricity. ■