I once posted about a torch that is powered by a shake. It’s quite handy because you’ll get an unlimited power source. It implements Faraday’s Law of Induction and uses combination of kinetic energy and induction to transform the shakes into energy. Gadgets.Co.Uk is currently selling a calculator that uses the same principle. Named Shake-U-Later, you have to shake the calculator first before you can use it.

Every 25 shakes from side to side generates enough energy for 10 minutes of mathematical calculation. The calculator costs around $15.

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