How to Make a Potato Clock

    by eHow Contributor

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    Don't be shocked, but the next time you order "fries with that," you'll be eating nature's veritable battery. Potatoes can function as an electrolyte and provide the minimal voltage necessary to power a simple LED clock.

    Things You'll Need

    • 2 Drywall Nails
    • 3 Alligator Clips
    • Copper Wire
    • Galvanized Nails
    • 2 baking potatoes

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    Assemble your supplies. You'll need two common galvanized nails; three alligator clip/wire units - that is, alligator clips connected to one another with wire; two short pieces of heavy copper wire; a simple low-voltage LED clock unit; and two potatoes. Obtain a simple LED clock unit that functions from the power of a 1- to 2-volt, button-type battery.

    Open the battery compartment and remove the battery.

    Note that there is a positive (+) and a negative (-) terminal point where the battery was installed.

    Identify the potatoes as number one and number two.

    Insert one nail in each potato.

    Insert one short piece of heavy copper wire in each potato, placing it as far from the nail as possible.

    Use one alligator clip/wire to connect the copper wire inserted in potato one to the positive terminal in the clock unit.

    Use one alligator clip/wire to link the nail in potato two to the negative terminal in the clock unit.

    Use the final alligator clip/wire to link the nail in potato one to the copper wire in potato two.

    Set your clock.

    • Experiment with bananas, lemons or even a carbonated cola drink as a power source.
    • Some hobby shops have all the necessary materials - except the potatoes - in a simple kit.
    • Experiment by using copper pennies for the copper electrode.
    • Kids will have fun learning what other simple low-voltage devices - like an old computer case fan - can be powered by a potato battery.
    • Make certain the nails you choose are galvanized. The "battery" chemical component requires the zinc used in galvanizing.