Building a model windmill can be a great, cheap and simple way to show kids how wind energy can be used to power anything electrical. A standard industrial wind turbine generates electricity when wind hits a propeller blades, turning an attached rotor. The rotor is attached to a shaft that spins a generator, making electricity. Any model wind turbine must also have these components: propeller blades, a rotor and a generator.
Making the Turbine
If the bulb is glowing dimly, the generator is producing less than 1.5 volts and needs to spin faster. A digital multimeter can be used to measure the true voltage being put out by the wind turbine. Computer fan motors are designed to work at relatively low rotational speeds and may be a better choice than a small DC motor; however, some of these motors are brushless and won’t work in the wind turbine.
Remove the bladed disc from your desk fan by taking apart the fan with a screwdriver. This will serve as the propeller blades for the turbine.
Adhere the shaft from motor to the rotational center of the bladed disc from the fan, using superglue. This setup will serve as the propeller blades, rotor and generator. The DC motor can function as a generator, since it has the magnets and wire coil arrangement found in standard generators.
Secure the motor to the microphone stand with duct tape in a way that allows the propeller blades of the turbine to rotate freely.
Wire the turbine to the LED bulb, using the alligator clip leads if necessary, completing the electrical circuit. The wind turbine is now ready to provide electricity to the tiny bulb with the first gust of wind.
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