Build a Wind Turbine

Build a Wind Turbine

Step 1 of 7:

Here's the Materials You'll Need:

Three PVC pipes, one about 30 cm long and the others at least 15 cm long
Three PVC T-joints
One PVC elbow joint
Motor
Wire (about two feet long)
Wire cutters
Hub (available from Kid Wind Project)
Wood dowels
Multimeter
Alligator clips
Scissors
Tape
Hair dryer or fan
Materials for blades, such as balsa wood, aluminum foil, construction paper, popsicle sticks, etc.

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Step 2 of 7:

Insert a 15-cm PVC pipe into the middle hole of a PVC T-joint. Repeat with another 15-cm PVC pipe and T-joint. Join the two pieces together by inserting the free ends of the pipes into the sides of a third T-joint, with the middle hole facing up.

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Step 3 of 7:

Insert the remaining PVC pipe into the T-joint hole that is facing up, so that the pipe stands upright. Place the final T-joint on the free end of the tower.

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Step 4 of 7:

Attach two wires to the motor. Place the motor securely into the joint at the top of the tower. Run the wires down the tower pipe and out one of the T-joints on the base. If needed, use duct tape to keep the motor in place securely.

Attach the plastic, round piece called the hub to the straight, metal piece on the outside of the motor.

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Step 5 of 7:

Connect the wires to the multimeter using the alligator clips. Set the multimeter to 20 volts.

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Step 6 of 7:

Place a few small, wooden dowels into the holes of the hub. Create wind using a hair dryer or fan. Check the multimeter to see how much energy is generated.

Using a variety of  materials, design different blades for the wind turbine. Consider the weight, smoothness of surface and number of blades needed. Attach the blades to the dowels using tape.

Turn on the hair dryer or fan again and test the turbine with each type of blade you design. How does the electrical output differ? Test the turbine with different wind speeds, such as low, medium and high fan settings. Does the wind speed affect the electrical energy output?

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Step 7 of 7:

As the kinetic mechanical energy of the moving wind moves and rotates the blades of the wind turbine, a generator inside the turbine is also rotated. This causes a coiled wire to rotate around a magnet and creates an electrical current which we measure with a multimeter.

Since energy is neither created nor destroyed, the greater the energy input, the greater the energy output will be. Therefore, the more mechanical energy you start with -- the faster the blades turn -- the more electrical energy will be created by the turbine.

How can electricity help us communicate?

How can electricity help us communicate?

Materials needed

• Two small light sockets with bulbs 
• Two switches
• Lantern battery 
• Six 1 m (1 yd.) lengths of insulated copper wire.

Procedure

1. Use your materials to construct a circuit like the one in figure 8.22-1.
2. Press one switch. What happened?
3. Release the first switch and press the second one. What happened?
4. Press both switches at once.
5. Can you think of some use for a device like this?
6. If it is available, you could splice more wire into the circuit and take one switch and light into another room.

For problem solvers:

 look up the mores code in an encyclopedia. If you and a friend would care to learn the mores code, you could have a lot of fun sending messages to each other. Or you might prefer to create your own code. Set up your telegraph sets so that you can be in separate rooms, or in separate parts of the room, and make each other's light blink with your switch.

Teacher information

This is a variation of the telegraph. There are several ways to wire the circuit. This one is parallel. The original telegraph sets were wired in series so all keys to but one had to be closed and all messages went through all the sounders in the circuit. Telegraphs offices often followed the railroads and needed only one wire on the poles. The iron rails were used as the second or ground wire. The original telegraph, patented by Morse, used an electromagnet to attract a magnetic material (soft iron) and make a loud clicking sound. Telegraphers were trained to hear combinations of long and short "dots and dashes" to represent letters of the alphabet. This is called the mores code.
The completion of the transcontinental telegraph near the end of the civil war was extremely significant. For the first time, a message could travel across the nation in seconds rather than in weeks. The circuit above uses the electric light, which was not invented until much later.
In addition to the activity suggested in the "for problem solvers" section, your motivated students might enjoy designing and constructing a telegraph using electromagnets.