Testing

Materials Needed:

1. Voltmeters: To measure the output voltage of the wind turbines.
2. LEDs: (Optional), but can be used to visualize if the turbine generates enough power to light them up.
3. Pedestal Fan with Variable Speed Settings: To simulate different wind speeds.

(Note: If a fan is unavailable, you can just wait for a windy day. You can check the current wind speeds on your local weather app and record the changes in the voltmeter reading at different wind speeds. While this might ot be as accurate as having a fan, it simulates real-life conditions better!)

Steps to Set Up the Experiment:

1. Place the wind turbine in front of the fan. Ensure it’s at a consistent distance that allows for effective wind capture and uniform testing.
2. Connect the motor leads to a load resistor.
3. Connect the voltmeter parallel to the resistor i.e., connect the positive end to the positive (red) of the voltmeter and the negative end to the negative (black) of the voltmeter.
4. Make sure the connections are secure and the voltmeter is set to measure DC voltage.
5. Optionally, connect an LED to the turbine instead of the load resistor to see if it lights up for better visualisation.
6. Turn on the fan to its lowest setting.
7. Record the voltage reading from the voltmeter.
8. Gradually increase the fan speed and record the voltage at each setting.
9. Change the gear setting and repeat steps 1-8. Observe how the voltage reading changes with change in wind speed and gear ratio.

Time to Think!

1. Do you think your turbine can charge your phone? What about your laptop?
2. With your existing design, how long does your wind turbine need to keep running to charge your phone fully?
3. How can you improve the output of your turbine? (Hint: Don’t just think about the vane design!)