Short Wind Power

Project Number: 60

Description: Build the circuit shown. Set the meter to the 5V setting, and set the slide switch (S5) to position B. The meter measures how much voltage your "windmill" produces. The 470uF capacitor (C5) stores energy from the windmill. This project works best if you get the fan spinning really fast for just a moment by blowing on it. Push the press switch (S2). Depending on the slide switch (S5) position, either the horn (W1) makes a short sound or the yellow LED (D5) flashes as the energy stored in the capacitor discharges through it. Repeat this several times by blowing on the fan to charge up the capacitor, and then pressing the switch to discharge it. If nothing happens then you need to blow harder to make a higher voltage.

Snappy: Capacitors can store energy but only small amounts. Rechargeable batteries are expensive, so sometimes capacitors are used when you only need a little storage.