Elenco Green Projects - Manual (Page 76)

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5V
+
5V
Project #126 Anemometer
Volt Meter
To make a voltage measurement, the meter
(M6) is set to 5V and connected in parallel
between the two points where the
measurement is to be made. Since the
voltmeter is in parallel and has a high
resistance, very low current flows through it.
To measure the voltage of the battery (B4),
set the slide switch (S5) to position C. Look
at the scale and read the voltage, it should
be over 3 volts. If the voltage is less then 3
volts, you need to charge the battery.
You can change the meter scale from 5V to
10V by adding a 10K
Ω resistor in the pivot
stand in series with the meter. Set the switch
to position B. The meter pointer drops to a
lower position since each segments now
equal 2V.
The energy in the moving wind can be used to generate electricity. An
anemometer is a device used for measuring wind
speed, and is one instrument used in a weather
station. The term comes from the Greek word
anemos, meaning wind. Leon
Battista Alberti invented the
anemometer.
Set the meter (M6) to the 5V
setting. Slowly blow on the fan and
notice the reading on the meter. The meter
measures the voltage generated by the spinning
shaft on the motor. The faster the shaft spins, the
greater voltage generated. See how fast the fan
must spin to light the LED.
Project #125
Wind speed is important for wind energy. Wind turbines need a
constant, average wind speed of about 14 miles per hour before the
wind turbines can generate electricity.
See projects 1 & 3 if you need to recharge the battery (B4).