Elenco Green Projects - Manual (Page 43)

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Project #60 Short Wind Power
Wind Horn Project #61
5V
Build the circuit shown. Set the
meter to the 5V setting. Blow on
the fan or place it in a strong wind
(either outside or near an electric
fan). The meter measures how
much voltage your “windmill”
produces, and the horn (W1)
makes noise from the voltage.
Capacitors can store
energy but only small
amounts. Rechargeable
batteries are expensive,
so sometimes capacitors
are used when you only
need a little storage.
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 470
μF capacitor (C5)
stores energy from the windmill. This
project works best if 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) setting, 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, then pressing the switch to
discharge it. If nothing happens then you
need to blow harder on the fan to make a
higher voltage.
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5V
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The electricity produced by the windmill motor is constantly changing,
due to the mechanical design of the motor and variations in wind speed.
The horn needs a steady voltage to work properly, so the 470
μF
capacitor (C5) is used. The capacitor stores a small amount of electricity
and then releases it as needed to steady the voltage.
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