SunWind Energy Lessons |
In almost any Dollar store you can find an inexpensive birthday card that
plays the tune "Happy Birthday" when you open it.
If you remove the works and remove the battery, you can hook up a solar panel as shown. (The panel shown is 1.5 volts. You'd need two 1 volt panels in series to make the speaker work.)
After removing the battery,
use one alligator clip to clip together the contacts where the small piece
of card slipped in and out as a "switch",
and attach the other clip to one of the two solder connections leading
to the speaker. With very little light it will start playing "Happy Birthday
to You".
Now,
here's the neat part - if you rapidly move your hand back and forth between
the solar panel and the oncoming sunlight, alternately shading and unshading
the solar panel, the music will change pitch. It can create a somewhat ghostly
sound, not unlike the Theremin, of early last century.
What is a Theremin?