Manual
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50. Rainbow of Colors
Build the circuit, move the magnet (7) towards the reed
switch (83), and the alarm (78) will sound very faintly.
Then you will see the ber optic tree (40) turn on with the
light of the colorful LED (72). If you move the magnet (7)
away the alarm (78), the colorful LED (72) will turn off.
The colorful LED (72) cycles through a rainbow of colors.
A rainbow is a meteorological phenomenon that is caused
by reection, refraction, and dispersion of light in water
droplets resulting in a spectrum of light appearing in the
sky. It takes the form of a multicolored circular arc.
51. Four Switches in Series
Build the circuit, press the switch (62), then hold
the press switch (61); you will hear the alarm (78)
start with its pitch varying from low to high, also
the LED (69) will turn on. Release the press switch
(61), the alarm (78) and LED (69) will turn off. You
can think of this circuit as four switches in series
because the press switch (61) and switch (62) have
to both be ON and the LED (69) and alarm (78) both
have to be in the circuit in the correct direction for
the circuit to be closed.