Project 60
Blinking Double
Flashlight
Project 59
Periodic Sounds
Project 57
Space Battle
Project 58
Bizarre
Blinker
Periodic electrical
signals are used for
things like flashing
yellow lights or
sometimes
in
consumer devices
to indicate batteries
are low.
Build the circuit shown on
the left. Turn on the
switch (S1) and you will
hear exciting sounds, as
if a space battle is raging!
The preceding circuit is loud and
may bother people around you, so
replace the speaker (SP2) with the
color LED (D8, “+” on top and away
from U3).
Build the circuit shown on the left and turn
it on. The lamp (L1) alternates between
being on and off while the speaker (SP2)
alternates between two musical tones...
like someone is flipping a switch, but at a
very consistent rate. Periodic signals like
this are very important in electronics.
In the circuit at left, replace the speaker
(SP2) with the color LED (D8). Make sure
you connect the color LED with the positive
(+) side on A5, not U1. The lamp (L1)
alternates between being on and off while
the color LED alternates between being
dimmer and brighter.
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