Elenco Electronics 202 - Manual (Page 29)

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OBJECTIVE: To build a circuit with
light and sound that change and repeat.
Project #38
Blinking
Double
Flashlight
Build the circuit shown on the left and turn
it on. The lamp (L2) alternates between
being on and off while the speaker (SP)
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.
Project #37 Periodic Sounds
Project #35 Space Battle
OBJECTIVE: To show
another way of using the
space war integrated circuit.
Build the circuit shown on the
left, which is based on the
circuit in the Space War
project #19. Turn on the slide
switch (S1) and you will hear
exciting sounds, as if a space
battle is raging!
The motor (M1) is used here
as a 3-snap wire, and will not
spin.
Project #36
Silent Space
Battle
OBJECTIVE: To show another
way of using the space war part.
OBJECTIVE: To build a circuit with two
lights that alternate.
The preceding circuit is loud and
may bother people around you, so
replace the speaker (SP) with the
LED (D1). Make sure you connect
the LED with the positive (+) side
on A6, not U3. Now you have a
silent space battle.
In the circuit at left, replace the speaker
(SP) with the LED (D1). Make sure you
connect the LED with the positive (+) side
on A5, not U1. The lamp (L2) alternates
between being on and off while the LED
alternates between being dimmer and
brighter.