Elenco Electronics EP-130, Руководство пользователя

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Here’s another siren that changes its pitch. The
siren we built in our last project changes pitch from
low to high, but this one changes its pitch from high
to low and finally stops making any sound. When it
stops, press the key and the siren sound will start
again.
Set the switch to position B and assemble the
circuit. When you complete the wiring, slide the
switch to position A to turn on the power. You hear a
high-pitched siren sound that becomes
progressively lower. Press the key to start the sound
again.
Like the siren in our last project, this siren uses IC 1
as a buffer and IC 2 as an astable multivibrator. The
capacitor C and the resistor R change the pitch of
the siren sound. The pitch changes slowly when you
increase the values of C and R, and it changes
quickly when you decrease their values. Use the
3.3
μ
F capacitor for C and notice how the pitch
changes.
Notes:
EXPERIMENT #85: FALLING BOMB SOUND
Wiring Sequence:
o
1-29
o
2-30
o
3-116
o
5-84-94-106-70-121
o
63-113-131-138
o
64-90-92-115
o
65-105-89
o
66-82-83-91
o
68-67-81
o
93-69-114-137
o
119-124
o
122-132
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Schematic