Elenco Electronics EP-130, Руководство пользователя

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The sirens we built in Projects 84 and 85 (“Hand-
Operated Sweep Oscillator” and “Falling Bomb
Sound”, respectively) change pitch only in one
direction, but this one makes a low sound that
becomes higher, and goes back to its original low
sound. The siren sounds only once when you press
the key.
Assemble the circuit after setting the switch to
position B. Turn on the siren by sliding the switch to
position A. When you press the key, the siren starts
over at the original low pitch. Do you hear the siren
sound change pitch as you expected? IC 1 is an
oscillator that produces current that forms a
triangular wave, so when you press the key, it
produces a triangular wave output. Then the output
is sent to IC 2 which acts as an astable multivibrator.
In projects 84, 85, and 86, the astable multivibrator
produces the siren sound and the pitch changes
according to the values of R and C. Find out how the
pitch changes when you set C to 0.02
μ
F and then to
0.1
μ
F.
Notes:
EXPERIMENT #86: EMERGENCY SIREN
-105-
Wiring Sequence:
o
1-29
o
2-30
o
3-116
o
5-70-108-137-121
o
80-63-132
o
64-90-92-115
o
65-89-107
o
66-82-91
o
81-67-118
o
78-79-68-117
o
69-119-124
o
77-138
o
122-131
Schematic