Owner manual
-
123
-
This circuit chan
g
es the intervals between eac
h
sound accordin
g
to the amount of li
g
ht fallin
g
on the
CdS cell. The sound chan
g
es continuously as yo
u
a
lter the li
g
ht intensity.
Build the circuit, and set the switch to position A t
o
turn on the
p
ower. The s
p
eaker makes a sound. To
chan
g
e the sound, move your hand over the
C
d
S.
You can calculate the a
pp
roximate value o
f
th
e
frequency of the signal by using the equation 1
/
2
x
C1 x R1. However, R1, in this project, is the CdS and
is not constant. By changing C1 you can change th
e
value o
f
the output
f
requency. In this experiment
,
a
nother o
p
erational am
p
li
f
ier is used as a bu
ff
er, so
the li
g
ht-controlled sound part o
f
the circuit is no
t
aff
ected by the speaker sound.
No
t
es
:
EXPERIMENT #1
03
: LI
G
HT-
CO
NTR
O
LLED
SOU
ND
Wirin
g
Sequence:
1
-
29
2
-
30
3-64-65
5-86-110-119-124
1
5-
68
-
109
1
6-66-67-88
63
-
131
69
-
8
7-
85
7
0
-
134
121
-
135
122
-
132
Schematic