Elenco Electronics EP-130 - Page 112

Do you sleep late? Even if you do, don’t fear!
Because you can make the siren in this circuit alar
m
so t
h
at wa
k
es you up gra
d
ua
ll
y as t
h
e
d
ay
d
awns.
S
et the switch to position B, construct the circuit, then
set the switch to
p
osition A to turn it on. You shoul
d
hear sound from the speaker.
When you expose the
C
d
S
cell to light, the siren
sounds. The siren sound stops when
y
ou cover th
e
CdS. The alarm siren is made with a multivibrator
,
and controls its operation with the
C
d
S.
When you
g
o to bed at ni
g
ht and sleep with you
r
room dark, turn on this circuit. The next morning, th
e
alarm siren will wake you up.
No
t
es
:
EXPERIMENT #
93
:
G
ET
U
P
S
IREN
-
112
-
Schematic
Wirin
g
S
equence:

1-2
9

2-
30

3-116

5
-
83
-1
08
-7
0
-12
1

1
5
-
63
-1
3
2

16
-
81

6
7-
90
-
9
2-11
5

9
1-
68
-1
0
7

69
-
82
-
84
-
89

11
9
-124

122-131