Manual

-13-
H
ere is the first siren you are going to do – don’t be
shocked if this experiment becomes the most
famous circuit in this kit.
This siren sounds like a real siren on a police car!
After the wiring is competed press the key. The tone
you eventually hear gets higher after pressing the
key. When you release the key, the tone gets lower
and then fades out.
Try some of these modifications:
1. If you change the 10mF capacitor to a 100mF or a
470mF it will give a very long delay for both turn
off and turn on.
2. Change the circuit to remove the delays by
temporarily disconnecting the 10mF capacitor.
3. Change out the 0.02mF capacitor to a 0.01mF
capacitor, and then to a 0.05mF capacitor.
N
otes:
EXPERIMENT #2: POLICE SIREN
Wiring Sequence:
o 1-29
o 2-30
o 3-103-109
o 4-119-137
o 5-47-110
o 46-104-90
o 114-48-120
o 85-138
o 86-89-113
Schematic
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