User Manual

Build the circuit shown. When you turn on the slide switch (S1), the
circuit produces a very loud alarm sound and also lights the green LED
(D2). This circuit is designed to sweep through all the frequencies so
even hard of hearing people can be warned by the alarm.
Project 103 Machine Gun
Use the preceding circuit, but add a
connection between the points marked B &
C using a 1-snap and a 2-snap. Now it
sounds like a machine gun.
Use the preceding
circuit, but remove the
connection between A
& B and add a
connection between A
& D. Now it sounds
like a European siren.
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Project 102
Alarm Circuit
Project 105
European
Siren
Project 104 Fire Engine
Use the preceding circuit, but remove the
connection between B & C, and add a
connection between A & B. Now it sounds
like a fire engine.
Use the project 102 circuit but reposition the green LED (D2) so that it is
in series with the speaker (SP2), as shown. Now the circuit is not as loud.
Project 107 Quieter Machine Gun
Use the preceding circuit, but add a
connection between the points marked B &
C using a 1-snap and a 2-snap. Now it
sounds like a machine gun.
Use the preceding
circuit, but remove the
connection between A
& B and add a
connection between A
& D. Now it sounds
like a European siren.
Project 106
Quieter Alarm Circuit
Project 109
Quieter
European
Siren
Project 108 Quieter Fire Engine
Use the preceding circuit, but remove the
connection between B & C, and add a
connection between A & B. Now it sounds
like a fire engine.