User Manual

Turn on the slide switch (S1); the display on the LED-MC (U29) shows
“00”. Press the A button on the selector (S8) to increase the ones digit
on the display, and press the C button on the selector to increase the
tens digit on the display. When the display shows “21”, press the B
button on the selector to start.
Strange sounds will be heard on the speaker (SP2).
Project 53
Funky Siren
(II)
Use the preceding circuit, but add
a connection between the points
marked B & C using a 1-snap and
a 2-snap. The sound is different
now.
Use the preceding circuit, but
remove the connection between B
& C, and add a connection
between C & D. The sound is
different now.
Use the preceding circuit, but
remove the connection between C
& D, and add a connection
between A & D. The sound is
different now.
Use the project 52 circuit, but
remove the connection between
C & E, and add a connection
between D & E using a blue
jumper wire. The sound is
different now.
-33-
Project 52
Funky Siren
Project 54
Funky Siren
(III)
Project 55
Funky Siren
(IV)
Project 56
Funky Siren
(V)
The LED MC (U29) is turning on
the alarm IC (U2) in short bursts,
and varying their duration.