Description:
This circuit uses a UM3561 IC to produce four different
sound effects.
Notes:
Nothing too complicated here. The IC produces all the sound
effects, the output at Pin 3 being amplified by the
transistor. A 64 ohm loudspeaker can be substituted in place
of the 56 ohm resistor and 8 ohm loudspeaker. The 2 pole 4
way switch controls the sound effects. Position 1 (as drawn)
being a Police siren, position 2 is a fire engine sound, 3
is an ambulance and position 4 is a machine gun effect. The
IC is manufactured by UMC and was available from Maplin
electronics code UJ45Y. At the time of writing this has now
been discontinued, but they have have limited stocks
available.
