Siren Generator using IC UM3561
IC UM3561 is a CMOS LSI IC commonly used in alarm and toy applications. It is able to generate Police Siren, Ambulance Siren, Fire Engine Siren and Machine Gun Sound just by changing simple connections. It is a low cost and low power IC which can work down to 2.4V. We need only a few additional components as this Integrate Circuits has built in oscillator and selector circuits.