This kit produces a warble siren sound when
connected to a 9V battery. No IC were used in the circuit.
Only 5 transistors & some passive components. Transistors Q3 &
Q4 are configured as a astable flip-flop which generates
a fixed tone. Transistors Q1 & Q2 form a saw-tooth wave generator which
modulates the frequency of the tone generated by
Q3 & Q4 thereby creating a warble siren sound. Ideal for used as sound indicator or
audible warning device
( 2 1/4 in speaker & 9V battery clip included )
