This circuit is a circuit that sounds a siren-like sound of ambulance sirens. This circuit is different to an ambulance siren circuit generally, is to use transistors instead of IC 555. Which allows economical and easy to tailor a network.
Operation of the circuit. This cycle can be divided into three main parts is the low frequency production. Production of high frequency. The amplifier. The manufacture low-frequency includes Q1, Q2, R2, R3, C2, C3. Which will produce low-frequency out and to extend the Q3. Before you sent with high frequency of origin from Q4, Q5, R8, R9. , C5, C6 signal is included, then the output will come out to the leg E of the Q5. and then be expanded with Q6 to drive the speakers. The C1, C4 is intended to stir filter collects them. The R11 will help prevent speaker damage.