Electronic ship siren

Posted on Jul 31, 2012

The circuit consists of a multivibrator (Ql & Q2), and a low power output stage Q3. The speaker should have an impedance in the region of 40 to 80 ohms. To use a low impedance speaker, connect an output transformer from the emitter of Q3 to ground. Cl and C2 determine the pitch of the siren and the values specified will provide a tone of about 300 Hz. Quiescent current is negligible.

Electronic ship siren
Click here to download the full size of the above Circuit.

The output at the collector of Q2 can also be fed into an amplifier input via a 1 µf electrolytic, in series with a 12 k resistor.

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Me   Feb 28, 2018

Be really good if there was an explanation of how the circuit works.

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