Fire_siren

Published:2009/7/19 23:13:00 Author:Jessie | From:SeekIC

This LM3909 circuit produces a rapidly rising wail upon pressing the button, and a slower coasting down sound upon release. If it is desirable to have the tone stop sometime after the button is released, an 18-kΩ resistor can be placed between pins 8 and 6 of the LM3909. The sound is then much like that of a motor-driven siren, National Semiconductor Linear Applications Handbook, 1991 p. 402.



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