White County has just announced the installation of the necessary hardware to be part of the Digital Siren network; it's the first county in Tennessee to do so ...

CROWLEY, Louisiana -- Emergency curfews in south Louisiana usually happen during natural disasters like hurricanes, but the coronavirus pandemic is unprecedented. Apparently, the way law enforcement ...

The Police Siren circuit uses two 555’s to produce an up-down wailing sound. The first 555 is wired as a low-frequency oscillator to control the VOLTAGE CONTROL pin 5 of the second 555. The voltage ...

CULVER CITY, CA — Police cars in Culver City are now equipped with additional, distinctive-sounding sirens — and if residents happen to hear the alarm, it means it's time to evacuate. Culver City ...