State police say they will soon have an easier time communicating with motorists on the road thanks to patrol vehicle ...
A new siren system uses four speakers, and a device called a Rumbler, which creates low-frequency vibrations to help ...
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 ...
Tennessee law enforcement agencies are encouraging drivers to download a smartphone application designed to reduce crashes ...
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 ...