Category:Rotating Sirens

Rotational sirens are sirens which utilize a rotating mechanism to spin a projector 360 degrees, which allows more focused concentration of sound compared to omnidirectional sirens. This allows the siren to project sound better with higher raw sound output and range, at the cost of only being able to project its full volume in one direction at a time as well as increased maintenance costs. These sirens can use belts, chains, gears, or other ways to rotate, driven either by the chopper motor or a separate motor. Most sirens use collector rings and brushes to rotate freely without losing power, though some electronic sirens are direct-wired instead, requiring the siren to oscillate back and forth to prevent the wire from snapping. Sirens that have a narrow, unidirectional sound beam but rotate to cover more area.