Electromechanical sirens generally use a cylindrical, slotted rotor inside of a similar stator. The rotor spins inside the nonmoving stator, causing air to be forced out like a squirrel cage blower. The slots are alternately blocked and opened as the rotor spins, causing vibration and sound.
Pages in category "Electromechanical Sirens"
The following 42 pages are in this category, out of 42 total.