The piezoelectric ceramic buzzer has a simple structure in which a
ceramic piezo-element is glued to a vibration plate. The piezoceramic
element expands or shrinks diametrically when an alternating voltage is
applied. This characteristic is used to bend the vibration plate, which
generates sound.
The
acoustic generating method can be subdivided roughly into the
self-drive oscillation method and the external drive oscillation
method. The former yields the lowest impedance on the acoustic
generator and produces sound through the oscillator circuit's positive
feedback. This allows the creation of sound pressure using a simple
circuit. The external drive oscillation method uses a fixed frequency
and produces sound through the oscillator.
