Piezoelectric speaker is developed based on the reverse piezo-electrification effect. As a brand new branch of speaker family, its superior high pitch quality ,ultra-thin structure, and low power consumption are the reasons why it became a popular product for portable devices.
A. Working Principal of Piezoelectric Speaker
Piezoelectric speaker is a multi-layered（5-6 layer, normally) piezo ceramic film combined with a ultra-thin metal plate, this combination is a diaphragm. When a electric field is generated to the diaphragm, according to the reverse piezo-electrification effect, the piezo ceramic layers will deform. It bends the entire diaphragm upwards when expand, and downwards when the ceramic layers contract. Therefore, the diaphragm vibrates the air with different voltage change.
B.Features of Piezoelectric Ceramic :
1.Ultra-thin, Ultra-light, minimizes space-occupation.
2.High efficiency of energy conversion & Low power consumption
3.No electromagnetic interference, no need of magnet-proof design
4. Immune to electromagnetic interference, and fire-proof
5.No mechanical connecting points, no electrical noises, simple structure and can be directly driven by IC.
6.Wide frequency range, nature and clear sound
7.Low requirement for speaker cavity，the dimension of the cavity has little impact to the S.P.L to the speaker.
8.It vibrates to both direction, creates a relatively smooth resonance frequency, high quality S.P.L
4.Handheld transceiver (Walkie-talkie)
5.Other portable devices that have size restrictions