Piezoelectric element is a piezoelectric ceramic plate which is pasted on the vibrating metal plate after high pressure extreme pressure. When the ac voltage is added, the piezoelectric effect will cause mechanical deformation, stretching and contraction, and the use of this feature to make the metal sheet vibration and sound. 1. Peripheral support mode - the outer diameter edge of the buzzer piece is fixed in the resonance cavity. Generally, no feedback piezoelectric sensor is adopted, and the Piezoelectric Disk must be matched with the frequency of the resonance cavity to have a high sound pressure output, and the external oscillation circuit generates a driving signal to make the buzzer sound. 2. Node support mode - the buzzer plate is fixed in the annular structure of about the same size as the diameter of ceramic plate. If the resonator cavity is properly designed and matched with the correct frequency feedback piezoelectric diaphragms and positive feedback circuit, the sound pressure and correct frequency can be generated. FBelec is your best Choose of suppliers, factories, wholesalers, distributors!