Piezoelectric Buzzers Are Commonly Fixed in Several Ways

There are generally two fixed methods of piezoelectric buzzer: peripheral support mode and node support mode, which are explained in detail below.
The so-called peripheral support method is to fix the outer diameter edge of the piezoelectric buzzer in the resonance cavity, generally without a feedback buzzer (other excited piezoelectric buzzer), and its piezoelectric buzzer frequency must be matched with the resonance cavity frequency to have a higher sound pressure output, and the external oscillation circuit generates a push signal to make the buzzer sound. Due to vibration in the same plane, although the phase is the same plane, the phase direction sound wave of the cavity must be isolated first.
The smaller the edge, the better, so as not to suppress buzzer vibration
The peripheral support method generally uses the piezoelectric buzzer above
The so-called nodal support method means that the piezoelectric buzzer is fixed in a ring structure of about the same size as the diameter of the ceramic plate. If the resonator is properly designed and paired with a feedback buzzer with the correct frequency (self-excited piezoelectric buzzer) and a forward feedback circuit, a large sound pressure and the correct frequency will be generated. Because the support position is the node of the piezoelectric buzzer, the phase difference between A space and B space (B1, B2) is 180°, so that the sound pressure will not cancel each other out, and then increase the specific frequency tone, the central part and the peripheral part are acoustically isolated, and the central part is taken out in phase.