Principle of piezo diaphragm design structure:

Therefore, we design the resonant frequency of the piezo ceramic bimorph at around 3KHz. However, due to these low frequencies, it is difficult to manufacture with a piece of piezoelectric ceramic sheet. Generally, a double diaphragm structure is used, and the diameter is 10~~50mm, and the total thickness is 0.1~~0.5mm. When an alternating voltage is applied to the piezoelectric ceramic sounding element, it generates flexural vibration. Therefore, when the material is constant, the frequency of the piezoelectric ceramic piezo bimorph is proportional to its total thickness and inversely proportional to the square of the radius of the material. 1: The diameter of the metal vibrating piece can be increased; 2: or the thickness of the composite vibrating piece can be reduced; the size of the piezoelectric ceramic piece in the sound generating element is mainly determined according to the requirement of the impedance. The ratio of the diameter d of the piezoelectric ceramic piece to the diameter D of the metal vibrating piece, and the relationship between the resonance resistance. For fundamental vibration, the d/D ratio is closer to 1, and the resonance impedance of custom piezoelectric element is smaller, that is, to obtain a lower impedance value, the diameter of the piezoelectric ceramic piezoelectric diaphragm must be close to the diameter of the metal vibrating piece. The ratio cannot be less than 0.7.