The source of the piezoelectric buzzer sound element comes mainly from the Piezo Element. The piezoelectric diaphragm consists of a piezoelectric ceramic plate printed with electrodes on both sides and a metal plate (brass or stainless steel, etc.). The use of adhesives, the Piezo Element, and metal bonding together, this is what we commonly knew as the buzzer.
Figure 2 shows the piezoelectric vibrating plate oscillation system. When a DC voltage is applied between two electrodes of the piezoelectric diaphragm, mechanical deformation occurs due to the piezoelectric effect. For distorted piezo elements, the deformation of the piezo element extends in the direction of radiation.
The Piezo Element is bent in the direction shown in FIG. 2 (a), and the metal plate bonded to the Piezo Element does not extend. In contrast, when the piezoelectric element contracts, the piezoelectric vibrating plate bends in the direction shown in FIG. 2 (b). Therefore, when the AC voltage is passed through the electrodes, as shown in Fig. 2 (c), the bending is shown in Fig. 2 (a) and Fig. 2 (b) alternately occurs repeatedly to generate sound waves in the air.
Buzzers In general, people's audio range is about 20Hz to 20kHz. The easiest people to hear are 2kHz to 4kHz. Therefore, the vast majority of piezoelectric sound components in this audio range.
Buzzers In general, people's audio range is about 20Hz to 20kHz. The easiest people to hear are 2kHz to 4kHz. Therefore, the vast majority of piezoelectric sound components in this audio range. Meanwhile, the buzzer resonant frequency (f0) is also generally selected in the same range. As shown in Figure 3, the resonant frequency depends on the method used to support the Piezo Element. If the Piezo Element has the same shape, its value will decrease in the order of (a), (b) and (c).
In general, a Piezo Element is installed in the resonance chamber to generate a high sound pressure (see FIG. 4). Using equation (1) (Helmholtz equation), the resonance frequency (fcav) of the resonance chamber in Figure 4 can be calculated. Since the piezoelectric vibrating plate and the resonance chamber have appropriate resonance frequencies (f0) and (fcav), respectively, the position of both can be controlled
Increase the sound pressure at a specific frequency and obtain a specific bandwidth.
Welcome you to send us inquires, We can custom various piezo element as per your requirement.
Self-drive and external piezo element.