The piezoelectric buzzer is mainly composed of a multivibrator, a piezoelectric buzzer, an impedance matching device, a resonance box, an outer casing and the like. Some piezoelectric buzzer housings are also equipped with light-emitting diodes. A multivibrator is composed of a transistor or an integrated circuit.
When the power is turned on (1.5~15V DC working voltage), the multivibrator starts to oscillate and outputs an audio signal of 1.5~2.5kHZ
Piezoelectric buzzers can be divided into: passive piezoelectric buzzer (external drive series), active piezoelectric buzzer (including drive series), and self-excited piezoelectric buzzer.
The characteristics of the piezoelectric buzzer are: small size, light weight, thin thickness, low power consumption, good reliability, and low cost.
It is suitable for sounding devices on small electronic products such as electronic watches, pocket calculators, electronic doorbells and electronic toys. Electronic clocks, electrical products, burglar alarms, downhole alarms, smoke alarms and the use of electronic toys. It can also be used as an acoustic sensor for voice-activated toys.