A piezo buzzer is an audio signalling device powered using piezoelectricity, which is created using a material that generates an electric charge when placed under mechanical stress. Piezo buzzers were invented by Japanese manufacturers.
Piezo buzzers have a piezoelectric element that is driven by a source such as an oscillating electronic circuit. A piezoelectric amplifier will then make the click, ring or beep produced by the buzzer louder.
Piezo buzzer components can vary in a number of different ways. They differ in their mounting style, the volume of sound they can produce, and their size. Piezo buzzers can be mounted in a range of ways, from bracket, to panel mount, to surface mount. They can have a volume range of anywhere from 60 to 115 decibels, and sometimes beyond.