When an alternating current is applied to the electrodes, the piezoelectric disk or metal disk vibrates, creating sound waves. The frequency of the sound depends on the thickness and shape of the disk, as well as the applied voltage.
The basic principle of operation is as follows:
1. Electrical Energy Conversion: When an alternating current (AC) voltage is applied to the piezoelectric ceramic or metal disk, it causes the material to experience rapid contractions and expansions due to the piezoelectric effect.
2. Mechanical Vibration: These vibrations in the disk create mechanical oscillations, resulting in the movement or vibration of the disk itself.
3. Sound Production: As the disk vibrates, it disrupts the surrounding air, generating sound waves. The shape, size, and thickness of the disk, along with the frequency of the applied AC voltage, determine the pitch and volume of the sound produced.
4. Resonant Chamber: Many buzzers incorporate a resonant chamber or enclosure around the vibrating disk. This chamber amplifies the sound waves and enhances the overall loudness of the buzzer.
Electronic buzzers are commonly used in various electronic devices, such as alarms, timers, toys, and electronic appliances, to provide audible alerts or signals. They offer advantages like compact size, low cost, and the ability to generate a wide range of sounds with different pitches and volumes.