Piezoelectric Buzzer

Piezoelectric buzzer

Piezoelectric buzzer structure appearance

Piezoelectric buzzers are usually circular and consist of a piezoelectric ceramic chip, leads and resonators.

The middle of the piezoelectric ceramic plate and by the metal coating, ceramic, glue, metal sheet.

Common piezoelectric buzzer shape and circuit symbols as shown on the right:

From an electrical point of view, piezoelectric ceramics can be simplified as a series model of an inductor and a capacitor.

In addition to the two electrode all-electrode piezo buzzer shown above, there is a three-electrode feedback electrode piezo buzzer. Usually all-electrode type buzzer drive circuit is simple, but the sound is smaller; the feedback electrode type drive circuit is relatively complex, but the sound is larger.

To distinguish between the feedback mode, the piezoelectric buzzer is divided into feedback buzzer (self-excited) and non-feedback buzzer (external stimulus) two. When the feedback buzzer with the positive feedback oscillation circuit will produce a single tone with the same frequency as the resonant cavity, while the feedbackless buzzer can be used with an external oscillation circuit to select any frequency to make a sound.

Piezoelectric buzzer with small size, high sensitivity, low power consumption, good reliability, low cost features and good frequency characteristics. Therefore, it is widely used in various electrical products alarm, sound use. The most common is music devices, electronic watches, pocket calculators, electronic doorbell and electronic toys and other small electronic devices for the sound components.