The beeping film mainly plays the role of voice prompt.
Different buzzers sound different meanings.
1. The function of buzzer buzzer is a kind of electronic sound sounder with integrated structure, which adopts dc voltage power supply, and is used as sound device in computer, printer, copier, alarm, electronic toy, automobile electronic equipment, telephone, timer and other electronic products.
2. There are two types of buzzer: piezoelectric buzzer and electromagnetic buzzer.
3. In the circuit, the buzzer is represented by the letters "H" or "HA" (the old standard used "FM", "LB", "JD", etc.).
Fundamentals In ionic crystals, positive and negative ions are regularly staggered to form crystalline lattice. As the crystal is exposed to the air, these charges are neutralized over a period of time by the different ions falling on the surface of the crystal and in the air. Therefore, the polarization surface charge and the electric moment do not appear. But as the crystal deforms mechanically, the lattice changes. Thus, the electric moment changes and the value of the surface polarization charge changes. Thus, both positive and negative charges on the surface have measurable increments (increase or decrease), which is the amount of electricity produced by the piezoelectric effect.