3 Pin Active Buzzer SMD Sensor Small 3.3-5V

(1) Introduction of buzzer 1. Function of buzzer: the buzzer is a kind of electronic sounder with integrated structure. It is powered by DC power supply and widely used in computers, printers, copiers, alarms, electronic toys, automobile electronic equipment, telephones, timers and other electronic products as sounder parts. 2. Buzzer classification: mainly divided into piezoelectric buzzer and electromagnetic buzzer. (2) Structure and principle of buzzer 1. Piezoelectric buzzer: the piezoelectric buzzer is mainly composed of a multi vibrator, a piezoelectric buzzer, an impedance matching device, a resonance box, a shell, etc. Some piezoelectric buzzer housings are also equipped with light-emitting diodes. The multi vibrator consists of transistors or integrated circuits. When the power supply is connected (1.5v-15v DC working voltage), the multi vibrator vibrates and outputs 1.5 2.5khz audio signal. The impedance matching device pushes the piezoelectric buzzer to make sound. Piezoelectric buzzer is made of lead zirconated titanite or lead niobite. Silver electrode is plated on both sides of the ceramic sheet. After polarization and aging treatment, it is bonded with brass sheet or stainless steel sheet. 2. Electromagnetic buzzer: the electromagnetic buzzer is composed of oscillator, electromagnetic coil, magnet, vibration diaphragm and shell, etc. When the power supply is turned on, the audio signal current generated by the oscillator passes through the electromagnetic coil, which generates a magnetic field. The diaphragm vibrates and makes sound periodically under the interaction of electromagnetic coil and magnet.