1. Piezo buzzer mainly by multivibrator, piezoelectric buzzer, impedance matching and resonance box, shell and other components. Some of the piezoelectric buzzer shell is also equipped with light-emitting diodes.
Multivibrator composed of transistors or integrated circuits. When the power is turned on (1.5 ~ 15V DC voltage), multi-harmonic oscillator start-up, 1.5 ~ 2.5kHZ output audio signals, impedance matching is pushing the piezoelectric buzzer sounded.
Piezoelectric buzzer made of lead zirconate titanate or lead magnesium niobate piezoelectric ceramic material. Both sides of the ceramic-plated silver electrode, the polarization and aging treatment, and then glued together with brass or stainless steel sheet.
2. Magnetic buzzer by the oscillator, the electromagnetic coil, magnet, diaphragm and housing and other components.
After power on, the audio signal generated by the oscillator current through the electromagnetic coil, the electromagnetic coil generates a magnetic field. Diaphragm in the electromagnetic interaction between the coil and the magnet, periodically vibrating sound.