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What You Should Know about the Working principle of the Buzzer and the Principle of Parallel Resistance

Rhere are two types of buzzers widely used in the market electromagnetic and piezoelectric. We will talk about the working principle of the buzzer today.

The piezoelectric buzzer mainly consists of a multi-harmonic oscillator, a piezoelectric ceramic buzzer as shown in the figure below, an impedance matcher, a resonance box, and a housing.
The piezoelectric buzzer consists of a multi-harmonic oscillator, a piezoelectric buzzer (mainly piezoelectric ceramics, as shown in the figure below), an impedance matching device, a resonance box, and a housing. The main principle is to use the piezoelectric effect of the piezoelectric ceramic to drive the vibration of the metal sheet and make a sound.

Piezoelectric ceramics are actually functional ceramic materials that can convert mechanical and electrical energy into each other. The piezoelectric effect refers to certain media when they are subjected to mechanical pressure. Even if this pressure is as small as a sound wave vibration, it will produce shape changes such as compression or elongation. Piezoelectric ceramics have the function of conversion and inverse conversion between mechanical and electrical energy.

The main application circuit of the piezoelectric buzzer is shown in the following diagram.

When the pulse signal is high, the triode is turned on, and a VDC voltage is formed across the buzzer, causing the piezoelectric ceramic to deform. When the pulse signal is low, the triode turns off. At this time, the piezoelectric ceramic deformation recovery, then at its two ends
A voltage converted from mechanical energy to electrical energy is generated. This voltage needs to be released through an impedance matching resistor so that the buzzer can produce a stable frequency sound signal.

Amplitude is equal to VDC and frequency is equal to chip control port frequency
equal to the frequency of the chip control port.