The subtle difference between the piezoelectric buzzer and electromagnetic buzzer.

We have analyzed the relevant situation of piezoelectric buzzers and electromagnetic buzzers before, so we know a little about both of them, but usually, we will put them together for comparison, Because it is true that they have similarities, but there are also differences, let's analyze them below.

1. Structural part:

The main piezoelectric buzzer is mainly composed of the following components:

(1). Piezoelectric buzzer

(2). Consensus box

(3). Multivibrator

(4). Impedance matcher

(5). Shell

(6). LED

Well, we all know that piezoelectric buzzers mainly rely on pulse current to act on piezoelectric ceramics, so piezoelectric ceramics vibrate and sound, but in this case, the sound is relatively small, so we need to add Install an auxiliary sound chamber to improve the sound, so some piezoelectric buzzers are equipped with light-emitting diodes, mainly because the coil of the electrified part moves in the magnetic field formed by the permanent magnet, driving the sound plate stuck together with the coil to vibrate and sound, and the sound quality is better than Piezoelectric is better.

The electromagnetic buzzer is composed of the following parts:

(7). Vibrator

(8). Electromagnetic coil

(9). Magnets

(10). Vibrating diaphragm

(11). Shell

piezoelectric buzzer

Then when the electromagnetic buzzer is powered on, the audio signal current generated by the vibrator will pass through the electromagnetic coil, causing the electromagnetic coil to generate a magnetic field, then the vibrating diaphragm will be under the interaction between the electromagnetic coil and the magnet. , vibrating periodically.

2. Piezoelectric buzzers and electromagnetic buzzers are both series products of buzzers, among which:

The piezoelectric buzzer uses the piezoelectric effect of the piezoelectric ceramic to drive the vibration of the metal sheet to make a sound;

The electromagnetic buzzer uses the principle of electromagnetism to absorb the metal vibrating film after energization and bounces back according to the elasticity of the vibrating film when it is not energized.

Through the above analysis, we can know that the piezoelectric buzzer is mainly driven by a square wave to sound, while the electromagnetic buzzer is driven by a 1/2 square wave; secondly, the piezoelectric buzzer also needs A higher voltage can produce sufficient sound pressure, and it is generally recommended to be above 9V.

3. The electromagnetic buzzer can emit a sound pressure of more than 85 decibels as long as the voltage of 1.5V is used, so the 9v equivalent to the piezoelectric buzzer may only be higher than the current consumption. Piezo buzzer.

4. When they are at the same scale, the response frequency of the electromagnetic buzzer can be lower than that of the piezoelectric buzzer.