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How does a piezo buzzer work?

Views:20     Author:Site Editor     Publish Time: 2021-05-08      Origin:Site

The piezo buzzer uses the piezoelectric effect of the piezo ceramics and uses the pulse current to drive the vibration of the metal plate to generate sound and is widely used as a sounding device in electronic products such as computers, home appliances,consumer electronics, automotive electronic equipment and alarms.

You may wonder why the piezo buzzer can generate a sound, or even stimulate human sound in some toys. So, let’s demystify how does a piezo buzzer work.

 

How does a piezo buzzer work?

How can we use a piezo buzzer safely?

 

piezo buzzer

How does a piezo buzzer work?

A piezoelectric buzzer is a simple device that can produce basic beeps and sounds. They work by using piezoelectric crystals, which are special materials that change shape when voltage is applied. If the crystal is pushed toward the diaphragm like a tiny speaker cone, it will generate a pressure wave, which the human ear will pick up as sound. Frequency ranges of 2kHz to 4kHz are most easily heard by human beings, and most piezo buzzers are designed in this frequency range. Just change the frequency of the voltage sent to the piezo and it will start to produce sound by quickly changing its shape,  

Piezo buzzers have two technologies. The first type is node support method. It is to fix the buzzer piece of the piezo buzzer in a ring structure approximately the same size as the diameter of the ceramic piece. If the resonant cavity is properly designed, being matched with the correct frequency of the feedback buzzer and the positive feedback circuit, then the correct frequency and greater sound pressure can be generated. The node support method is pupular in self-drive buzzers. 

The second type is edge support method. It is to fix the edge of the outer diameter of the buzzer of the piezo buzzer in the resonant cavity. This method is generally a non-feedback buzzer, and it must be matched with the frequency of the resonant cavity to have a relatively high sound pressure output. An external oscillator circuit must generate a driving signal to make the buzzer sound.

 

How can we use a piezo buzzer safely?

The piezo buzzer produces sound waves from the oscillation of the piezoelectric diaphragm via sound emission hole, so it is not sealed from the environment. Therefore, do not close the sound emitting hole and ensure no obstacle within 15mm from the sound emitting hole on the front side of the casing; avoid compressed air blown onto the piezo buzzer, this may cause deformation of the piezo buzzer or cracking of the piezo ceramic, resulting in unstable sound.

Pay attention to whether the piezo buzzer is waterproof. Since not all passive piezo buzzers are waterproof, water will cause rust, short circuit and vibration blocking of the product components for non-waterproof buzzers. Therefore, these piezo buzzers should be avoided where they may come into contact with water.

Also, the piezo buzzer needs to be used in a temperature environment within the marked working temperature. If the piezo buzzer is used in a temperature environment other than the marked working temperature, the performance of the piezoelectric sheet and the housing may deform, and the sound will be very small. 

 

Learning something about piezo buzzer can help you know the knowledge of the piezo buzzers and even make a piezo buzzer by ourselves. If you want to buy high-quality piezo buzzers with reasonable price, Kailitech Company can provide you with the best products. We also have other piezo buzzers and piezo transducer, having an independent factory and a complete production line. It is our honor if you contact with us by searching our website.


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