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What is the function of the passive piezo buzzers?

Views:69     Author:Site Editor     Publish Time: 2021-02-22      Origin:Site

  The piezo buzzer is an electronic buzzer with an integrated structure powered by a DC/AC voltage and is widely used as a sounding device in electronic products such as computers, telephones, timers, printers, copiers, alarms, electronic toys, household appliances, automotive electronic equipment, etc.

    What technology do the passive piezo buzzers have?

    How do the passive piezo buzzers work?

    What is the function of the passive piezo buzzers?


What technology do the passive piezo buzzers have?

  Piezoelectric buzzer is a kind of sound-emitting body that uses piezoelectric ceramics as electroacoustic transducers. The core is a piezoelectric ceramic sheet pasted onto a metal sheet to convert the transducer, also known as a piezoelectric buzzer element. The main features are with lower power consumption and without radio frequency..

  The first type is node support method. It is to fix the buzzer piece of the passive 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 higher sound pressure level can be generated.

  The second type is peripheral support method. It is to fix the edge of the outer diameter of the buzzer of the passive 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 do the passive piezo buzzers work?

  Piezoelectric buzzer is a piezoelectric ceramic sheet that can be subjected to high-voltage extreme pressure and adhered to a vibrating metal sheet. When an AC voltage is added, it will generate mechanical deformation and contraction due to the piezoelectric effect, which will make the metal sheet vibrate and make a sound. Piezoelectric buzzer’s sound needs to vibrate back and forth through a piezoelectric buzzer slice, therefore we need to use square wave signal data to drive. Driving piezoelectric buzzers work requires a higher driving system voltage to get a larger sound. 

  The passive piezoelectric buzzer is constructed by placing electrical contacts on both of the disc electrodes, and then supporting the disc on the edge of the housing. When a voltage is applied between the two electrodes, the piezoelectric material is mechanically deformed due to the applied voltage. This movement of the piezoelectric disc in the passive piezo buzzer is similar to the sound produced by the movement of a magnetic buzzer or a ferromagnetic disc in a speaker cone.

 passive piezo buzzers

What is the function of the passive piezo buzzers?

  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. Just change the frequency of the voltage sent to the piezo and it will start to produce sound by quickly changing its shape.

  Passive piezoelectric buzzers actually have three commercial forms, namely piezoelectric buzzer complex, piezoelectric buzzer sounding body and piezoelectric buzzer in order to meet different needs in the market. Regardless of the form, its use is inseparable from the three types of alarm, judgment and notification.

  The passive piezoelectric buzzer for alarm is used for fire, smoke concentration, air leakage, anti-theft and automobile alarms.

  The passive piezoelectric buzzer for notification is used in fish finder, instrument, medical equipment, vending machine, washing machine, electric stove and various household appliances.  As a notification, it is more advantageous than light indication.

  In addition, the passive piezoelectric buzzer with analogue sound and complex sound can also be used in toys and video games.


  Learning something about passive piezo buzzer can help you know how do the passive piezo buzzers work and the functions of the passive piezo buzzers. If you want to buy high-quality piezo buzzers with reasonable price, Kailitech Company can provide you with the best products. You can search our website to get more knowledge with the help of our customer service staff.

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   Silvia Shen
   No. 8th, Jingquan Yi Road, Yonghe Economic Zone, Huangpu, Guangzhou, China