Working principle of piezoelectric ceramic buzzer circuit

                       Working principle of piezoelectric ceramic buzzer

There are two driving methods for the piezoelectric buzzer,piezo ceramic element is the external driving method and the self-driving method. As shown in Figure 5.

The external driving method uses an electric signal from an external oscillation circuit such as a multi-frequency oscillator to drive a piezoelectric vibration plate to generate sound. Using this method, the piezoelectric buzzer acts like a speaker. By appropriately suppressing the mechanical oscillation Qm of the vibration plate of the piezoelectric buzzer, a wide sound pressure band is obtained. This method is usually applied to the switch of various household appliances, the input sound of office automation equipment and the alarm sound of digital electronic watches, etc., all of which use composite sound. In addition to these, there are also bells, telephone receivers, transmitters, card radios and LCD TV speakers.

Piezo ceramic diaphragm adopts the external driving method of the circuit by four types, namely, The circuit driven by the output signal of the unstable multi-frequency oscillator.Circuit using two NAND gates. Use the input signal to turn on and off the operation to produce oscillation or stop. The circuit driven by the output signal. The piezoelectric vibrating plate connected with the telephone bell integrated circuit.

Piezoelectric ceramic buzzer circuit diagram

Amplifying circuit of piezoelectric ceramic buzzer

The piezoelectric ceramic buzzer is a voltage-driven device. The following circuit can be used. The audio signal generated by the single chip is amplified by the transistor. The load of the transistor is a boost inductor, which can ensure the collector path and boost the amplified signal N times. The buzzer can obtain signals above 40V at both ends. If the piezo disc benders piezoelectric ceramic buzzer is coupled with a resonance box, the sound will be even louder.