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Piezo sensor as output


Himanshu Choudhary


The generation of pressure variation or strain by the application of electric potential across a piezoelectric material is reverse of the piezoelectric effect. The circuit based project mentioned here uses this principle to use a piezo diaphragm as an output device. This is the concept used in commonly used piezo buzzers. As buzzers, they are also used in horns, telephone keypads, calculators etc. Shown below is an image of external features of a piezo buzzer.

Piezo Buzzer

To get more information on how a piezo buzzer, catch its Insight on how a piezo buzzer works.



Lets get to know about the working of the project. The voltage drop across resistors R1(10k) and R2 (150k) is provided to the piezoelectric diaphragm. Due to the applied potential, the diaphragm starts vibrating. These vibrations are fed to the base of a transistor T1 (BC547


). T1 acts as an amplifier to amplify these vibrations and the output appears across the collector resistor R3 (100). 



Circuit Diagram


Resistor Image

Resistor is a passive component used to control current in a circuit. Its resistance is given by the ratio of voltage applied across its terminals to the current passing through it. Thus a particular value of resistor, for fixed voltage, limits the current through it. They are omnipresent in electronic circuits.

BC547 | Transistor BC547  | PDF Datasheet
Transistor BC547
BC547 is an NPN bi-polar junction transistor. A transistor, stands for transfer of resistance, is commonly used to amplify current. A small current at its base controls a larger current...
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