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PROJECT BASICS
POWER SUPPLY
SENSORS
INTRODUCTION
LIGHT SENSOR
LDR
PRESSURE SENSOR
RELAY
CURRENT BUFFER
BIDIRECTIONAL CURRENT BUFFER
PARALLEL PORT
LEVEL SHIFTER
WIRELESS COMMUNICATION
PROJECT IDEAS
 

 

 

PIEZOELECTRIC SENSOR

This sensor is used to detect the pressure. This sensor is based upon piezoelectric effect. The word piezo is a geek word for pressure. When a pressure is applied to a piezoelectric material, it causes a mechanical deformation and a displacement of charges. Those charges are proportional to the applied pressure. Hence due to movement of charges, we get the electrical output. Now we consider the output voltage and pressure or force applied:

 

figure736

 

When we apply some pressure to this sensor, we get a voltage output but if we applied force remains same then, the voltage starts dropping as shown above. Hence we must detect the voltage produced at the proper time to effectively use the sensor.

HOW TO USE: The output voltage of the piezoelectric sensor is quiet small in the range 2 to 10 mV. Hence to use this in the circuits, we use an amplifier to amplify the output voltage.

 

 

HOW IT WORKS: The output of the sensor is amplified to such a value that it can be used in the circuit. The amplified voltage level is dependent on the application. We need to amplify the voltage to about    3-5 V so that it can be detected by the micro-controller.

 WHERE TO USE: We can use the piezoelectric sensor in many application where we have to detect the pressure. Some of the applications can be:

    • Electric buzzer
    • Detecting the entry of a person (by placing the sensor below some base at the door entry).

     

     

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