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How are piezoelectric sensors used?

How are piezoelectric sensors used?

(Summary description)Using the property of piezoelectric sensors to change resistance in response to pressure, it is possible to determine the pressure to which the pressure sensor is subjected by the voltage output from the sensor.

How are piezoelectric sensors used?

(Summary description)Using the property of piezoelectric sensors to change resistance in response to pressure, it is possible to determine the pressure to which the pressure sensor is subjected by the voltage output from the sensor.

Information

Using the characteristic of a piezoelectric sensor to change resistance in response to pressure, it is possible to determine the pressure to which the pressure sensor is subjected by the voltage output from the sensor.

 

The pressure sensor circuit of the pressure sensor monitoring loop consists of a control module, a piezoelectric sensor, a wire and a connector. The control module comprises a voltage regulator, a current limiting resistor, and a signal processing section that functions like a voltmeter.

 

Said voltage regulator provides a constant voltage to the circuit, the current limiting resistor is a fixed resistor to prevent excessive current in the circuit, and the resistor can function in limiting the current when a short circuit to earth occurs between the control module and the sensor.

 

The control module measures the voltage value at point M. Its magnitude is determined in part by a voltmeter from the pressure (resistance) on the piezoelectric sensor, for the voltage divider circuit in this embodiment to calculate the voltage at point M by the formula: VM = (R2 / RT) x VR

 

Vm is the monitored voltage, i.e. the voltage at point M R2 is the resistance of the pressure sensor, Rt is the sum of the resistances of R1 and R2, and Vr is equal to the reference output of the voltage regulator.

 

For example, when VR = 5V, R1 = 10W, and R2 = 10W is at rest.

 

VM = 2.5V can be made according to the above formula, and as the pressure increases, the pressure increases, and as the pressure increases, the resistance increases.

 

For example, when R2 increases to 40W and VM increases to 4V according to the above formula, when the pressure decreases, the resistance decreases with said pressure as the pressure decreases.

 

If R2 drops to 1W, then according to the formula above, it can be concluded that this VM drops to 0.45V, from which we can conclude that

 

Under normal operating conditions, when the detected pressure rises, the piezoelectric sensor resistance and the voltage at point M will also rise. Conversely, when the pressure drops, the sensor resistance and voltage will drop at point M. Said control module uses said point M voltage value as an input signal to determine which changes should be taken in the system accordingly, and this circuit generates an analogue voltage signal of 0 to 5 V.

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