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Why the generated voltage is negative? (in a piezoelectric pressure sensor, frequency domain)
Posted 8 apr 2015, 00:32 GMT-4 MEMS & Nanotechnology, Acoustics & Vibrations, MEMS & Piezoelectric Devices, Results & Visualization, Structural Mechanics Version 5.0 2 Replies
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Hi,
I am using frequency domain study to analyse a piezo sensor. But it is so strange that in some frequencies the generated voltage is negative, while in other frequencies it is positive.
I do not understand why in frequency domain the sign will be different? What I applied is a 100 Pa pressure on the membrane.
Besides, the displace of the membrane is similar, in some frequencies negative, in some frequencies positive.
I think in frequency domain we enter the amplitude of a pressure, but why different frequencies give results with different signs?
Thanks!
Guofeng
I am using frequency domain study to analyse a piezo sensor. But it is so strange that in some frequencies the generated voltage is negative, while in other frequencies it is positive.
I do not understand why in frequency domain the sign will be different? What I applied is a 100 Pa pressure on the membrane.
Besides, the displace of the membrane is similar, in some frequencies negative, in some frequencies positive.
I think in frequency domain we enter the amplitude of a pressure, but why different frequencies give results with different signs?
Thanks!
Guofeng
2 Replies Last Post 9 apr 2015, 15:25 GMT-4
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Posted:
10 years ago
Hi,
The results of a frequency domain analysis are complex, and as a default you will see the real part of the result. A negative sign will thus mean that the quantity you are looking at is much out of phase with the load. To see that amplitude, plot abs(V) for example.
Regards,
Henrik
The results of a frequency domain analysis are complex, and as a default you will see the real part of the result. A negative sign will thus mean that the quantity you are looking at is much out of phase with the load. To see that amplitude, plot abs(V) for example.
Regards,
Henrik
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Posted:
10 years ago
Thanks!!