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| === Noise Spectrum === |
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| we obtain the entire spectrum from 0.005 Hz to 1600 Hz of the voltage fluctuation in the Hall-effect sensor. | we obtain the entire spectrum from 0.005 Hz to 1600 Hz of the voltage fluctuation in the Hall-effect sensor. As we can see that the noise spectrum is almost flat from low frequencies to high frequencies. |
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| Vout_normalized_spectrum.JPG | attachment:Vout_normalized_spectrum.JPG === Displacement sensitivity === |
We measured the voltage fluctuation of the Hall-effect sensor, from which we infer the displacement sensitivity given the suspended magnet we used. The circuit for this experiment is shown in the following figure, which is a simple high-pass filtering of the sensor output.
attachment:hall_sensor_mea_config.JPG
The corresponding transfer function of the filter is shown below. It has a corner frequency around 0.1 Hz.
attachment:high_pass_TF.JPG
Noise Spectrum
The raw data from the spectrum analyzer by measuring different frequency bands are shown in the figure below.
attachment:Vout_rawdata.JPG
By normalizing with respect to the high-pass transfer function and piecing different frequency bands together, we obtain the entire spectrum from 0.005 Hz to 1600 Hz of the voltage fluctuation in the Hall-effect sensor. As we can see that the noise spectrum is almost flat from low frequencies to high frequencies.
attachment:Vout_normalized_spectrum.JPG