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The defense date of the thesis is 2004-07-15
The current date is 2017-11-25
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URN etd-0715104-123303 Statistics This thesis had been viewed 2028 times. Download 11 times. Author Xiang-lin Sue Author's Email Address No Public. Department Mechanical Engineering Year 2003 Semester 2 Degree Master Type of Document Master's Thesis Language English Page Count 89 Title Circuit Design for Humidity Sensor Signal Processing Keyword PWM oscillator circuit capacitance type humidity sensor capacitance type humidity sensor oscillator circuit PWM Abstract This article focuses on capacity type humidity sensors to design sensor circuits and this research adopts oscillator circuits as a design architecture to derive two sensor signal conversion platforms for the capacitance type humidity sensor and these two platforms are capacitance-to-frequency and capacitance-to-voltage converters.
For the capacitance-to-frequency converter circuit, the Intel 8254 chip is integrated in the circuit to count the change of the frequency. For the capacitance-to-voltage converter circuit, the concept of phase pulse modulation is adopted in the oscillator circuit mode design, and the output voltage increases with increase the magnitude of the pulse.
The value of humidity sensor varies from 30 %RH to 80 %RH in the test channel at 25℃, then the frequency is measured between 6334 Hz and 6334Hz. The out voltage in the capacitance-to-voltage converter circuit is varied from 1.21V to 1.44V.
Advisor Committee none - advisor
none - co-chair
none - co-chair
Files Date of Defense 2004-07-09 Date of Submission 2004-07-15