A presentation of the some of the most fun and interesting projects I have worked on.

1. FAVORITE PROJECTS ALEXANDER
FITZSIMMONS

2. THERMISTOR
SENSOR PROTOTYPE
FOR WFIRST
PROGRAM
 WFIRST temperature sensor employed a negative temperature coefficient
(NTC) thermistor
 Additional circuitry, such as operational amplifiers, bipolar junction transistors,
were employed to stabilize and linearize the NTC thermistor voltage signal
 A Raspberry Pi was programmed to emulate the operations of a computer
system the sensor would be operated by
 These operations included coordination of an ADC with conversion of
resultant binary signal into decimal and hexadecimal form
 I assisted in the construction of the prototype with trouble shooting and
addressment of technical issues related to circuit design
 Also, I programmed the Raspberry Pi to coordinate ADC operation, read and
convert resultant data
 Further assisted in the construction of a Thermal Vacuum Chamber and in
testing that ranged from -330° to 60° Fahrenheit
Performed in 2018
Part of internship for then
Harris, now L3Harris
WFIRST has since been
renamed Nancy Grace Roman
Space Telescope

3. PHOTORESISTOR
CHARACTERIZATION
THROUGH
DIFFRACTION
Performed in 2021
Course Project while attending the
Rochester Institute of Technology
Photoresistor tested was a CDS-55
Two performance characteristics
were tested; full scale output and
resolution

4. UTILITY OF A DIFFRACTION BAND
 While a beautiful display of optical principles, diffraction bands are very useful in characterizing optical
transducers
 A diffraction grating was constructed with index cards to create a diffraction band
 Central maximum is high in intensity, but subsequent bands decrease by decreasing amounts
 By the eight and ninth bands the difference in intensity is very slight
 Resolution was characterized by measuring change in resistance that occurred with the smallest intensity
change
 The range of light intensity associated with a diffraction band allows for characterization of a photoresistors
full-scale-output

5. RESULTS
 An approximation of the photoresistors response
to illuminance was able to be made
 The smallest change in light intensity that
generated an observable change in resistance
was 0.04 Lux