1. Mid-Semester Presentation Senior Design 1 October 8, 2009

2. Randall Vaughan Oscillator Interface Layout and Design Electrical Engineering Caroline Quijano Op-Amp Configuration Layout and Design Electrical Engineering Zach Jordan Op-Amp Configuration Phase Shift Detection Computer Engineering Jonathan Lynch Oscillator Interface Website Design Circuit Board Production Electrical Engineering

3.  Problem  Solution  Constraints TechnicalTechnical PracticalPractical  Alternatives  Progress

4.  Dr. Jack Liu of the Department of Forestry Products requires the use of a portable RF moisture content sensor  Needs a smaller, inexpensive, repackage of his patented prototype

5.   The moisture content sensor will apply a high frequency sine wave using a XR2206 waveform generator, two PS-05 48V power supplies, and a PA78 350V operational amplifier.   The resultant phase shift and attenuation measurements between the applied and received signal will be used to compute the moisture content. MC= -11403+1665.637Att – 80.843Att^2 + 1.305Att^3 + 0.571Phase^2

6. Power Supply Operational Amplifier PIC 24 Waveform Generator LCD Screen Transmitting/ Receiving Sensors

7.  Technical Constraints  Practical Constraints

10.  Sensor must withstand debris, electrical noise, and moisture  Sealed, electrically shielded, rugged housing [5]

11.  Isolated high voltages  Partition that separates gap from user interface  Appropriate warning labels displayed [6]

12.  Power Supplies  Sine Wave Generation  Operational Amplifiers  Phase Shift Detection

13.  Mean Well PS-05 Pros: Supplies +/-48 volts, Inexpensive, Easily- Accessible, Low Power Dissipation, AC/DC SwitchingPros: Supplies +/-48 volts, Inexpensive, Easily- Accessible, Low Power Dissipation, AC/DC Switching Cons: Requires Separate CablesCons: Requires Separate Cables  Charge Pump Pros: High Efficiency, Electrically-Simple CircuitsPros: High Efficiency, Electrically-Simple Circuits Cons: High Current DrawCons: High Current Draw  DC/DC Converter Pros: Regulates Output VoltagePros: Regulates Output Voltage Cons: Several Sub-Circuits (each with its own voltage level requirement different from the external source)Cons: Several Sub-Circuits (each with its own voltage level requirement different from the external source)

14.  XR2206 Waveform Generator Pros: Frequency easily set by a resistor and capacitor, excellent temperature stability (20ppm/deg C)Pros: Frequency easily set by a resistor and capacitor, excellent temperature stability (20ppm/deg C) Cons: Requires a minimum 10V supply voltageCons: Requires a minimum 10V supply voltage  DS1077 Programmable Oscillator Pros: I2C Interface, Inexpensive, Dual Output, Programmable Frequencies 8.1kHz – 133MHzPros: I2C Interface, Inexpensive, Dual Output, Programmable Frequencies 8.1kHz – 133MHz Cons: Does not output a sine waveCons: Does not output a sine wave  Analog Edge Sine Wave Generation Pros: Simple Circuit, InexpensivePros: Simple Circuit, Inexpensive Cons: Sine Wave Distortion, Square Wave GenerationCons: Sine Wave Distortion, Square Wave Generation  Resonant Crystal Pros: Very accurate, High precision, StablePros: Very accurate, High precision, Stable Cons: Comes with a fixed frequency, unchangeableCons: Comes with a fixed frequency, unchangeable

15.  PA78 350V Op-Amp Pros: Has High Voltage Specification, High Slew Rate for Phase Shift, Low Idle CurrentPros: Has High Voltage Specification, High Slew Rate for Phase Shift, Low Idle Current  OPA445 90V Op-Amp Pros: Meets minimum requirements for voltage specificationPros: Meets minimum requirements for voltage specification Cons: Low slew rateCons: Low slew rate  OPA453 80V 50mA Op-Amp Pros: Has high slew ratePros: Has high slew rate Cons: Does not meet rail-to-rail voltage specificationCons: Does not meet rail-to-rail voltage specification

16.  Zero Crossing Circuits  Logic Gates [7]

17. AugustSeptemberOctoberNovemberResearch HardwareDesign Prototyping Testing

18.  Programmed DS1077 Oscillator to 250 kHz  Ordered Power Supplies  PA78 350V Operational Amplifier Designed alternative feedback loopsDesigned alternative feedback loops

19. PIC 24

20. DS1077 Programmable Oscillator XR2206 Waveform Generator

21. Mean Well PS-05

23.  [1] United States of America. Federal Communications Commission. Code of Federal Regulations, Title 47, Part 15. Washington, D.C.: Federal Communications Commission, 2008.  [2] Panel Layup Operations, by Phil Mitchell, Raleigh, NC. [Online] Available: http://www.ces.ncsu.edu/nreos/wood/RMOG/Adobe/Panel.pdf.  [3] Forestry Facts: Guide for Using the Oven-Dry Method for Determining the Moisture Content of Wood, by R.S Boone and E.M. Wengert, Madison, Wisconsin, 1998. [Online] Available: http://forest.wisc.edu/extension/Publications/89.pdf. http://forest.wisc.edu/extension/Publications/89.pdf.  [4] Wood Products Notes: Methods of Moisture Content Measurement in the Lumber and Furniture Industries, by Phil Mitchell, Raleigh, NC. [Online]Available: http://www.ces.ncsu.edu/nreos/wood/wpn/methods_moisture.htm.  [5] Google Images. 2009. http://www.waltsense.com/storage/articles/20090429_finger-in-socket.jpg.  [6] Microsoft Office Online, Clip Art. 2009. http://office.microsoft.com/en- us/clipart/results.aspx?qu=warning&sc=20.  [7] Phase Shift. Algebra 2 Trig., by Donna Roberts. Copyright 1998-2009. http://www.regentsprep.org/Regents/math/algtrig/ATT7/phaseshift.htm.