ECE 363
Lab 4 Report
Fall 2015
Title
Your Name
Your Major
Your Minor or Second Major (if applicable)
Union College, Schenectady, NY 12308
ABSTRACT
This is the template for your lab report. Margins are 1-inch all around. All text is in Times New Roman
font with a line-spacing of 1.5. The title is bold-faced, 18 pt, and centered. All other text is in 11 pt font.
The author is bold-faced and centered. The author affiliation is also centered. Each page should have a
header and page number. The abstract should be short (seven lines or so). It summarizes the overall goal
of your lab work, what you actually did, and noteworthy results. The last sentence or two should describe
how you benefited from the lab.
CIRCUIT DESIGN
This is where you describe the circuit design procedure. Put detailed calculations (e.g. from your PreLab)
in an appendix. If your original PreLab contained errors, you must correct them for the report.
1) Design specs
Describe the overall specifications (e.g. 4.5V supply) and desired behavior of the circuit (e.g.
response to ambient light level).
Show a Multisim schematic of your triangle wave generator with the final component values
from your design calculations.
2) Triangle Wave Generator Design
BRIEFLY describe each of the following (put detailed calculations in the appendix!):
Desired specifications.
How you determined R1 and R2 and the resulting triangle wave amplitude.
How you determined R3, C, and R4 and the resulting triangle wave frequency.
How you determined the voltage reference VREF and R5 and R6.
Simulated waveform of the triangle wave and Schmitt trigger output.
Does your simulated circuit satisfy the design requirements?
Remember to place the actual calculations (hand-written is fine) in an appendix!
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ECE 363
Lab 4 Report
Fall 2015
3) Pulse Width Modulator (PWM) Design
BRIEFLY describe each of the following (put detailed calculations in the appendix!):
Whether you used the common emitter or emitter follower configuration for the
phototransistor.
How you chose R to drive the LED
How you determined the connection of the phototransistor to the comparator input.
BREADBOARD PROTOTYPE
This is where you describe the testing of your breadboard prototype. Obviously, you needed to make
measurements to confirm your circuit satisfies the design specs. Remember to attach calculations (handwritten is fine) in an appendix. Please be neat and clearly label the calculations (e.g. computing input i).
For your convenience, the expected information is shown below:
1) Triangle Wave Generator
How you tested VREF.
How you tested the integrator.
Provide the scope snapshot of the triangle wave and Schmitt trigger outputs.
Measurements of the triangle wave and Schmitt trigger waveforms.
Does your circuit satisfy the design requirements (yes, hopefully)?
2) PWM Measurements
Explain how you obtained the value of RSENSOR for your phototransistor.
Provide the scope snapshots of the PWM output.
Does the LED brightness change as you move your hand across the phototransistor?
3) Modifications
Did you need to modify any resistor or capacitor values to make the circuit work properly?
Overall, did your breadboard prototype perform as expected?
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ECE 363
Lab 4 Report
Fall 2015
SOLDERED CIRCUIT
This is where you describe the construction and testing of your soldered circuit. Your figures do not have
to be in color – grayscale figures are OK. If possible, keep each figure to be less than or equal to 3
inches across. This way you can place two figures side by side and save some paper.
1) Soldered Circuit Version 1.0 (benchtop supply)
Briefly describe how you constructed and tested Version 1.0 of the circuit.
Did you need to make any modifications (e.g. additional bypass capacitors)?
2) Soldered Circuit Version 2.0 (battery powered)
Briefly describe how you modified your soldered circuit for battery operation.
Provide the scope trace of the triangle wave output.
Measured peak-to-peak amplitude and frequency of the triangle wave.
Did your LED night light work properly?
Please provide a photo of your soldered circuit!
DISCUSSION
This was a two-week lab. Lots of stuff happened along the way -- you had to do calculations, simulations,
breadboarding, soldering, and probably a lot of circuit debugging.
What did you find the most challenging about the circuit design?
What was most challenging about prototyping (the breadboard circuit)?
What was most challenging about the final circuit construction (soldering)?
CONCLUSIONS
This is where you write about the concepts or any valuable lessons you learned in the lab. If possible,
discuss how they relate to other aspects of the course or to the general field of electronics. Your
conclusion section should NOT be a summary of your results or what tasks you performed. The
conclusion is supposed to reveal what you have learned from your lab experience.
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