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PHYS 351 · Advanced Instrumentation

Lab 1 · LED drivers & light detectors

SlidesLecture notesLab 1Lab 2
PHYS 351 LAB 1
Design and Analysis of LED Drivers, Light Detectors, and Operational Amplifier Circuits
© Ran Yang, Ph.D.
SUBMISSION   Submit the completed lab report as a PDF on Gradescope.

Due: 2:00 p.m. next Monday.

Policies and Instructions
  1. Report Format: Submit a formal, typed lab report in PDF format. Handwritten lab reports will not be accepted. Hand-drawn circuit schematics are allowed only when explicitly permitted in the task instructions. Include screenshots and simulation results where specified.
  2. AI Policy: The use of any AI tool, including a large language model (LLM), to write, generate, debug, or modify code or any portion of the lab report is prohibited unless the course instructor grants explicit permission in advance. A teaching assistant (TA) cannot grant permission to use AI tools.

By signing below, I acknowledge that I have read and understood the policies and instructions above and agree to follow them.

Student Name (print):  

Student Signature:       Date:  

Task 1: LED Driver Design (20 points)

Task 1.1: Basic LED Driver (10 points)

  1. Design: Design an adjustable LED driver that limits the maximum voltage applied to an LED to 5.0 V. Include current limiting to prevent damage to the LED.
  2. Calculation: Show your calculations for the circuit elements.
  3. Schematic: Include the circuit schematic in your report.
  4. Simulation: Simulate the circuit using Multisim and include screenshots of the simulation results.
  5. Implementation: Build the circuit on a breadboard. Verify that the LED illuminates and is not damaged. Demonstrate the working circuit to the course instructor or a TA.

Task 1.2: LED Driver with Op-Amp (10 points)

  1. Design: Design a second LED driver that uses an op-amp to limit the voltage applied to the LED to no more than 5.0 V.
  2. Calculation: Show your circuit calculations.
  3. Schematic: Include the circuit schematic in your report.
  4. Simulation: Simulate the circuit using Multisim and include screenshots of the simulation results.
  5. Implementation: Build the circuit on a breadboard. Verify that the LED illuminates and is not damaged. Demonstrate the working circuit to the course instructor or a TA.
TASK APPROVAL Task 1 (LED Driver Circuits)

Course Instructor or TA Signature:  

Date and Time:  

Task 2: Light Detectors (20 points)

Task 2.1: Basic Light Detector (10 points)

  1. Design: Design a light detector circuit using a photodiode and a resistor.
  2. Schematic: Include the circuit schematic in your report. If a required component is unavailable in Multisim, you may draw the schematic by hand using a pencil and ruler.
  3. Calculation: Calculate the current if the digital multimeter (DMM) reads −3.0 V.
  4. Implementation: Build the circuit on a breadboard and demonstrate the working circuit to the course instructor or a TA.

Task 2.2: Light Detector with Op-Amp (10 points)

  1. Design: Design a second light detector circuit using a photodiode and an op-amp.
  2. Schematic: Include the circuit schematic in your report.
  3. Calculation: Calculate the current if the DMM reads −3.0 V.
  4. Implementation: Build the circuit on a breadboard and demonstrate the working circuit to the course instructor or a TA.
TASK APPROVAL Task 2 (Light Detector Circuits)

Course Instructor or TA Signature:  

Date and Time:  

Task 3: Circuit Analysis (10 points)

  1. Study the Circuit: Study the provided op-amp circuit. The supply rails are ±15 V, and V1 is a sine wave with a peak amplitude of 1 V.
  2. Calculation: Calculate Va and Vb.
  3. Sketch: Plot Vin, Va, and Vb on the same set of axes for at least two complete periods.
  4. Explanation: Explain the operation of the circuit by describing each functional block.
  5. Simulation: Simulate the circuit using Multisim and compare the simulation results with your calculated and sketched waveforms. Include screenshots of the simulation results.
Task 3 circuit: a 1 V, 10 kHz sine source drives the inverting op-amp input through 10 kΩ; a 10 kΩ resistor feeds back output Va. The noninverting input is biased from 15 V through 40 kΩ with 10 kΩ to ground. Va feeds a 10 kΩ series resistor to output Vb, with 10 nF from Vb to ground.
Figure: Circuit for Task 3
TASK APPROVAL Task 3 (Circuit Analysis)

Course Instructor or TA Signature:  

Date and Time:  

Submission Reminder

  1. Circuit schematics for all designed circuits (both LED drivers, both light detectors, and the Task 3 op-amp circuit).
  2. Multisim simulation screenshots for each task.
  3. All required calculations, including current-limiting resistor values, the DMM-based current calculations, and Va and Vb for Task 3.
  4. The sketch or plot of Vin, Va, and Vb and your explanation of the circuit’s functional blocks (Task 3).
  5. Photographs demonstrating each working breadboard circuit.
  6. A discussion of any challenges encountered and how you overcame them.

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