The BJT Curve Tracer was initially a collaborative project for the “Mechatronics lab” course but ultimately became a solo endeavor since my teammates gave up on the major. This project involved developing a LabVIEW program to analyze the input and output characteristics of Bipolar Junction Transistors (BJTs) by generating characteristic curves, including the input (\(V_{BE}\) vs. \(I_B\)) and output (\(V_{CE}\) vs. \(I_C\)) curves.

Project Overview

  1. Objective:
    • To automate the measurement of key BJT characteristics, allowing users to control input values (e.g., base and collector voltages) and visualize the resulting curves.
  2. Circuit Design:
    • The setup included a voltage-controlled current source connected to the BJT, enabling precise control over the base current.
    • Key instruments:
      • HMC8012 multimeters for voltage and current measurements
      • HMC8043 triple output power supply for controlling both V1 (base current source) and V2 (collector-emitter voltage)
  3. LabVIEW Programming:
    • Developed a LabVIEW application with a structured UI for setting parameters such as current steps, voltage sweeps, and measurement range.
    • Programmed to save all measurement data to a .csv file with relevant settings for easy data retrieval and comparison.
    • A graphical interface allowed real-time visualization of the measured curves and parameter adjustment, supporting both input and output characteristic curves.
  4. Functionality:
    • The program supports automated adjustments of base and collector currents in specified steps, captures data in real-time, and plots the curves dynamically.
    • Additional features include safe program stopping and easy retrieval of previous measurement data for analysis and comparison.

screenshot of end result

A screenshot of the LabView application with the transistor curve

This project served as an extensive application of LabVIEW for circuit analysis, requiring in-depth knowledge of both BJT characteristics and LabVIEW’s graphical programming capabilities.

This project was less fun but it greatly improved my skills to work independently and modularly.

Project supervisor: Jan Poelaert
Completion date: September 2022
Rating: 1/5

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