Produces Ic vs. Vce characteristic curves for NPN and PNP transistors. 

Measure parameters such as Beta, and Early Voltage.

This Document explains how it works.
This Schematic shows how it is built.
Example Curves – NPN  -  PNP
Python Source Code Requires pythonxy package

Stand Alone Windows Executable
          bjt_curve_tracer_1.zip
          bjt_curve_tracer_2.zip
          bjt_curve_tracer_3.zip

          Here is a Program Screen Shot