Purpose
To gain experience in working with bipolar junction transistors (BJT's). We'll be using the 2N3904 an NPN transistor to control large current with small current. Also we will make a constant current source.
Procedure
Build the BJT switch shown below in figure 1. Compare current through the lamp Ic current through the base Ib. Then measure Vce in the on and off states. Make a more careful analysis using lab view. Do these values make sense, explain what is going on. Build the constant-current source shown in figure 2. Measure collector current Ic as a function of the variable load resistance. Explain how this works. Estimate \(\beta\) for the transistor.