Build the circuit shown, where the transistor is in a collector circuit. The high-resistance resistor R1 provides the weak signal as it allows only a very small current into the base of the transistor.
As you are turning the potentiometer P1 over a wide area you can turn without the LED light up completely and the transistor saturates. |
From the experiments on "Transistor Basic Circuits" you know that a typicalBC547B transistor has the following characteristics....
But now you observe the changes with a Darlington Pair...