Use the circuit shown.
Turn the potentiometer P1, until a current of approx. Iin = 0.010 mA flows into the base. At the same time you measure at the output a typical value of approx. Iout = 2.50 mA.
Turn P1 a little further until a current of approx. Iin = 0.015 mA flows into the base. Now you measure a typical value of approx. Iout = 3.50 mA at the output.
A change of only 0.005 mA into the base results in a rise of 1.00 mA at the output. This corresponds to a gain hhe = 200.
The gain hhe can vary greatly in your experiments. Important however is the finding...
The current gain of a common collector circuit is high. |
And what about the voltage gain...?