Determining The Current Amplification Of A Bipolar Transistor - Maker Factory ELECTRONICS EXPERIMENTS BOX Manual

2.4 Determining the current amplification of a bipolar transistor

Circuit 9: PNP transistor B test
Setup information
Install the transistor as shown in Fig. 2.9. Install all other resistors. Now it is time for the jumpers. Connect
the moving-coil instrument. Check the placement on the board again and only then connect the battery.
Experiment
If everything is wired correctly, the moving-coil instrument will show a strong deflection. The deflection
shows the transistor's current amplification factor B. Full scale means B = 500. In our present case the
circuit can be used to determine the current amplification factor of any low power PNP silicon bipolar tran-
sistor. The simple design of the moving-coil instrument however, sets limits to its accuracy.
The circuit diagram for this experiment is shown in Chap. 3, Fig. 3.9.
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Components required:
1 x 2N3906 transistor,
1 x 1 MΩ resistor, 1 x 220 Ω
resistor, 1 x 100 Ω resistor,
1 x moving-coil instrument,
1 x breadboard, 1 x 9V bat-
tery with clip connector
Fig. 2.9: PNP transistor B test