Casio fx-7400G PLUS Booklet page 31

3. What is the small signal current amplification ratio h
The small signal current amplification ratio h
increases during transistor operation when base current is increased slightly.
h =
fe
4. Measurement
(1) First, measure transistor 2SC1815. Connect it to the circuit.
(2) Adjust variable resistor VR to allow collector-emitter current to flow, and record base
current at that time. Increase and measure current up to 2mA in about 0.1mA steps.
Collector-emitter Current (mA)
Base Current
5. Drawing the graph
Use a graphic calculator to graph the results with base current on the horizontal axis and
collector-emitter current on the vertical axis.
Operation
Data Input
From the Main Menu, enter the STAT mode.
After confirming that the cursor is located in line 1 of List 1, input base current values.
E-
9
Example:
E-
10
E-
11
After confirming that the cursor is located in line 1 of List 2, input collector-emitter current
values.
E-
3.17
Example:
E-
3.57
E-
3.86
(µA)
w
6
w
6
w
6
... etc.
w
3
w
3
w
3
... etc.
EE-3 Small Signal Amplification Factor of a Transistor
fe
expresses how much collector-emitter current
fe
=
– 28 –
?