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3. What is the small signal current amplification ratio h fe?
The small signal current amplification ratio h fe expresses how much collector-emitter current
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.
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.
Example: 9E-6w
10E-6w
11E-6w... etc.
After confirming that the cursor is located in line 1 of List 2, input collector-emitter current
values.
Example: 3.17E-3w
3.57E-3w
3.86E-3w... etc.
EE-3 Small Signal Amplification Factor of a Transistor
Collector-emitter Current (mA)
Base Current (µA)
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