Electronics · Semiconductor devices / Principles and inquiry
BJT amplifier experiment guide
Change bias and input amplitude to observe inverted amplification and clipping.
How does it work?
Active-region voltage gain is −Rc/Re; cutoff and saturation clip the waveform.
Key relationship
Ic ≈ max(0,(Vb−0.7)/Re) · Vout = clamp(Vcc−IcRc,0.2,Vcc)
Try this investigation
- Change bias and input amplitude to observe inverted amplification and clipping.
- Run and record each of the three baseline presets.
- Compare the changed variable and its result with the baseline records.
Interpreting your results
With a 6 V supply, what is the output when base voltage falls to 0.55 V and cuts off the transistor?
6 V
Assumptions and limitations
The actual bias divider, base current, junction dynamics and bypass capacitor are omitted. Experiment on screen; do not reproduce this with real power supplies, outlets or high voltage.