Inverter Base Resistance Three-Row Scan - Electronic Circuits XI: Transistor Switching and Device Regions Step by Step

With input fixed, base resistance changes drive and moves the inverter output. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Sixteen ohms leaves the output near the top

Input stays 5 V while base resistance 16 ohm sets collector current 3/4 A and output 9 V, and checked state MIDDLE.

R_B=16\ \Omega\Rightarrow V_\text{out}=9\ \text{V}

Eight ohms pulls the output to the middle

Input stays 5 V while base resistance 8 ohm sets collector current 3/2 A and output 6 V, and checked state MIDDLE.

R_B=8\ \Omega\Rightarrow V_\text{out}=6\ \text{V}

Four ohms reaches the low output floor

Input stays 5 V while base resistance 4 ohm sets collector current 3 A and output 0 V, and checked state LOW.

R_B=4\ \Omega\Rightarrow V_\text{out}=0\ \text{V}