Loaded Node Stiffness Three-Row Scan - Electronic Circuits V: Front-End Conditioning and Gain Contracts Step by Step

Three divider rows show how source stiffness changes the front-end node. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Eight-ohm source resistance leaves four volts

The load stays 4 ohms. With source resistance 8 ohms, the node is 4 volts.

12\ \text{V}\cdot4\ \text{ohm}/(8\ \text{ohm}+4\ \text{ohm})=4\ \text{V}

Matched source and load split the voltage

When both resistances are 4 ohms, the current is checked as an exact fraction and the load node is 6 volts.

12\ \text{V}/(4\ \text{ohm}+4\ \text{ohm})=\tfrac{3}{2}\ \text{A}\quad\tfrac{3}{2}\ \text{A}\cdot4\ \text{ohm}=6\ \text{V}

Two-ohm source resistance leaves eight volts

A stiffer source with 2 ohms inside leaves 8 volts at the same input load.

12\ \text{V}\cdot4\ \text{ohm}/(2\ \text{ohm}+4\ \text{ohm})=8\ \text{V}