Thevenin's Theorem

Category: Algorithms

Thevenin's Theorem

Any two-terminal circuit with only linear elements (resistors) and sources can be replaced by an equivalent circuit consisting of a voltage source in series with a resistor.

Voltage source represented as $V_{th}$, and resistor as $R_{th}$.

Algorithm

  1. Find $V_{th}$, the open circuit voltage from A to B using KCL and KVL.
  2. Find $R_{th}$, the equiv resistance between A and B by replacing voltage sources with short circuits and current sources with open circuits.

Norton's Theorem

Any two-terminal circuit with only linear elements (resistors) and sources can be replaced by an equivalent circuit consisting of a current source in parallel with a resistor.

Current source represented as $I_{no}$, and resistor as $R_{no}$.

Algorithm

  1. find $I_{no}$, the short circuit current from A to B using KCL and KVL.
  2. find $R_{no}$, the equiv shunt (parallel with source) resistance between A and B by replacing voltage sources with short circuits and current sources with open circuits.