1. Superposition Principle of “Superposition”
When a linear circuit is excited by more than one independent source of energy, the total response is the sum of the responses to each source acting individually.
To find the response due to each independent source
suppress voltage sources by replacing them with short circuits (V=0).
suppress current sources by replacing them with open circuits (I=0).
ECE 201 Circuit Theory I

2. Example, page 130 of the text
Find the branch currents in the circuit shown. i1 i3 i2 i4
ECE 201 Circuit Theory I

3. Find the response to the voltage source
ECE 201 Circuit Theory I

4. Find the response to the current sourcev3 v4
i1”
i3”
i2”
i4”
ECE 201 Circuit Theory I

5. Find the branch currents by adding the results due to each source
ECE 201 Circuit Theory I