Thevenin and Norton Equivalent Circuit

Thevenin's & Norton Equivalent Circuit

Thevenin's Equivalent Theorem

- Thévenin’s theorem, as stated for sinusoidal AC circuits, is changed only to include the term impedance instead of resistance.

- Any two-terminal linear ac network can be replaced with an equivalent circuit consisting of a voltage source and an impedance in series.

- VTh is the Open circuit voltage between the terminals a-b.

- ZTh is the impedance seen from the terminals when the independent sources are
set to zero.

**Take note that: VTh is the Open circuit voltage between the terminals a-b while ZTh is the impedance seen from the terminals when the independent sources are set to zero**

Norton's Equivalent Theorem

 - The linear circuit is replaced by a current source in parallel with an impedance. IN is the Short circuit current flowing between the terminals a-b when the terminals are short circuited. 

 - In Norton’s theorem, it states that a linear two-terminal circuit can be replaced by an equivalent circuit consisting of a current source IN in parallel with a resistor RN, where IN is the short-circuit current through the terminals and RNis the input or equivalent resistance at the terminals when the independent sources are turned off.

 









Thevenin and Norton equivalents are related by:

In Thevenin's and Norton's Equivalent Theorem, This is good if we are going to put concentration on a particular part of a circuit so that in other part in other way around, The circuit can be replaced by using Thevenin's equivalent.