# supermesh and supernode

#### PG1995

Joined Apr 15, 2011
819
Mesh analysis and supermesh:
In mesh analysis we apply KVL. Voltage sources offer no problem and the same is true of current source when it exists ONLY in one mesh. As a side note, a mesh is a loop which does not contain any other loop within itself. The problem arises when the current source (independent or dependent) exists between two meshes. So, then to solve the circuit a supermesh is created by excluding the current source and any elements connected in series with it.

Nodal analysis and supernode:
In nodal analysis we use KCL. Therefore, the number of current sources and their placement does not offer problem and the same is true when the voltage source is connected between the reference node (at 0V) and the nonreference node; we simply set the voltage at the nonreference node equal to the voltage of the voltage source. The problem arises when the voltage source (independent or dependent) is connected between two two nonreference nodes. Then, to solve the circuit a supernode is formed by enclosing the voltage source between the two nonreference nodes and any element connected in parallel with it.

Please correct or modify the text above if you think I have missed on something important, so that I don't run into trouble while doing the problems. Thanks

#### PG1995

Joined Apr 15, 2011
819
Would someone please comment on my post above? Thanks.

#### jegues

Joined Sep 13, 2010
733
Mesh analysis and supermesh:
In mesh analysis we apply KVL. Voltage sources offer no problem and the same is true of current source when it exists ONLY in one mesh. As a side note, a mesh is a loop which does not contain any other loop within itself. The problem arises when the current source (independent or dependent) exists between two meshes. So, then to solve the circuit a supermesh is created by excluding the current source and any elements connected in series with it.

Nodal analysis and supernode:
In nodal analysis we use KCL. Therefore, the number of current sources and their placement does not offer problem and the same is true when the voltage source is connected between the reference node (at 0V) and the nonreference node; we simply set the voltage at the nonreference node equal to the voltage of the voltage source. The problem arises when the voltage source (independent or dependent) is connected between two two nonreference nodes. Then, to solve the circuit a supernode is formed by enclosing the voltage source between the two nonreference nodes and any element connected in parallel with it.

Please correct or modify the text above if you think I have missed on something important, so that I don't run into trouble while doing the problems. Thanks
I don't like how you are calling some of these situations "problems"! There is certainly no problem with supermeshes and supernodes!

In mesh analysis we apply KVL followed by Ohms Law.

In nodal analysis we apply KCL followed by Ohms Law.

It's good to read through the theory, I but find you learn the most by working through examples.

Good luck!

#### PG1995

Joined Apr 15, 2011
819
Thanks a lot, jegues.