# One Term is missing for Circuit Analysis Help to Solve it?

• Engineering
• ravenprp
In summary, the conversation is about using nodal analysis to find I_0 in a circuit. The person is unsure about how to model a Vsource as a current and has questions about the connections between nodes. They are reminded to include the (v3-v1)/1k current in their calculation and are informed about a (super-)supernode formed by the 20V source, node 4, and the reference node. They then realize their mistake and correct it.

## Homework Statement

Find I_0 using Nodal Analysis.

http://img263.imageshack.us/img263/394/untitledph7.png [Broken]

I'm kind of lost for where my box is on the upper right corner. I don't know how to model the 20v Vsource as a current... can you even do that? I've done the other nodes, though I'm not particularly sure yet.

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Hmm.. I'm having second doubts. Is the connection between the V3 and V1 one single node or is there another node in the middle (near that big blob of dot that I have there.. above the second 1k resistor from the left)?

No it's the same as the V3 node.

You have missed out the (v3-v1)/1k current when you took the KCL on supernode 3-4. Apart from that, due the to 20V source, node 4 and the reference node will form a supernode, hence you'd have a (super-)supernode 3-4-ref.

Try again.

doodle said:
You have missed out the (v3-v1)/1k current when
you took the KCL on supernode 3-4.

Wait... I thought I put that down? It's the first term when I start writing my KCL equation for the supernode.

Apart from that, due the to 20V source, node 4 and the reference node will form a supernode, hence you'd have a (super-)supernode 3-4-ref.

Try again.

I see. You're right. I completely forgot about having a super-super-node!

Whoops. I meant the (v3-v2)/1k current.