Nodal analysis- Current directions for KCL

[Neon32]

In node analysis, after labeling the nodes. I don't know how to choose currents direction to apply KCL. it seems too complicated.. and I end up every time getting different answers the the solution sheet. I've an exam tomorrow. would be much appreciated if you could help me better understand the current directions and signs convention related to it.

Here is an example of a node voltage analysis problem

 

[Orodruin]

Assign whatever current directions you want. For every node the sum of currents in must be equal to the sum of currents going out. You may find that some currents become negative. That just means the current goes in the direction opposite to what you assigned.

 

[berkeman]

Here is an example of a node voltage analysis problem

Wow, that's incredible!

J/K, nothing got Uploaded.

Anyway, the best way to use the KCL equations (at least for me) is just to write them as the sum of all currents leaving each identified node is zero. That's real and physical, and easy to remember. Does that work for you?

You don't end up labeling the currents with directions in the overall network, you just apply that KCL rule at each node that you want to write the equations for. Once you have solved for the node voltages using the KCL equations, that gives you the final element currents and directions.

 

[Neon32]

Wow, that's incredible!

J/K, nothing got Uploaded.

Anyway, the best way to use the KCL equations (at least for me) is just to write them as the sum of all currents leaving each identified node is zero. That's real and physical, and easy to remember. Does that work for you?

You don't end up labeling the currents with directions in the overall network, you just apply that KCL rule at each node that you want to write the equations for. Once you have solved for the node voltages using the KCL equations, that gives you the final element currents and directions.

Oh got it. Thanks, appreciated.