1. Chapter 4-1 Terminology and rules Node Voltage Review Matrix
representation of a systems
of equations

2. Planar circuit: a circuit that can be drawn on a plane with
no crossing branches

4. Identify essential nodes and meshes

5. Need n equations to solve for n unknowns
Let be represent number of essential branches
Let ne represent number of essential nodes
Node-Voltage method: allows us to solve a circuit using
(ne – 1) equations
Mesh-Current method: allows us to solve a circuit using
be – (ne -1) equations

6. Node-Voltage method
1. Draw circuit with no branches crossing

7. Node-Voltage method
2. Count the number of essential nodes (ne ), you will need
(ne -1) equations to describe the circuit,

8. Node-Voltage method
3. This circuit has three essential nodes
4. Choose one as a reference node, typically the node with the
most branches
5. Assign remaining essential nodes with node voltages, in this
case, nodes 1 and 2.
A Node Voltage is defined as the voltage rise from the reference node to a
non-reference node

9. 6. Label the nodes and label currents as leaving the nodes, one node at a time
apply KCL, using ohms law to write in terms of voltages summed to zero at the
node
7. Repeat step 6 for the other nodes

10. Things to remember: work on one node at a time.
Define currents as leaving the node, based on node voltage definition
If a current exist in the circuit that enters the node, it is assigned a minus sign

11. Matrix representation for a system of equations

12. You Do

13. CoolMath.com

14. What you should know
Basic circuit definitions required for node-voltage method.
Application of node-voltage
Have a method to solve a system of equations