ECE 201 Circuit Theory I1 Node-Voltage Method Identify the nodes –There are 3 “essential” nodes. –Node 0 is the “ground” or “reference” node where the voltage is equal to zero. Therefore there will be 2, or (n e – 1) node- voltage equations.

ECE 201 Circuit Theory I2 Node-Voltage Method (continued) Identify the node voltages –The node voltage is the voltage rise from the reference node (0) to a non-reference node (1 or 2). Label the voltages as v 1 and v 2.

ECE 201 Circuit Theory I3 Node-Voltage Method (continued) Write KCL at each non-reference node Consider the current to be positive if it is leaving the node. Accept the given directions of any current sources.

ECE 201 Circuit Theory I4 Node-Voltage Method (continued)

ECE 201 Circuit Theory I5 Node-Voltage Method (continued) Solving for the voltages yields, V 1 = 9.09 volts V 2 = volts With polarities as assigned