Circuit Analysis For Dummies

Chapter 5

Giving the Nod to Node-Voltage Analysis

In This Chapter

Describing node-voltage analysis

Applying Kirchhoff’s current law to node-voltage analysis

Putting node-voltage equations in matrix form

You can describe voltages across each device in a circuit by using node-voltage analysis (NVA), one of the major techniques in circuit analysis. Better yet, NVA reduces the number of equations you have to deal with. I tell you all about the key ingredients of NVA — node voltages and reference nodes — in this chapter. I also walk you through the technique, first with a basic example and then with more-complex ones.

Getting Acquainted with Node Voltages and Reference Nodes

A node is a particular junction or point on a circuit. To use node voltages, you need to select a reference point (or ground point) defined as 0 volts. Node voltages are voltages at circuit nodes measured with respect to that reference node.

Figure 5-1 shows you the notation for node voltage variables as well as the voltage across each device. The voltages VA and VB are the node voltages measured with respect to a reference node, which is identified by the ground symbol. These node voltages can describe the voltages ...