Impedance

To be able to calculate voltages and currents in networks, we need two things:

• Component equations: the relationship between voltage and current for all components
• Network equations: mesh equations and node equations

All network equations, such as voltage dividers and current dividers or the relationships in series and parallel connections, apply to AC voltage in exactly the same way as to DC voltage. The component equations, however, change for AC voltage. This is shown in the following chapters.