Circuit Theorems and Techniques

The analysis of complex circuits can usually be accomplished by either the node voltage or the mesh current method. If a circuit has both current sources and voltage sources, it is desirable to make adjustments to the circuit so that all the sources are of the same type. A source transformation allows a voltage source in series with a resistor to be replaced by a current source in parallel with a resistor, or vice versa. Using Kirchhoff's laws or node-voltage/mesh current methods one can calculate voltages and current anywhere in the circuit. Thevenin or Norton theorems allow to obtain an equivalent circuit model with respect to the specified pair of terminals of the network. Another way of describing the circuit with respect to the two terminals is by treating the network as a two-port circuit.