Chapter 13 - Analysis of Analog Circuits and Models

Abstract

Conservation laws are invoked to generate an orderly set of descriptive equations from any collection of mechanical or electrical elements. In electric circuits, the law of conservation of energy leads directly to Kirchhoff's voltage law, which states that the voltages around the loop must sum to zero. Combining this rule with the phasor representation of network elements leads to an analysis technique known as mesh analysis. The law of conservation of charge leads to Kirchhoff's current law, which can also be used to find the voltages and currents in any network in an approach known as nodal analysis. The conservation law active in mechanical systems is Newton's law, which states that the forces on any element must sum to zero. The equations generated by the application of Newton's law can be solved for velocities and these velocities can be used to determine all of the forces in the system. These conservation laws, and the analysis procedures they lead to, allow us to develop equations for even very complex electrical or mechanical systems.