Page 195 - The Mechatronics Handbook

11

Electrical Engineering

11.1 Introduction
11.2 Fundamentals of Electric Circuits
Electric Power and Sign Convention • Circuit Elements and
Their i-v Characteristics • Resistance and Ohm’s Law
• Practical Voltage and Current Sources • Measuring Devices
11.3 Resistive Network Analysis
The Node Voltage Method • The Mesh Current Method
• One-Port Networks and Equivalent Circuits • Nonlinear
Circuit Elements
11.4 AC Network Analysis
Energy-Storage (Dynamic) Circuit Elements • Time-
Giorgio Rizzoni Dependent Signal Sources • Solution of Circuits Containing
Ohio State University Dynamic Elements • Phasors and Impedance

11.1 Introduction

The role played by electrical and electronic engineering in mechanical systems has dramatically increased
in importance in the past two decades, thanks to advances in integrated circuit electronics and in materials
that have permitted the integration of sensing, computing, and actuation technology into industrial
systems and consumer products. Examples of this integration revolution, which has been referred to as
a new field called Mechatronics, can be found in consumer electronics (auto-focus cameras, printers,
microprocessor-controlled appliances), in industrial automation, and in transportation systems, most
notably in passenger vehicles. The aim of this chapter is to review and summarize the foundations of
electrical engineering for the purpose of providing the practicing mechanical engineer a quick and useful
reference to the different fields of electrical engineering. Special emphasis has been placed on those topics
that are likely to be relevant to product design.

11.2 Fundamentals of Electric Circuits

This section presents the fundamental laws of circuit analysis and serves as the foundation for the study
of electrical circuits. The fundamental concepts developed in these first pages will be called on through
the chapter.
The fundamental electric quantity is charge, and the smallest amount of charge that exists is the charge
carried by an electron, equal to

×
q e = – 1.602 10 – 19 coulomb (11.1)
As you can see, the amount of charge associated with an electron is rather small. This, of course, has
to do with the size of the unit we use to measure charge, the coulomb (C), named after Charles Coulomb.
However, the definition of the coulomb leads to an appropriate unit when we define electric current,

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