Book Details :
LanguageEnglish
Pages416
FormatPDF
Size17.5 MB

# Introduction to Electrical Circuit Analysis by Ozgur Ergul

## PREFACE TO Introduction to Electrical Circuit Analysis by Ozgur Ergul

Since the first known electricity experiments more than 25 centuries ago by Thales of Miletus, who believed that there should be better ways than mythology to explain physical phenomena, humankind has worked hard to understand and use electricity in many beneficial ways.

The last three centuries have seen rapid developments in understanding electricity and related concepts, leading to constantly accelerating technology advancements in the last several decades.

Today, most of us simply cannot live without electricity, and it is almost ubiquitous in daily life. We are so attached to and dependent on electricity that there are even post-apocalyptic fiction movies and film series based on sudden electrical power blackouts.

And they are terrifying. Electricity is one of a few subjects with which we have a strange relationship. The more we use it, less we know about it.

Electrical and electronic devices, where electricity is somehow used to produce beneficial outputs, are a closed book to most of us, until we open them (not a suggested activity!)

and see that they contain incredibly small but highly intelligent parts. These parts, some of which once had huge dimensions and even filled entire rooms, are now so tiny that we are able to place literally billions of them (at the time of writing) in a smartphone microprocessor.

One billion is a huge number; at a rate of one a second, it takes 31 years to count. And we are able to put these uncountable (OK, countable, but not feasibly so) numbers of components together and make them work in harmony for our enjoyment.

Yet most of us know little about how they actually work. The topic of circuit analysis has naturally developed in parallel with electrical circuits and devices starting from centuries ago.

To provide some intuition, Ohm’s law has been known since 1827, while Kirchhoff’s laws were described in 1845. Nodal and mesh analysis methods have been developed and used for systematically applying Kirchhoff’s laws.

Phasor notation is borrowed from mathematics to deal with time-harmonic circuits. These fundamental laws have not changed, and they will most probably remain the same in the coming years.

In general, basic laws describe everything when they are wisely used. Hence, more and more sophisticated circuits in future technologies will also benefit from them, independent of their complexity.

Circuit analysis is naturally linked to all other technologies involving electricity, including medical, automotive, computer, energy, and aerospace industries, as well as all subcategories of electrical and electronic engineering.

Interestingly, with the rapid development of technology, we tend to learn fundamental laws more superficially. One can identify two major factors, among many:

• As circuits become more complicated and specialized, we are attracted and guided to focus on higher-level representations, such as inputs and outputs of microchips with well-defined functions, without spending time on fundamental laws.

• Great advancements in circuit-solver software “eliminate” the need to fully understand fundamental laws and appreciate their importance in everyday life, reducing circuit analysis to numbers.

Unfortunately, without absorbing fundamental laws, we tend to make major conceptual mistakes. Most instructors have had a student who offers infinite energy by rotating something (usually a car wheel if s/he is a mechanical engineering student), disregarding the conservation of energy.

It is often a confusing issue for a biomedical student to appreciate the necessity of grounding for medical safety.

And it is probably a computational mistake but not a new technology if a circuit analyzer program provides a negative resistor value.

The aim of this book is to gradually construct the basics of circuit analysis, even though they are not new material, while accelerating our understanding of electrical circuits and all technologies using electricity.

This is intended as an introductory book, mainly designed for college and university students who may have different backgrounds and, for whatever reason, need to learn about circuits for the first time.

It mainly focuses on a few essential components of electrical components, namely,

• resistors,

• independent voltage and current sources,

• dependent sources (as closed components, not details),

• capacitors, and

• inductors.

On the other hand, transistors, diodes, OP-AMPs, and similar popular and inevitable components of modern circuits, which are fixed topics (and even starting points) in many circuit books, are not detailed.

The aim of this book is not to teach electrical circuits, but rather to teach how to analyze them. From this perspective, the components listed above provide the required combinations and possibilities to cover the fundamental techniques, namely,

• Ohm’s and Kirchhoff’s laws,

• nodal analysis,

• mesh analysis,

• the black-box approach and Thévenin/Norton equivalent circuits.

This book also covers the analysis methods for both DC and AC cases in transient and steady states. To sum up, the technology that is covered in this book is well established.

The analysis methods and techniques, as well as components, listed above have been known for decades. However, the fundamental methods and components need to be known in sufficient depth in order to understand how electrical circuits work, including state-of-the-art devices and their ingredients.

Many books in this area are dominated by an increasing number of new electrical and electronic components and their special working principles, while the fundamental techniques are squeezed into short descriptions and limited to a few examples.

Therefore, the purpose of this book is to provide sufficient basic discussion and hands-on exercises (with solutions at the back of the book) before diving into modern circuits with higher-level properties. Enjoy!