This Article is written to bring together two topics: circuit theory and field theory.
Electromagnetic field theory is an important part of basic physics. In school it
is usually taught as a separate course. Because physics is a very mathematical
subject, the connection to everyday problems is not emphasized. Circuit theory,
by its very nature, is very practical. It provides a methodology that connects
with the many problems that students will encounter in practice. It is natural
for most technical people to reinforce circuit concepts and push basic physics
into the background.
Circuit theory is not a match for describing the nature of a facility, the
interconnection of many pieces of hardware, or the power grid that interfaces
each piece of hardware. In circuit theory the emphasis is on components, not
on such items as facilities or power distribution. A building or a power grid
is not a topic for discussion in a physics course, as these areas are far too
complex to consider. Basic physics can handle only very simple geometries,
not buildings. Given an interference problem, an engineer defaults to circuit
theory and circuit diagrams, as this is where he or she is usually most successful.
The circuits that might be considered for a facility usually do not
communicate well and bring little understanding to the problem. The fact that
there are no actual circuit components to consider is just one of the problems.
Circuit theory is a very powerful tool. If the right circuits are considered,
the answers can be meaningful. In this book we place the concepts of fields
into every aspect of circuit behavior. Every component functions because of
internal or external fields. A facility has its own fields, and these fields enter
into every circuit. When all the fields are considered, many problem areas
become clearer. A solution may require changing the geometry of a system
to limit the influence of the extraneous fields. Circuit theory is still used, but
the influence of the environment becomes a part of the design. In effect, field
theory brings geometry into circuit design. Experienced designers understand
how important geometry can be to circuit performance.
Fields are fundamental even in static circuits, and this is where the first
chapter starts. All circuits function through the motion of field energy, and this
idea must be considered at all circuit speeds. This includes batteries, utility
power, audio, radio frequencies, and microwaves. Fields are needed to operate
every circuit component, and conductors are needed to bring fields to each
1
2 THE ELECTRIC FIELD
component. This means that the flow of field energy, to every component
describes performance. The environment also includes field energy and this
energy cannot be ignored. Understanding this fact makes it possible to design
practical products.
Today’s circuits operate at very high speeds. The demand to process vast
amounts of data in very short periods is ever present. To understand high-speed
problems, it is necessary to start slowly. The fields involved in all electrical
phenomena are the same. In the first chapter we treat static charge and the
concept of voltage. These very elementary ideas lay the foundation for understanding
circuit behavior at all speeds. In later chapters, when the fields are
changing more rapidly, the problems of radiation are discussed. All circuits,
including the lowly flashlight, are explained using the same physics. This is
where the book starts: fields, batteries, and resistors.
Electromagnetic field theory is an important part of basic physics. In school it
is usually taught as a separate course. Because physics is a very mathematical
subject, the connection to everyday problems is not emphasized. Circuit theory,
by its very nature, is very practical. It provides a methodology that connects
with the many problems that students will encounter in practice. It is natural
for most technical people to reinforce circuit concepts and push basic physics
into the background.
Circuit theory is not a match for describing the nature of a facility, the
interconnection of many pieces of hardware, or the power grid that interfaces
each piece of hardware. In circuit theory the emphasis is on components, not
on such items as facilities or power distribution. A building or a power grid
is not a topic for discussion in a physics course, as these areas are far too
complex to consider. Basic physics can handle only very simple geometries,
not buildings. Given an interference problem, an engineer defaults to circuit
theory and circuit diagrams, as this is where he or she is usually most successful.
The circuits that might be considered for a facility usually do not
communicate well and bring little understanding to the problem. The fact that
there are no actual circuit components to consider is just one of the problems.
Circuit theory is a very powerful tool. If the right circuits are considered,
the answers can be meaningful. In this book we place the concepts of fields
into every aspect of circuit behavior. Every component functions because of
internal or external fields. A facility has its own fields, and these fields enter
into every circuit. When all the fields are considered, many problem areas
become clearer. A solution may require changing the geometry of a system
to limit the influence of the extraneous fields. Circuit theory is still used, but
the influence of the environment becomes a part of the design. In effect, field
theory brings geometry into circuit design. Experienced designers understand
how important geometry can be to circuit performance.
Fields are fundamental even in static circuits, and this is where the first
chapter starts. All circuits function through the motion of field energy, and this
idea must be considered at all circuit speeds. This includes batteries, utility
power, audio, radio frequencies, and microwaves. Fields are needed to operate
every circuit component, and conductors are needed to bring fields to each
1
2 THE ELECTRIC FIELD
component. This means that the flow of field energy, to every component
describes performance. The environment also includes field energy and this
energy cannot be ignored. Understanding this fact makes it possible to design
practical products.
Today’s circuits operate at very high speeds. The demand to process vast
amounts of data in very short periods is ever present. To understand high-speed
problems, it is necessary to start slowly. The fields involved in all electrical
phenomena are the same. In the first chapter we treat static charge and the
concept of voltage. These very elementary ideas lay the foundation for understanding
circuit behavior at all speeds. In later chapters, when the fields are
changing more rapidly, the problems of radiation are discussed. All circuits,
including the lowly flashlight, are explained using the same physics. This is
where the book starts: fields, batteries, and resistors.
