Fields of Study

Mathematics; physics; electronics; electrical engineering; automotive mechanics; analytical technology; chemical engineering; aeronautics; avionics; robotics; computer programming; audio/video technology; metrology; audio engineering; telecommunications; broadcast technology; computer technology; computer engineering; instrumentation

Summary

A workable understanding of the phenomenon of electricity originated with proof that atoms were composed of smaller particles bearing positive and negative electrical charges. The modern field of electronics is essentially the science and technology of devices designed to control the movement of electricity to achieve some useful purpose. Initially, electronic technology consisted of devices that worked with continuously flowing electricity, whether direct or alternating current. Since the development of the transistor in 1947 and the integrated circuit in 1970, electronic technology has become digital, concurrent with the ability to assemble millions of transistor structures on the surface of a single silicon chip.

Key Terms and Concepts

Cathode Rays: Descriptive term for energetic beams emitted from electrically stimulated materials inside of a vacuum tube, identified by J. J. Thomson in 1897 as streams of electrons.

Channel Rays: Descriptive term for energetic beams having the opposite electrical charge of cathode rays, emitted from electrically stimulated materials inside a vacuum tube, also identified by J. J. Thomson in 1897.

Gate: A transistor structure that performs a specific function on input electrical signals to produce specific output signals.

Operational Amplifier (Op-Amp): An integrated circuit device that produces almost perfect signal reproduction with high gains of amplification and precise, stable voltages and currents.

Sampling: Measurement of a specific parameter such as voltage, pressure, current, and loudness at a set frequency determined by a clock cycle such as 1 MHz.

Semiconductor: An element that conducts electricity effectively only when subjected to an applied voltage.

Zener Voltage: The voltage at which a Zener diode is designed to operate at maximum efficiency to produce a constant voltage, also called the breakdown voltage.

Definition and Basic Principles

The term “electronics” has acquired different meanings in different contexts. Fundamentally, “electronics” refers to the behavior of matter as affected by the properties and movement of electrons. More generally, electronics has come to mean the technology that has been developed to function according to electronic principles, especially pertaining to basic digital devices and the systems that they operate. The term “electronic engineering” refers to the practice of designing and building circuitry and devices that function on electronic principles.

The underlying principle of electronics derives from the basic structure of matter: that matter is composed of atoms composed of smaller particles. The mass of atoms exists in the atomic nucleus, which is a structure composed of electrically neutral particles called neutrons and positively charged particles called protons. Isolated from the nuclear structure by a relatively immense distance is an equal number of negatively charged particles called electrons. Electrons are easily removed from atoms, and when a difference in electrical potential (voltage) exists between two points, electrons can move from the area of higher potential toward that of lower potential. This defines an electrical current.

Devices that control the presence and magnitude of both voltages and currents are used to bring about changes to the intrinsic form of the electrical signals so generated. These devices also produce physical changes in materials that make comprehensible the information carried by the electronic signal.

Background and History

Archaeologists have found well-preserved Parthian relics that are now believed to have been rudimentary, but functional, batteries. It is believed that these ancient devices were used by the Parthians to plate objects with gold. The knowledge was lost until 1800, when Italian physicist Alessandro Volta reinvented the voltaic pile. Danish physicist and chemist Hans Christian Oersted demonstrated the relationship between electricity and magnetism in 1820, and in 1821, British physicist and chemist Michael Faraday used that relationship to demonstrate the electromagnetic principle on which all electric motors work. In 1831, he demonstrated the reverse relationship, inventing the electrical generator in the process.

Electricity was thought, by American statesman and scientist Benjamin Franklin and many other scientists of the eighteenth and nineteenth centuries, to be some mysterious kind of fluid that might be captured and stored. A workable concept of electricity was not developed until 1897, when J. J. Thomson identified cathode rays as streams of light electrical particles that must have come from within the atoms of their source materials. He arbitrarily ascribed their electrical charge as negative. Thomson also identified channel rays as streams of massive particles from within the atoms of their source materials that are endowed with the opposite electrical charge of the electrons that made up cathode rays. These observations essentially proved that atoms have substructures. They also provided a means of explaining electricity as the movement of charged particles from one location to another.

With the establishment of an electrical grid, based on the advocacy of alternating current by Serbian American engineer and inventor Nikola Tesla (1856-1943), a vast assortment of analogue electrical devices were soon developed for consumer use, though initially these devices were no more than electric lights and electromechanical applications based on electric motors and generators.

As the quantum theory of atomic structure came to be better understood and electricity better controlled, electronic theory became much more important. Spurred by the success of the electromagnetic telegraph of American inventor Samuel Morse (1791-1872), scientists sought other applications. The first major electronic application of worldwide importance was wireless radio, first demonstrated by Italian inventor Guglielmo Marconi (1874-1937). Radio depended on electronic devices known as vacuum tubes, in which structures capable of controlling currents and voltages could operate at high temperatures in an evacuated tube with external contacts. In 1947, American physicist William Shockley and colleagues invented the semiconductor-based transistor, which could be made to function in the same manner as vacuum tube devices, but without the high temperatures, electrical power consumption, and vacuum construction of those analogue devices.

In 1970, the first integrated circuit “chips” were made by constructing very small transistor structures on the surface of a silicon chip. This gave rise to the entire digital technology that powers the modern world.

Applications and Products

Electronics are applied in practically every conceivable manner today, based on their utility in converting easily-produced electrical current into mechanical movement, sound, light, and information signals.

Basic Electronic Devices. Transistor-based digital technology has replaced older vacuum tube technology, except in rare instances in which a transistorized device cannot perform the same function. Electronic circuits based on vacuum tubes could carry out essentially the same individual operations as transistors, but they were severely limited by physical size, heat production, energy consumption, and mechanical failure. Nevertheless, vacuum tube technology was the basic technology that produced radio, television, radar, X-ray machines, and a broad variety of other electronic applications.

Electronic devices that did not use vacuum tube technology, but which operated on electronic and electromagnetic principles, were, and still are, numerous. These devices include electromagnets and all electric motors and generators. The control systems for many such devices generally consisted of nothing more than switching circuits and indicator lights. More advanced and highly sensitive devices required control systems that utilized the more refined and correspondingly sensitive capabilities available with vacuum tube technology.

Circuit Boards. The basic principles of electricity, such as Ohm’s resistance law and Kirchoff’s current law and capacitance and inductance, are key features in the functional design and engineering of analogue electronic systems, especially for vacuum-tube control systems. An important application that facilitated the general use and development of electronic systems of all kinds is printed circuit board technology. A printed circuit board accepts standardized components onto a nonconducting platform made initially of compressed fiber board, which was eventually replaced by a resin-based composite board. A circuit design is photo-etched onto a copper sheet that makes up one face of the circuit board, and all nonetched copper is chemically removed from the surface of the board, leaving the circuit pattern. The leads of circuit components such as resistors, capacitors, and inductors are inserted into the circuit pattern and secured with solder connections.

Mass production requirements developed the flotation soldering process, whereby preassembled circuit boards are floated on a bed of molten solder, which automatically completes all solder connections at once with a high degree of consistency. This has become the most important means of circuit board production since the development of transistor technology, being highly compatible with mechanization and automation and with the physical shapes and dimensions of integrated circuit (IC) chips and other components.

Digital Devices. Semiconductor-based transistors comprise the heart of modern electronics and electronic engineering. Unlike vacuum tubes, transistors do not work on a continuous electrical signal. Instead, they function exceedingly well as simple on-off switches that are easily controlled. This makes them well adapted to functions based on Boolean algebra. All transistor structures consist of a series of “gates” that perform a specific function on the electronic signals that are delivered to them.

Digital devices now represent the most common (and rapidly growing) application of electronics and electronic engineering, including relatively simple consumer electronic devices such as compact fluorescent light bulbs and motion-detecting air fresheners to the most advanced computers and analytical instrumentation. All applications, however, utilize an extensive, but limited, assortment of digital components in the form of IC chips that have been designed to carry out specific actions with electrical or electromagnetic input signals.

Input signals are defined by the presence or absence of a voltage or a current, depending upon the nature of the device. Inverter gates reverse the sense of the input signal, converting an input voltage (high input) into an output signal of no voltage (low output), and vice versa. Other transistor structures (gates) called AND, NAND, OR, NOR and X-OR function to combine input signals in different ways to produce corresponding output signals. More advanced devices (for example, counters and shift registers) use combinations of the different gates to construct various functional circuits that accumulate signal information or that manipulate signal information in various ways.

One of the most useful of digital IC components is the operational amplifier, or Op-Amp. Op-Amps contain transistor-based circuitry that boosts the magnitude of an input signal, either voltage or current, by five orders of magnitude (100,000 times) or more, and are the basis of the exceptional sensitivity of the modern analytical instruments used in all fields of science and technology.

Electrical engineers are involved in all aspects of the design and development of electronic equipment. Engineers act first as the inventors and designers of electronic systems, conceptualizing the specific functions a potential system will be required to carry out. This process moves through the specification of the components required for the system’s functionality to the design of new system devices. The design parameters extend to the infrastructure that must support the system in operation. Engineers determine the standards of safety, integrity, and operation that must be met for electronic systems.

Consumer Electronics. For the most part, the term “electronics” is commonly used to refer to the electronic devices developed for retail sale to consumers. These devices include radios, television sets, DVD and CD players, cell phones and messaging devices, cameras and camcorders, laptops, tablets, printers, computers, fax and copy machines, cash registers, and scanners. Millions such devices are sold around the world each day, and numerous other businesses have formed to support their operation.

Impact on Industry

With electrical and electronic technology now intimately associated with all aspects of society, the impact of electronics and electronic engineering on industry is immeasurable. It would be entirely fair to say that modern industry could not exist without electronics. Automated processes, which are ubiquitous, are not possible without the electronic systems that control them.

The transportation industry, particularly the automotive industry, is perhaps the most extensive user of electronics and electronic engineering. Modern automobiles incorporate an extensive electronic network in their construction to provide the ignition and monitoring systems for the operation of their internal combustion engines and for the many monitoring and control systems for the general safe operation of the vehicle; an electronic network also informs and entertains the driver and passengers. In some cases, electronic systems can completely take control of the vehicle to carry out such specific programmable actions as speed control and parallel parking. Every automated process in the manufacture of automobiles and other vehicles serves to reduce the labor required to carry out the corresponding tasks, while increasing the efficiency and precision of the process steps. Added electronic features also increase the marketability of the vehicles and, hence, manufacturer profits.

Processes that have been automated electronically also have become core components of general manufacturing, especially in the control of production machinery. For example, shapes formed from bent tubing are structural components in a wide variety of applications. While the process of bending the tubing can be carried out by the manual operation of a suitably equipped press, an automated process will produce tube structures that are bent to exact angles and radii in a consistent manner. Typically, a human operator places a straight tube into the press, which then positions and repositions the tube for bending over its length, according to the program that has been entered into the manufacturing system’s electronic controller. Essentially, all continuous manufacturing operations are electronically controlled, providing consistent output.

Electronics and electronic engineering make up the essence of the computer industry; indeed, electronics is an industry worth billions of dollars annually. Electronics affects not only the material side of industry but also the theoretical and actuarial side. Business management, accounting, customer relations, inventory and sales data, and human resourcesmanagement all depend on the rapid information-handling that is possible through electronics.

XML (extensible markup language) methods and applications are being used (and are in development) to interface electronic data collection directly to physical processes. This demands the use of specialized electronic sensing and sampling devices to convert measured parameters into data points within the corresponding applications and databases. XML is an application that promises to facilitate information exchange and to promote research using large-applications are being used (and are in development) to interface electronic data collection directly to physical processes. This demands the use of specialized electronic sensing and sampling devices to convert measured parameters into data points within the corresponding applications and databases. XML is an application that promises to facilitate information exchange and to promote research using large-scale databases. The outcome of this effort is expected to enhance productivity and to expand knowledge in ways that will greatly increase the efficiency and effectiveness of many different fields.

An area of electronics that has become of great economic importance in recent years is that of electronic commerce: the exclusive use of electronic communication technology for the conduct of business between suppliers and consumers. Electronic communications encompasses interoffice faxing, e-mail exchanges, and the Web commerce of companies such as eBay, Amazon, Google, and of the New York and other stock exchanges. The commercial value of these undertakings is measured in billions of dollars annually, and it is expected to continue to increase as new applications and markets are developed.

The fundamental feature here is that these enterprises exist because of the electronic technology that enables them to communicate with consumers and with other businesses. The electronics technology and electronics engineering fields have thus generated entirely new and different daughter industries, with the potential to generate many others, all of which will depend on persons who are knowledgeable in the application and maintenance of electronics and electronic systems.

Careers and Coursework

Many careers depend on knowledge of electronics and electronic engineering because almost all machines and devices used in modern society either function electronically or utilize some kind of electronic control system. The automobile industry is a prime example, as it depends on electronic systems at all stages of production and in the normal operation of a vehicle. Students pursuing a career in automotive mechanics can therefore be expected to study electronic principles and applications as a significant part of their training. The same reasoning applies in all other fields that have a physical reliance on electronic technology.

Knowledge of electronics has become so essential that atomic structure and basic electronic principles, for example, have been incorporated into the elementary school curriculum. Courses of study in basic electronics in the secondary school curriculum are geared to provide a more detailed and practicable knowledge to students.

Specialization in electronics and other fields in which electronics play a significant role is the province of a college education. Interested students can expect to take courses in advanced mathematics, physics, chemistry, and electronics technology as part of the curriculum of their specialty programs. Normally, a technical career, or a skilled trade, requires a college-level certification and continuing education. In some cases, recertification on a regular schedule is also required to maintain specialist standing in that trade.

Students who plan to pursue a career in electronic engineering at a more theoretical level will require, at minimum, a bachelor’s degree. A master’s degree can prepare a student for a career in forensics, law, and other professions in which an intimate or specialized knowledge of the theoretical side of electronics can be advantageous. (The Vocational Information Center provides an extensive list of careers involving electronics at http://www.khake.com/page19.html.)

Social Context and Future Prospects

It is difficult, if not impossible, to imagine modern society without electronic technology. Electronics has enabled the world of instant communication, wherein a person on one side of the world can communicate directly and almost instantaneously with someone on the other side of the world. As a social tool, such facile communication has the potential to bring about understanding between peoples in a way that has until now been imagined only in science fiction.

Consequently, this facility has also resulted in harm. While social networking sites, for example, bring people from widely varied backgrounds together peacefully to a common forum, network hackers and socalled cyber criminals use electronic technology to steal personal data and disrupt financial markets.

Electronics itself is not the problem, for it is only a tool. Electronic technology, though built on a foundation that is unlikely to change in any significant way, will nevertheless be transformed into newer and better applications. New electronic principles will come to the fore. Materials such as graphene and quantum dots, for example, are expected to provide entirely new means of constructing transistor structures at the atomic and molecular levels. Compared with the 50 to 100 nanometer size of current transistor technology, these new levels would represent a difference of several orders of magnitude. Researchers suggest that this sort of refinement in scale could produce magnetic memory devices that can store as much as ten terabits of information in one square centimeter of disk surface. Although the technological advances seem inevitable, realizing such a scale will require a great deal of research and development.

Further Reading

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