Electrical Engineering

Summary

Electrical engineering is a broad field ranging from the most elemental electrical devices to high-level electronic systems design. An electrical engineer is expected to have a fundamental understanding of electricity and electrical devices as well as be a versatile computer programmer. All of the electronic devices that permeate modern living originate with an electrical engineer. Items such as garage door openers and smartphones are based on the application of electrical theory. Even the computer tools, fabrication facilities, and math to describe it all are the purview of the electrical engineer. Within the field, there are many specializations. Some focus on high-power analog devices, while others focus on integrated circuit design or computer systems.

Definition and Basic Principles

Electrical engineering is the application of multiple disciplines converging to create simple or complex electrical systems. An electrical system can be as simple as a light bulb, power supply, or switch and as complicated as the Internet, including all its hardware and software subcomponents. The spectrum and scale of electrical engineering are extremely diverse. At the atomic scale, electrical engineers can be found studying the electrical properties of electrons through materials. For example, silicon is an extremely important semiconductive material found in all integrated circuit (IC) devices, and knowing how to manipulate it is extremely important to those who work in microelectronics.

While electrical engineers need a fundamental background in basic electricity, many (if not most) electrical engineers do not deal directly with wires and devices, at least on a daily basis. An important subdiscipline in electrical engineering includes IC design engineering: A team of engineers is tasked with using computer software to design IC circuit schematics. These schematics are then passed through a series of verification steps (also done by electrical engineers) before being assembled. Because computers are ubiquitous, and the reliance on good computer programs to perform complicated operations is so important, electrical engineers are adept computer programmers as well. The steps would be the same in any of the subdisciplines of the field.

Background and History

Electrical engineering has its roots in the pioneering work of early experimenters in electricity in the eighteenth and nineteenth centuries, who lent their names to much of the nomenclature, such as French physicist André-Marie Ampère and Italian physicist Alessandro Volta. The title electrical engineer began appearing in the late nineteenth century, although to become an electrical engineer did not entail any special education or training, just ambition. After American inventor Thomas Edison's direct current (DC) lost the standards war to Croatian-born inventor Nicola Tesla's alternating current (AC), it was only a matter of time before AC power became standard in every household.

Vacuum tubes were used in electrical devices such as radios in the early twentieth century. The first computers were built using warehouses full of vacuum tubes. They required multiple technicians and programmers to operate because when one tube burst, computation could not begin until it had been identified and replaced.

The transistor was invented in 1947 by John Bardeen, Walter Brattain, and William Shockley, employees of Bell Laboratories. By soldering together boards of transistors, electrical engineers created the first modern computers in the 1960s. By the 1970s, integrated circuits were shrinking the size of computers and the purely electrical focus of the field.

Electrical engineers have dominated IC design and systems engineering, which include mainframes, personal computers, and cloud computing. There is still a demand for high-energy electrical devices, such as airplanes, tanks, and power plants, but because electricity has so many diverse uses, the field will continue to diversify as well.

How It Works

In a typical scenario, an electrical engineer, or a team of electrical engineers, will be tasked with designing an electrical device or system. It could be a computer, the component inside a computer (such as a central processing unit, or CPU), a national power grid, an office intranet, a power supply for a jet, or an automobile ignition system. In each case, however, the electrical engineer's grasp on the fundamentals of the field are crucial.

Electricity. For any electrical application to work, it needs electricity. Once a device or system has been identified for assembly, the electrical engineer must know how it uses electricity. A computer will use low voltages for sensitive IC devices and higher ones for fans and disks. Inside the IC, electricity will be used as the edges of clock cycles that determine what its logical values are. A power grid will generate the electricity itself at a power plant, then transmit it at high voltage over a grid of transmission lines.

Electric Power. When it is determined how the device or application will use electricity, the source of that power must also be understood. Will it be a standard AC power outlet? Or a DC battery? To power a computer, the voltage must be lowered and converted to DC. To power a jet, the spinning turbines (which run on jet fuel) generate electricity, which can then be converted to DC and will then power the onboard electrical systems. In some cases, it is possible to design for what happens in the absence of power, such as the battery backup on an alarm clock or an office's backup generator. An interesting case is the hybrid motor of certain cars such as the Toyota Prius. It has both an electromechanical motor and an electric one. Switching the drivetrain seamlessly between the two is quite a feat of electrical and mechanical engineering.

Circuits. If the application under consideration has circuit components, then its circuitry must be designed and tested. To test the design, mock-ups are often built onto breadboards (plastic rows of contacts that allow wiring up a circuit to be done easily and quickly). An oscilloscope and voltmeter can be used to measure the signal and its strength at various nodes. Once the design is verified, if necessary the schematic can be sent to a fabricator and mass manufactured onto a circuit board.

Digital Logic. Often, an electrical engineer will not need to build the circuits themselves. Using computer design tools and tailored programming languages, an electrical engineer can create a system using logic blocks, then synthesize the design into a circuit. This is the method used for designing and fabricating application-specific integrated circuits (ASICs) and field-programmable gate arrays (FPGAs).

Digital Signal Processing (DSP). Since digital devices require digital signals, it is up to the electrical engineer to ensure that the correct signal is coming in and going out of the digital circuit block. If the incoming signal is analog, it must be converted to digital via an analog-to-digital converter, or if the circuit block can only process so much data at a time, the circuit block must be able to time slice the data into manageable chunks. A good example is an MP3 player: The data must be read from the disk while it is moving, converted to sound at a frequency humans can hear, played back at a normal rate, and then converted to an analog sound signal in the headphones. Each one of those steps involves DSP.

Computer Programming. Many of the steps above can be abstracted into a computer programming language. For example, in a logical programming language such as Verilog, an electrical engineer can write lines of code that represent the logic. Another program can then convert it into the schematics of an IC block. A popular programming language called SPICE can simulate how a circuit will behave, saving the designer time by verifying the circuit works as expected before it is ever assembled.

Applications and Products

The products of electrical engineering are an integral part of our everyday life. Everything from cell phones and computers to stereos and electric lighting encompasses the purview of the field.

For example, a cell phone has at every layer the mark of electrical engineering. An electrical engineer designed the hardware that runs the device. That hardware must be able to interface with the established communication channels designated for use. Thus, a firm knowledge of DSP and radio waves went into its design. The base stations with which the cell phone communicates were designed by electrical engineers. The network that allows them to work in concert is the latest incarnation of a century of study in electromagnetism. The digital logic that allows multiple phone conversations to occur at the same time on the same frequency was crafted by electrical engineers. The whole mobile experience integrates seamlessly into the existing landline grid. Even the preexisting technology (low voltage wire to every home) is an electrical engineering accomplishment—not to mention the power cable that charges it from a standard AC outlet.

One finds the handiwork of electrical engineers in such mundane devices as thermostats to the ubiquitous Internet, where everything from the network cards to the keyboards, screens, and software are crafted by electrical engineers. Electrical engineers are historically involved with electromagnetic devices as well, such as the electrical starter of a car or the turbines of a hydroelectric plant. Many devices that aid artists, such as sound recording and electronic musical instruments, are also the inspiration of electrical engineers.

Below is a sampling of the myriad electrical devices that are designed by electrical engineers.

Computers. Computer hardware and often computer software are designed by electrical engineers. The CPU and other ICs of the computer are the product of hundreds of electrical engineers working together to create ever-faster and more miniature devices. Many products can be considered computers, though they are not often thought of as such. Smartphones, video game consoles, and even controls in modern automobiles are computers, as they employ microprocessors. Additionally, the peripherals that are required to interface with a computer have to be designed to work with the computer as well, such as printers, copiers, scanners, and specialty industrial and medical equipment.

Test Equipment. Although these devices are seldom seen by the general public, they are essential to keeping all the other electrical devices in the world working. For example, an oscilloscope can help an electrical engineer test and debug a failing circuit because it can show how various nodes are behaving relative to each other over time. A carpenter might use a wall scanner to find electrical wire, pipes, and studs enclosed behind a wall. A multimeter, which measures voltage, resistance, and current, is handy not just for electrical engineers but also for electricians and hobbyists.

Sound Amplifiers. Car stereos, home theaters, and electric guitars all have one thing in common: They all contain an amplifier. In the past, these have been purely analogue devices, but since the late twentieth century, digital amplifiers have supplanted their analogue brethren due to their ease of operation and size. Audiophiles, however, claim that analogue amplifies sound better.

Power Supplies. These can come in many sizes, both physically and in terms of power. Most people encounter a power supply as a black box plugged into an AC outlet with a cord that powers electrical devices such as a laptop, radio, or television. Inside each is a specially designed power inverter that converts AC power to the required volts and amperes of DC power.

Batteries. Thomas Edison is credited with creating the first portable battery, a rechargeable box that required only water once a week. Batteries are an electrochemical reaction, that is the realm of chemistry, and demonstrate how far afield electrical engineering can seem to go while remaining firmly grounded in its fundamentals. Battery technology is entering a new renaissance as the charge life is extending and the size is shrinking. Edison first marketed his “A” battery for use in electric cars before they went out of fashion. Electric cars that run on batteries may be making a comeback, and their cousin, the hybrid, runs on both batteries and combustion.

The Power Grid. This is one of the oldest accomplishments of electrical engineering. A massive, nationwide, interdependent network of transmission lines delivers power to every corner of the country. The power is generated at hydroelectric plants, coal plants, nuclear plants, and wind and solar plants. The whole thing works such that if any one section fails, the others can pick up the slack. Wind and solar pose particular challenges to the field, as wind and sunshine do not flow at a constant rate, but the power grid must deliver the same current and voltage at all times of day.

Electric Trains and Buses. Many major cities have some kind of public transportation that involves either an electrified rail, or bus wires, or both. These subways, light rails, and trolleys are an important part of municipal infrastructure, built on many of the same principles as the power grid, except that it is localized.

Automobiles. There are many electronic parts in a car. The first to emerge historically is the electric starter, obviating the hand crank. Once there was a battery in the car to power the starter, engineers came up with all sorts of other uses for it: headlamps, windshield wipers, interior lighting, a radio (and later tape and CD players), and the dubious car alarm, to name a few. The most important electrical component of modern automobiles is the computer-controlled fuel injector. This allows for the right amount of oxygen and fuel to be present in the engine for maximum fuel efficiency (or for maximum horsepower). The success of hybrids, and the emerging market of all electric vehicles, to say nothing of self-driving cars, means that there is still more electrical innovation to be had inside a more than century-old technology.

Medical Devices. Though specifically the domain of biomedical engineering, many, if not most, medical devices are designed by electrical engineers who have entered this subdiscipline. Computed axial tomography (CAT) scanners, X-rays, ultrasound, and magnetic resonance imaging (MRI) machines all rely on electromagnetic and nuclear physics applied in an electrical setting (and controlled by electronics). These devices can be used to look into things other than human bodies as well. Researchers demonstrated that an MRI could determine if a block of cheese had properly aged. In addition, ophthalmic equipment such as optical coherence tomography (OCT) can be used to detect glaucoma, macular holes, and hypertensive retinopathy. Micro- or nano-scale devices combined with biological microelectromechanical systems (Bio-MEMS) can be used to make micropumps for drug delivery, biosensors for in-vivo diagnostics, microrobots for making medical procedures less invasive, and stents for widening the blocked artery.

Telecommunications. This used to be an international grid of telephone wires and cables connecting as many corners of the globe where wire could be strung. However, even the most remote outposts can now communicate voice, data, and video thanks to advances in radio technology. The major innovation in this field has been the ability for multiple connections to ride the same signal. The original cell phone technology picked a tiny frequency for each of its users, thus limiting the number of total users to a fixed division in that band. Mobile communication has multiple users on the same frequency, which opens up the band to more users.

Broadcast Television and Radio. These technologies are older but still relevant to the electrical engineer. Radio is as vibrant as ever, and ham radio is even experiencing a mini-renaissance. While there may not be much room for innovation, electrical engineers must understand them to maintain them as well as understand their derivative technologies.

Lighting.Light-emitting diodes (LEDs) are low-power alternatives to incandescent bulbs (the light bulb that Edison invented). They are just transistors, but as they have grown smaller and more colors have been added to their spectrum, they have found their way into interior lighting, computer monitors, flashlights, indicator displays, and control panels.

Careers and Course Work

Electrical engineering requires a diverse breadth of background coursework—math, physics, computer science, and electrical theory—and a desire to specialize while being flexible enough to work with other electrical engineers in their areas of expertise. A bachelor of science degree in electrical engineering usually entails specialization after completing the general coursework. Specializations include circuit design, communications and networks, power systems, and computer science. A master's degree is generally not required for an electrical engineer to work in the industry. However, it would be required to enter academia or to gain a deeper understanding of the specialization. An electrical engineer wishing to work as an electrical systems contractor will probably require professional engineer (PE) certification issued by the state after one has several years of work experience and has passed the certification exam. Organizations such as the Institute of Electrical and Electronics Engineers (IEEE), the Institution of Electrical Engineers (IEE), and the International Society for Optics and Photonics (SPIE) also conduct a variety of research programs.

Careers in the field of electrical engineering are as diverse as its applications. Manufacturing uses electrical engineers to design and program industrial equipment. Telecommunications employs electrical engineers because of their understanding of DSP. More than half of all electrical engineers work in the microchip sector, which uses legions of electrical engineers to design, test, and fabricate ICs on a continually shrinking scale. Though these companies seem dissimilar—medical devices, smartphones, computers (any device that uses an IC)—they have their own staff of electrical engineers that design, test, fabricate, and retest the devices.

Electrical engineers are increasingly seen in the role of computer scientists. The coursework has been converging since the twentieth century. University electrical engineering and computer science departments may share lecturers between the two disciplines. Companies may use electrical engineers to solve a computer programming problem, hoping that the electrical engineer can debug both the hardware and software. Aspirants can work in energy, automotive, pharmaceutical, marine, oil and gas, medical, and naval industries.

Social Context and Future Prospects

Electrical engineering may be the most underrecognized driving force behind modern living. Electrical engineers have facilitated various vital developments, from the electrical revolution to the rise of the personal computer, the Internet, and social networking. This field brought electricity into homes and then ushered in the age of transistors. Much modern technology is consumed as software and requires computer programmers. However, the power grid, hardware, and Internet that power it were designed and maintained by electrical engineers.

As the field continues to diversify and the uses for electricity expand, the need for electrical engineers, as well as the demands placed on the knowledge base required to enter the field, expands. Modern electrical engineers increasingly work with professionals in the biological sciences—a field rarely explored by electrical engineers. The neurons that comprise the human brain are an electrical system, and it makes sense for both fields to embrace the knowledge acquired in the other.

Other disciplines rely on electrical engineering as the foundation. Robotics, for example, merges mechanical and electrical engineering. As robots move out of manufacturing plants and into offices and homes, engineers with a strong understanding of physics are essential. Another related field, biomedical engineering, combines medicine and electrical engineering to produce lifesaving devices such as pacemakers, defibrillators, and CAT scanners. The need for advanced medical treatments and early detection devices becomes paramount as the population ages. Green power initiatives require electrical engineers with strong mechanical engineering and chemistry knowledge.

Electrical engineers are important in a variety of fields. During the COVID-19 pandemic, the electrical engineering sector helped produce economical ventilators, face shields, and prototype medical devices, and in 2021, researchers at the University of Illinois, Chicago, developed a fast method to check COVID-19 infection using graphene sheets. Research in electric car technology, such as long-life, reliable batteries and charging capabilities, is increasingly in demand as governmental regulations and sustainable living initiatives drive innovation. Other areas of research include smart grids and wearable technology. Electrical engineers continually incorporate new materials in their work, such as wide bandgap (WBG) semiconductors like silicon carbide and gallium nitride. Additionally, electrical engineers are needed to aid in the development of prosthetics and other medical devices.

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