Electrical engineering explained




See main article: History of electrical engineering. Electricity has been a subject of scientific interest since at least the early 17th century. The first electrical engineer was probably William Gilbert who designed the versorium: a device that detected the presence of statically charged objects. He was also the first to draw a clear distinction between magnetism and static electricity and is credited with establishing the term electricity.[2] In 1775 Alessandro Volta's scientific experimentations devised the electrophorus, a device that produced a static electric charge, and by 1800 Volta developed the voltaic pile, a forerunner of the electric battery.[3]


During these years, the study of electricity was largely considered to be a subfield of physics. It was not until the late 19th century that universities started to offer degrees in electrical engineering. The Darmstadt University of Technology founded the first chair and the first faculty of electrical engineering worldwide in 1882. In 1883 Darmstadt University of Technology and Cornell University introduced the world's first courses of study in electrical engineering, and in 1885 the University College London founded the first chair of electrical engineering in the United Kingdom.[5] The University of Missouri subsequently established the first department of electrical engineering in the United States in 1886.[6] During this period, the work concerning electrical engineering increased dramatically. In 1882, Edison switched on the world's first large-scale electrical supply network that provided 110 volts direct current to fifty-nine customers in lower Manhattan. In 1887, Nikola Tesla filed a number of patents related to a competing form of power distribution known as alternating current. In the following years a bitter rivalry between Tesla and Edison, known as the "War of Currents", took place over the preferred method of distribution. AC eventually replaced DC for generation and power distribution, enormously extending the range and improving the safety and efficiency of power distribution.

The efforts of the two did much to further electrical engineering - Tesla's work on induction motors and polyphase systems influenced the field for years to come, while Edison's work on telegraphy and his development of the stock ticker proved lucrative for his company, which ultimately became General Electric. However, by the end of the 19th century, other key figures in the progress of electrical engineering were beginning to emerge.[7]

Modern developments

During the development of radio, many scientists and inventors contributed to radio technology and electronics. In his classic UHF experiments of 1888, Heinrich Hertz transmitted (via a spark-gap transmitter) and detected radio waves using electrical equipment. In 1895, Nikola Tesla was able to detect signals from the transmissions of his New York lab at West Point (a distance of 80.4 km / 49.95 miles).[8] In 1897, Karl Ferdinand Braun introduced the cathode ray tube as part of an oscilloscope, a crucial enabling technology for electronic television.[9] John Fleming invented the first radio tube, the diode, in 1904. Two years later, Robert von Lieben and Lee De Forest independently developed the amplifier tube, called the triode.[10] In 1895, Guglielmo Marconi furthered the art of hertzian wireless methods. Early on, he sent wireless signals over a distance of one and a half miles. In December 1901, he sent wireless waves that were not affected by the curvature of the Earth. Marconi later transmitted the wireless signals across the Atlantic between Poldhu, Cornwall, and St. John's, Newfoundland, a distance of 2100miles.[11] In 1920 Albert Hull developed the magnetron which would eventually lead to the development of the microwave oven in 1946 by Percy Spencer.[12] [13] In 1934 the British military began to make strides towards radar (which also uses the magnetron) under the direction of Dr Wimperis, culminating in the operation of the first radar station at Bawdsey in August 1936.[14]

In 1941 Konrad Zuse presented the Z3, the world's first fully functional and programmable computer.[15] In 1946 the ENIAC (Electronic Numerical Integrator and Computer) of John Presper Eckert and John Mauchly followed, beginning the computing era. The arithmetic performance of these machines allowed engineers to develop completely new technologies and achieve new objectives, including the Apollo missions and the NASA moon landing.[16]

The invention of the transistor in 1947 by William B. Shockley, John Bardeen and Walter Brattain opened the door for more compact devices and led to the development of the integrated circuit in 1958 by Jack Kilby and independently in 1959 by Robert Noyce.[17] In 1968 Marcian Hoff invented the first microprocessor at Intel and thus ignited the development of the personal computer. The first realization of the microprocessor was the Intel 4004, a 4-bit processor developed in 1971, but only in 1973 did the Intel 8080, an 8-bit processor, make the building of the first personal computer, the Altair 8800, possible.[18]


See main article: Education and training of electrical and electronics engineers. Electrical engineers typically possess an academic degree with a major in electrical engineering. The length of study for such a degree is usually four or five years and the completed degree may be designated as a Bachelor of Engineering, Bachelor of Science, Bachelor of Technology or Bachelor of Applied Science depending upon the university. The degree generally includes units covering physics, mathematics, computer science, project management and specific topics in electrical engineering. Initially such topics cover most, if not all, of the sub-disciplines of electrical engineering. Students then choose to specialize in one or more sub-disciplines towards the end of the degree.

Some electrical engineers also choose to pursue a postgraduate degree such as a Master of Engineering/Master of Science (MEng/MSc), a Master of Engineering Management, a Doctor of Philosophy (PhD) in Engineering, an Engineering Doctorate (EngD), or an Engineer's degree. The Master and Engineer's degree may consist of either research, coursework or a mixture of the two. The Doctor of Philosophy and Engineering Doctorate degrees consist of a significant research component and are often viewed as the entry point to academia. In the United Kingdom and various other European countries, the Master of Engineering is often considered an undergraduate degree of slightly longer duration than the Bachelor of Engineering.[19]

Practicing engineers


The advantages of certification vary depending upon location. For example, in the United States and Canada "only a licensed engineer may seal engineering work for public and private clients".[20] This requirement is enforced by state and provincial legislation such as Quebec's Engineers Act.[21] In other countries, such as Australia, no such legislation exists to practise engineering, however it is a mandate that if an engineer is to sign off or seal an engineering document or drawing then that person must be registered as a Certified Practising Engineer (or CPEng).[22] Practically all certifying bodies maintain a code of ethics that they expect all members to abide by or risk expulsion.[23] In this way these organizations play an important role in maintaining ethical standards for the profession. Even in jurisdictions where certification has little or no legal bearing on work, engineers are subject to contract law. In cases where an engineer's work fails he or she may be subject to the tort of negligence and, in extreme cases, the charge of criminal negligence. An engineer's work must also comply with numerous other rules and regulations such as building codes and legislation pertaining to environmental law.

Professional bodies of note for electrical engineers include the Institute of Electrical and Electronics Engineers (IEEE) and the Institution of Engineering and Technology (IET). The IEEE claims to produce 30% of the world's literature in electrical engineering, has over 360,000 members worldwide and holds over 3,000 conferences annually.[24] The IET publishes 21 journals, has a worldwide membership of over 150,000, and claims to be the largest professional engineering society in Europe.[25] [26] Obsolescence of technical skills is a serious concern for electrical engineers. Membership and participation in technical societies, regular reviews of periodicals in the field and a habit of continued learning are therefore essential to maintaining proficiency.[27]

In countries such as Australia, Canada and the United States electrical engineers make up around 0.25% of the labor force (see

note). Outside of these countries, it is difficult to gauge the demographics of the profession due to less meticulous reporting on labor statistics. However, in terms of electrical engineering graduates per-capita, electrical engineering graduates would probably be most numerous in countries such as Taiwan, Japan, India and South Korea.[28]

Tools and work














See main article: Electronic engineering. Electronic engineering involves the design and testing of electronic circuits that use the properties of components such as resistors, capacitors, inductors, diodes and transistors to achieve a particular functionality. The tuned circuit, which allows the user of a radio to filter out all but a single station, is just one example of such a circuit. Another example (of a pneumatic signal conditioner) is shown in the adjacent photograph.

Prior to the second world war, the subject was commonly known as radio engineering and basically was restricted to aspects of communications and radar, commercial radio and early television. Later, in post war years, as consumer devices began to be developed, the field grew to include modern television, audio systems, computers and microprocessors. In the mid to late 1950s, the term radio engineering gradually gave way to the name electronic engineering.



See main article: Microelectronics. Microelectronics engineering deals with the design and microfabrication of very small electronic circuit components for use in an integrated circuit or sometimes for use on their own as a general electronic component. The most common microelectronic components are semiconductor transistors, although all main electronic components (resistors, capacitors, inductors) can be created at a microscopic level.


Signal processing


Signal Processing is a very mathematically oriented and intensive area forming the core of Digital Signal Processing (DSP) and it is rapidly expanding with new applications in every field of electrical engineering such as communications, control, radar, TV/Audio/Video engineering, power electronics and bio-medical engineering as many already existing analog systems are replaced with their digital counterparts.

Although in the classical era, analog signal processing only provided a mathematical description of a system to be designed, which is actually implemented by the analog hardware engineers, Digital Signal Processing both provides a mathematical description of the systems to be designed and also actually implements them (either by software programming or by hardware embedding) without much dependency on hardware issues, which exponentiates the importance and success of DSP engineering.

The deep and strong relations between signals and the information they carry, makes signal processing equivalent of information processing. Which is the reason why the field finds so many diversified applications. DSP processor ICs are found in every type of modern electronic systems and products including, SDTV | HDTV sets, radios and mobile communication devices, Hi-Fi audio equipments, Dolby noise reduction algorithms, GSM mobile phones, mp3 multimedia players, camcorders and digital cameras, automobile control systems, noise cancelling headphones, digital spectrum analyzers, intelligent missile guidance, radar, GPS based cruise control systems and all kinds of image processing, video processing, audio processing and speech processing systems...Just to mention a few of the possibly much more.


See main article: Telecommunications engineering. Telecommunications engineering focuses on the transmission of information across a channel such as a coax cable, optical fiber or free space. Transmissions across free space require information to be encoded in a carrier wave in order to shift the information to a carrier frequency suitable for transmission, this is known as modulation. Popular analog modulation techniques include amplitude modulation and frequency modulation. The choice of modulation affects the cost and performance of a system and these two factors must be balanced carefully by the engineer.



See main article: Instrumentation engineering. Instrumentation engineering deals with the design of devices to measure physical quantities such as pressure, flow and temperature. The design of such instrumentation requires a good understanding of physics that often extends beyond electromagnetic theory. For example, radar guns use the Doppler effect to measure the speed of oncoming vehicles. Similarly, thermocouples use the Peltier-Seebeck effect to measure the temperature difference between two points.




Related disciplines


The term mechatronics is typically used to refer to macroscopic systems but futurists have predicted the emergence of very small electromechanical devices. Already such small devices, known as micro electromechanical systems (MEMS), are used in automobiles to tell airbags when to deploy, in digital projectors to create sharper images and in inkjet printers to create nozzles for high definition printing. In the future it is hoped the devices will help build tiny implantable medical devices and improve optical communication.[31]

Biomedical engineering is another related discipline, concerned with the design of medical equipment. This includes fixed equipment such as ventilators, MRI scanners and electrocardiograph monitors as well as mobile equipment such as cochlear implants, artificial pacemakers and artificial hearts.

See also



Note I - There are around 370,000 people working as computer hardware or electrical engineers in the United States constituting 0.24% of the labor force .[32] [33] In Australia, there are around 24,000 constituting 0.23% of the labour force and in Canada, there are around 34,600 constituting 0.21% of the labour force . Australia and Canada also report that 96% and 89% of their electrical engineers respectively are male.[34] [35]

External links

Notes and References

  1. Web site: What is the difference between electrical and electronic engineering?. FAQs - Studying Electrical Engineering. mdy. 4 February 2005.
  2. Web site: William Gilbert (1544–1603). Pioneers in Electricity. mdy. 13 May 2007.
  3. Vaunt Design Group. (2005).Inventor Alessandro Volta Biography. Troy MI: The Great Idea Finder. Accessed 21 March 2008.
  4. Encyclopedia: Encyclopedia Britannica. 11. 1911. "Ohm, Georg Simon", "Faraday, Michael" and "Maxwell, James Clerk".
  5. Web site: Welcome to ECE!. Cornell University - School of Electrical and Computer Engineering. mdy. 29 December 2005.
  6. Book: Ryder, John and Fink, Donald;. Engineers and Electrons. IEEE Press. 1984. 0-87942-172-X.
  7. Web site: History. National Fire Protection Association (NFPA). mdy. 19 January 2006. (published 1996 in the NFPA Journal)
  9. Web site: Karl Ferdinand Braun. mdy. 10 September 2006.
  10. Web site: History of Amateur Radio. What is Amateur Radio?. mdy. 18 January 2006.
  11. http://nobelprize.org/nobel_prizes/physics/laureates/1909/marconi-bio.html Marconi's biography at Nobelprize.org
  12. Web site: Albert W. Hull (1880–1966). IEEE History Center. mdy. 22 January 2006.
  13. Web site: Who Invented Microwaves?. mdy. 22 January 2006.
  14. Web site: Early Radar History. Peneley Radar Archives. mdy. 22 January 2006.
  15. Web site: The Z3. mdy. 18 January 2006.
  16. Web site: The ENIAC Museum Online. mdy. 18 January 2006.
  17. Web site: Electronics Timeline. Greatest Engineering Achievements of the Twentieth Century. mdy. 18 January 2006.
  18. Web site: Computing History (1971–1975). mdy. 18 January 2006.
  20. Web site: Why Should You Get Licensed?. National Society of Professional Engineers. mdy. 11 July 2005.
  21. Web site: Engineers Act. Quebec Statutes and Regulations (CanLII). mdy. 24 July 2005.
  22. Web site: Professional Engineers - Application. Engineers Australia. mdy. 28 September 2008.
  23. Web site: Codes of Ethics and Conduct. Online Ethics Center. mdy. 24 July 2005.
  24. Web site: About the IEEE. IEEE. mdy. 11 July 2005.
  25. Web site: About the IET. The IET. mdy. 11 July 2005.
  26. Web site: Journal and Magazines. The IET. mdy. 11 July 2005.
  27. Web site: Electrical and Electronics Engineers, except Computer. Occupational Outlook Handbook. mdy. 16 July 2005. (see here regarding copyright)
  28. Web site: National Science Foundation. 2004. Science and Engineering Indicators 2004, Appendix 2-33. PDF.
  29. Web site: Electrical and Electronics Engineers, except Computer. Occupational Outlook Handbook. mdy. 16 July 2005. (see Internet Archive)
  31. Web site: MEMS the world!. IntelliSense Software Corporation. mdy. 17 July 2005.
  32. Web site: Electrical Engineers. Bureau of Labor Statistics. 2008-06-20.
  33. Web site: Work Experience of the Population in 2006. Bureau of Labor Statistics. 2008-06-20.
  34. Web site: Electrical and Electronics Engineers. Australian Careers. mdy. 27 August 2005.
  35. Web site: Electrical and Electronics Engineers (NOC 2133). Job Futures (National Edition). mdy. 27 August 2005.