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| '''Electrical engineering''' (sometimes referred to as electrical and electronic engineering) is a professional ] discipline that deals with the study and application of ], ] and ]. The field first became an identifiable occupation in the late nineteenth century with the commercialization of the electric ] and electrical power supply. The field now covers a range of sub-disciplines including those that deal with ], ], ], ], ], ], ], ], ] and ]. | |||
| The term ''electrical engineering'' may or may not encompass ''electronic engineering''. Where a distinction is made, electrical engineering is considered to deal with the problems associated with large-scale electrical systems such as ] and ], whereas electronic engineering deals with the study of small-scale electronic systems including ] and ].<ref>{{cite web | title = What is the difference between electrical and electronic engineering? | work = FAQs - Studying Electrical Engineering | url = http://www.ieee.org/organizations/eab/faqs1.htm | accessdate = February 4 | accessyear = 2005 }}</ref> Another way of looking at the distinction is that electrical engineers are usually concerned with using electricity to transmit energy, while electronics engineers are concerned with using electricity to transmit information. | |||
| == History == | |||
| {{main|History of electrical engineering}} | |||
| === Early developments === | |||
| ] has been a subject of scientific interest since at least the 17th century, but it was not until the 19th century that research into the subject started to intensify. Notable developments in this century include the work of ], who in 1827 quantified the relationship between the ] and ] in a conductor, ], the discoverer of ] in 1831, and ], who in 1873 published a unified ] of electricity and ] in his treatise on ''Electricity and Magnetism''.<ref>{{cite encyclopedia| ency = Encyclopædia Britannica | edition = 11 | year = 1911 | article = "Ohm, Georg Simon", "Faraday, Michael" and "Maxwell, James Clerk"}}</ref> | |||
| During these years, the study of electricity was largely considered to be a subfield of ]. It was not until the late 19th century that ] started to offer ] in electrical engineering. The ] founded the first chair and the first faculty of electrical engineering worldwide in 1882. In 1883 ] and ] introduced the world's first courses of study in electrical engineering and in 1885 the ] founded the first chair of electrical engineering in the ].<ref>{{cite web | title = Welcome to ECE! | work = Cornell University - School of Electrical and Computer Engineering | url = http://www.ece.cornell.edu | accessdate = December 29 | accessyear = 2005 }}</ref> The ] subsequently established the first department of electrical engineering in the United States in 1886.<ref>{{cite book | author = Ryder, John and Fink, Donald; | title = Engineers and Electrons | publisher = IEEE Press | year = 1984 | id = ISBN 0-87942-172-X }}</ref> | |||
| ] built the world's first large-scale electrical supply network]] During this period, the work concerning electrical engineering increased dramatically. In 1882, ] switched on the world's first large-scale electrical supply network that provided 110 volts ] to fifty-nine customers in lower Manhattan. In 1887, ] filed a number of patents related to a competing form of power distribution known as ]. In the following years a bitter rivalry between Tesla and Edison, known as the "]", 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. | |||
| ] made long-distance electrical transmission networks possible.]] The efforts of the two did much to further electrical engineering—Tesla's work on ]s and ]s influenced the field for years to come, while Edison's work on telegraphy and his development of the ] proved lucrative for his company, which ultimately became ]. However, by the end of the 19th century, other key figures in the progress of electrical engineering were beginning to emerge.<ref>{{cite web | title = History | work = National Fire Protection Association | url = http://www.nfpa.org/itemDetail.asp?categoryID=500&itemID=18020&URL=About%20Us/History | accessdate = January 19 | accessyear = 2006 }} ''(published 1996 in the NFPA Journal)''</ref> | |||
| ===Modern developments=== | |||
| ; Emergence of radio and electronics | |||
| During the ], many scientists and ]s contributed to ] and electronics. In his classic ] experiments of 1888, ] transmitted (via a ]) and detected ] 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). <ref>Leland Anderson, "''Nikola Tesla On His Work With Alternating Currents and Their Application to Wireless Telegraphy, Telephony, and Transmission of Power''", Sun Publishing Company, LC 92-60482, ISBN 0-9632652-0-2 (''ed''. )</ref> In 1897, ] introduced the ] as part of an ], a crucial enabling technology for ].<ref>{{cite web | title = Karl Ferdinand Braun | url = http://nobelprize.org/nobel_prizes/physics/laureates/1909/braun-bio.html | accessdate = September 10 | accessyear = 2006 }}</ref> ] invented the first radio tube, the ], in 1904. Two years later, ] and ] independently developed the amplifier tube, called the ]. <ref>{{cite web | title = History of Amateur Radio | work = What is Amateur Radio? | url = http://www.amateurradio.uni-halle.de/hamradio.en.html | accessdate = January 18 | accessyear = 2006 }}</ref> In 1920 ] developed the ] which would eventually lead to the development of the ] in 1946 by ].<ref>{{cite web | title = Albert W. Hull (1880 - 1966) | work = IEEE History Center | url = http://www.ieee.org/organizations/history_center/legacies/hull.html | accessdate = January 22 | accessyear = 2006 }}</ref><ref>{{cite web | title = Who Invented Microwaves? | url = http://www.gallawa.com/microtech/history.html | accessdate = January 22 | accessyear = 2006 }}</ref> In 1934 the British military began to make strides towards ] (which also uses the magnetron), under the direction of Dr Wimperis culminating in the operation of the first radar station at ] in August 1936.<ref>{{cite web | title = Early Radar History | work = Peneley Radar Archives | url = http://www.penleyradararchives.org.uk/history/introduction.htm | accessdate = January 22 | accessyear = 2006 }}</ref> | |||
| In 1941 ] presented the ], the world's first fully functional and programmable computer.<ref>{{cite web | title = The Z3 | url = http://irb.cs.tu-berlin.de/~zuse/Konrad_Zuse/en/Rechner_Z3.html | accessdate = January 18 | accessyear = 2006 }}</ref> In 1946 the ] (Electronic Numerical Integrator and Computer) of ] and ] followed, beginning the computing era. The arithmetic performance of these machines allowed engineers to develop completely new technologies and achieve new objectives, including the ] and the ].<ref>{{cite web | title = The ENIAC Museum Online | url = http://www.seas.upenn.edu/~museum/guys.html | accessdate = January 18 | accessyear = 2006 }}</ref> | |||
| The invention of the transistor in 1947 by ], ] and ] opened the door for more compact devices and led to the development of the ] in 1958 by ] and independently in 1959 by ].<ref>{{cite web | title = Electronics Timeline | work = Greatest Engineering Achievements of the Twentieth Century | url = http://www.greatachievements.org/?id=3956 | accessdate = January 18 | accessyear = 2006 }}</ref> In 1968 ] invented the first ] at ] and thus ignited the development of the ]. The first realization of the microprocessor was the ], a 4-bit processor developed in 1971, but only in 1973 did the ], an 8-bit processor, make the building of the first personal computer, the ], possible.<ref>{{cite web | title = Computing History (1971 - 1975) | url = http://mbinfo.mbdesign.net/1971-75.htm | accessdate = January 18 | accessyear = 2006 }}</ref> | |||
| == Education == | |||
| Electrical engineers typically possess an ] 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 ], ], ] or ] depending upon the university. The degree generally includes units covering ], ], ], ] and ]. 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 ]/], a Master of ], a ] in Engineering or an ]. The Master and Engineer's degree may consist of either ], ] or a mixture of the two. The ] consists of a significant research component and is often viewed as the entry point to ]. In the United Kingdom and various other European countries, the ] is often considered an undergraduate degree of slightly longer duration than the ].<ref>Various including graduate degree requirements at MIT , study guide at UWA , the curriculum at Queen's and Aberdeen's unit tables </ref> | |||
| == Practicing engineers == | |||
| In most countries, a Bachelor's degree in engineering represents the first step towards ] and the degree program itself is certified by a ]. After completing a certified degree program the engineer must satisfy a range of requirements (including work experience requirements) before being certified. Once certified the engineer is designated the title of ] (in the United States, Canada and ] ), ] (in the ], ], ] and ]), ] (in ] and ]) or ] (in much of the ]). | |||
| 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".<ref>{{cite web | title = Why Should You Get Licensed? | work = National Society of Professional Engineers | url = http://www.nspe.org/lc1-why.asp | accessdate = July 11 | accessyear = 2005 }}</ref> This requirement is enforced by state and provincial legislation such as ] Engineers Act.<ref>{{cite web | title = Engineers Act | work = Quebec Statutes and Regulations (CanLII) | url = http://www.canlii.org/qc/laws/sta/i-9/20050616/whole.html | accessdate = July 24 | accessyear = 2005 }}</ref> In other countries, such as Australia, no such legislation exists. Practically all certifying bodies maintain a ] that they expect all members to abide by or risk expulsion.<ref>{{cite web | title = Codes of Ethics and Conduct | work = Online Ethics Center | url = http://onlineethics.org/codes/ | accessdate = July 24 | accessyear = 2005 }}</ref> 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 ]. In cases where an engineer's work fails he or she may be subject to the ] and, in extreme cases, the charge of ]. An engineer's work must also comply with numerous other rules and regulations such as ] and legislation pertaining to ]. | |||
| Professional bodies of note for electrical engineers include the ] (IEEE) and the ] (IEE). The IEEE claims to produce 30 percent of the world's literature in electrical engineering, has over 360,000 members worldwide and holds over 300 conferences annually. <ref>{{cite web | title = About the IEEE | work = IEEE | url = http://www.ieee.org/about/ | accessdate = July 11 | accessyear = 2005 }}</ref> The IEE publishes 14 journals, has a worldwide membership of 120,000, and claims to be the largest professional engineering society in Europe. <ref>{{cite web | title = About the IEE | work = The IEE | url = http://www.iee.org/TheIEE/about.cfm | accessdate = July 11 | accessyear = 2005 }}</ref> <ref>{{cite web | title = Journal and Magazines | work = The IEE | url = http://www.iee.org/Publish/Journals/ | accessdate = July 11 | accessyear = 2005 }}</ref> 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. <ref>{{cite web | title = Electrical and Electronics Engineers, except Computer | work = Occupational Outlook Handbook | url = http://www.bls.gov/oco/ocos031.htm | accessdate = July 16 | accessyear = 2005 }} (see ] regarding copyright)</ref> | |||
| In countries such as ], ] and the ] electrical engineers make up around 0.25% of the labour force (see <span id="demographics_back">]</span>). Outside of these countries, it is difficult to gauge the demographics of the profession due to less meticulous reporting on labour statistics. However, in terms of electrical engineering graduates per-capita, electrical engineering graduates would probably be most numerous in countries such as ], ] and ].<ref>{{cite web | publisher = National Science Foundation | date = 2004 | url = http://www.nsf.gov/statistics/seind04/append/c2/at02-33.pdf | title = Science and Engineering Indicators 2004, Appendix 2-33 | format = PDF }}</ref> | |||
| == Tools and work == | |||
| From the ] to ], electrical engineers are responsible for a wide range of technologies. They design, develop, test and supervise the deployment of electrical systems and electronic devices. For example, they may work on the design of ], the operation of ]s, the ] and ] of ]s, the design of ] or the electrical ] of industrial machinery.<ref>{{cite web | title = Electrical and Electronics Engineers, except Computer | work = Occupational Outlook Handbook | url = http://www.bls.gov/oco/ocos031.htm | accessdate = July 16 | accessyear = 2005 }}</ref> | |||
| ] is one of many projects an electrical engineer might work on]] | |||
| Fundamental to the discipline are the sciences of ] and ] as these help to obtain both a ] and ] description of how such systems will work. Today most ] work involves the use of ] and it is commonplace to use ] programs when designing electrical systems. Nevertheless, the ability to sketch ideas is still invaluable for quickly communicating with others. | |||
| Although most electrical engineers will understand basic ] (that is the interactions of elements such as ], ], ], ] and ] in a circuit), the theories employed by engineers generally depend upon the work they do. For example, ] and ] might be relevant to an engineer working on ] (the design of integrated circuits), but are largely irrelevant to engineers working with macroscopic electrical systems. Even ] may not be relevant to a person designing telecommunication systems that use ] components. Perhaps the most important technical skills for electrical engineers are reflected in university programs, which emphasize ], ] and the ability to understand the ] that relate to electrical engineering. | |||
| For most engineers technical work accounts for only a fraction of the work they do. A lot of time is also spent on tasks such as discussing proposals with clients, preparing ]s and determining ].<ref>Trevelyan, James; (2005). ''What Do Engineers Really Do?''. University of Western Australia. (seminar with )</ref> Many senior engineers manage a team of ]s or other engineers and for this reason ] skills are important. Most engineering projects involve some form of documentation and ] skills are therefore very important. | |||
| The ]s of electrical engineers are just as varied as the types of work they do. Electrical engineers may be found in the pristine lab environment of a ], the offices of a ] or on site at a ]. During their working life, electrical engineers may find themselves supervising a wide range of individuals including ]s, ]s, ] and other engineers. | |||
| == Sub-disciplines == | |||
| Electrical engineering has many sub-disciplines, the most popular of which are listed below. Although there are electrical engineers who focus exclusively on one of these sub-disciplines, many deal with a combination of them. Sometimes certain fields, such as electronic engineering and computer engineering, are considered separate disciplines in their own right. | |||
| === Power === | |||
| {{Main|Power engineering}} | |||
| ] | |||
| ] deals with the ], ] and ] of ] as well as the design of a range of related devices. These include ]s, ]s, ]s and ]. In many regions of the world, governments maintain an electrical network called a ] that connects a variety of generators together with users of their energy. Users purchase electrical energy from the grid, avoiding the costly exercise of having to generate their own. Power engineers may work on the design and maintenance of the power grid as well as the power systems that connect to it. Such systems are called ''on-grid'' power systems and may supply the grid with additional power, draw power from the grid or do both. Power engineers may also work on systems that do not connect to the grid, called ''off-grid'' power systems, which in some cases are preferable to on-grid systems. | |||
| ===Control=== | |||
| {{Main|Control engineering}} | |||
| ] | |||
| ] focuses on the ] of a diverse range of ]s and the design of ] that will cause these systems to behave in the desired manner. To implement such controllers electrical engineers may use ], ], ]s and ]s (Programmable Logic Controllers). ] has a wide range of applications from the flight and propulsion systems of ] to the ] present in many modern ]s. It also plays an important role in ]. | |||
| Control engineers often utilize ] when designing ]s. For example, in an ] with ] the vehicle's ] is continuously monitored and fed back to the system which adjusts the ] ] accordingly. Where there is regular feedback, ] can be used to determine how the system responds to such feedback. | |||
| ===Electronics=== | |||
| {{Main|Electronic engineering}} | |||
| ] | |||
| ] involves the design and testing of ]s that use the properties of ] such as ]s, ]s, ]s, ]s and ]s to achieve a particular functionality. The ], which allows the user of a ] to ] 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 ], ] and ]. Later, in post war years, as consumer devices began to be developed, the field grew to include modern television, audio systems, ]s and ]. In the mid to late 1950s, the term ''radio engineering'' gradually gave way to the name ''electronic engineering''. | |||
| Before the invention of the ] in 1959, electronic circuits were constructed from discrete components that could be manipulated by humans. These discrete circuits consumed much space and ] and were limited in speed, although they are still common in some applications. By contrast, ]s packed a large number—often millions—of tiny electrical components, mainly ]s, into a small chip around the size of a ]. This allowed for the powerful ]s and other electronic devices we see today. | |||
| ===Microelectronics=== | |||
| {{Main|Microelectronics}} | |||
| ] | |||
| ] engineering deals with the design of very small electronic circuit components for use in an ] or sometimes for use on their own as a general electronic component. The most common microelectronic components are ] ], although all main electronic components (], ], ]) can be created at a microscopic level. | |||
| Microelectronic components are created by chemically fabricating wafers of semiconductors such as silicon (at higher frequencies, gallium arsenide and indium phosphide) to obtain the desired transport of electronic charge and control of current. The field of microelectronics involves a significant amount of chemistry and material science and requires the electronic engineer working in the field to have a very good working knowledge of the effects of ]. | |||
| ===Signal processing=== | |||
| {{Main|Signal processing}} | |||
| ] | |||
| ] deals with the analysis and manipulations of ]. Signals can be either ], in which case the signal varies continuously according to the information, or ], in which case the signal varies according to a series of discrete values representing the information. For analog signals, signal processing may involve the ] and ] of audio signals for audio equipment or the ] and ] of signals for ]s. For digital signals, signal processing may involve the ], ] and ] of digitally sampled signals. | |||
| ===Telecommunications=== | |||
| {{Main|Telecommunications engineering}} | |||
| ] | |||
| ] focuses on the ] of ] across a ] such as a ], ] or ]. Transmissions across free space require information to be encoded in a ] in order to shift the information to a ] suitable for transmission, this is known as ]. Popular analog modulation techniques include ] and ]. The choice of modulation affects the cost and performance of a system and these two factors must be balanced carefully by the engineer. | |||
| Once the transmission characteristics of a system are determined, telecommunication engineers design the ]s and ] needed for such systems. These two are sometimes combined to form a two-way communication device known as a ]. A key consideration in the design of transmitters is their ] as this is closely related to their ]. If the signal strength of a transmitter is insufficient the signal's information will be corrupted by ]. | |||
| ===Instrumentation engineering=== | |||
| {{Main|Instrumentation engineering}} | |||
| ] | |||
| ] deals with the design of devices to measure physical quantities such as ], ] and ]. The design of such instrumentation requires a good understanding of ] that often extends beyond ]. For example, ]s use the ] to measure the speed of oncoming vehicles. Similarly, ]s use the ] to measure the temperature difference between two points. | |||
| Often instrumentation is not used by itself, but instead as the ]s of larger electrical systems. For example, a thermocouple might be used to help ensure a furnace's temperature remains constant. For this reason, instrumentation engineering is often viewed as the counterpart of control engineering. | |||
| ===Computers=== | |||
| {{Main|Computer engineering}} | |||
| ] | |||
| ] deals with the design of ]s and ]s. This may involve the design of new ], the design of ] or the use of computers to control an ]. Computer engineers may also work on a system's ]. However, the design of complex software systems is often the domain of ], which is usually considered a separate discipline. ]s represent a tiny fraction of the devices a computer engineer might work on, as computer-like architectures are now found in a range of devices including ]s and ]s. | |||
| == Related disciplines == | |||
| ] is an engineering discipline which deals with the convergence of electrical and ] systems. Such combined systems are known as ] systems and have widespread adoption. Examples include ], ] and various subsystems of ] and ]s. | |||
| The term ''mechatronics'' is typically used to refer to ] systems but ] have predicted the emergence of very small electromechanical devices. Already such small devices, known as ] (MEMS), are used in automobiles to tell ]s when to deploy, in ]s to create sharper images and in ]s to create nozzles for high-definition printing. In the future it is hoped the devices will help build tiny implantable medical devices and improve ].<ref>{{cite web | title = MEMS the world! | work = IntelliSense Software Corporation | url = http://www.intellisensesoftware.com/Technology.html | accessdate = July 17 | accessyear = 2005 }}</ref> | |||
| ] is another related discipline, concerned with the design of ]. This includes fixed equipment such as ]s, ] and ] as well as mobile equipment such as ]s, ]s and ]s. | |||
| == See also == | |||
| {{portalpar|Electronics|Zenerdiod symbol.png}} | |||
| *] | |||
| *] | |||
| *] | |||
| *] (alphabetical) | |||
| *] (thematic) | |||
| *] | |||
| == References == | |||
| <div class="references-small"> | |||
| '''Notes''' | |||
| :<cite id="demographics">]</cite> - There are around 366,000 people working as electrical engineers in the ] constituting 0.25% of the labour force (]).<ref>{{cite web | title = Electrical and Electronics Engineers, except Computer | work = Occupational Outlook Handbook | url = http://www.bls.gov/oco/ocos031.htm | accessdate = August 27 | accessyear = 2005 }} and {{cite web | title = Computer Hardware Engineers | work = Occupational Outlook Handbook | url = http://www.bls.gov/oco/ocos266.htm | accessdate = August 27 | accessyear = 2005 }}</ref> In ], there are around 24,000 constituting 0.23% of the labour force (]) and in ], 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.<ref>{{cite web | title = Electrical and Electronics Engineers | work = Australian Careers | url = http://jobsearch.gov.au/joboutlook/default.aspx?PageId=AscoDesc&AscoCode=2125 | accessdate = August 27 | accessyear = 2005 }}</ref><ref>{{cite web | title = Electrical and Electronics Engineers (NOC 2133) | work = Job Futures (National Edition) | url = http://www.jobfutures.ca/noc/2133p1.shtml | accessdate = August 27 | accessyear = 2005 }}</ref> | |||
| '''Citations''' | |||
| <references /> | |||
| </div> | |||
| == External links == | |||
| {{Wikibooks}} | |||
| * | |||
| * Learn the nuts and bolts about building electrical circuits, and to build appliances based on electrical circuits | |||
| * A virtual museum that illustrates many of the basic electrical engineering and electricity concepts through examples, figures, and interviews. | |||
| * This is an excellent resource for anyone that is interested in electrical engineering as a career. Learn what electrical engineers do on a daily basis, where they work, how much they earn, and much more. | |||
| * In-depth look at Electrical Engineering with online courses featuring video lectures. | |||
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Revision as of 14:04, 14 January 2007
sucks ass