Glossary of electrical and electronics engineering: Difference between revisions

Revision as of 08:24, 16 August 2020

Revision as of 17:56, 16 August 2020

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{{defn|An external power supply for portable devices that allows them to operate from wall-socket electricity.}}

{{term|[[AC power plugs and sockets]]}}

{{defn|Electrical connectors used with {{gli|alternating current}}.}}

{{term|[[AC power]]}}

{{defn|Electric power where the current reverses direction periodically.}}

{{term|[[AC/AC converter]]}}

{{defn|A power converter where the input and output are both {{gli|alternating current}}, but may differ in frequency or other characteristics.}}

{{term|[[AC/DC receiver design]]}}

{{defn|A radio receiver that can operate from either {{gli|alternating current}} or {{gli|direct current}} wall socket power.}}

{{term|[[AC/DC conversion]]}}

{{defn|Rectification of AC current, so that current flows in only one direction.}}

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{{term|[[alpha–beta transformation]]}}

{{defn|A mathematical technique useful in analysis of three-phase circuits.}}

{{term|[[Altair 8800]]}}

{{defn|An early microcomputer.}}

{{term|[[alternating current]]}}

{{defn|Electric current that reverses direction periodically.}}

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{{defn|A power transformer where the metallic core is made of metals cooled so quickly that they do not form a crystal structure; such transformers can reduce some kinds of energy loss.}}

{{term|[[ampacity]]}}

{{defn|CurrentThe {{gli|current}} carrying capacity of a conductor, in the context of electric power wiring. }}

{{term|[[ampere]]}}

{{defn|The [[International System of Units|SI]] unit of electrical current.}}

{{term|[[Ampère's circuital law]]}}

{{defn|The mathematical relation between the integral of the magnetic field over some closed curve to the {{gli|current}} passing through the region bound by the curve.}}

{{term|[[Ampère's force law]]}}

{{defn|The mathematical relation between the force between two {{gli|current}} carrying conductors and the current flowing in them.}}

{{term|[[Ampère's law]]}}

{{defn|Ampère's circuital law.}}

{{term|[[amplidyne]]}}

{{defn|An electric machine that allows a small {{gli|current}} to control a much larger current.}}

{{term|[[amplifier]]}}

{{defn|A system that produces an output that replicates an input signal but with a larger magnitude.}}

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{{defn|Generally, techniques used to alter signals that rely on voltages or currents that vary continually over a practical range.}}

{{term|[[analog signal]]}}

{{defn|A signal whose properties ({{gli|current}}, {{gli|voltage}}) vary proportionally to the information transmitted.}}

{{term|[[analog-to-digital converter]]}}

{{defn|A circuit that produces a number proportional to the magnitude of a {{gli|voltage}} or {{gli|current}}.}}

{{term|[[anode]]}}

{{defn|The terminal of an electrochemical or electronic device through which conventional {{gli|current}} flows inward.}}

{{term|[[antenna (radio)|antenna]]}}

{{defn|A structure which converts between electromagnetic waves in space and currents in a conductor.}}

{{term|[[apparent power]]}}

{{defn|In an {{gli|alternating current}} power circuit, the product of the magnitude of RMS {{gli|voltage}} and {{gli|current}}.}}

{{term|[[Apple Computer]]}}

{{defn|A company that makes mobile telephones and computers.}}

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{{defn|The fraction of time that a power plant is available to produce power.}}

{{term|[[avalanche diode]]}}

{{defn|A diode intended for regular operation in the reverse, avalanche breakdown, mode. Used as a {{gli|voltage}} reference, noise source, and in certain classes of microwave oscillator device. }}

{{term|[[average rectified value]]}}

{{defn|The average value of an {{gli|alternating current}} waveform, taking the absolute value of the waveform. The average value is generally different from the root-mean-square value. }}

{{glossary end}}

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{{defn|A type of algebra that deals with values that can only hold values "true" and "false", of great use in design and analysis of digital systems.}}

{{term|[[boost converter]]}}

{{defn|Any power converter circuit that can produce an output {{gli|voltage}} larger than its input voltage.}}

{{term|[[booster (electric power)|booster]]}}

{{defn|A device used to increase voltage on an electric power distribution system, such as a motor-generator set on a DC system.}}

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{{defn|In building wiring, any circuit from the main panelboard to utilization equipment or receptacles.}}

{{term|[[breakdown voltage]]}}

{{defn|The maximum {{gli|voltage}} a device can withstand without damage.}}

{{term|[[bridge rectifier]]}}

{{defn|A set of rectifier diodes used to convert {{gli|alternating current}} to {{gli|direct current}}.}}

{{term|[[broadcasting]]}}

{{defn|Transmission of a signal to many receivers.}}

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{{defn|A gas pressure sensing device for protection of oil-filled transformers.}}

{{term|[[Buck converter]]}}

{{defn|Any power converter circuit that produces an output {{gli|voltage}} less than its input voltage.}}

{{term|[[Buck–boost converter]]}}

{{defn|Any power converter circuit that can provide a voltage greater or less than its input voltage.}}

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{{defn|A power supply network where a capacitor is the first element following the rectfier.}}

{{term|[[capacitor voltage transformer]]}}

{{defn|In electrical power systems, an instrument transformer for measuring {{gli|voltage}} that uses a capacitive voltage divider.}}

{{term|[[capacity factor]]}}

{{defn|The ratio of energy produced by a power plant over some period, over its maximum possible energy production in that time.}}

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{{defn|A form of filter that has a steep frequency selective characteristic.}}

{{term|[[choke (electronics)|choke]]}}

{{defn|An induction coil used to block {{gli|alternating current}} and pass {{gli|direct current}}, or to block high frequencies and pass lower frequencies.}}

{{term|[[chopper (electronic)|chopper]]}}

{{defn|A circuit that switches on and off at a high rate, used either for power conversion or to convert a DC signal to a more easily processed AC signal. }}

{{term|[[circle diagram]]}}

{{defn|A representation of the {{gli|voltage}} and {{gli|current}} characteristics of an electrical machine; the plot traces out a circle or part of a circle.}}

{{term|[[circuit breaker panel]]}}

{{defn|A distribution board for electric power that uses circuit breakers as protective elements.}}

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{{defn|A satellite in Earth orbit designed for international telephone, television, or data transmission.}}

{{term|[[commutation cell]]}}

{{defn|The elementary switching device in a power converter circuit; it could be a transistor, a {{gli|thyristor}}, a mercury-arc valve, or others.}}

{{term|[[commutator (electric)|commutator]]}}

{{defn|A component of a DC electric machine that connects the rotating coils with an external circuit through brushes.}}

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{{term|[[computer programming]]}}

{{defn|The practice of producing instructions for a computer to achieve some desired effect.}}

{{term|[[computer-aided design]] (CAD)}}

{{defn|A design discipline where a computer is used to produce graphical representation of the design or to assist in calculating performance parameters.}}

{{term|[[conduction band]]}}

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{{defn|That portion of an electric machine or transformer's loss attributed to the resistance of conductors (which are not necessarily made of copper).}}

{{term|[[corona ring]]}}

{{defn|A component of a high -voltage system intended to smooth out the electric field distribution around energized parts.}}

{{term|[[coulomb]]}}

{{defn|The [[International System of Units|SI]] unit of electric charge.}}

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{{defn|An instrument transformer used for measuring current in AC power systems.}}

{{term|[[current-to-voltage converter]]}}

{{defn|A {{gli|transducer}} that produces an output {{gli|voltage}} in response to an input {{gli|current}}.}}

{{term|[[cybernetics]]}}

{{defn|The science of automatic control systems.}}

{{term|[[cycloconverter]]}}

{{defn|A type of variable -frequency power converter that does not first convert {{gli|alternating current|AC}} to {{gli|direct current|DC}}.}}

{{glossary end}}

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{{defn|A network for interconnection of computers and peripherals.}}

{{term|[[DC injection braking]]}}

{{defn|A method of slowing an AC electric motor by passing {{gli|direct current}} through its windings.}}

{{term|[[DC-to-DC converter]]}}

{{defn|A circuit that takes power from a DC source and generates a different DC voltage.}}

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{{defn|The fraction of actual use of some quantity, related to the maximum that could be used in a specified time.}}

{{term|[[demand response]]}}

{{defn|The ability of a generating station or grid to follow changes in load while maintaining {{gli|voltage}} and frequency within acceptable limits.}}

{{term|[[demodulation]]}}

{{defn|The process of recovery of information (sound, video, data) from a modulated carrier.}}

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{{defn|Transmission of images using digital techniques.}}

{{term|[[digital-to-analog converter]]}}

{{defn|A device that produces a {{gli|voltage}} or {{gli|current}} that is proportional to a digital value sent to it.}}

{{term|[[diode bridge]]}}

{{defn|An interconnection of diodes to rectify {{gli|alternating current}} to {{gli|direct current}}.}}

{{term|[[diode]]}}

{{defn|A two-terminal passive circuit element, with a preferred direction of current flow.}}

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{{defn|Electric current that flows in one direction only.}}

{{term|[[direct on line starter]]}}

{{defn|A kind of motor starter that does not reduce the {{gli|voltage}} at the motor terminals.}}

{{term|[[direct torque control]]}}

{{defn|A method of estimating motor torque as part of a variable speed motor drive.}}

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{{defn|A piece of electrical switchgear which distributes electric power to multiple branch circuits.}}

{{term|[[distribution transformer]]}}

{{defn|A power transformer, usually used to change the utility distribution voltage to a lower voltage for use on the customer premises. }}

{{term|[[Dolby]]}}

{{defn|A trademark for a noise reduction technique for analog sound recordings.}}

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==E==

{{glossary}}

{{term|[[Earth leakage circuit breaker]]}}
{{defn|A protective device that opens a {{gli|circuit}} when stray {{gli|voltage}} or {{gli|current}} is detected that would present a hazard of electric shock.}}

{{term|[[eddy current]]}}
{{defn|AAn {{gli|electric current}} induced inside a {{gli|conductor}} exposed to a changing magnetic field.}}

{{term|[[edge detection]]}}
{{defn|An image processing technique used to identify boundaries of objects.}}

{{term|[[Edison effect]]}}
{{defn|The emission of an electric current from a hot wire; Edison did not realize he'd discovered the fundamental mechanism of the vacuum tube, thermionic emission.}}

{{term|[[electret]]}}
{{defn|A dielectric material that permanently retains an impressed electric field; the dual to a magnet.}}

{{term|[[electric arc]]}}
{{defn|Discharge of electric current through an open space between conductors; may be produced intentionally as a source of intense light and heat, or may be a result of an electrical fault.}}

{{term|[[electric charge]]}}
{{defn|The physical property of matter that causes it to experience a force when placed in an electromagnetic field.}}

{{term|[[electric circuit]]}}
{{defn|A closed path through which an {{gli|electric current}} can flow.}}

{{term|[[electric current]]}}
{{defn|The motion of {{gli|electric charge|electric charges}}.}}

{{term|[[electric displacement field]]}}
{{defn|In Maxwell's equations, a vector field due to electric charges.}}

{{term|[[electric distribution systems]]}}
{{defn|That portion of an electrical grid that connects customers to substations or the bulk transmission system.}}

{{term|[[electric field gradient]]}}
{{defn|The rate of change of electric field with respect to distance.}}

{{term|[[electric field]]}}
{{defn|A vector field that exerts a force on electric charges.}}

{{term|[[electric generator]]}}
{{defn|A machine that converts mechanical energy to electrical energy by moving {{gli|conductor|conductors}} through magnetic fields.}}

{{term|[[electric motor]]}}
{{defn|A machine that produces mechanical energy from electrical energy, by moving conductors through magnetic fields.}}

{{term|[[electric multiple unit]]}}
{{defn|Use of more than one electric locomotive on a train.}}

{{term|[[electric potential]]}}
{{defn|A measure of the work required to move a unit electric charge in an electric field.}}

{{term|[[electric power conversion]]}}
{{defn|Generally, changing the form of electric power.}}

{{term|[[electric power distribution]]}}
{{defn|In an electric grid, the network that brings power from a substation or bulk supply to individual customers.}}

{{term|[[Electric Power Research Institute]]}}
{{defn|A non-profit organization that carries out research on behalf of the US electric power industry.}}

{{term|[[electric power transmission]]}}
{{defn|The bulk movement of electric power for many customers from a generating plant to a local distribution network, usually at high voltage.}}

{{term|[[electric power]]}}
{{defn|The rate of transfer of electrical energy past a given point.}}

{{term|[[electric shock]]}}
{{defn|An injury caused to people or animals by electric current.}}

{{term|[[electrical cable]]}}
{{defn|A flexible conducting wire to carry electrical power or signals, usually covered with an insulating material.}}

{{term|[[electrical code]]}}
{{defn|A set of regulations for the use of electricity; they may vary from municipal to international in scope.}}

{{term|[[electrical conductivity]]}}
{{defn|A measure of a substance's ability to pass an electric current.}}

{{term|[[electrical conductor]]}}
{{defn|An object that carries an electric current, with little loss.}}

{{term|[[electrical contact]]}}
{{defn|A separable part of an electric device that carries current when touching another contact.}}

{{term|[[electrical discharge machining|electrical discharge machining]] (EDM)}}
{{defn|Shaping of a work place by small sparks.}}

{{term|[[electrical element]]}}
{{defn|In circuit theory, a node at which some electrical property is concentrated (resistance, etc.).}}

{{term|[[electrical engineering]]}}
{{defn|The profession of applying electricity to practical problems.}}

{{term|[[electrical equipment]]}}
{{defn|Apparatus for generation, transmission or utilization of electric power.}}

{{term|[[electrical grid]]}}
{{defn|A geographically distributed system to connect source and users of electric power.}}

{{term|[[electrical impedance]]}}
{{defn|That property of a circuit that resists the passage of electric current, usually in the context of {{gli|alternating current}}.}}

{{term|[[electrical insulation paper]]}}
{{defn|A grade of paper used for insulation of transformers, electrical machines, capacitors, and some cables.}}

{{term|[[electrical insulation]]}}
{{defn|A material that resists electrical current flow.}}

{{term|[[electrical load]]}}
{{defn|A consumer of electrical energy, turning it into light, heat, mechanical power, data, or chemical changes.}}

{{term|[[electrical machine]]}}
{{defn|Motors and generators, apparatus that converts between electrical power and mechanical power.}}

{{term|[[electrical measurements]]}}
{{defn|That branch of metrology concerned with electrical quantities.}}

{{term|[[electrical network]]}}
{{defn|A network of electrical components and conductors.}}

{{term|[[electrical polarity]]}}
{{defn|Identification of electrical terminals where current is flowing in the same direction relative to the device.}}

{{term|[[electrical steel]]}}
{{defn|Any of several types of steel used for manufacturing the magnetic field components of machines and transformers.}}

{{term|[[electrical substation]]}}
{{defn|A facility connecting a distribution network to a transmission network, usually with one or more transformers.}}

{{term|[[electrical technologist]]}}
{{defn|A specialist in applying electrical theory and technique to practical problems.}}

{{term|[[electrical wiring regulations]]}}
{{defn|The legal framework for electrical installations in buildings.}}

{{term|[[electrical wiring]]}}
{{defn|The installation of conductors, fixtures and protection devices for a structure or vehicle.}}

{{term|[[electricity meter]]}}
{{defn|An instrument to measure the electrical energy used by a customer for revenue purposes.}}

{{term|[[electricity pylon]]}}
{{defn|A structure, generally of wood or metal, to support wires.}}

{{term|[[electricity]]}}
{{defn|The set of physical phenomena associated with electric charges.}}

{{term|[[electrification]]}}
{{defn|Applying electric power to a process that was previously done by other means,or, development of an electric power system in a region that previously had none.}}

{{term|[[electroactive polymers]]}}
{{defn|A polymer that significantly changes size or shape when exposed to an electric field.}}

{{term|[[electrocardiograph]]}}
{{defn|A record of the electrical activity of the heart.}}

{{term|[[electrochemical engineering]]}}
{{defn|The profession of application of electrochemistry to practical problems.}}

{{term|[[electrodes]]}}
{{defn|An electrical contact that connects some medium to an electric circuit, such as in an electrochemical cell or a vacuum tube.}}

{{term|[[electro-diesel locomotive]]}}
{{defn|A railway locomotive with a diesel engine, generator, and electric driving motors that can be powered by the diesel engine or the track electrical supply.}}

{{term|[[electrodynamics]]}}
{{defn|The branch of physics that studies electrical charges and electrical currents.}}

{{term|[[electrolyte]]}}
{{defn|A liquid or solid medium that carries electric current in the form of ions.}}

{{term|[[electromagnet]]}}
{{defn|A magnet that generates a magnetic field from an {{gli|electric current}}.}}

{{term|[[electromagnetic compatibility]]}}
{{defn|The control of unwanted electromagnetic interference.}}

{{term|[[electromagnetic field]]}}
{{defn|The field produced by moving electric charges and magnetic fields.}}

{{term|[[electromagnetic induction]]}}
{{defn|The production of current in a circuit by the change of magnetic field intersecting the circuit.}}

{{term|[[electromagnetic radiation]]}}
{{defn|Radio waves, light and other radiation that travels through space at the speed of light. }}

{{term|[[electromagnetic spectrum]]}}
{{defn|The range of frequencies of electromagnetic radiation.}}

{{term|[[electromagnetic wave equation]]}}
{{defn|A a second-order partial differential equation that describes the propagation of electromagnetic waves through a medium or in a vacuum.}}

{{term|[[electromagnetism]]}}
{{defn|The science of electric fields, magnetic fields, currents, charges,and forces.}}

{{term|[[electromechanical]]}}
{{defn|A system that has both an electrical component and a mechanical component, such as a motor or a relay.}}

{{term|[[electromote]]}}
{{defn|An 1882 demonstration of a prototype electric trolley bus.}}

{{term|[[electromotive force]]}}
{{defn|A difference in electrical potential between two points, such as produced by a battery or a generator.}}

{{term|[[electron microscope]]}}
{{defn|An instrument that provides highly magnified images by use of an electron beam.}}

{{term|[[electronic amplifier]]}}
{{defn|A device that increases the power of an electrical signal by electronic means.}}

{{term|[[electronic circuit]]}}
{{defn|A circuit using one or more electronic devices.}}

{{term|[[electronic component]]}}
{{defn|An active or passive element of an electronic circuit.}}

{{term|[[electronic control unit]]}}
{{defn|In an automobile, an embedded electronic system that controls some aspect of a vehicle (ignition, transmission, and so on).}}

{{term|[[electronic design automation]]}}
{{defn|A system in which a computer provides assistance to the designer of a device or system.}}

{{term|[[electronic engineering]]}}
{{defn|The profession of applying electronics to practical problems.}}

{{term|[[electronic filter]]}}
{{defn|A filter that alters some frequency-related characteristic of a signal.}}

{{term|[[electronics]]}}
{{defn|The study of the flow of electrons through a vacuum, gases or semiconductors.}}

{{term|[[electronic speed control]]}}
{{defn|A device for regulating the speed of a motor.}}

{{term|[[electrophorus]]}}
{{defn|An instrument used to produce electrostatic charge through electrostatic induction.}}

{{term|[[electrostatic motor]]}}
{{defn|A motor that relies on the forces generated by electric fields, instead of magnetic fields.}}

{{term|[[electrostatics]]}}
{{defn|The study of stationary electric charges and resulting forces.}}

{{term|[[embedded operating system]]}}
{{defn|The common operating environment that supports embedded software; it may be a highly tailored version of a general purpose operating system, or written solely for the purpose of embedded system operations.}}

{{term|[[embedded software]]}}
{{defn|A firmware component of a microprocessor controlled system.}}

{{term|[[embedded system]]}}
{{defn|A computer system that controls a device or system, with no or a minimal user interface; for example, the ignition system in a car may have a microprocessor to control it.}}

{{term|[[enameled wire]]}}
{{defn|Wire insulated with a thin flexible layer of enamel, used for electrical windings.}}

{{term|[[energy demand management]]}}
{{defn|A system to adjust energy demand to reduce costs.}}

{{term|[[energy economics]]}}
{{defn|A branch of economics concerned with energy supply and demand.}}

{{term|[[energy efficient transformer]]}}
{{defn|A power transformer designed to have lower than average energy loss.}}

{{term|[[energy returned on energy invested]]}}
{{defn|A measure of how long an energy producing system takes to replace the energy it took to make it.}}

{{term|[[energy subsidies]]}}
{{defn|Payments to a consumer or producer of electric energy that are used as incentives for production or consumption.}}

{{term|[[engine-generator]]}}
{{defn|A combination of an internal combustion engine and a generator, often used as a standby power plant.}}

{{term|[[ENIAC]]}}
{{defn|The first general purpose electronic digital computer.}}

{{term|[[Epstein frame]]}}
{{defn|An apparatus used for testing of magnetic materials.}}

{{term|[[equalization (audio)]]}}
{{defn|Adjustment of the frequency response of a system to improve its utility.}}

{{term|[[equalization (communications)]]}}
{{defn|Adjustment of the frequency spectrum of a signal to cancel out the effect of the frequency response of a communication path.}}

{{term|[[equivalent circuit]]}}
{{defn|In circuit theory, a simple combination of elements that behaves at its terminals like a more complex combination.}}

{{term|[[equivalent impedance transforms]]}}
{{defn|A mathematical method to determine values of an equivalent circuit.}}

{{term|[[error correction and detection]]}}
{{defn|Techniques used to improve reliability of computer memory or communications channels by including extra information along with the desired data.}}

{{term|[[exponential stability]]}}

{{term|[[Ethernet]]}} {{defn|A standard for wired computer data networks.}}

{{term|[[exponential stability]]}} {{defn|A system that settles to a steady state after a disturbance, at a rate proportional to exponential time.}}

{{term|[[extended Kalman filter]]}}
{{defn|A strategy for estimating an unknown value in a non-linear system by combining multiple measurements.}}

{{glossary end}}

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==F==

{{glossary}}

{{term|[[farad]]}}
{{defn|The [[International System of Units|SI]] unit of capacitance.}}

{{term|[[Faraday shield]]}}
{{defn|A solid conductive shield around a volume, which blocks electromagnetic fields.}}

{{term|[[Faraday–Lenz law]]}}
{{defn|One of Maxwell's equations, describing the relation between a changing magnetic field and production of an electromotive force.}}

{{term|[[Faraday's law of induction]]}}
{{defn|The relation between a changing magnetic field and the resulting {{gli|voltage}} produced in a closed path.}}

{{term|[[fast Fourier transform]]}}
{{defn|A digital algorithm to analyze a time series of sampled data into a set of sine and cosine frequency components.}}

{{term|[[fault (power engineering)|fault]]}}
{{defn|A {{gli|short circuit}}, open circuit, or other disruption of a power system.}}

{{term|[[fax]]}}
{{defn|Facsimile, the transmission of paper images by radio or by wire.}}

{{term|[[feed forward (control)]]|feed forward}}
{{defn|A control system that adjusts the controlled variable based on a model of the process and measurements of disturbances, instead of feedback from measurement of the process.}}

{{term|[[feedback amplifier]]}}
{{defn|An amplifier that feeds back a small sample of its output to its input, to improve linearity.}}

{{term|[[feedback]]}}
{{defn|A system that samples part of its output and adds that to its input; feedback may be either positive or negative, aiding or opposing the initial input signal.}}

{{term|[[feed-in tariff]]}}
{{defn|A premium rate paid to distributed generators to encourage alternative energy sources.}}

{{term|[[ferrite core]]}}
{{defn|A magnetic core for an {{gli|inductor}} made from a metal oxide compound.}}

{{term|[[ferroelectricity]]}}
{{defn|The property of materials that spontaneously maintain an electrical polarization, as a ferromagnetic material maintains magnetic polarization.}}

{{term|[[fiber optic cable]]}}
{{defn|A transmission medium that uses infrared energy or light to transmit information down a long thin transparent filament such as glass.}}

{{term|[[field effect transistor]]}}
{{defn|A transistor that relies on modulation of conductivity of a channel instead of injection of minority carriers as does a bipolar transistor.}}

{{term|[[field-oriented control]]}}
{{defn|A control strategy for variable frequency drives that models the magnetic field of the motor to control its torque.}}

{{term|[[filter (signal processing)|filter]]}}
{{defn|A circuit that selectively alters a signal based on its frequency components.}}

{{term|[[filter capacitor]]}}
{{defn|In a power supply, a {{gli|capacitor}} that smooths the {{gli|direct current|DC}} {{gli|voltage}} produced by a {{gli|rectifier}} stage.}}

{{term|[[finite impulse response]]}}
{{defn|A class of digital filters whose response to an impulse returns to zero in finite time.}}

{{term|[[firmware]]}}
{{defn|Software of a computer that is never or rarely altered during its working life, for example, the control computer program for an automotive ignition system.}}

{{term|[[Fleming valve]]}}
{{defn|The first important vacuum tube device, used as a radio detector.}}

{{term|[[Fleming's left-hand rule for motors]]}}
{{defn|A mnemonic to recall the relative orientation of current, magnetic field and resulting force for electric motors.}}

{{term|[[Fleming's right-hand rule]] for generators}}
{{defn|A mnemonic to recall the relative orientation of current, magnetic field and resulting force for electric generators.}}

{{term|[[fluorescent lamp]]}}
{{defn|A type of electric lamp that relies on a phosphor coating to produce visible light from the ultraviolet light generated by a mercury discharge.}}

{{term|[[flux linkage]]}}
{{defn|In a magnetic system, that part of the magnetic flux that passes through a given closed path, which may be a winding.}}

{{term|[[flyback converter]]}}
{{defn|A type of {{gli|voltage converter}} that stores energy in an inductor.}}

{{term|[[flyback transformer]]}}
{{defn|A type of transformer that recovers energy stored in its own core. Historically used in the deflection circuits of CRT display systems.}}

{{term|[[forward converter]]}}
{{defn|A type of {{gli|voltage converter}} that relies on {{gli|transformer}} action to couple energy to its output circuit.}}

{{term|[[fossil-fuel phase-out]]}}
{{defn|A plan to replace coal, oil, or natural gas fuel with other sources to produce electrical energy.}}

{{term|[[fossil-fuel power station]]}}
{{defn|A power plant using coal, oil, or natural gas fuel.}}

{{term|[[Fourier series]]}}
{{defn|A set of coefficients of sine and cosine waves; this can represent a time function as a function of frequency.}}

{{term|[[Fourier transform]]}}
{{defn|An algorithm for converting a continuous waveform in the time ___domain into an equivalent set of spectral components in the frequency ___domain.}}

{{term|[[free space optical communications]]}}
{{defn|Transfer of information from point to point by a beam of light or infrared energy, instead of a wired connection or radio waves.}}

{{term|[[frequency changer]]}}
{{defn|An electric machine used to transfer power between two networks with different frequencies, or, an electronic device (more usually called a frequency mixer) that changes the frequency of an input signal to some other frequency.}}

{{term|[[frequency modulation]]}}
{{defn|A method of impressing information on a carrier wave by changing its frequency.}}

{{term|[[frequency response]]}}
{{defn|The measure of the output of a system in response to an input of varying frequency.}}

{{term|[[full load current]]}}
{{defn|The current drawn by a motor or other electrical machine at its full rated power and standard voltage.}}

{{term|[[full-wave rectifier]]}}
{{defn|A rectifier circuit that converts both positive and negative parts of the input {{gli|alternating current}} waveform into a unidirectional, {{gli|direct current}}.}}

{{term|[[fuse (electrical)|fuse]]}}
{{defn|A circuit protective device that interrupts excessive {{gli|current}} by melting a metal strip.}}

{{term|[[fuzzy control]]}}
{{defn|A control system that relies on fuzzy logic instead of binary true/false conditions.}}

{{glossary end}}

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==G==

{{glossary}}

{{term|[[gain scheduling]]}}
{{defn|A technique for control of non-linear systems that use different control parameters based on some measurement of the process controlled.}}

{{term|[[galvanic corrosion]]}}
{{defn|Electrochemical corrosion of one metal in contact with another.}}

{{term|[[galvanometer]]}}
{{defn|An instrument for detecting small electric currents.}}

{{term|[[gamma ray]]}}
{{defn|Electromagnetic radiation with wavelengths shorter than ten nanometres. Strictly: radiation that is produced in the nucleus of atoms.}}

{{term|[[gas-filled tube]]}}
{{defn|An electron tube device that relies on the presence of gas for operation, usually at less than atmospheric pressure.}}

{{term|[[gate turn-off thyristor]] (GTO)}}

{{defn|A four-layer power semiconductor device that can be turned on and off by signals at a control (gate) terminal.}}

Line 719 ⟶ 861:

{{defn|A mathematical relation between the electric flux passing through a surface and the charge contained within that surface.}}

{{term|[[generator (circuit theory)|generator]]}}

{{defn|In {{gli|circuit theory}}, an ideal {{gli|voltage}} source or an ideal {{gli|current}} source, whose properties are independent of the connected {{gli|circuit}}.}}

{{term|[[geothermalgovernor power(device)|governor]]}}

{{defn|A speed regulator for a machine such as a steam engine; an early important feedback control cybernetic system.}}

{{defn|Extraction of energy from underground hot rock or natural steam sources.}}

{{term|[[grid energy storage]]}}

{{term|[[gigabit]]}} {{defn|One billion (short scale) bits, a unit of digital data; the Project Gutenberg plain ASCII text of the King James Bible is about 0.034 gigabits.}}

{{defn|Any system tied to an electrical grid that stores electrical energy at low demand times and releases it to meet peak loads; it might be a centralized station like a pumped-storage hydroelectric plant, or might be distributed over many customer sites such as by the use of electric vehicle batteries.}}

{{term|[[governor (device)|governor]]}} {{defn|A speed regulator for a machine such as a steam engine; an early important feedback control cybernetic system.}}

{{term|[[grid-tie inverter]]}}

{{term|[[grid energy storage]]}} {{defn|Any system tied to an electrical grid that stores electrical energy at low demand times and releases it to meet peak loads; it might be a centralized station like a pumped-storage hydroelectric plant, or might be distributed over many customer sites such as by the use of electric vehicle batteries.}}

{{term|[[grid-tie inverter]]}} {{defn|A power inverter that allows synchronization with the electrical grid for export of energy surplus to the facility's needs.}}

{{term|[[ground (electricity)|ground]]}}
{{defn|A reference point for electrical potential; often connected to the Earth.}}

{{term|[[ground and neutral]]}}

{{defn|Protective and circuit return conductors in a wiring system.}}

{{term|[[ground-level power supply]]}}
{{defn|A system for providing powers for electric trams without overhead wires and without a permanently energized third rail.}}

{{term|[[growler (electrical device)|growler]]}}

{{defn|A test instrument that is used to diagnose some faults with AC motors.}}

Line 748 ⟶ 892:

{{term|[[Hall effect sensor]]}}

{{defn|A device that detects and measures magnetic field by the Hall effect voltage induced in a current-carrying semiconductor.}}

{{term|[[harmonic distortion]]}}
{{defn|An effect of a non-linear signal path that introduces frequencies that are integer multiples of an input frequency.}}

{{term|[[harmonic oscillator]]}}
{{defn|An oscillator which produces sinusoidal output, such as a simple RLC oscillator.}}

{{term|[[harmonic]]}}
{{defn|A waveform that has a frequency which is an integer multiple of another frequency.}}

{{term|[[harmonics (electrical power)|harmonics]]}}
{{defn|Distortion of the power line voltage due to non-linear loads such as rectfiers{{gli|rectifier|rectifiers}}.}}

{{term|[[H-bridge]]}}
{{defn|An array of four controlled switches that coverts {{gli|direct current}} to {{gli|alternating current}}, with peak value equal to the supply voltage. }}

{{term|[[HDTV]]}}
{{defn|High Definition Television, any television system with more than 625 scan lines.}}

{{term|[[headphone]]}}
{{defn|An audio transducer or pair of transducers arranged to be worn on (or in) the ear.}}

{{term|[[heat transfer]]}}
{{defn|The study of the flow of heat energy; heat transfer concerns dictate major design features of most electrical and electronic systems.}}

{{term|[[heatsink]]}}
{{defn|In electronics, aA structure intended to dissipate heat from an active device into the ambient environment.}}

{{term|[[Heaviside step function]]}}
{{defn|A mathematical unit step function useful in the solution of certain differential equations by the methods of operational calculus.}}

{{term|[[Helmholtz coil]]}}
{{defn|An arrangement of coils useful for producing a uniform magnetic field within a certain volume.}}

{{term|[[henry (unit)|henry]]}}
{{defn|The [[International System of Units|SI]] unit of inductance.}}

{{term|[[Hertz]]}}
{{defn|The [[International System of Units|SI]] unit of frequency, equivalent to one cycle per second.}}

{{term|[[heterodyne]]}}
{{defn|The process of mixing signals of a number of frequencies to produce new frequencies.}}

{{term|[[heterostructure]]}}
{{defn|A {{gli|semiconductor}} device built of two or more dissimilar materials.}}

{{term|[[Hi-Fi]]}}
{{defn|High Fidelity, the set of techniques for reproduction of sounds that appear natural in source.}}

{{term|[[high-voltage cable]]}}
{{defn|A flexible insulated electrical conductor designed to withstand a significant {{gli|voltage}}; "high" voltage may be hundreds or hundreds of thousands of volts, depending on the context.}}

{{term|[[high voltage]]}}
{{defn|Any voltage at which safety concerns apply; in some contexts anything over 100 volts may be a high voltage; in electric power transmission, voltages over 66,000 volts are considered "high voltage".}}

{{term|[[high-pass filter]]}}
{{defn|An electrical network that tends to pass higher frequencies and block lower ones.}}

{{term|[[high-voltage direct current]]}}
{{defn|A system for power transmission that uses high dc{{gli|direct current|DC}} {{gli|voltage|voltages}} for reasons of economy or stability.}}

{{term|[[high-voltage switchgear]]}}
{{defn|Electrical apparatus designed for control of high-voltage circuits.}}

{{term|[[Hilbert transform]]}}
{{defn|A mathematical operation used in signal processing.}}

{{term|[[holography]]}}
{{defn|The technique of representing the image of a scene by a recording of interference patterns of the light field.}}

{{term|[[home appliance]]}}
{{defn|Any electrical appliance intended for use in a home.}}

{{term|[[homopolar generator]]}}
{{defn|A generator in which {{gli|current}} and {{gli|magnetic field}} direction are constant as the machien rotor revolves.}}

{{term|[[homopolar motor]]}}
{{defn|A motor that produces torque from a current and magnetic field that does not change direction.}}

{{term|[[horsepower]]}}
{{defn|A unit of {{gli|power}}, equivalent to around 746 watts.}}

{{term|[[hot wire barretter]]}}
{{defn|A current dependent resistor formed of a fine wire in an envelope, useful for regulating current.}}

{{term|[[humidistat]]}}
{{defn|A switch that operates automatically on detecting a change in moisture content of the air.}}

{{term|[[HVAC]]}}
{{defn|High Voltage Alternating Current; depending on context, this could be hundreds or hundreds of thousands of volts.}}

{{term|[[HVDC converter station]]}}
{{defn|An element of a high -voltage {{gli|direct current}} power transmission system; each end of the transmission line has a converter station connected to the local AC grid.}}

{{term|[[HVDC]]}}
{{defn|High Voltage Direct Current.}}

{{term|[[hybrid coil]]}}
{{defn|A kind of transformer used for bidirectional transmission of signals over one pair of wires, for example, as in an analog telephone set.}}

{{term|[[hydroelectricity]]}}{{defn|Electric power generated from falling water.}}

{{term|[[hydropower]]}}{{defn|PowerThe (nowgeneration nearly alwaysof electric power) generated from the kinetic energy of falling water; hydroelectricity.}}

{{term|[[hydropower]]}}

{{term|[[hysteresis]]}}{{defn|A characteristic of a system where its state is history-dependent.}}

{{defn|Power (now nearly always electric power) generated from falling water; hydroelectricity.}}

{{term|[[hysteresis]]}}

{{defn|A characteristic of a system where its state is history-dependent.}}

{{glossary end}}

Line 790 ⟶ 970:

==I==

{{glossary}}

{{term|[[IGBT]]}}
{{defn|Insulated Gate Bipolar Transistor, a power semiconductor device that combines some of the advantages of field-effect and bipolar transistors.}}

{{term|[[Imageimage impedance]]}}{{defn|A parameter used in design of electrical networks such as filters.}}

{{term|[[Imageimage noise reduction]]}}{{defn|Any technique used to reduce interfering effects in processing of an image.}}

{{term|[[Imageimage processing]]}}{{defn|Electronic recording, storage, alteration and reproduction of pictures.}}

{{term|[[Impulseimpulse response]]}}{{defn|The response of a network to a sudden narrow pulse input.}}

{{term|[[Incandescentincandescent light bulb]]}}{{defn|A device that uses a fine wire filament heated by an electric current to make light...and heat.}}

{{term|[[Inductioninduction coil]]}}{{defn|An early name for a transformer; a type of transformer for high-voltage uses.}}

{{term|[[induction cooker]]}}{{defn|A cooking appliance that heats pots with magnetic fields.}}

{{term|[[Inductioninduction generator]]}}{{defn|A type of generator where the rotating field winding is excited by induction from the stationary armature winding. }}

{{term|[[Inductioninduction motor]]}}{{defn|A type of motor where the rotating field winding is excited by induction from the stationary armature winding.}}

{{term|[[Inductioninduction regulator]]}}{{defn|A kind of variable transformer that provides stepless control of the output by changing the coupling between two coils.}}

{{term|[[Inductiveinductive coupling]]}}{{defn|Transfer of energy between two circuits through the magnetic field that passes through both.}}

{{term|[[Inductiveinductive output tube]]}}{{defn|A high power, high frequency amplifier tube, in some forms capable of megawatt pulses at hundreds of megahertz.}}

{{term|[[Inductorinductor]]}}{{defn|A circuit component with a concentrated inductance; a coil; stores energy in a magnetic field.}}

{{term|[[Industrialindustrial and multiphase power plugs and sockets]]}}{{defn|Electrical fittings used to connect cables to three-phase power circuits.}}

{{term|[[Industrialindustrial automation]]}}{{defn|The general practice of automatic control applied to industrial operations.}}

{{term|[[Infiniteinfinite impulse response]]}}{{defn|A filter which, mathematically, never gets to a zero effect of an impulse at its input, though practically the response may become negligible after a definite time.}}

{{term|[[Informationinformation appliance]]}}{{defn|Conceptually, an embedded computer system with a specialized user interface designed to simplify one task, such as e-mail or photos; a modern smart phone approaches this concept.}}

{{term|[[Informationinformation theory]]}}{{defn|The mathematical study of information.}}

{{term|[[Informationinformation]]}}{{defn|In one sense, the answers to uncertainties.}}

{{term|[[Inputinput/output]] (I/O)}}{{defn|That part of a computer system devoted to exporting and importing data, for example, in human-readable form.}}

{{term|[[Inrushinrush current]]}}
{{defn|The transient current that flows when first connecting a device to a power source.}}

{{term|[[Institute of Electrical and Electronics Engineers|Institute of Electrical and Electronics Engineers]] (IEEE)]]}}{{defn|The American -based society for electrotechnology.}}

{{term|[[Institution of Engineering and Technology]]}}
{{defn|The British society of electrical and electronics engineers.}}

{{term|[[Instrumentationinstrumentation engineering]]}}
{{defn|The profession dealing with development of measuring systems.}}

{{term|[[Instrumentationinstrumentation]]}}{{defn|A device that turns some physical property into a measurement.}}

{{term|[[Insulationinsulation monitoring device]]}}{{defn|A supervisory device to detect failure of electrical insulation.}}

{{term|[[Insulatorinsulator (electrical)|insulator]]}}
{{defn|A substance that does not permit easy flow of electric current; a fitting intended to support a conductor.}}

{{term|[[Integratedintegrated circuit]]}}
{{defn|An interconnected array of electronic devices, factory assembled on a single substrate.}}

{{term|[[Intelligentintelligent control]]}}{{defn|The application of artificial intelligence techniques to process control.}}

{{term|[[Intelligentintelligent transportation system]]}}{{defn|The application of information technology to manage some aspects of a transportation system.}}

{{term|[[Intermittentintermittent energy source]]}}{{defn|An energy source whose availability is not under human control; it may be sporadically available or available on some natural schedule not coincident with human demands; energy sources that are not dispatchable.}}

{{term|[[International Electrotechnical Commission|International Electrotechnical Commission]] (IEC)]]}}
{{defn|An international standards organization devoted to electrical standards; most countries are members.}}

{{term|[[International Organization for Standardization]]}}
{{defn|An international organization coordinating the efforts of national technical standards organizations.}}

{{term|[[Interrupterinterrupter]]}}{{defn|Any of a series of automatically operated electromechanical switches that periodically opened and closed a circuit.}}

{{term|[[Inverter (electrical)|Inverterinverter]]}}
{{defn|A system that converts {{gli|direct current}} power to {{gli|alternating current}}, without the use of rotating machines, using electron devices such as mercury arc valves or {{gli|thyristor|thyristors}}.}}

{{term|[[Magnetic core#Core loss|Ironiron loss]]}}
{{defn|That portion of the wasted power of a machine or transformer attributed to hysteresis and eddy currents in the iron core.}}

{{term|[[Isolatedisolated-phase bus]]}}{{defn|A bus where each phase is in its own grounded metal enclosure to prevent faults from spreading from phase to phase; often used in large power plant generators.}}

{{term|[[Isolationisolation transformer]]}}{{defn|A transformer especially intended to prevent leakage current from passing from its primary circuit to the secondary circuit.}}

{{term|[[Iterativeiterative learning control]]}}{{defn|A technique for improving the accuracy of control systems that carry out the same sequence repeatedly.}}

{{glossary end}}

Line 839 ⟶ 1,029:

{{term|[[Jedlik's dynamo]]}}{{defn|An early form of electric generator using electromagnets.}}

{{term|[[JFET]]}}{{defn|A field effect transistor with a reverse-biased PN junction between gate and channel.}}

{{term|[[Jitterjitter]]}}
{{defn|Deviation from the true periodicity of a periodic signal.}}

{{term|[[Joule heating]]}}
{{defn|Heating in a conductor due to passage of current.}}

{{term|[[joule]]}}

{{term|[[Joule]]}}{{defn|The SI unit of work; one joule is of the order of the energy dissipated when an apple falls off a table top.}}

{{defn|The [[International System of Units|SI]] unit of work; one joule is of the order of the energy dissipated when an apple falls off a table top.}}

{{glossary end}}

==K==

{{glossary}}

{{term|[[Kalman filter]]}}
{{defn|An alrogithmalgorithm for estimating an unknown value from a series of approximate measurements.}}

{{term|[[Kelvin–Stokes theorem]]}}
{{defn|A theorem in calculus, useful in analytic solutions of problems in electromagnetism.}}

{{term|[[Kilovolt-ampere]]}}
{{defn|A unit of apparent power.}}

{{term|[[Kirchhoff's circuit laws]]}}
{{defn|The observation that the sum of the {{gli|current|currents}} at any node of a {{gli|circuit}} must be zero, and the sum of the {{gli|voltage}} differences around any loop must be zero; often abbreviated "KCL" and "KVL" in lecture notes.}}

{{term|[[Klystron]]}}
{{defn|A type of microwave oscillator vacuum tube.}}

{{glossary end}}

Line 857 ⟶ 1,055:

==L==

{{glossary}}

{{term|[[LAN]]}}
{{defn|Local Area Network, an interconnection of computers over a building or small campus.}}

{{term|[[Laplace transform]]}}
{{defn|A mathematical operation for solution of differential equations by transforming them to the s ___domain from the time ___domain.}}

{{term|[[Laserlaser diode]]}}
{{defn|A semiconductor device that produces coherent laser radiation when properly energized.}}

{{term|[[Leakageleakage inductance]]}}
{{defn|The inductance of a transformer that results from magnetic flux not linked by both primary and secondary windings.}}

{{term|[[Lightlight-emitting diode]]}}
{{defn|A semiconductor device that produces light or infrared or ultraviolet radiation when properly energized.}}

{{term|[[Linearlinear alternator]]}}
{{defn|An electrical machine that generates electric power from the relative straight line motion of its parts.}}

{{term|[[Linearlinear motor]]}}
{{defn|An electrical machine that generates electric force in a straight line by the interaction of its moving parts and magnetic fields.}}

{{term|[[Linearlinear variable differential transformer]]}}
{{defn|A transducer that produces an electrcialelectrical signal proportional to the movement between its parts.}}

{{term|[[Lineman (technician)|Lineman (occupation)lineman]]}}
{{defn|A specialist technician who installs outside plant wiring (overhead circuits, power transmission lines).}}

{{term|[[Litz wire]]}}
{{defn|A kind of stranded wire used to minimize losses in coils.}}

{{term|[[Loadload flow study]]}}
{{defn|A mathematical prediction of the flow of electric power in a network, based on a model of the actual or proposed system; necessary for planning of electrical grids.}}

{{term|[[Loadload following power plant]]}}
{{defn|A power plant that can economically be operated over a significant range of output, so as to meet varying electric power demand.}}

{{term|[[Loadload-loss factor]]}}
{{defn|A factor for estimating energy lost in a distribution network due to load current.}}

{{term|[[Loadload management]]}}
{{defn|Any strategy for altering the operation of customer loads so as to reduce peak demand on an electrical grid.}}

{{term|[[Loadload profile]]}}
{{defn|The daily, weekly, or annual plot of electrical load against time.}}

{{term|[[Locallocal positioning system]]}}
{{defn|A navigation system that doesn't cover the whole Earth; such as over a continent, or even within a building.}}

{{term|[[LORAN]]}}
{{defn|A radio navigation system developed from a World War II military system (GEE), used for civilian purposes till the 1980s.}}

{{term|[[Lorentz force law]]}}
{{defn|The mathematical relation between currents in conductors and the resulting magnetic forces between them.}}

{{term|[[Losslesslossless data compression]]}}
{{defn|Any data compression method where the source can be reconstructed exactly; where approximations are tolerable, lossy data compression can be used.}}

{{term|[[Lossylossy data compression]]}}
{{defn|Any data compression method which allows only a close approximation of the source to be reconstructed; useful for images or music, where the human perceptual system compensates for the errors.}}

{{term|[[Loudspeakerloudspeaker]]}}
{{defn|A transducer that converts electrical current into sound, perceptible to more than one listener.}}

{{term|[[Lowlow-noise amplifier]]}}
{{defn|In a satellite radio receiving system, an amplifier placed near the antenna.}}

{{term|[[Lowlow-noise block downconverter]]}}
{{defn|In a satellite radio receiving system, a device that amplifes and converts signlas to a lower frequency band that will have lower losses in interconnecting cables.}}

{{term|[[Lowlow-pass filter]]}}
{{defn|An electric filter network that passes lower frequencies and blocks higher ones.}}

{{term|[[LTI system theory]]}}
{{defn|The theory of systems that, over a useful range, respond proportionally to inputs and don't change characteristics while responding. }}

{{term|[[Lumenlumen (unit)|lumen]]}}
{{defn|The [[International System of Units|SI]] unit of luminous flux, the energy of visible light.}}

{{term|[[Lumpedlumped parameters]]}}
{{defn|Describes an electrical network where the circuit elements are small compared to the wavelengths of the signals passing through it.}}

{{term|[[Lyapunov stability]]}}
{{defn|A criterion for stability of a dynamical system; if disturbances from a stable point reduce and the system returns to that stable point, it can be said to be Lyapunov stable.}}

{{glossary end}}

Line 891 ⟶ 1,117:

==M==

{{glossary}}

{{term|[[Machinemachine learning]]}}
{{defn|The set of artificial intelligence techniques for systems that can follow examples to solve new problems.}}

{{term|[[Magnetmagnet wire]]}}
{{defn|The class of wire manufactured for winding electromagnetic coils such as in motors or transformers.}}

{{term|[[Magneticmagnetic blowout]]}}
{{defn|A component of a switching device that uses a magnetic field to assist in extinguishing the arc, using a permanent magnet or a coil.}}

{{term|[[Magneticmagnetic circuit]]}}
{{defn|A path through which magnetic flux passes.}}

{{term|[[Magneticmagnetic constant]]}}
{{defn|The constant that relates the strength of magnetic flux to magnetic induction in free space.}}

{{term|[[Magneticmagnetic core memory]]}}
{{defn|A type of computer memory that stores data as magnetization in tiny rings of ferrite material.}}

{{term|[[Magneticmagnetic field]]}}
{{defn|A field that causes magnets and currents to experience forces.}}

{{term|[[Magneticmagnetic flux density]]}}
{{defn|The amount of magnetic field per unit area; in [[International System of Units|SI]] units, measured in webers per square metre.}}

{{term|[[Magneticmagnetic flux]]}}
{{defn|The magnetic field; a conductor that encloses a changing magnetic flux will have a {{gli|voltage}} induced in it.}}

{{term|[[Magneticmagnetic moment]]}}
{{defn|The proportionality constant that relates the twisting torque produced on an object to the magnetic field.}}

{{term|[[Magnetismmagnetism]]}}
{{defn|The class of natural phenomena related to magnets and magnetic fields. }}

{{term|[[Magnetizationmagnetization]]}}
{{defn|A property of a material that measures its response to a magnetic field.}}

{{term|[[Magnetizationmagnetization current]]}}
{{defn|In a transformer, that portion of the current used to support magnetic flux.}}

{{term|[[Magnetostaticsmagnetostatics]]}}
{{defn|The study of stationary magnetic fields.}}

{{term|[[Magnetostrictionmagnetostriction]]}}
{{defn|A property of some materials that change shape when subject to a magnetic field.}}

{{term|[[Magnifyingmagnifying transmitter]]}}
{{defn|A concept for a signal transmitter that used a resonant transformer to provide a high {{gli|voltage}}.}}

{{term|[[Mainmain distribution frame]]}}
{{defn|In a telephone central office, the equipment that connects to subscriber circuits.}}

{{term|[[mainframe computer]]}}

{{term|[[Mainframe computer]]}}{{defn|A large centralized computer system, used for large volumes of data or supporting multiple interactive terminals, with large input/output capacity, generally expected to provide critical services to a business or institution with a predictable degree of reliability.}}

{{defn|A large centralized computer system, used for large volumes of data or supporting multiple interactive terminals, with large input/output capacity, generally expected to provide critical services to a business or institution with a predictable degree of reliability.}}

{{term|[[Mains electricity]]}}{{defn|Commercial electric power, purchased from an off-site source shared by many consumers. Regional supplies vary in voltage, frequency, and technical standards.}}

{{term|[[mains electricity]]}}

{{term|[[Mains hum]]}}{{defn|Interference on an audio or visual signal related to the power line frequency.}}

{{defn|Commercial electric power, purchased from an off-site source shared by many consumers. Regional supplies vary in {{gli|voltage}}, frequency, and technical standards.}}

{{term|[[Marginal stability]]}}{{defn|Said of a system that neither returns to its initial state when disturbed nor diverges to some unstable condition.}}

{{term|[[mains hum]]}}

{{term|[[Marine energy]]}}{{defn|Any technique for extracting useful energy from tides, waves, salinity or temperature gradients of the ocean.}}

{{defn|Interference on an audio or visual signal related to the power line frequency.}}

{{term|[[Marx generator]]}}{{defn|A kind of circuit for generating very high DC voltage pulses.}}

{{term|[[marginal stability]]}}

{{term|[[Maser]]}}{{defn|A device that produces microwave energy in a similar manner to a LASER.}}

{{defn|Said of a system that neither returns to its initial state when disturbed nor diverges to some unstable condition.}}

{{term|[[Maximum prospective short-circuit current]]}}{{defn|The calculated value of current that could flow if a short circuit occurred; a parameter for selection of circuit protection devices.}}

{{term|[[marine energy]]}}

{{term|[[Maxwell's equations]]}}{{defn|The fundamental relations between electric and magnetic fields, expressed in concise mathematical form.}}

{{defn|Any technique for extracting useful energy from tides, waves, or salinity or temperature gradients of the ocean.}}

{{term|[[Mechanical rectifier]]}}{{defn|An electromechanical device for converting alternating current to direct current, using sets of contacts which operate in synchronism with the AC.}}

{{term|[[Marx generator]]}}

{{term|[[Mechatronics]]}}{{defn|Combinations of mechanical systems with electronics for sensing and control.}}

{{defn|A kind of circuit for generating very high DC {{gli|voltage}} pulses.}}

{{term|[[Memristor]]}}{{defn|A hypothetical non-linear passive two-terminal electrical component relating electric charge and magnetic flux linkage.}}

{{term|[[Maser]]}}

{{term|[[Mercury-arc rectifier]]}}{{defn|A Mercury-arc valve; a vacuum tube device that converts alternating current to direct current by an arc in mercury vapor; displaced by solid state devices, but formerly much used especially in high voltage direct current transmission.}}

{{defn|A device that produces microwave energy in a similar manner to a LASER.}}

{{term|[[Mercury vapor lamp]]}}{{defn|A lamp that generates light from a discharge struck in mercury vapor; formerly widely used in outdoor lighting, now replaced by lamps with better efficacy.}}

{{term|[[maximum prospective short-circuit current]]}}

{{term|[[Mesh analysis]]}}{{defn|A strategy for solution of the voltage distribution in some types of electrical networks.}}

{{defn|The calculated value of current that could flow if a short circuit occurred; a parameter for selection of circuit protection devices.}}

{{term|[[Mesh networking]]}}{{defn|A topology where infrastructure nodes connect to other nodes such as to convey information.}}

{{term|[[Maxwell's equations]]}}

{{term|[[Metadyne]]}}{{defn|A DC electric machine with crossed fields and two sets of brushes, used as an amplifier or rotary DC transformer.}}

{{defn|The fundamental relations between electric and magnetic fields, expressed in concise mathematical form.}}

{{term|[[Metal rectifier]]}}{{defn|Recifiers made from copper oxide or selenium; formerly widely used before development of silicon rectifiers.}}

{{term|[[mechanical rectifier]]}}

{{term|[[Micro combined heat and power]]}}{{defn|Equipment that generates process or space heat and electric power, of a size useful for a single building.}}

{{defn|An electromechanical device for converting {{gli|alternating current}} to {{gli|direct current}}, using sets of contacts which operate in synchronism with the AC.}}

{{term|[[Microcontroller]]}}{{defn|A microprocessor integrated with memory and input/output circuits, useful for embedded control.}}

{{term|[[mechatronics]]}}

{{term|[[Microelectromechanical systems]]}}{{defn|An electromechanical system of microscopic size; they may be sensors or actuators.}}

{{term|[[Microelectronics]]}}{{defn|That partCombinations of themechanical fieldsystems ofwith electronics dealingfor withsensing integratedand circuitscontrol.}}

{{term|[[memristor]]}}

{{term|[[Microgeneration]]}}{{defn|Small-scale electric power production, to provide the needs of a small building or individual consumer.}}

{{defn|A hypothetical non-linear passive two-terminal electrical component relating electric charge and magnetic flux linkage.}}

{{term|[[Microphone]]}}{{defn|A transducer that changes sound into electrical signals.}}

{{term|[[mercury-arc rectifier]]}}

{{term|[[Microprocessor]]}}{{defn|A computer with its logical, arithmetic and control functions implemented on one or a few integrated circuits.}}

{{defn|A mercury-arc valve; a vacuum tube device that converts {{gli|alternating current}} to {{gli|direct current}} by an arc in mercury vapor; displaced by solid state devices, but formerly much used especially in high-voltage {{gli|direct current}} transmission.}}

{{term|[[Microstrip]]}}{{defn|A planar transmission line that is fabricated by printed circuit board technology and is used for microwave-frequency signals}}

{{term|[[mercury vapor lamp]]}}

{{term|[[Microstrip antenna]]}}{{defn|A planar antenna that is fabricated by printed circuit board technology}}

{{defn|A lamp that generates light from a discharge struck in mercury vapor; formerly widely used in outdoor lighting, now replaced by lamps with better efficacy.}}

{{term|[[Microwave oven]]}}{{defn|A heating appliance that uses microwave energy.}}

{{term|[[mesh analysis]]}}

{{term|[[Microwave radio]]}}{{defn|The subset of radio technique using wavelengths that are in the range of 3 GHz or higher.}}

{{defn|A strategy for solution of the {{gli|voltage}} distribution in some types of electrical networks.}}

{{term|[[Microwave]]}}{{defn|Part of the radio spectrum with wavelengths shorter than 10 centimetres.}}

{{term|[[mesh networking]]}}

{{term|[[Millman's theorem]]}}{{defn|A theorem stating the relation between branch currents and voltages for multiple sources in parallel.}}

{{defn|A topology where infrastructure nodes connect to other nodes such as to convey information.}}

{{term|[[Mineral-insulated copper-clad cable]]}}{{defn|Cable with an outer metal cover and insulated by powdered inorganic material, suitable for high temperature; one kind of fire resistant cable.}}

{{term|[[Metadyne]]}}

{{term|[[Mobile phone]]}}{{defn|A handset that connects to the public switched telephone network by radio.}}

{{defn|A DC electric machine with crossed fields and two sets of brushes, used as an amplifier or rotary DC transformer.}}

{{term|[[Modbus]]}}{{defn|A brand name for a serial protocol for industrial control equipment communication.}}

{{term|[[metal rectifier]]}}

{{term|[[Model predictive control]]}}{{defn|A control strategy for process systems based on a mathematical model of the process and its disturbances.}}

{{defn|A {{gli|rectifier}} made from copper oxide or selenium; formerly widely used before development of silicon rectifiers.}}

{{term|[[Modem]]}}{{defn|Modulator-Demodulator, an interface between a computer system and a telephone network.}}

{{term|[[micro combined heat and power]]}}

{{term|[[Modulation transformer]]}}{{defn|Part of a radio transmitter used to impress modulation on one amplifying stage.}}

{{defn|Equipment that generates process or space heat and electric power, of a size useful for a single building.}}

{{term|[[Modulation]]}}{{defn|The impression of information on a carrier wave for transmission.}}

{{term|[[microcontroller]]}}

{{term|[[Monolithic microwave integrated circuit]]}}{{defn|An integrated circuit that operates in microwave frequencies and that can be fabricated by printed circuit board technology.}}

{{defn|A microprocessor integrated with memory and input/output circuits, useful for embedded control.}}

{{term|[[Monoscope]]}}{{defn|A raster scan video device that generates a single fixed image for test or identification purposes.}}

{{term|[[microelectromechanical systems]]}}

{{term|[[Moore's law]]}}{{defn|The observation that the number of transistors possible in an integrated circuit doubles approximately every two years. }}

{{defn|An electromechanical system of microscopic size; they may be sensors or actuators.}}

{{term|[[Morse code]]}}{{defn|A method of transmitting text by long and short impulses and varying delays between them.}}

{{term|[[microelectronics]]}}

{{term|[[MOSFET]]}}{{defn|Metal Oxide Semiconductor Field Effect Transistor, a class of transistor using a single type of charge carrier and with a very thin insulating layer between current channel and control gate. If you count those built into integrated circuits, nearly all transistors are MOSFETs.}}

{{term|[[Motion control]]}}{{defn|That part of automationthe thatfield dealsof withelectronics accuratelydealing controllingwith the movements ofintegrated machinescircuits.}}

{{term|[[microgeneration]]}}

{{term|[[Motor controller]]}}{{defn|Electrical apparatus that regulates and protects an electric motor, which may be as simple as an on-off switch or a servo system for precision machine tools.}}

{{defn|Small-scale electric power production, to provide the needs of a small building or individual consumer.}}

{{term|[[Motor soft starter]]}}{{defn|A device that reduces the inrush current when an electric motor is first connected to the power supply.}}

{{term|[[microphone]]}}

{{term|[[MP3]]}}{{defn|A standard for encoding audio in digital form.}}

{{defn|A {{gli|transducer}} that changes sound into electrical signals.}}

{{term|[[MRI]]}}{{defn|Magnetic Resonance Imaging, a technique for examining the interiors of, for example, medical patients, using sensitive measurements of the magnetic fields of atomic nuclei.}}

{{term|[[microprocessor]]}}

{{term|[[Multics]]}}{{defn|An influential early time sharing computer operating system, first released in 1969.}}

{{defn|A computer with its logical, arithmetic and control functions implemented on one or a few integrated circuits.}}

{{term|[[Multimeter]]}}{{defn|A test instrument that can measure current, voltage or resistance (though not concurrently).}}

{{term|[[microstrip]]}}

{{term|[[Multisim]]}}{{defn|A brand of computer software for electronic circuit simulation.}}

{{defn|A planar transmission line that is fabricated by printed circuit board technology and is used for microwave-frequency signals}}

{{term|[[microstrip antenna]]}}

{{defn|A planar antenna that is fabricated by printed circuit board technology}}

{{term|[[microwave oven]]}}

{{defn|A heating appliance that uses microwave energy.}}

{{term|[[microwave radio]]}}

{{defn|The subset of radio technique using wavelengths that are in the range of 3 GHz or higher.}}

{{term|[[microwave]]}}

{{defn|Part of the radio spectrum with wavelengths shorter than 10 centimetres.}}

{{term|[[Millman's theorem]]}}

{{defn|A theorem stating the relation between branch currents and {{gli|voltage|voltages}} for multiple sources in parallel.}}

{{term|[[mineral-insulated copper-clad cable]]}}

{{defn|Cable with an outer metal cover and insulated by powdered inorganic material, suitable for high temperature; one kind of fire resistant cable.}}

{{term|[[mobile phone]]}}

{{defn|A handset that connects to the public switched telephone network by radio.}}

{{term|[[Modbus]]}}

{{defn|A brand name for a serial protocol for industrial control equipment communication.}}

{{term|[[model predictive control]]}}

{{defn|A control strategy for process systems based on a mathematical model of the process and its disturbances.}}

{{term|[[modem]]}}

{{defn|Modulator-Demodulator, an interface between a computer system and a telephone network.}}

{{term|[[modulation transformer]]}}

{{defn|Part of a radio transmitter used to impress modulation on one amplifying stage.}}

{{term|[[modulation]]}}

{{defn|The impression of information on a carrier wave for transmission.}}

{{term|[[monolithic microwave integrated circuit]]}}

{{defn|An integrated circuit that operates in microwave frequencies and that can be fabricated by printed circuit board technology.}}

{{term|[[monoscope]]}}

{{defn|A raster scan video device that generates a single fixed image for test or identification purposes.}}

{{term|[[Moore's law]]}}

{{defn|The observation that the number of transistors possible in an integrated circuit doubles approximately every two years.}}

{{term|[[Morse code]]}}

{{defn|A method of transmitting text by long and short impulses and varying delays between them.}}

{{term|[[MOSFET]]}}

{{defn|Metal Oxide Semiconductor Field Effect Transistor, a class of transistor using a single type of charge carrier and with a very thin insulating layer between current channel and control gate. If you count those built into integrated circuits, nearly all transistors are MOSFETs.}}

{{term|[[motion control]]}}

{{defn|That part of automation that deals with accurately controlling the movements of machines.}}

{{term|[[motor controller]]}}

{{defn|Electrical apparatus that regulates and protects an electric motor, which may be as simple as an on-off switch or a servo system for precision machine tools.}}

{{term|[[motor soft starter]]}}

{{defn|A device that reduces the inrush current when an electric motor is first connected to the power supply.}}

{{term|[[MP3]]}}

{{defn|A standard for encoding audio in digital form.}}

{{term|[[MRI]]}}

{{defn|Magnetic Resonance Imaging, a technique for examining the interiors of, for example, medical patients, using sensitive measurements of the magnetic fields of atomic nuclei.}}

{{term|[[multics]]}}

{{defn|An influential early time sharing computer operating system, first released in 1969.}}

{{term|[[multimeter]]}}

{{defn|A test instrument that can measure {{gli|current}}, {{gli|voltage}}, or {{gli|resistance}} (though not concurrently).}}

{{term|[[Multisim]]}}

{{defn|A brand of computer software for electronic circuit simulation.}}

{{glossary end}}

Line 965 ⟶ 1,259:

==N==

{{glossary}}

{{term|[[Nameplatenameplate capacity]]}}{{defn|The design power output of a generator, at specified temperature rise.}}

{{term|[[Nanoinverternanoinverter]]}}{{defn|Grid tied inverters rated less than 100 watts, useful for connection of single solar PV panels to a building AC power system.}}

{{term|[[Nanotechnologynanotechnology]]}}{{defn|Technology that uses devices whose principal dimensions are of the order of a few nanometres.}}

{{term|[[National Electric Code]]}}{{defn|The United States national technical standard for building wiring installation.}}

{{term|[[National Electrical Manufacturers Association|National Electrical Manufacturers Association (NEMA)]]}}{{defn|A US trade association for electrical manufacturers that also develops technical standards.}}

{{term|[[Negativenegative feedback]]}}{{defn|Feedback from a control system output that tends to oppose the input.}}

{{term|[[Negativenegative resistance]]}}{{defn|A {{gli|voltage}}/{{gli|current}} characteristic where increasing current leads to decreased voltage drop across the device.}}

{{term|[[Negawattnegawatt power]]}}{{defn|In power grid demand management, that portion of load that can be met by conservation efforts or improved energy efficiency.}}

{{term|[[Neonneon sign]]}}{{defn|Strictly, a sign that glows orange because of a discharge through neon gas; less pedantically, any gas discharge tube formed into a sign.}}

{{term|[[Neonneon-sign transformer]]}}{{defn|A high-voltage {{gli|transformer}} with features intended to support operation of a {{gli|neon sign}}.}}

{{term|[[Netnet metering]]}}{{defn|A metering plan that allows grid customers with their own generation to be billed only for their net import of energy from the grid.}}

{{term|[[Networknetwork analyzer (AC power)|network analyzer]]}}{{defn|An analog computer system for modelling power grids; displaced now by digital computers.}}

{{term|[[Networknetwork cable]]}}{{defn|Cables intended for use in data interconnections, with defined performance parameters.}}

{{term|[[Networknetwork protector]]}}{{defn|A type of circuit breaker used to isolate a fault from a multi-transformer supply network.}}

{{term|[[Neuralneural networks]]}}{{defn|A network of individual logic elements in multiple layers that emulates some of the behavior of a biological nervous system; a technique in artificial intelligence.}}

{{term|[[Nodalnodal analysis]]}}{{defn|A technique for analysis of currents in an electrical network.}}

{{term|[[Nodenode (circuits)|node]]}}{{defn|A defined point in an electrical network, with some potential relative to a reference node and where currents can be summed.}}

{{term|[[Noisenoise cancelling]]}}{{defn|A type of microphone that preferentially picks up a near by sound source and rejects ambient noise.}}

{{term|[[Noisenoise reduction]]}}{{defn|The techniques used to reduce the perception of noise in a communications path.}}

{{term|[[Noisynoisy-channel coding theorem]]}}{{defn|A theorem that establishes the limits of the error-free data transmission in a noisy communication channel}}

{{term|[[Nominalnominal impedance]]}}{{defn|The rated impedance of an element of a circuit.}}

{{term|[[Nonlinearnonlinear control]]}}{{defn|The class of control problems relating to the control of systems that are non linear.}}

{{term|[[Nonodenonode]]}}{{defn|Any electron device, (although practically, only vacuum tubes) with nine internal active {{gli|electrode|electrodes}} controlling electron flow.}}

{{term|[[Norton's theorem]]}}{{defn|A theorem which states that any network of {{gli|current}} sources, {{gli|voltage}} sources, and {{gli|resistor|resistors}} can be simplified to an equivalent network with only a current source and shunt [[admittance]]; the dual of {{gli|Thevenin's Theoremtheorem}}.}}

{{term|[[Notchnotch filter]]}}{{defn|A filter with a narrow reject band, used to block, for example, a pilot tone out of a communications network.}}

{{term|[[NTSC]]}}{{defn|The US National Television Systems Committee, that developed the analog monochrome and color television standards used for more than 60 years for broadcasting.}}

{{term|[[Nuclearnuclear power]]}}{{defn|Production of electric power (or propulsion power) by nuclear fission or fusion.}}

{{term|[[Numericalnumerical control]]}}{{defn|Digital automatic control, especially of machine tools.}}

{{term|[[Nuvistor]]}}{{defn|A type of miniature vacuum tube, developed around the same time transistors became common in consumer electronics.}}

{{term|[[Nyquist frequency]]}}{{defn|The maximum frequency that a sampling system can represent accurately.}}

Line 1,003 ⟶ 1,297:

==O==

{{glossary}}

{{term|[[observability]]}}

{{term|[[Observability]]}}{{defn|In control theory, the measure of how well the internal state of a system corresponds to its measurable outputs.}}

{{defn|In control theory, the measure of how well the internal state of a system corresponds to its measurable outputs.}}

{{term|[[Oersted]]}}{{defn|The CGS unit of magnetic field H.}}

{{term|[[Oersted]]}}

{{term|[[Ohm]]}}{{defn|The SI unit of electrical resistance.}}

{{defn|The CGS unit of magnetic field H.}}

{{term|[[Ohmmeter]]}}{{defn|An instrument that measures electrical resistance.}}

{{term|[[ohm]]}}

{{term|[[Ohm's law]]}}{{defn|The mathematical relationship between voltage, current, and resistance.}}

{{defn|The [[International System of Units|SI]] unit of electrical {{gli|resistance}}.}}

{{term|[[One-line diagram]]}}{{defn|A simplified schematic diagram of a power system.}}

{{term|[[ohmmeter]]}}

{{term|[[On-premises wiring]]}}{{defn|Telecommunications wiring owned by the customer.}}

{{defn|An instrument that measures electrical resistance.}}

{{term|[[Open-circuit test]]}}{{defn|A test, of a transformer or other device, with no load connected.}}

{{term|[[Ohm's law]]}}

{{term|[[Open-circuit voltage]]}}{{defn|The voltage developed at the terminals of a device with no load connected.}}

{{defn|The mathematical relationship between {{gli|voltage}}, {{gli|current}}, and {{gli|resistance}}.}}

{{term|[[Open-circuit time constant method]]}}{{defn|A method for approximately evaluating the transfer function of an electrical network.}}

{{term|[[one-line diagram]]}}

{{term|[[Operational amplifier]]}}{{defn|A type of amplifier with differential inputs, widely used in circuits where feedback determines the circuit properties.}}

{{defn|A simplified schematic diagram of a power system.}}

{{term|[[Optical fiber]]}}{{defn|A glass or plastic fiber used to convey signals transmitted by visible light or infrared radiation.}}

{{term|[[on-premises wiring]]}}

{{term|[[Optimal control]]}}{{defn|The branch of control theory studying optimization of a control system to fit some optimization criterion.}}

{{defn|Telecommunications wiring owned by the customer.}}

{{term|[[Oscillation]]}}{{defn|A periodic cyclical motion or disturbance.}}

{{term|[[open-circuit test]]}}

{{term|[[Oscilloscope]]}}{{defn|An instrument for graphically displaying a waveform as a function of time.}}

{{defn|A test, of a transformer or other device, with no load connected.}}

{{term|[[Oudin coil]]}}{{defn|An early form of high voltage induction coil identical in principle to a Tesla coil except for being constructed essentially as an auto-transformer.}}

{{term|[[open-circuit voltage]]}}

{{term|[[Out of phase]]}}{{defn|The condition when AC generation sources are not synchronized.}}

{{defn|The {{gli|voltage}} developed at the terminals of a device with no load connected.}}

{{term|[[Overhead line]]}}{{defn|Outside plant run on poles or other structures; power transmission or telecommunication wires.}}

{{term|[[open-circuit time constant method]]}}

{{term|[[Oversampling]]}}{{defn|Sampling a signal at a rate higher than required by the Nyquist criterion.}}

{{defn|A method for approximately evaluating the transfer function of an electrical network.}}

{{term|[[Overshoot (signal)]]}}{{defn|A transient excursion of a signal beyond its stead state value.}}

{{term|[[operational amplifier]]}}

{{term|[[Overvoltage]]}}{{defn|Application of more than rated voltage to a device.}}

{{defn|A type of amplifier with differential inputs, widely used in circuits where feedback determines the circuit properties.}}

{{term|[[Oxygen-free copper]]}}{{defn|A grade of copper preferred for electrical applications for its low electrical resistance.}}

{{term|[[optical fiber]]}}

{{defn|A glass or plastic fiber used to convey signals transmitted by visible light or infrared radiation.}}

{{term|[[optimal control]]}}

{{defn|The branch of control theory studying optimization of a control system to fit some optimization criterion.}}

{{term|[[oscillation]]}}

{{defn|A periodic cyclical motion or disturbance.}}

{{term|[[oscilloscope]]}}

{{defn|An instrument for graphically displaying a waveform as a function of time.}}

{{term|[[Oudin coil]]}}

{{defn|An early form of high-voltage induction coil identical in principle to a Tesla coil except for being constructed essentially as an auto-transformer.}}

{{term|[[out of phase]]}}

{{defn|The condition when AC generation sources are not synchronized.}}

{{term|[[overhead line]]}}

{{defn|Outside plant run on poles or other structures; power transmission or telecommunication wires.}}

{{term|[[oversampling]]}}

{{defn|Sampling a signal at a rate higher than required by the Nyquist criterion.}}

{{term|[[overshoot (signal)|overshoot]]}}

{{defn|A transient excursion of a signal beyond its stead state value.}}

{{term|[[overvoltage]]}}

{{defn|Application of more than rated {{gli|voltage}} to a device.}}

{{term|[[oxygen-free copper]]}}

{{defn|A grade of copper preferred for electrical applications for its low electrical resistance.}}

{{glossary end}}

Line 1,032 ⟶ 1,347:

==P==

{{glossary}}

{{term|[[Padmountpadmount transformer]]}}{{defn|A kind of metal enclosed distribution transformer suitable for mounting on grade.}}

{{term|[[Pantographpantograph (rail)|pantograph]]}}{{defn|A linkage that supports the current collector of an electric locomotive.}}

{{term|[[Paraformerparaformer]]}}{{defn|A device similar to a transformer that couples energy between two circuits by varying magnetic parameters.}}

{{term|[[Parameterparameter estimation]]}}{{defn|In estimation theory, the practice of assigning values to a process model so it accurately predicts the process's behavior.}}

{{term|[[Park transform]]}}{{defn|A mathematical technique useful in the analysis of three-phase systems.}}

{{term|[[Partialpartial discharge]]}}{{defn|Breakdown of insulating gas or solid material by an electric field, but without formation of an arc.}}

{{term|[[passivity (engineering)|passivity]]}}{{defn|Incapable of adding energy to a signal or process.}}

.}}

{{term|[[patch cables]]}}{{defn|Short cables with connectors, used to make connections between outlets of a patch panel or for temporary connections to a system under test.}}

{{term|[[Passivity (engineering)]]}}{{defn|Incapable of adding energy to a signal or process.}}

{{term|[[peak demand]]}}{{defn|The maximum rate at which energy is consumed from an electrical grid; may be either an instantaneous measure or the maximum energy transferred in some interval such as 15 minutes.}}

{{term|[[Patch cables]]}}{{defn|Short cables with connectors, used to make connections between outlets of a patch panel or for temporary connections to a system under test.}}

{{term|[[Peak demand]]}}{{defn|The maximum rate at which energy is consumed from an electrical grid; may be either an instantaneous measure or the maximum energy transferred in some interval such as 15 minutes.}}

{{term|[[Peltier–Seebeck effect]]}}{{defn|The thermoelectric effect, movement of heat due to electric current flow.}}

{{term|[[Pentagridpentagrid converter]]}}{{defn|A type of self oscillating vacuum tube used a frequency mixer in superheterodyne receivers.}}

{{term|[[Pentodepentode]]}}{{defn|Any five-electrode electron device, but usually a kind of vacuum tube.}}

{{term|[[Permanentpermanent magnet synchronous generator]]}}{{defn|An AC generator that uses a permanent field magnet instead of an electromagnet.}}

{{term|[[Permanentpermanent magnet]]}}{{defn|A magnet that retains its polarization after an external field is removed.}}

{{term|[[Permeabilitypermeability (electromagnetism)|permeability]]}}{{defn|The amount of magnetisation in a material resulting from an applied magnetic field.}}

{{term|[[Personalphase computerconverter]]}}{{defn|AElectrical computerapparatus cheapthat enoughconverts topower befrom usefula system of phases to aanother system, for example, converting single-phase personpower to three-phase.}}

{{term|[[Personalphase-fired digital assistantcontrollers]]}}{{defn|AAn pocketAC sizepower devicecontroller that combinesadjusts anthe electroniceffective notepadvalue withof calendaroutput andby otherswitching functions;on something likeat a modernvariable smarttime phone,phase but withoutin the ability to make phoneAC callscycle.}}

{{term|[[Phasephase locked converterloop]]}}{{defn|ElectricalAn apparatusoscillator circuit that convertsproduces poweran fromoutput asignal systemthat ofis phasesin toa anotherfixed system,timing forrelation example,to convertinga single-phasereference power to three-phaseinput.}}

{{term|[[phase modulation]]}}{{defn|Impressing information on a carrier wave by advancing or delaying the waveform slightly; related to frequency modulation.}}

{{term|[[Phase-fired controllers]]}}{{defn|An AC power controller that adjusts the effective value of output by switching on at a variable time phase in the AC cycle.}}

{{term|[[Phasephasor locked loop(electronics)|phasor]]}}{{defn|AnA oscillatorvector circuitrepresenting that produces an outputa signal that is inof a fixedgiven timingfrequency relation to ain referencephase inputspace.}}

{{term|[[phasor measurement unit]]}}{{defn|A system that measures the timing and amplitude of {{gli|voltage|voltages}} and {{gli|current|currents}} on an electrical grid, synchronized over a wide geographic area; the resulting measurements can be used to manage power flow on the grid.}}

{{term|[[Phase modulation]]}}{{defn|Impressing information on a carrier wave by advancing or delaying the waveform slightly; related to frequency modulation.}}

{{term|[[Phasor (electronics)phonograph]]}}{{defn|A vectorrecord representingplayer, a signaldevice that converts the mechanical movements of a given frequencystylus in phasea disk or cylinder recording groove into spacesound.}}

{{term|[[photocell]]}}{{defn|A light sensor that produces or alters a {{gli|voltage}} when light is present.}}

{{term|[[Phasor measurement unit]]}}{{defn|A system that measures the timing and amplitude of voltages and currents on an electrical grid, synchronized over a wide geographic area; the resulting measurements can be used to manage power flow on the grid.}}

{{term|[[Phonographphotodetector]]}}{{defn|A record player, aAny device that converts the mechanical movements of a stylus in a disk or cylinder recording groovedetects intovisible soundlight.}}

{{term|[[Photocellphotodiode]]}}{{defn|A lighttwo-terminal sensordevice thatwhose producesterminal {{gli|voltage}} or alters{{gli|current}} achanges voltagein whenresponse lightto is presentlight.}}

{{term|[[Photodetectorphotometer]]}}{{defn|AnyAn deviceinstrument that detects visiblemeasures light.}}

{{term|[[Photodiodephotonics]]}}{{defn|AThe two-terminaltechnology deviceof whoseconveying terminalinformation voltagethrough light or currentinfrared changes in response to lightradiation.}}

{{term|[[Photometerphotoresistor]]}}{{defn|AnA instrumentresistor thatwhose measuresresistance varies when light strikes it.}}

{{term|[[Photonicsphototransistor]]}}{{defn|TheA technologytransistor ofsensitive conveying information throughto light or infrared radiation.}}

{{term|[[Photoresistor]]}}{{defn|A resistor whose resistance varies when light strikes it.}}

{{term|[[Phototransistor]]}}{{defn|A transistor sensitive to light.}}

{{term|[[PID controller]]}}{{defn|A process control system that has proportional, integral and derivative terms in its response to errors between measured value and setpoint.}}

{{term|[[Piezoelectricpiezoelectric effect]]}}{{defn|Production of a {{gli|voltage}} in response to mechanical pressure or mechanical deformation.}}

{{term|[[Piezoelectricpiezoelectric motor]]}}{{defn|A type of motor that uses {{gli|piezoelectric effect|piezoelectric}} elements to generate force.}}

{{term|[[PIN diode]]}}{{defn|A multilayer semiconductor diode with a thin region of intrinsic material between its p-doped and n-doped regions.}}

{{term|[[Planarplanar graph]]}}{{defn|In network theory, a set of nodes and interconnecting lines that can be given in one plane without crossing lines.}}

{{term|[[Plasmaplasma (physics)|plasma]]}}{{defn|A state of matter where electric charges are free to move.}}

{{term|[[Plenumplenum cable]]}}{{defn|A fire-resistant data communications cable that is permitted to be installed in the air handling spaces of a modern building.}}

{{term|[[Plugplug-in hybrid]]}}{{defn|A hybrid electric vehicle that can be recharged from grid power as well as its own engine/generator.}}

{{term|[[P-N junction]]}}{{defn|The boundary between two differently doped regions of a semiconductor.}}

{{term|[[Polarizationpolarization density]]}}{{defn|A measure of the increase of the intensity of an electric field over that in free space, owing to the separation of atomic-scale electric dipoles.}}

{{term|[[Polyphasepolyphase coil]]}}{{defn|A coil intended for connection to a polyphase power supply.}}

{{term|[[Polyphasepolyphase system]]}}{{defn|An {{gli|alternating current}} power transmission system using three or more wires, each of which carries a current that is displaced in time with respect to the others.}}

{{term|[[Pontryagin's minimum principle]]}}{{defn|A mathematical principle used in the theory of optimal control.}}

{{term|[[Portport (circuit theory)|port]]}}{{defn|Any place at which energy can be observed to enter or leave a system.}}

{{term|[[Positivepositive feedback]]}}{{defn|Feedback from the output of a system that tends to increase the effect of any input; if overdone, leads to instability.}}

{{term|[[Potentialpotential difference]]}}{{defn|VoltageA {{gli|voltage}} difference, the amount of work required to bring a test charge from one point to another divided by charge magnitude.}}

{{term|[[Potentiometerpotentiometer]]}}{{defn|A three -terminal variable resistor, which can be configured as an adjustable voltage divider.}}

{{term|[[Powerpower BJT]]}}{{defn|A bipolar junction transistor that can be used in circuits handling a watt or more of power.}}

{{term|[[Powerpower cable]]}}{{defn|Flexible insulated electrical conductors used to transmit electric power.}}

{{term|[[Powerpower conditioner]]}}{{defn|Any system intended to alter some property of the bulk power supply to improve it for some application; such as filters, surge suppressors, voltage regulators, uninterruptible power supplies, and many others.}}

{{term|[[Powerpower consumption]]}}{{defn|The rate at which a device consumes energy.}}

{{term|[[Powerpower converter]]}}{{defn|Apparatus intended to convert electric power to another form of electric power, such as conversion between acAC and dcDC or changing frequency or phase number.}}

{{term|[[Powerpower distribution]]}}{{defn|That portion of an electrical grid between the substation or bulk supply and the end consumer.}}

{{term|[[Powerpower electronics]]}}{{defn|The class of electronic devices handling power greater than a watt.}}

{{term|[[Powerpower engineering]]}}{{defn|That part of electrical engineering that deals with the generation, distribution and consumption of electrical power.}}

{{term|[[Powerpower-factor correction]]}}{{defn|Apparatus intended to bring the power factor of some load closer to 1.}}

{{term|[[Powerpower factor]]}}{{defn|The ratio of apparent power flowing to a load divided by the real power.}}

{{term|[[Powerpower-flow study]]}}{{defn|A load flow study; mathematical prediction of the magnitudes and direction of power flow in an existing or planned power grid; an essential part of grid management.}}

{{term|[[Powerpower generation]]}}{{defn|The practice of converting other energy sources to electric power.}}

{{term|[[Powerpower grid]]}}{{defn|An interconnected network of generators, transmission lines, and apparatus for reliable and economic transmission and utilization of electric power.}}

{{term|[[Powerpower inverter]]}}{{defn|A DC to AC power converter.}}

{{term|[[Powerpower-line communication]]}}{{defn|The impression of carrier waves on a power line circuit for signalling purposes.}}

{{term|[[Powerpower MOSFET]]}}{{defn|A metal oxide semiconductor field effect transistor suitable for use in circuits handling more than a watt of power.}}

{{term|[[Powerpower plant]]}}{{defn|A facility that converts other energy forms into electric power.}}

{{term|[[Powerpower rating]]}}{{defn|The nominal power that an apparatus or machine can handle, with specified or customary temperature rise and life expectancy.}}

{{term|[[Powerpower quality]]}}{{defn|Conformance of an electrical power supply with its specifications.}}

{{term|[[Powerpower storage]]}}{{defn|A facility that changes electric power into some form that can be stored and usefully reconverted back to electric power, for example, pumped storage or battery systems.}}

{{term|[[Powerpower supply]]}}{{defn|A subsystem of a computer or other electronic device that turns electric power from a wall plug or batteries into a form suitable for use by the system.}}

{{term|[[Powerpower-system automation]]}}{{defn|The implementation of power-operated switching and control that allows automatic operation of power system elements, instead of manual operation.}}

{{term|[[Powerpower-system protection]]}}{{defn|The technology of limiting the spread of failures of a power system to a minimum, and of preventing permanent damage to apparatus or conductors by such faults.}}

{{term|[[Printedprinted circuit board]]}}{{defn|An etched wiring assembly for interconnection of electronic components.}}

{{term|[[Printerprinter (computing)|printer]]}}{{defn|A device that makes permanent human readable images and text from computer data.}}

{{term|[[Processprocess control]]}}{{defn|The field of study of automatic control of processes.}}

{{term|[[Programmableprogrammable logic controller]]}}{{defn|A computer system designed to be rugged enough for industrial use and with a programming environment highly tuned to the ___domain of industrial control problems.}}

{{term|[[Programmingprogramming language]]}}{{defn|A formalism for human-readable instructions to a computer.}}

{{term|[[Protectiveprotective relay]]}}{{defn|An electromechanical or electronic device that detects faults on a power system and can signal circuit breakers to operate.}}

{{term|[[Proximityproximity effect (electromagnetism)|proximity effect]]}}{{defn|The increase in circuit resistance when the magnetic fields of multiple AC currents interact.}}

{{term|[[Pulsepulse transformer]]}}{{defn|A transformer designed to create or transmit pulses.}}

{{term|[[Pulsepulse-width modulation]]}}{{defn|Transmission of information by varying the duration of pulses,or, varying the average output voltage of a power converter by varying the duration of pulses.}}

{{term|[[Pulse-amplitude modulation|Pulsepulse-amplitude modulation]] (PAM)]]}}{{defn|Transmission of information by varying the magnitude of a stream of pulses of fixed frequency.}}

{{term|[[Pulsepulse-code modulation]]}}{{defn|Any system for conveying analog information by altering some property of a stream of pulses.}}

{{term|[[Pumpedpumped-storage hydroelectricity]]}}{{defn|A grid energy storage system that pumps water uphill for later use by a hydroelectric generator plant.}}

{{term|[[Pushpush switch]]}}{{defn|A device that closes or opens an electrical circuit when pushed.}}

{{term|[[Push–pullpush–pull converter]]}}{{defn|A converter with two sets of primary switching elements so that the transformer primary {{gli|voltage}} can be reversed on each cycle.}}

{{glossary end}}

Line 1,123 ⟶ 1,435:

==Q==

{{glossary}}

{{term|[[Quadraturequadrature booster]]}}
{{defn|A phase shifting transformer that can inject voltages that are time delayed with respect to the input voltage.}}

{{term|[[Qualityquality factor]]}}
{{defn|In a resonant circuit, the ratio of stored energy to energy dissipated on each cycle of oscillation.}}

{{term|[[Quantizationquantization (signal processing)|Quantizationquantization]]}}
{{defn|Analog to digital conversion, changing a continuously varying analog signal to discrete digital numbers.}}

{{glossary end}}

==R==

{{glossary}}

{{term|[[Radarradar cross section]]}}{{defn|The effective reflecting area of a radar target, which varies with frequency, geometry, and surface composition.}}

{{term|[[Radarradar]]}}{{defn|Radio Detection and Ranging, the techniques for observing the speed and position of objects by reflected radio waves.}}

{{term|[[Radioradio frequency]]}}{{defn|Electromagnetic waves with frequencies less than that of infrared radiation; commercially important radio frequencies range from tens of kilohertz up to around a terahertz.}}

{{term|[[Radioradio transmitter]]}}{{defn|Apparatus designed to generate radio frequency electric current, which, connected to an antenna, can radiate energy through space.}}

{{term|[[Radioradio]]}}{{defn|The technology of radio frequency devices.}}

{{term|[[Railwayrailway electrification system]]}}{{defn|A set of standardized methods for applying electric power in railway traction.}}

{{term|[[Rankine cycle]]}}{{defn|A thermodynamic cycle, an idealized version of the operation cycle of a steam turbine.}}

{{term|[[Reactivereactive power]]}}{{defn|That component of apparent power flow due to the return to the source of energy stored in a load's electric or magnetic fields, that does no useful work at the load.}}

{{term|[[Realreal-time operating system]]}}{{defn|A computer operating system that ensures responses with a bounded time to events such as in a controlled process.}}

{{term|[[Receiverreceiver (radio)|receiver]]}}{{defn|The apparatus that takes radio-frequency currents induced in an antenna and turns them into useful signals.}}

{{term|[[Rechargeablerechargeable battery]]}}{{defn|A secondary battery; a battery that can have a useful portion of its capacity restored by connection to a supply of electric current.}}

{{term|[[Reciprocityreciprocity (electrical networks)]]}}{{defn|A theorem that states that the current injected into one point in a network will produce a {{gli|voltage}} at a second point that is identical to the voltage produced at the first point by injection of the same current at the first point}}

{{term|[[Reciprocityreciprocity (electromagnetism)]]}}{{defn|An observation that electric currents and electric fields can be analyzed from either point of view as regards the source of the energy in the system; for example, in radio, a good transmitting antenna is generally also a good receiving antenna.}}

{{term|[[Recordrecord player]]}}{{defn|A phonograph; a device that turns the variations in a disk or cylinder recording groove into sound.}}

{{term|[[Rectifierrectifier]]}}{{defn|A device that converts {{gli|alternating current}} (which periodically reverses) to {{gli|direct current}} that flows in only one direction; may be a solid-state, vacuum tube or electromechanical device.}}

{{term|[[Rectiformerrectiformer]]}}{{defn|A combination of a transformer and a rectifier, used in electrochemical processes or supply of electrostatic precipitators.}}

{{term|[[Recursiverecursive least squares filter]]}}{{defn|An algorithm for a digital filter system.}}

{{term|[[Reed switch]]}}{{defn|An electrical switch made of two thin strips of ferromagnetic metal, which touch when subject to a magnetic field.}}

{{term|[[Regenerativeregenerative braking]]}}{{defn|A braking scheme that returns energy to the source.}}

{{term|[[Regenerativeregenerative circuit]]}}{{defn|A circuit that employs positive feedback; can be an amplifier or an oscillator.}}

{{term|[[Relaxationrelaxation oscillator]]}}{{defn|An oscillator that relies on an active device periodically changing state; such oscillators usually produce a square-wave or sawtooth waveform, different from the approximately sinusoidal waveshape of a harmonic oscillator.}}

{{term|[[Relayrelay]]}}{{defn|An electrically operated switch.}}

{{term|[[Reluctancereluctance motor]]}}{{defn|A type of electric motor that induces non-permanent magnetic poles on the ferromagnetic rotor, relying on varying magnetic reluctance; the rotor carries no windings.}}

{{term|[[Remanenceremanence]]}}{{defn|That portion of the applied magnetic field that the material retains when the external field is removed.}}

{{term|[[Remoteremote racking system]]}}{{defn|A system for inserting circuit breakers into switchgear that allows the operator to stay at a safe distance from any possible arc hazard.}}

{{term|[[Remoteremote sensing]]}}{{defn|Acquisition of measurements of an object without contact, for example, measuring soil moisture by radar from an aircraft.}}

{{term|[[Renewablerenewable electricity]]}}{{defn|Electric power derived from primary energy sources that replenish on a rapid scale or that are not appreciably diminished by human exploitation.}}

{{term|[[Renewablerenewable energy payments]]}}{{defn|Any incentive program to improve the economic return of a renewable energy project.}}

{{term|[[Renewablerenewable energy policy]]}}{{defn|Government plans to displace fossil fuels with renewable sources.}}

{{term|[[Repeatingrepeating coil]]}}{{defn|An old name for a transformer, especially used in telephone circuits.}}

{{term|[[Repoweringrepowering]]}}{{defn|Refurbishing the equipment of a power plant, with a view to improved efficiency or life span.}}

{{term|[[Repulsionrepulsion motor]]}}{{defn|A wound rotor induction motor using a pair of short-circuited brushes on a commutator.}}

{{term|[[Resettableresettable fuse]]}}{{defn|A circuit protective device that opens on excess current, and then, on cooling off, restores the circuit automatically.}}

{{term|[[Residualresidual current circuit breaker]]}}{{defn|A circuit breaker that detects unbalance of phase currents due to ground fault.}}

{{term|[[Resistiveresistive circuit]]}}{{defn|A circuit containing resistive elements only, no capacitors or inductors.}}

{{term|[[Resistivityresistivity]]}}{{defn|The property of a material that impedes current flow.}}

{{term|[[Resistorresistor]]}}{{defn|A circuit component that primarily has resistance.}}

{{term|[[Resolverresolver (electrical)|resolver]]}}{{defn|A transformer-like rotary transducer that measures rotation as an analog value.}}

{{term|[[Resonantresonant cavity]]}}{{defn|An opening that when excited by an electron stream or other means, oscillates at a particular frequency.}}

{{term|[[Resonantresonant inductive coupling]]}}{{defn|A form of energy transfer between two physically close tuned circuits.}}

{{term|[[Returnreturn loss]]}}{{defn|A measure of the power loss due to a signal reflection by a discontinuity in a transmission line or an optical fiber.}}

{{term|[[RF connector]]}}{{defn|An electrical fitting used to connect cables carrying radio frequency currents.}}

{{term|[[RF engineering]]}}{{defn|The profession that deals with application of radio frequency energy to useful ends.}}

{{term|[[Rheoscoperheoscope]]}}{{defn|Obsolete name for an ammeter; now an instrument for measuring fluid viscosity.}}

{{term|[[Rheostatrheostat]]}}{{defn|Obsolete name for a two terminal variable resistor, usually with a rotating shaft to allow manual or motor driven adjustment.}}

{{term|[[Rightright-hand rule]]}}{{defn|A mnemonic device for remembering the definitions of the directions of current and magnetic field in generators.}}

{{term|[[Rippleripple (electrical)|ripple]]}}{{defn|A periodic variation in the amplitude of a DC signal, such as found in a power supply with partly effective filtering.}}

{{term|[[RLC circuit]]}}{{defn|A circuit that has only resistors, inductors, and capacitors in it.}}

{{term|[[Roboticsrobotics]]}}{{defn|The field of automation that deals with manipulators, especially those that mimic human appendages.}}

{{term|[[Robustrobust control]]}}{{defn|A static control algorithm that can produce acceptable performance over an anticipated useful range of process disturbances.}}

{{term|[[Rogowski coil]]}}{{defn|A current sensing coil that produces a {{gli|voltage}} proportional to the rate of change of current; by integration, this can be turned into a measure of current.}}

{{term|[[Rootroot locus]]}}{{defn|A graphical method for analyzing the properties of a transfer function as some parameter is varied.}}

{{term|[[Rootroot mean square]]}}{{defn|The root mean square value of a waveform is the DC value that corresponds to equivalent heating value.}}

{{term|[[Rotaryrotary converter]]}}{{defn|An electric machine that converts electric power between two forms, say, AC and DC or single-phase and three phase, or between two different frequencies of AC (the latter two can be performed by the same machine).}}

{{term|[[Rotaryrotary encoder]]}}{{defn|A transducer that converts rotation of a shaft to a measurement.}}

{{term|[[Rotaryrotary switch]]}}{{defn|A switch operated manually or electrically with a rotary motion of the contacts.}}

{{term|[[Rotaryrotary transformer]]}}{{defn|A transformer used to couple electric signals or power between rotating parts.}}

{{term|[[Rotaryrotary variable differential transformer]]}}{{defn|A transformer-like transducer that measures rotation as an analog value.}}

{{term|[[Rotorrotor (electric)|rotor]]}}{{defn|That part of an electrical machine that rotates. Not necessarily the armature.}}

{{term|[[Routh–Hurwitz stability criterion]]}}{{defn|A criterion for predicting the stability of a system with a given transfer function.}}

{{glossary end}}

Line 1,200 ⟶ 1,513:

{{glossary}}

{{term|[[Sallen–Key filter]]}}{{defn|A family of active filters with a second-order characteristic, first described in 1955.}}

{{term|[[Samplesample and hold]]}}{{defn|A circuit that takes a sample of a changing analog value and holds onto it until the value can be processed by some other stage.}}

{{term|[[Samplingsampling (information theory)|sampling]]}}{{defn|The process of taking a continually varying signal and turning it into a stream of numbers taken at regular intervals.}}

{{term|[[Samplingsampling frequency]]}}{{defn|The rate at which an analog value is sampled.}}

{{term|[[Satellite radiosatellite]]}}{{defn|A radionatural broadcastingor serviceartificial usingobject signalsthat fromcircles ananother, Earth satellitebound toonly customerby receiversgravity.}}

{{term|[[Satellitesatellite radio]]}}{{defn|A naturalradio broadcasting orservice artificialusing objectsignals thatfrom circlesan another,Earth boundsatellite onlyto bycustomer gravityreceivers.}}

{{term|[[Saturationsaturation (magnetic)|saturation]]}}{{defn|That point in the magnetization of a substance where most magnetic domains are aligned with the external field; further increase of the magnetizing force (H) gives only small increase in the magnetization (B).}}

{{term|[[SCADA]]}}{{defn|Supervisory Control and Data Acquisition, management of geographically distributed automation systems such as for an electrical grid.}}

{{term|[[Scatteringscattering parameters]]}}{{defn|A matrix that describes the electrical behavior of linear electrical networks, most prominently the distributed microwave systems.}}

{{term|[[Schmitt trigger]]}}{{defn|A circuit that behaves like a snap-action switch, suddenly changing state as an analog signal increases; displays hysteresis.}}

{{term|[[Schottky diode]]}}{{defn|A diode that relies on the junction between a semiconductor and a metal.}}

Line 1,213 ⟶ 1,526:

{{term|[[s-___domain]]}}{{defn|A Laplace transform converts a function from the time ___domain to the "complex frequency" s-___domain; making certain mathematical operations much simpler to evaluate.}}

{{term|[[SDTV]]}}{{defn|"Standard definition television"{{Snd}} what descriptions of HDTV call any system with 625 scan lines or less.}}

{{term|[[Segmentationsegmentation (image processing)|segmentation]]}}{{defn|A step in digital image processing that groups picture elements of an image that notionally represent some physically significant property of the imaged objects.}}

{{term|[[Seleniumselenium rectifiers]]}}{{defn|One type of metal rectifier, though selenium is considered a "metalloid"{{Snd}} formerly much used but now replaced by silicon semiconductors.}}

{{term|[[Semiconductor devicesemiconductor]]}}{{defn|A device that relies on substancessubstance with electrical conductivity between that of insulators and conductors; thedisplays a negative temperature coefficient of resistance, and is also sensitive to light. controllableThe conductivity of thesesemiconductors materialscan makesreadily mostbe altered by trace amounts of other substances, leading to devices that are the foundation of nearly all modern electronics possible.}}

{{term|[[semiconductor device]]}}{{defn|A device that relies on substances with electrical conductivity between that of insulators and conductors; the controllable conductivity of these materials makes most of modern electronics possible.}}

{{term|[[Semiconductor fabrication]]}}{{defn|The process of turning the raw source of silicon into transistors and integrated circuits.}}

{{term|[[semiconductor fabrication]]}}{{defn|The process of turning the raw source of silicon into transistors and integrated circuits.}}

{{term|[[Semiconductor]]}}{{defn|A substance with electrical conductivity between that of insulators and conductors; displays a negative temperature coefficient of resistance, and is also sensitive to light. The conductivity of semiconductors can readily be altered by trace amounts of other substances, leading to devices that are the foundation of nearly all modern electronics.}}

{{term|[[Sensorsensor]]}}{{defn|A device or system that converts some physical event into an electronic signal, for further use in measurement or control.}}

{{term|[[Serialserial communication]]}}{{defn|Transmission of data as a single series of bits over a communication path.}}

{{term|[[Seriesseries and parallel circuits]]}}{{defn|Electrical circuits where current passes through multiple elements either one after the other, or side by side, like the rungs of a ladder, or both.}}

{{term|[[Shadedshaded-pole motor]]}}{{defn|An {{gli|alternating current}} single phase motor that produces a rotating magnetic field by a turn of wire around part of a field pole.}}

{{term|[[Shaftshaft voltage]]}}
{{defn|An objectionable stray voltage that appears on the rotating part of an electrical machine; very deleterious to supporting bearings.}}

{{term|[[Shieldedshielded twisted pair]]}}
{{defn|Two wires, wrapped around each other and covered with a flexible shield conductor; intended to reject external interference.}}

{{term|[[Shortshort-circuit test]]}}{{defn|A test of machines or apparatus where the load terminals are directly connected; usually done at reduced power to prevent damage, but destructive short circuit testing may be carried out on circuit protective devices.}}

{{term|[[Shortshort circuit]]}}{{defn|A path in a circuit that has negligible resistance; often un-intended, a fault.}}

{{term|[[Shuntshunt (electrical)|shunt]]}}{{defn|A small value resistor connected around a metering element to carry most of the current; only a small part passes through the meter.}}

{{term|[[Siemenssiemens (unit)|siemens]]}}{{defn|A reciprocal ohm, the [[International System of Units|SI]] unit of conductance. The former Siemens mercury unit was a unit of resistance.}}

{{term|[[Signalsignal]]}}{{defn|Some intentional modification of a physical communication path that is intended to convey information from one place to another.}}

{{term|[[Signalsignal processing]]}}{{defn|The technology to extract information from signals.}}

{{term|[[Signalsignal strength]]}}{{defn|A measure of the usable power of a physical signal.}}

{{term|[[Signalsignal-flow graph]]}}{{defn|A formal mathematical treatment of the representation of signal flow through a system, such as an analog computer or a radio receiver.}}

{{term|[[Signalsignal-to-noise ratio]]}}{{defn|A measure of the power contained in the useful part of the signal, to the power contained in noise. Often measured in decibels; for example, in sound reproduction a 40 or 50 decibel signal to noise ratio would be broadcast quality, whereas a 10 decibel ratio would represent very difficult operating conditions for a voice radio system.}}

{{term|[[Siliconsilicon controlled rectifier]]}}{{defn|A four layer semiconductor switching device that can stand off an applied {{gli|voltage}} until triggered by an electrical pulse on a control lead.}}

{{term|[[Silicon Valley]]}}{{defn|Initially, a region of California known for a large number of electronics technology firms.}}

{{term|[[Sinesine wave]]}}{{defn|The waveform of the mathematical sine function; a fundamental wave shape, free of harmonics.}}

{{term|[[Singlesingle-phase electric power]]}}{{defn|AlternatingAn {{gli|alternating current}} power system using only two wires, where peak voltages in each wire occur at the same time.}}

{{term|[[Singlesingle-sideband modulation]]}}{{defn|A radio carrier modulation system where redundant frequencies of one duplicate side band are filtered out along with the carrier, to save transmitter power.}}

{{term|[[Skinskin effect]]}}{{defn|The tendency of {{gli|alternating current}} to flow at the periphery of a conductor; significant for large conductors at power frequencies, and increasingly significant as the frequency increases.}}

{{term|[[Slidingsliding mode control]]}}{{defn|A control strategy for a nonlinear system that uses discontinuous control signals.}}

{{term|[[Slipslip ring]]}}{{defn|A sliding continuous electrical contact between a machine's rotating parts and the fixed external circuit.}}

{{term|[[Smallsmall signal model]]}}{{defn|An analytical tool for systems that show significant non-linearity for large signal excursions.}}

{{term|[[Smartsmart grid]]}}{{defn|The application of information technology to improve performance of the electrical grid.}}

{{term|[[Smith chart]]}}{{defn|A graphical tool for display of the impedance of devices at varying frequencies, and for solution of problems of impedance matching in radio frequency design.}}

{{term|[[Softwaresoftware engineering]]}}{{defn|The profession of designing software systems to meet specified performance requirements.}}

{{term|[[Softwaresoftware]]}}{{defn|The set of instructions and data that direct a computer system.}}

{{term|[[Solarsolar cell]]}}{{defn|A photovoltaic cell, used to produce power from sunlight.}}

{{term|[[Solarsolar energy]]}}{{defn|Useful energy extracted by some means from sunlight.}}

{{term|[[Solarsolar micro-inverter]]}}{{defn|An inverter suitable for use with a single solar panel.}}

{{term|[[Solderingsoldering]]}}{{defn|The process of joining metals using a low melting point filler metal; a critical process in the assembly of most electronic devices.}}

{{term|[[Solenoidsolenoid]]}}{{defn|A coil of wire used to create a magnetic field; often a device with a ferromagnetic plunger that moves when the coil is energized.}}

{{term|[[Solidsolid state (electronics)|solid state]]}}{{defn|Electronics that relies on current flow through crystalline lattices.}}

{{term|[[Solidsolid state physics]]}}{{defn|That branch of physics that studies arrangements of atoms in fixed arrays.}}

{{term|[[Soundsound recording]]}}{{defn|The technology of recording sound for later reporduction.}}

{{term|[[Spacespace vector modulation]]}}{{defn|A control strategy for variable frequency motor drives.}}

{{term|[[Sparkspark spread]]}}{{defn|The difference between the revenue from selling a unit of electricity and the cost of the fuel used to make it.}}

{{term|[[Sparkspark-gap transmitter]]}}{{defn|A former type of radio transmitter that generated radio frequency current by exciting resonance of a tuned system with an electric spark, used almost entirely for transmission of Morse code.}}

{{term|[[Spectrumspectrum analyzer]]}}{{defn|An instrument that graphically displays the amplitude of signals in a narrow bandwidth across a frequency band.}}

{{term|[[Speechspeech processing]]}}{{defn|The techniques for improving the intelligibility of human speech in a communications system.}}

{{term|[[SPICE]]}}{{defn|A set of computer programs for modelling the behavior of electronic circuits.}}

{{term|[[Split phase|Splitsplit phase distribution]]}}{{defn|A type of distribution system that uses a center tapped transformer to provide two voltages to a building wiring system.}}

{{term|[[Induction motor#Starting|Splitsplit phase motor]]}}{{defn|A type of single phase motor that uses a resistor, inductor, or capacitor and two windings to obtain a rotating magnetic field.}}

{{term|[[Squaresquare wave]]}}{{defn|A waveform that spends equal times at the positive and negative peak values with rapid transitions between them.}}

{{term|[[Stabilitystability theory]]}}{{defn|The systematic study of control systems that deals with their response to disturbances.}}

{{term|[[Stablestable polynomial]]}}{{defn|That class of polynomials representing the transfer functions of stable control systems.}}

{{term|[[Stackingstacking factor]]}}{{defn|A measure of the efficiency of filling the space of a machine core or winding; the proportion of active material in any given unit cross section.}}

{{term|[[Standingstanding wave ratio]]}}{{defn|A measure of impedance mismatch for transmission lines in microwave engineering; the ratio of peak amplitude of a standing wave to its minimum.}}

{{term|[[Starstar-mesh transform]]}}{{defn|A mathematical technique used in circuit analysis.}}

{{term|[[Statestate observer]]}}{{defn|In control theory, that which discovers and reports the internal state of a controlled system.}}

{{term|[[Statestate space representation]]}}{{defn|A mathematical technique to represent the internal state of a controlled system as a vector in a Euclidean space.}}

{{term|[[Staticstatic VAR compensator]]}}{{defn|A system that adjusts reactive power flow without moving parts, such as an electronically controlled capacitor bank.}}

{{term|[[Statorstator]]}}{{defn|That part of a rotating electrical machine that remains stationary.}}

{{term|[[Steadysteady-state]]}}{{defn|The condition of a control system where changes due to some disturbance are no longer occurring at a significant rate.}}

{{term|[[Steamsteam turbine]]}}{{defn|A rotating machine that converts the energy of expanding steam to mechanical power through its interactions with sets of moving and stationary blades.}}

{{term|[[Stepstep response]]}}{{defn|The behavior of a control system in response to an abrupt change of input.}}

{{term|[[Stepperstepper motor]]}}{{defn|An electric motor that moves its shafts in discrete steps as different poles are energized.}}

{{term|[[Stereophonicstereophonic sound]]}}{{defn|Sound reproduction systems intended to reproduce sound emanating from more than one direction.}}

{{term|[[Stokes' theorem]]}}{{defn|A theorem about integration of three-dimensional functions, much used in analysis of electric fields.}}

{{term|[[Storagestorage tube]]}}{{defn|A type of cathode ray tube, used for storing images or data.}}

{{term|[[Straystray capacitance]]}}{{defn|A property of every conductor, when considered as a non-ideality.}}

{{term|[[Structuredstructured cabling]]}}{{defn|A system for design of the telephone and data communications cable systems of a building.}}

{{term|[[Submarinesubmarine communications cable]]}}{{defn|A telephone or telegraph cable that is substantially under water.}}

{{term|[[Sulfursulfur hexafluoride circuit breaker]]}}{{defn|A kind of automatic circuit protection switch that breaks current in an atmosphere of pressurized sulfur hexafluoride gas to extinguish the arc.}}

{{term|[[Supersuper grid]]}}{{defn|A wide area power transmission network that allows interchange over continental distances.}}

{{term|[[Supercomputersupercomputer]]}}{{defn|A computer with a substantially higher level of performance than a general purpose machine; especially adapted for high intensity calculation on large data sets.}}

{{term|[[Superconductingsuperconducting electric machine]]}}{{defn|An experimental type of generator or motor that has part of its electric circuits in the superconducting state.}}

{{term|[[Superconductivitysuperconductivity]]}}{{defn|The loss of all electrical resistance at inconveniently low temperatures.}}

{{term|[[Superheterodynesuperheterodyne receiver]]}}{{defn|A radio receiver that changes incoming frequencies to a fixed intermediate frequency for processing.}}

{{term|[[Superpositionsuperposition theorem]]}}{{defn|The useful property of a system where the response to the sum is the sum of the responses.}}

{{term|[[Surgesurge arrester]]}}{{defn|A device intended to absorb brief transient overvoltages to protect machines or apparatus.}}

{{term|[[Surgesurge protection]]}}{{defn|The measures taken to protect machines and apparatus from transient overvoltages.}}

{{term|[[Switchswitch]]}}{{defn|An electrical device that opens and closes a circuit; it may be manually operated, automatically operated by some other electrical circuit, or operated by the change in some physical condition such as flow, level, or temperature.}}

{{term|[[Switchedswitched reluctance motor]]}}{{defn|A motor that relies on induced magnetism in salient poles, instead of a rotor winding.}}

{{term|[[Switchedswitched-mode power supply]]}}{{defn|A power converter that regulates {{gli|voltage}} by adjusting the time duration of a switching device; this gives reduced heat dissipation compared to an equivalent linear regulator device.}}

{{term|[[Switchgearswitchgear]]}}{{defn|An array of switches, circuit breakers and related apparatus for power distribution.}}

{{term|[[Symbolicsymbolic circuit analysis]]}}{{defn|Analytical circuit analysis in terms of expressions with variables, instead of numerical solutions for a particular case of values.}}

{{term|[[Symmetricalsymmetrical components]]}}{{defn|A technique to simplify analysis of unbalanced polyphase systems.}}

{{term|[[Synchrosynchro]]}}{{defn|A synchromotor, a class of electrical motors that follows the rotation of a source.}}

{{term|[[Synchronizationsynchronization (alternating current)|synchronization]]}}{{defn|Aligning the timing of two or more sources, such as synchronizing a generator before connecting it to a grid.}}

{{term|[[Synchronoussynchronous circuit]]}}{{defn|A logic circuit where internal state changes only propagate in step with a master clock signal.}}

{{term|[[Synchronoussynchronous motor]]}}{{defn|A motor that rotates at a speed exactly related to the supply frequency.}}

{{term|[[Synchronoussynchronous rectification]]}}{{defn|A converter from alternating to {{gli|direct current}}, where switching devices actively are operated in step with the positive and negative excursions of the supply.}}

{{term|[[Synchroscopesynchroscope]]}}{{defn|An instrument used to bring an {{gli|alternating current}} generator into synchronization with a grid, that uses a moving pointer or set of lamps.}}

{{term|[[Systemsystem identification]]}}{{defn|The technique of development of a mathematical model of a controlled system; model identification.}}

{{term|[[Systemsystem on a chip]]}}{{defn|An integrated circuit that combines multiple significant subsytems of a product on one die, for example, analog signal processing and digital controls.}}

{{term|[[Systemsystem on module]]}}{{defn|A packaging of significant functions of a complete product in a form that can be used in more than one product.}}

{{glossary end}}

Line 1,312 ⟶ 1,627:

==T==

{{glossary}}

{{term|[[Tachometertachometer]]}}{{defn|An instrument that measures rotational speed (or angular velocity).}}

{{term|[[Taptap (transformer)|tap]]}}{{defn|A connection to a winding at some point between the ends, used to adjust {{gli|voltage}}.}}

{{term|[[Taptap changer]]}}{{defn|A switch that selects which transformer tap is connected to an external circuit; may be manually operated, or power operated; some types can be operated under load for voltage regulation purposes.}}

{{term|[[Technicaltechnical drawing]]}}{{defn|Drawings intended to convey information for construction, operation or maintenance of a system or equipment.}}

{{term|[[telecommunication]]}}{{defn|The field that deals with transmission of information over distances longer than can be covered by an unaided human.}}

{{term|[[Technology]]}}{{defn|Applied science.}}

{{term|[[Telecommunication]]}}{{defn|The field that deals with transmission of information over distances longer than can be covered by an unaided human.}}

{{term|[[Telecommunications Industry Association]]}}{{defn|A US based trade association that develops technical standards.}}

{{term|[[Telegraphtelegraph]]}}{{defn|A system for transmitting text messages, by wire or other means.}}

{{term|[[Telegraphertelegrapher's equations]]}}{{defn|Coupled linear partial differential equations that relate the voltage and current on a transmission line.}}

{{term|[[Telephonetelephone balance unit]]}}{{defn|A balun, a transformer used to convert between balanced and unbalanced lines, as used in telephone circuits.}}

{{term|[[Telephonetelephone line]]}}{{defn|Outside plant that connects a central office to subscriber equipment.}}

{{term|[[Telephonetelephone]]}}{{defn|Transmission of voice by electrical means.}}

{{term|[[Televisiontelevision]]}}{{defn|Transmission of moving images by electrical means.}}

{{term|[[Tellegen's theorem]]}}{{defn|A theorem relating to branch currents in an electrical network.}}

{{term|[[Teslatesla (unit)|tesla]]}}{{defn|The [[International System of Units|SI]] unit of magnetic flux density.}}

{{term|[[Tesla coil]]}}{{defn|A kind of resonant transformer capable of very high voltages; almost identical to an Oudin coil except that it has separately wound primary and secondary.}}

{{term|[[Tetrodetetrode]]}}{{defn|An electron device, nearly always a vacuum tube, with four internal active electrodes.}}

{{term|[[Thermionicthermionic emission]]}}{{defn|Emission of electrons from a hot surface; the Edison Effect was an early instance of description of this phenomenon.}}

{{term|[[Thermistorthermistor]]}}{{defn|A temperature sensitive resistor with a large, somewhat variable, temperature coefficient of resistance.}}

{{term|[[Thermocouplethermocouple]]}}{{defn|A junction of two dissimilar metals that generates {{gli|voltage}} when at a temperature above absolute zero.}}

{{term|[[Thermoelectricthermoelectric effect]]}}{{defn|The conversion between heat flow and current flow, and the reverse.}}

{{term|[[Thermostatthermostat]]}}{{defn|A temperature sensing switch.}}

{{term|[[Thévenin theorem]]}}{{defn|A theorem which states that any network of current sources, voltage sources and resistors can be simplified to an equivalent network with only a {{gli|voltage}} source and series impedance; the dual of Norton's Theorem.}}

{{term|[[Thirdthird rail]]}}{{defn|An energized conductor in the track bed, using a sliding contact to transfer power to an electric train.}}

{{term|[[Threethree-phase AC railway electrification]]}}{{defn|Application of three-phase power to railways.}}

{{term|[[Threethree-phase electric power]]}}{{defn|Electric power transmission using three conductors carrying currents which peak at separate evenly spaced times in each cycle; widely used for motors.}}

{{term|[[Thyristor drivethyristor]]}}{{defn|A variablefour speedlayer drive,semiconductor usuallydevice withthat directstands currentoff motors,applied using thyristors as the{{gli|voltage}} switchinguntil elementstriggered.}}

{{term|[[thyristor drive]]}}{{defn|A variable speed drive, usually with {{gli|direct current}} motors, using {{gli|thyristor|thyristors}} as the switching elements.}}

{{term|[[Thyristor]]}}{{defn|A four layer semiconductor device that stands off applied voltage until triggered.}}

{{term|[[Tidaltidal power]]}}{{defn|Extraction of useful energy, usually as electric power, from the tidal rise and fall of water.}}

{{term|[[Timetime sharing]]}}{{defn|A system whereby multiple human users of a computer can proceed as if they had sole use, while the computer processes each user's software in round-robin fashion.}}

{{term|[[Timetime-invariant system]]}}{{defn|A systems whose characteristics don't vary significantly with time.}}

{{term|[[Topologytopology (electrical circuits)|topology]]}}{{defn|The shape of an electrical network, independent of its size or values.}}

{{term|[[Toroidaltoroidal inductors and transformers]]}}{{defn|Magnetic coils wound around a ring of ferromagnetic material.}}

{{term|[[Total harmonic distortion|Totaltotal harmonic distortion]] (THD)]]}}{{defn|A measure of the magnitude of harmonically-related frequency components a signal processing stage adds.}}

{{term|[[Tractiontraction battery]]}}{{defn|A battery used to store energy for propelling a wheeled electric vehicle.}}

{{term|[[Tractiontraction current]]}}{{defn|Power supply for wheeled electric vehicles.}}

{{term|[[Tractiontraction motor]]}}{{defn|An electric motor for a wheeled vehicle.}}

{{term|[[Tractiontraction substation]]}}{{defn|A substation that supplies current to a railway, subway or similar electric wheeled transit.}}

{{term|[[Transatlantictransatlantic communications cable]]}}{{defn|A cable for voice or data running under the Atlantic Ocean.}}

{{term|[[Transceivertransceiver]]}}{{defn|Apparatus that combines a receiver and transmitter.}}

{{term|[[Transconductancetransconductance]]}}{{defn|}}

{{term|[[Transducerstransducer]]}}{{defn|An instrument that converts a physical quantity into another electrical or physical quantity.}}

{{term|[[Transfertransfer function]]}}{{defn|The mathematical relation between input and output, usually expressed in terms of frequency or complex frequency (s-___domain).}}

{{term|[[Transformertransformer oil testing]]}}{{defn|Examination of transformer oil for its insulating strength, dissolved moisture and other properties, to ensure it is still suitable for use.}}

{{term|[[Transformertransformer oil]]}}{{defn|A hydrocarbon liquid that cools and insulates transformers and other types of electrical apparatus.}}

{{term|[[Transformertransformer]]}}{{defn|A static arrangement of conductors and possibly magnetic materials, that transfers energy by electromagnetic induction.}}

{{term|[[Transformerboardtransformerboard]]}}{{defn|A kind of insulating paperboard used for internal structures of large oil filled power transformers.}}

{{term|[[Transienttransient response]]}}{{defn|The short-time response of a system to a disturbance.}}

{{term|[[Transil]]}}{{defn|A brand of transient {{gli|voltage}} suppression diode.}}

{{term|[[Transistortransistor]]}}{{defn|A three terminal solid state device used as an amplifier or switch.}}

{{term|[[Transmissiontransmission (telecommunications)|transmission]]}}{{defn|The process of getting a signal from one point to another.}}

{{term|[[Transmissiontransmission line]]}}{{defn|An arrangement of conductors for movement of electric power; used from DC to upper radio frequencies.}}

{{term|[[Transmissiontransmission system operator]]}}{{defn|A corporation that runs the transmission system between sources of power and distribution substations.}}

{{term|[[Transmissiontransmission tower]]}}{{defn|A structure for support of overhead transmission wires.}}

{{term|[[Transmittertransmitter]]}}{{defn|Apparatus that prepares a signal for emission into some medium, such as a radio transmitter or a sonar transmitter.}}

{{term|[[Travelingtraveling-wave tube]]}}{{defn|A type of microwave amplifier vacuum tube. }}

{{term|[[Tremblertrembler coil]]}}{{defn|A kind of high -voltage coil that includes an interrupting mechanism, formerly used in automobile ignition systems.}}

{{term|[[TRIAC]]}}{{defn|A variation of the {{gli|thyristor}} that can pass bidrectional (ac) current.}}

{{term|[[Triangletriangle wave]]}}{{defn|A waveform composed of straight line segments that extend from minus peak to plus peak.}}

{{term|[[Triggertrigger transformer]]}}{{defn|A transformer that generates a pulse to initiate some other device, such as a {{gli|thyristor}} or a flash tube.}}

{{term|[[Triodetriode]]}}{{defn|An electron device, nearly always a vacuum tube, that has three active electrodes.}}

{{term|[[Trolleytrolley pole]]}}{{defn|A support for a current collector on a vehicle.}}

{{term|[[Trolleybustrolleybus]]}}{{defn|Strictly, a passenger vehicle that collects motive electric power from a pair of overhead conductors.}}

{{term|[[Tunedtuned circuit]]}}{{defn|A circuit that displays a peak response at some frequency.}}

{{term|[[Twistedtwisted pair]]}}{{defn|Two wires twisted around each other, possibly covered with an overall sheath; this configuration rejects some kinds of interference.}}

{{term|[[Twotwo-phase electric power]]}}{{defn|An electric power system using two sets of {{gli|alternating current|alternating currents}}, displaced in time by a quarter period.}}

{{term|[[Twotwo-port network]]}}{{defn|A network that has two places to exchange energy with its surroundings.}}

{{term|[[Twotwo-sided Laplace transform]]}}{{defn|A variant of the Laplace transform that simplifies certain operations.}}

{{glossary end}}

Line 1,386 ⟶ 1,700:

==U==

{{glossary}}

{{term|[[Ubiquitousubiquitous computing]]}}
{{defn|A scenario where computer science is made to appear everywhere.}}

{{term|[[Ultrasonicultrasonic motor]]}}
{{defn|A motor that relies on a component oscillating at an ultrasonic frequency.}}

{{term|[[ultrasonics]]}}

{{term|[[Ultrasonics]]}}{{defn|Term for the field of study pertaining to pressure oscillations in air or other media that are above the range of human hearing.}}

{{defn|Term for the field of study pertaining to pressure oscillations in air or other media that are above the range of human hearing.}}

{{term|[[Ultrasound]]}}{{defn|Sound having a frequency above the range of normal human hearing. A portmanteau of the former description of 'ultrasonic sound'}}

{{term|[[ultrasound]]}}

{{term|[[Undersampling]]}}{{defn|Sampling a signal at less than the Nyquist rate; can produce alias frequencies or other artifacts.}}

{{defn|Sound having a frequency above the range of normal human hearing. A portmanteau of the former description of 'ultrasonic sound'}}

{{term|[[Unijunction transistor]]}}{{defn|A three terminal semiconductor device with a definite switching characteristic and only one PN junction.}}

{{term|[[undersampling]]}}

{{term|[[Unipolar motor]]}}{{defn|A heteropolar motor; all currents in this design flow in only one direction.}}

{{defn|Sampling a signal at less than the Nyquist rate; can produce alias frequencies or other artifacts.}}

{{term|[[Unix]]}}{{defn|A computer operating system.}}

{{term|[[unijunction transistor]]}}

{{term|[[Unshielded twisted pair]]}}{{defn|Two wires wrapped around each other, but without a conductive cover.}}

{{defn|A three terminal semiconductor device with a definite switching characteristic and only one PN junction.}}

{{term|[[Upsampling]]}}{{defn|Sampling at greater than the Nyquist rate, which makes filter design easier.}}

{{term|[[unipolar motor]]}}

{{term|[[Utility frequency]]}}{{defn|60 or 50 cycles per second, used for electric power.}}

{{defn|A heteropolar motor; all currents in this design flow in only one direction.}}

{{term|[[Utility pole]]}}{{defn|A columnar structure that carries wires for electrical power distribution, cable television, telephone or similar services.}}

{{term|[[unshielded twisted pair]]}}

{{defn|Two wires wrapped around each other, but without a conductive cover.}}

{{term|[[upsampling]]}}

{{defn|Sampling at greater than the Nyquist rate, which makes filter design easier.}}

{{term|[[utility frequency]]}}

{{defn|60 or 50 cycles per second, used for electric power.}}

{{term|[[utility pole]]}}

{{defn|A columnar structure that carries wires for electrical power distribution, cable television, telephone or similar services.}}

{{glossary end}}

Line 1,404 ⟶ 1,728:

==V==

{{glossary}}

{{term|[[Vacuumvacuum capacitor]]}}
{{defn|A capacitor using vacuum as its dielectric; useful at high voltages or radio frequency.}}

{{term|[[vacuum tube]]}}

{{term|[[Vacuum tube]]}}{{defn|An electron device that relies on flow of electrons through a vacuum or low-pressure gas; a valve. The first electronic devices that could amplify.}}

{{defn|An electron device that relies on flow of electrons through a vacuum or low-pressure gas; a valve. The first electronic devices that could amplify.}}

{{term|[[HVDC converter|Valve]]}}{{defn|A switching element (mercury arc, thyristor, or other device) in a high voltage direct current converter; each phase contains two or more valves, which may be series-connected for higher voltages. Or, a vacuum tube.}}

{{term|[[HVDC converter|valve]]}}

{{term|[[Variable capacitor]]}}{{defn|A capacitor whose value can be changed, by rotating a shaft, squeezing a plate or by an electrical signal; for example, as used to tune a radio.}}

{{defn|A switching element (mercury arc, {{gli|thyristor}}, or other device) in a high-voltage {{gli|direct current}} converter; each phase contains two or more valves, which may be series-connected for higher voltages. Or, a vacuum tube.}}

{{term|[[Variable-frequency drive]]}}{{defn|A power converter that varies the speed of an AC motor by changing its frequency; usually, today, a solid=-state device. }}

{{term|[[variable capacitor]]}}

{{term|[[Variac]]}}{{defn|One brand of adjustable transformer, that can essentially continuously vary the ratio between primary and secondary.}}

{{defn|A capacitor whose value can be changed, by rotating a shaft, squeezing a plate or by an electrical signal; for example, as used to tune a radio.}}

{{term|[[Varicap]]}}{{defn|Variable capacitor{{Snd}} usually a diode whose reverse-biased junction capacitance can be varied by applied voltage.}}

{{term|[[variable-frequency drive]]}}

{{term|[[Varistor]]}}{{defn|Variable resistor{{Snd}} a protective device that has a high resistance at low voltage but momentarily switches to lower resistance on exposure to a high voltage.}}

{{defn|A power converter that varies the speed of an AC motor by changing its frequency; usually, today, a solid-state device.}}

{{term|[[Vector control (motor)]]}}{{defn|A strategy for control of variable-speed motor drives.}}

{{term|[[Variac]]}}

{{term|[[Vector group]]}}{{defn|The classification of the connections of a polyphase transformer.}}

{{defn|One brand of adjustable transformer, that can essentially continuously vary the ratio between primary and secondary.}}

{{term|[[Vehicle-to-grid]]}}{{defn|A concept to use electric vehicle batteries as a form of grid energy storage.}}

{{term|[[varicap]]}}

{{term|[[Vehicular automation]]}}{{defn|Automatic systems to assist, or replace, the driver of a vehicle.}}

{{defn|Variable capacitor{{Snd}} usually a diode whose reverse-biased junction capacitance can be varied by applied {{gli|voltage}}.}}

{{term|[[Versorium]]}}{{defn|An antique version of an electroscope.}}

{{term|[[varistor]]}}

{{term|[[Vibrator (electronic)]]}}{{defn|An electromechanical interrupter, part of a DC to AC converter in a battery-operated vacuum tube radio, or similar application. Some had additional contacts to act as a synchronous rectifier.}}

{{defn|Variable resistor{{Snd}} a protective device that has a high resistance at low voltage but momentarily switches to lower resistance on exposure to a high voltage.}}

{{term|[[Video camera tube]]}}{{defn|A family of vacuum tube devices used to pick up images and transmit them electronically.}}

{{term|[[vector control (motor)|vector control]]}}

{{term|[[Video game console]]}}{{defn|An entertainment electronics device that allows one or more players to simulate such activities as ping pong or deadly combat; usually can use a home TV set as a graphical display .}}

{{defn|A strategy for control of variable-speed motor drives.}}

{{term|[[Video processing]]}}{{defn|The techniques used to enhance video images.}}

{{term|[[vector group]]}}

{{term|[[Virtual instrumentation]]}}{{defn|A software-intensive measuring system that can be programmed to emulate any of a number of conventional measuring instruments, or some combination of measuring functions.}}

{{defn|The classification of the connections of a polyphase transformer.}}

{{term|[[Virtual power plant]]}}{{defn|A strategy for managing a collection of disparate power sources, interconnected with a communications network, as if they were a single centralized power plant.}}

{{term|[[vehicle-to-grid]]}}

{{term|[[VLSI]]}}{{defn|Very Large Scale Integration, the ability to put hundreds of thousands of interconnected transistors onto one chip.}}

{{defn|A concept to use electric vehicle batteries as a form of grid energy storage.}}

{{term|[[Volt]]}}{{defn|The SI unit of electrical potential difference; moving a charge of one coulomb through a potential of one volt transfers one joule of energy.}}

{{term|[[vehicular automation]]}}

{{term|[[Voltage compensation]]}}{{defn|Generally, adjustment of a voltage source to compensate for voltage drop; techniques differ widely between a computer power supply and a long-distance power line.}}

{{defn|Automatic systems to assist, or replace, the driver of a vehicle.}}

{{term|[[Voltage-controlled amplifier]]}}{{defn|An amplifier that has its gain controlled by a voltage signal.}}

{{term|[[Versorium]]}}

{{term|[[Voltage controller]]}}{{defn|A device that adjusts the (effective) voltage to a load.}}

{{defn|An antique version of an electroscope.}}

{{term|[[Voltage converter]]}}{{defn|Any device that changes electric power at one voltage to power at a second; a transformer is a common example of an AC voltage converter.}}

{{term|[[vibrator (electronic)|vibrator]]}}

{{term|[[Voltage division]]}}{{defn|A circuit that produces an output voltage that is some, perhaps adjsutable, fraction of the input voltage.}}

{{defn|An electromechanical interrupter, part of a DC-to-AC converter in a battery-operated vacuum tube radio, or similar application. Some had additional contacts to act as a synchronous rectifier.}}

{{term|[[Voltage doubler]]}}{{defn|A rectifier circuit that can product an output DC voltage of nearly twice the input AC voltage.}}

{{term|[[video camera tube]]}}

{{term|[[Voltage regulation]]}}{{defn|A measure of how a source maintains its output voltage for varying load.}}

{{defn|A family of vacuum tube devices used to pick up images and transmit them electronically.}}

{{term|[[Voltage regulator]]}}{{defn|A system that automatically stabilizes the voltage at which power is supplied to a downstream system.}}

{{term|[[video processing]]}}

{{term|[[Voltage source]]}}{{defn|In circuit theory, a hypothetical element that maintains a specified voltage between its terminals independent of the current through it.}}

{{defn|The techniques used to enhance video images.}}

{{term|[[Voltage spike]]}}{{defn|A transient electrical voltage higher than normal appearing on an electrical supply.}}

{{term|[[virtual instrumentation]]}}

{{term|[[Voltage]]}}{{defn|The electric potential difference between two points.}}

{{defn|A software-intensive measuring system that can be programmed to emulate any of a number of conventional measuring instruments, or some combination of measuring functions.}}

{{term|[[Voltage-to-current converter]]}}{{defn|A circuit that produces an output current proportional to an input voltage.}}

{{term|[[Volt-ampere]]}}{{defn|The unit of apparentvirtual power in an AC circuit.plant]]}}

{{defn|A strategy for managing a collection of disparate power sources, interconnected with a communications network, as if they were a single centralized power plant.}}

{{term|[[Voltmeter]]}}{{defn|An instrument for measuring potential difference.}}

{{term|[[VLSI]]}}

{{defn|Very Large Scale Integration, the ability to put hundreds of thousands of interconnected transistors onto one chip.}}

{{term|[[volt]]}}

{{defn|The [[International System of Units|SI]] unit of electrical potential difference; moving a charge of one coulomb through a potential of one volt transfers one joule of energy.}}

{{term|[[voltage]]}}

{{defn|The electric potential difference between two points.}}

{{term|[[voltage compensation]]}}

{{defn|Generally, adjustment of a voltage source to compensate for voltage drop; techniques differ widely between a computer power supply and a long-distance power line.}}

{{term|[[voltage-controlled amplifier]]}}

{{defn|An amplifier that has its gain controlled by a {{gli|voltage}} signal.}}

{{term|[[voltage controller]]}}

{{defn|A device that adjusts the (effective) {{gli|voltage}} to a load.}}

{{term|[[voltage converter]]}}

{{defn|Any device that changes electric power at one {{gli|voltage}} to power at a second; a transformer is a common example of an AC voltage converter.}}

{{term|[[voltage division]]}}

{{defn|A circuit that produces an output {{gli|voltage}} that is some, perhaps adjustable, fraction of the input voltage.}}

{{term|[[voltage doubler]]}}

{{defn|A rectifier circuit that can product an output DC {{gli|voltage}} of nearly twice the input AC voltage.}}

{{term|[[voltage regulation]]}}

{{defn|A measure of how a source maintains its output {{gli|voltage}} for varying load.}}

{{term|[[voltage regulator]]}}

{{defn|A system that automatically stabilizes the {{gli|voltage}} at which power is supplied to a downstream system.}}

{{term|[[voltage source]]}}

{{defn|In circuit theory, a hypothetical element that maintains a specified {{gli|voltage}} between its terminals independent of the current through it.}}

{{term|[[voltage spike]]}}

{{defn|A transient electrical {{gli|voltage}} higher than normal appearing on an electrical supply.}}

{{term|[[voltage-to-current converter]]}}

{{defn|A circuit that produces an output current proportional to an input {{gli|voltage}}.}}

{{term|[[volt-ampere]]}}

{{defn|The unit of apparent power in an AC circuit.}}

{{term|[[voltmeter]]}}

{{defn|An instrument for measuring potential difference.}}

{{glossary end}}

Line 1,445 ⟶ 1,802:

==W==

{{glossary}}

{{term|[[Warwar of the currents]]}}
{{defn|The late 19th century commercial dispute on whether AC or DC was the best system for power distribution.}}

{{term|[[Ward Leonard control]]}}
{{defn|A speed control system for DC machines using an interconnected generator and motor.}}

{{term|[[Wattwatt]]}}
{{defn|The [[International System of Units|SI]] unit of power, work done per unit time.}}

{{term|[[Wattmeterwattmeter]]}}
{{defn|An instrument that measures electrical power.}}

{{term|[[Waveguide (electromagnetism)|Waveguidewaveguide]]}}
{{defn|A tubular structure that guides electromagnetic waves, much used at microwave frequencies; an optical fiber is a kind of optical waveguide.}}

{{term|[[Weberweber (unit)|Weberweber]]}}{{defn|The SI unit of magnetic flux.}}

{{defn|The [[International System of Units|SI]] unit of magnetic flux.}}

{{term|[[Line isolation transformer|Wet transformer]]}}{{defn|In telephone systems, a matching transformer that can operate while carrying a substantial DC "wetting" current.}}

{{term|[[Line isolation transformer|wet transformer]]}}

{{term|[[Wien bridge oscillator]]}}{{defn|A type of electronic oscillator that generates sine waves and is based on a bridge circuit.}}

{{defn|In telephone systems, a matching transformer that can operate while carrying a substantial DC "wetting" current.}}

{{term|[[Wiener filter]]}}{{defn|A class of filters used in signal processing, used to fit an estimate to noisy signal data.}}

{{term|[[Wien bridge oscillator]]}}

{{term|[[Williams tube]]}}{{defn|A cathode ray vacuum tube used as an early form of computer memory.}}

{{defn|A type of electronic oscillator that generates sine waves and is based on a bridge circuit.}}

{{term|[[Wind farm]]}}{{defn|An array of two or more wind turbines, usually sharing a substation.}}

{{term|[[Wiener filter]]}}

{{term|[[Wind power]]}}{{defn|Generation of electricity (sometimes mechanical power) from wind.}}

{{defn|A class of filters used in signal processing, used to fit an estimate to noisy signal data.}}

{{term|[[Wind turbine]]}}{{defn|A rotating machine that extracts energy from wind.}}

{{term|[[Williams tube]]}}

{{term|[[Wire]]}}{{defn|A strand of metal much, much, longer than it is wide; a conductor, often coated with insulation.}}

{{defn|A cathode ray vacuum tube used as an early form of computer memory.}}

{{term|[[Wireless network]]}}{{defn|Data network relying on radio for the connection to end device; may span a building or a larger area.}}

{{term|[[wind farm]]}}

{{term|[[Wireless telegraphy]]}}{{defn|Transmission of text by radio; usually implies Morse or radio-teletype.}}

{{defn|An array of two or more wind turbines, usually sharing a substation.}}

{{term|[[wind power]]}}

{{defn|Generation of electricity (sometimes mechanical power) from wind.}}

{{term|[[wind turbine]]}}

{{defn|A rotating machine that extracts energy from wind.}}

{{term|[[wire]]}}

{{defn|A strand of metal much, much, longer than it is wide; a conductor, often coated with insulation.}}

{{term|[[wireless network]]}}

{{defn|Data network relying on radio for the connection to end device; may span a building or a larger area.}}

{{term|[[wireless telegraphy]]}}

{{defn|Transmission of text by radio; usually implies Morse or radio-teletype.}}

{{glossary end}}

==X==

{{glossary}}

{{term|[[X-ray]]}}
{{defn|Electromagnetic radiation with wavelengths shorter than ten nanometres. Strictly: radiation that is produced in the electron shell of atoms.}}

{{term|[[X-ray lithography]]}}
{{defn|A developing technique for production of very high density structures in integrated circuits.}}

{{glossary end}}

==Y==

{{glossary}}

{{term|[[Yagi antenna]]}}

{{term|[[Yagi antenna]]}}{{defn|A type of radio antenna using a feeder element, one or more parasitic reflector elements, and one or more director parasitic elements to provide a directional characteristic; the classic home TV rooftop antenna was usually a Yagi antenna .}}

{{defn|A type of radio antenna using a feeder element, one or more parasitic reflector elements, and one or more director parasitic elements to provide a directional characteristic; the classic home TV rooftop antenna was usually a Yagi antenna .}}

{{term|[[Y-delta transform]]}}{{defn|A mathematical technique in circuit analysis to simplify a circuit.}}

{{term|[[Y-delta transform]]}}

{{defn|A mathematical technique in circuit analysis to simplify a circuit.}}

{{glossary end}}

==Z==

{{glossary}}

{{term|[[Z3Zener (computer)diode]]}}{{defn|An electromechanical computer.}}

{{term|[[Zener diode]]}}{{defn|Nickname for "voltage regulator diodes" which may rely either on the Zener effect or avalanch breakdown to maintain a roughly constant voltage; the two effects have opposite temperature coefficients of voltage.}}

{{term|[[Zigzagzigzag transformer]]}}
{{defn|A multiwinding three phase transformer, sometimes used for grounding.}}

{{term|[[Z-transform]]}}
{{defn|A mathematical operation that converts a set of evenly spaced measurements of an analog signal into a series of frequency components.}}

{{glossary end}}

Line 1,490 ⟶ 1,869:

*[[Glossary of mechanical engineering]]

*[[Glossary of structural engineering]]

*[[National Council of Examiners for Engineering and Surveying]]

*[[Fundamentals of Engineering Examination]]

*[[Principles and Practice of Engineering Examination]]

*[[Graduate Aptitude Test in Engineering]]

{{Engineering fields}}