Glossary of electrical and electronics engineering

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This glossary of electrical and electronics engineering pertains specifically to electrical and electronics engineering. For a broad overview of engineering, see glossary of engineering.

A

AC adapter
An external power supply for portable devices that allows them to operate from wall-socket electricity.
AC power plugs and sockets
Electrical connectors used with alternating current.
AC power
Electric power where the current reverses direction periodically.
AC/AC converter
A power converter where the input and output are both alternating current, but may differ in frequency or other characteristics.
AC/DC receiver design
A radio receiver that can operate from either alternating current or direct current wall socket power.
AC/DC conversion
Rectification of AC current, so that current flows in only one direction.
Active rectification
A circuit where rectifier devices are externally controlled to change AC to current flowing in one direction.
Actuator
An end device of a control system, that manipulates a physical variable such as a valve opening or position of a machine part.
Adaptive control
A control strategy where parameters are adjusted as the controlled process changes.
Adjustable-speed drive
Control for a motor that allows more than one speed to be selected.
Advanced Z-transform
A mathematical technique used to model and analyze digital systems.
Affinity laws
Mathematical formulas that relate the speed, flow, and diameter of pumps, fans, blowers, and turbines, useful for predicting output under varying conditions.
Agbioeletric
A brand name of a kind of vegetable oil for use in transformers.
AIEE
American Institute of Electrical Engineers, predecessor organization to IEEE.
Alpha–beta transformation
A mathematical technique useful in analysis of three-phase circuits.
Altair 8800
An early microcomputer.
Alternating current
Electric current that reverses direction periodically.
Alternator
An electrical machine that converts mechanical power into AC electric power.
Alternator synchronization
The process of synchronizing an alternator to a grid or another alternator.
Aluminium smelting
Reduction of aluminium ore to metal, by use of large amounts of electric power.
Ammeter
An instrument that measures electric current.
Amorphous metal transformer
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.
Ampacity
Current carrying capacity of a conductor, in the context of electric power wiring.
Ampere
The SI unit of electrical current.
Ampère's circuital law
The mathematical relation between the integral of the magnetic field over some closed curve to the current passing through the region bound by the curve.
Ampère's force law
The mathematical relation between the force between two current carrying conductors and the current flowing in them.
Ampère's law
Ampère's circuital law.
Amplidyne
An electric machine that allows a small current to control a much larger current.
Amplifier
An system that produces an output that replicates an input signal but with a larger magnitude.
Amplitude modulation
Transmission of information by changing the magnitude of a carrier signal, for example sending sound by radio.
Analog circuit
A circuit where currents and voltages vary continually within some practical range, in proportion to some signal.
Analog filter
An analog circuit that alters some frequency-related property of a signal.
Analog signal processing
Generally, techniques used to alter signals that rely on voltages or currents that vary continually over a practical range.
Analog signal
A signal whose properties (current, voltage) vary proportionally to the information transmitted.
Analog-to-digital converter
A circuit that produces a number proportional to the magnitude of a voltage or current.
Anode
The terminal of an electrochemical or electronic device through which conventional current flows inward.
Antenna (radio)
A structure which converts between electromagnetic waves in space and currents in a conductor.
Apparent power
In an alternating current power circuit, the product of the magnitude of RMS voltage and current.
Apple Computer
A company that makes mobile telephones and computers.
Arbitrary waveform generator
A type of signal generator that can generate almost any waveform.
Arc converter
A device once used to generate radio waves.
Arc furnace
A furnace that melts material by use of an electric arc.
Arc lamp
An electric lamp that generates light from an electric arc.
Arc welder
A device used to join metals by melting them with an electric arc.
Armature (electrical engineering)
That part of an electrical machine that converts electrical energy to mechanical energy (or vice versa).
Artificial intelligence
A computer system that replicates some feature of human intelligence.
Artificial neural networks
An electrical network that mimics the function of a biological nervous system.
Asymptotic stability
A condition of a control system where the output eventually reaches a steady-state value in response to any input.
Asynchronous circuit
A digital circuit where states propagate through a circuit without a synchronizing clock impulse.
Audio and video connector
An electrical fitting used to connect cables carrying audio or video signals.
Audio equipment
Equipment used to handle signals at frequencies within the human range of hearing.
Audio filter
A circuit intended to alter some frequency-related property of a signal carrying sound information.
Audio frequency
A signal whose frequency is within the range of human hearing.
Audio noise reduction
Reduction of interfering signals in an audio signal.
Audio signal processing
Alteration of any properties of a signal carrying sound information (dynamic range, frequency response, or others).
Audion tube
An early three electrode vacuum tube that had amplifying properties.
Austin transformer
A kind of isolation transformer.
Automatic gain control
A circuit that automatically adjusts the magnitude of a signal to prevent it from becoming too small or too large.
Automatic transfer switch
An electrical switch used to automatically select a standby source of electrical power when the principal source is lost.
Automation
Automatic control of a process.
Autorecloser
A circuit protection device for overhead power distribution lines which briefly interrupts a circuit when a fault is detected, then restores the circuit in the expectation the fault has cleared.
Autotransformer
A transformer where the primary and secondary circuits share some of the transformer windings.
Availability factor
The fraction of time that a power plant is available to produce power.
Avalanche diode
A diode intended for regular operation in the reverse, avalanche breakdown, mode. Used as a voltage reference, noise source, and in certain classes of microwave oscillator device.
Average rectified value
The average value of an alternating current waveform, taking the absolute value of the waveform. The average value is generally different from the root-mean-square value.