Electrical Engineers and Master Electricians (EEAME) Portal

Dictionary of Electrical Engineering

Commonly used terms in the Electrical industry.

conversion a method by which a continuously varying signal (voltage) is sampled at regularly occurring intervals. Each sample is quantized to a discrete value by comparisons to preestablished reference levels. These quantized samples are then formatted to the required digital output (e.g., binary pulse code words).
The A/D converter is "clocked" to provide updated outputs at regular intervals. In order not to lose any baseband information, sampling must occur at a rate higher than twice the highest incoming signal frequency component.

analog-to-digital (A/D)

converter a device that changes an analog signal to a digital signal of corresponding magnitude. This device is also called an encoder, ADC, or A/C converter.

asymmetric digital subscriber line (ADSL)

a digital subscriber line (DSL) in which the rate from central switching office (CO) to customer premise is much faster than the rate from customer premise to CO.

broadband integrated services digital network (B-ISDN)

a generic term that generally refers to the future network infrastructure that will provide ubiquitous availability of integrated voice, data, imagery, and video services.

brush rigging

the components used to hold the brushes of a rotating machine in place, and to insure proper brush tension is applied.

charging current

that portion of an electric power line's current which goes to charge the capacitance of the line. The charging current is not available for power transmission.

digital tachometer

a device with a sensor that senses pulses from a rotating axis and converts them to digital output calibrated in rotations per minute (rpm).

digital voltmeter (DVM)

a modern solid-state device capable of measuring voltage and displaying the value in digitized form. The term is also used loosely for the digital multimeter, which can also measure current and resistance.

G (giga)

a prefix indicating a quantity of 109. For instance, a gigabyte (GB) of storage is 1;000;000;000 (typically implemented as 230) bytes.

common notation for current gain. GI is dimensionless.

imaginary power

See reactive power

Institute of Electrical and Electronics Engineers (IEEE)

a professional organization of electrical engineers and computer scientists. The world's largest professional organization.

knowledge engineering

the process of developing an expert system.

magnetic resonance imaging (MRI)

(1) a form of medical imaging with tomographic display that represents the density and bonding of protons (primarily in water) in the tissues of the body, based upon the ability of certain atomic nuclei in a magnetic field to absorb and reemit electromagnetic radiation at specific frequencies. nuclear magnetic resonance

(2) an imaging modality that uses a pulsed radio frequency magnetic field to selectively change the orientation of the magnetization vectors of protons within the object under study. The change in net magnetic moment as the protons relax back to their original orientation is detected and used to form an image.

reverse engineering

the reverse analysis of an old application to conform to a new methodology.

semi-rigid cable

a coaxial cable with a solid metal outer-conductor. Typically used where the cable is bent to fit the application only once.

systems engineering

an approach to the overall life cycle evolution of a product or system. Generally, the systems engineering process comprises a number of phases. There are three essential phases in any systems engineering life cycle: formulation of requirements and specifications, design and development of the system or product, and deployment of the system. Each of these three basic phases may be further expanded into a larger number. For example, deployment generally comprises operational test and evaluation, maintenance over an extended operational life of the system, and modification
and retrofit (or replacement) to meet new and evolving user needs.

tap changing under load (TCUL)

a type of transformer in which the output voltage can be adjusted while the load is connected to the transformer. The voltage is adjusted by changing the turns ratio of the primary and secondary coils. That, in turn, is accomplished by bringing out connections (taps) at several points on the coil. Changing from one tap to another either adds or subtracts turns from the coil and raises or lowers the voltage, respectively.