Dictionary of Electrical Engineering

Commonly used terms in the Electrical industry.

compound-connected DC machine
a direct current machine with two field windings in which one field winding is connected
in series and one field winding is connected in parallel (shunt) with the armature winding. The shunt winding may be connected ahead of the series winding (long-shunt connection), or behind the series winding (short-shunt connection).
disconnect switch
a manually operated switching device used to disconnect circuit conductors and their associated load(s) their source of electrical power.
electronic bottleneck
the factor limiting the speed and capacity of a fiber optic communication network is ultimately the link between photons of light and the electronics required to transmit or receive and process them. In order to exploit the full bandwidth capacity of a single-mode optical fiber an optical network should minimize the number of
optical to electrical conversions and instead process the signals in the optical domain.
female connector
a connector presenting receptacles for the insertion of the corresponding male connector that presents pins.
fiber-optic interconnect
interconnect that uses an optical fiber to connect a source to a detector. An optical fiber is used for implementing a bus. The merits are large bandwidth and high speed of propagation.
fused disconnect
a disconnect switch that also employs fuse(s) for the purpose of over-current protection.
holographic interconnect
free-space interconnect that uses holograms to control optical paths from sources to detectors. The hologram provides the interconnection by forming the intentionally distorted image of the source array on the detector array. A hologram can be viewed as a combination of gratings. Each grating directs a light beam passing through it to a new direction. The hologram can be displayed by a spatial light modulator to achieve dynamic reconfiguration.
line-connected reactor

See shunt reactor
male connector
a connector presenting pins to be inserted into a corresponding female connector that presents receptacles.
National Electrical Code (NEC)
a standard for electrical construction, published by the National Fire Protection Association (NFPA 70-1). The National Electrical Code is often adopted by local jurisdictions and used by their electrical inspectors.

See National Electrical Code
star connection

See Y connection
term often used to describe, with some ambiguity, two distinct transformer connections - one to simply convert voltage levels in a 3-phase power system, and the other to convert between 3-phase and a 2-phase voltages. Both connections use only two single-phase transformers, one called the main and the other the teaser, arranged in a T
configuration. Details of each configuration are described below. These connections are also often referred to as Scott connections, since they were first proposed by Charles F. Scott.

Conversion of 3-phase voltage levels: In this configuration, the main transformer in the T-connection is a center-tapped unit that is connected between two lines of the three-phase system. The teaser transformer is connected between the center-tap of the main transformer and the third line of the 3-phase power system. Additionally, the coils of the
teaser transformer have 86.6% of the turns in the corresponding coils in the main transformer. The result is a balanced three-phase voltage on the secondary. In most applications, the main and teaser transformers are actually identical, full voltage units with center taps and two 86.6% taps, one with respect to each terminal. This allows main and teaser units to be interchanged, plus it provides for true, 3-phase, 4-wire system with a neutral connection.
See teaser transformer
wye connection

See Y connection
a three phase source or load connected in the form of Y.
Y connection
a three-phase source or load which is connected such that the elements are connected in parallel and are thus represented in a schematic diagram in a Y or star-shaped configuration.