18WuD2x

398 lamp extractor • Laplace transform
lamp extractor A special tool used to insert or extract
miniature lamps for electronic equipment.
lamp jack A receptacle with a spring release that
holds a small incandescent bulb. The bulb is removed
and replaced by pushing and twisting.
lamp jack
lamp-type expander A volume expander in which
the tungsten filament in an incandescent lamp
serves as the nonlinear resistor.
lamp-type readout For counters, calculators, and
digital meters, a readout device in which each
digit is indicated by a lamp.
LAN Abbreviation of LOCAL AREA NETWORK.
land 1. The flat, reflective surface between pits on
a compact disc (CD). Compare PIT, 1. 2. The thin
vinyl wall between grooves on a phonograph
record. 3. A bonding point in a microcircuit. 4.
Pertaining to earthbound communications stations.
Land camera See POLAROID CAMERA.
landing beacon The aircraft landing-beam transmitter.
Also see LANDING BEAM.
landing beam A highly directional airport radio
signal beamed upward to guide aircraft landing
during conditions of poor visibility.
landline A telephone or telegraph circuit completed
with wires.
landmark beacon Any beacon that is not an airway
or airport beacon.
land mobile service Two-way radio service between
a base station and mobile land vehicles, or
among mobile land vehicles.
land mobile station A radio station aboard a mobile,
earthbound vehicle.
land return Ground reflection of radar signals
back to the transmitter.
land station A fixed ground station.
Langevin ion An electrically charged particle, such
as a grain of dust or droplet of water, resulting
from the accumulation of ions.
Langmuir dark space In a luminous gas discharge,
the dark region around a negatively
charged probe inserted into the positive column.
Compare CROOKES’ DARK SPACE.
Langmuir’s law See CHILD’S LAW.
language In digital-computer operations, any one
of the detailed systems for representing data, instructions,
and procedures through the use of
symbols and symbol sequences. See MACHINE
LANGUAGE, ASSEMBLY LANGUAGE, COBOL,
FORTRAN, and BASIC.
language laboratory An electronic contribution to
the teaching and learning of languages. It consists
of recordings in a language being studied
and all the equipment associated with recording,
playback, and monitoring. Students listen to the
speech of experts in the language record, listen
to, and later erase their own utterances in the
language.
language translation 1. The conversion of statements
in one computer language to equivalent
statements in another. 2. The conversion of one
written natural language into another (e.g., French
to Russian) by means of a computer program.
language translator 1. An assembly program,
compiler, or other routine used for translation between
computer languages. 2. A high-level program
that allows a computer to translate one
written natural language into another (e.g., Chinese
to Italian).
L antenna See INVERTED-L ANTENNA.
lantern battery A moderate-sized electrochemical
battery usually rated at 6 volts. Derives its name
from its original use as a power source for portable
lamps. One type has spring contacts on the top.
Another type has thumbscrew terminals. The nonrechargeable
battery consists of 4 zinc–carbon
or alkaline cells in series. Some varieties are
rechargeable, consisting of nickel–cadmium (NiCd)
or nickel–metal-hydride (NiMH) cells. This type of
battery can provide enough energy to operate a
low-power radio transceiver. Two units connected
in series, or four units in series-parallel, make a
12-volt battery that can power a small portable
Citizen Band (CB) or amateur radio station.
lanthanum Symbol, La. An elemental metal of the
rare-earth group. Atomic number, 57. Atomic
weight, 138.906.
lanyard A wire or cable used to quickly pull apart
the halves of a quick-disconnect connector.
lap A device used for grinding piezoelectric crystals
for resonance at a desired frequency.
lap dissolve The simultaneous fading out of one
televised scene while another is fading in so that
one is apparently dissolving into the next. It is
also applicable to motion pictures.
lapel microphone A small microphone that is
clipped to a lapel of a user’s jacket or coat.
lap joint An overlapping splice of two conductors.
Laplace transform Symbol, L. An operator that reduces
the work of solving certain differential
equations by permitting them to be handled by
simpler algebraic methods.