18WuD2x

712 univibrator • unsaturated operation
univibrator See MONOSTABLE MULTIVIBRATOR.
unknown quantity Any variable quantity sought
in calculations; it is usually represented by lowercase
italic letters from the second half of the alphabet
(e.g., x, y, z).
unlike charges Dissimilar electric charges (i.e.,
positive and negative).
unlike poles Dissimilar poles, such as the north
and south poles of a magnet.
unload 1. To remove data from a file. 2. To disconnect
the load from a circuit.
unloaded amplifier See UNTERMINATED AMPLI-
FIER.
unloaded antenna An antenna operated without
added inductance or capacitance.
unloaded-applicator impedance In dielectricheating
operations, the unloaded impedance of
applicator electrodes placed in their normal
working position without the dielectric-material
load in place.
unloaded battery 1. A battery in the standby condition.
2. A battery tested for open-circuit terminal
voltage (i.e., with no load, except the voltmeter).
unloaded generator See UNTERMINATED GEN-
ERATOR.
unloaded line See UNTERMINATED LINE.
unloaded potentiometer A potentiometer or voltage
divider with an open-circuited output.
unloaded Q The Q factor (degree of selectivity) of a
coil or tuned circuit that is activated by a signal,
but that delivers no output to a load.
unloaded transmitter A transmitter operated under
open-circuit conditions (i.e., without an external
load, such as an antenna or dummy resistor).
unmanned factory A manufacturing plant run
largely by robots and computers. There must
generally be at least one human being, whose
job(s) is/are to oversee and maintain the operation
of the machines.
unmatched elements 1. Components (such as resistors,
capacitors, semiconductors, etc.) having
different values. 2. Mating elements or devices
not having the same impedance. Also called
MISMATCH.
unmodulated carrier See CONTINUOUS WAVE.
unmodulated current A current whose characteristics
(amplitude, phase, or frequency) are not
varied by a signal or by noise.
unmodulated voltage A voltage whose characteristics
(amplitude, phase, or frequency) are not
varied by a signal or by noise.
unmodulated wave See CONTINUOUS WAVE.
unnilennium See MEITNERIUM.
unnilhexium See SEABORGIUM.
unniloctium See HASSIUM.
unnilpentium See DUBNIUM.
unnilquadium See RUTHERFORDIUM.
unnilseptium See BOHRIUM.
unode See MONODE.
unpack In computer operations, to remove data
from a storage location into which, with other
data, it has been packed (as a memory-conservation
measure).
unpolarized light Light in which the wave orientation
is random around the axis of the beam.
unpolarized plug A plug that can be inserted into
a socket in two or more different ways, thus increasing
the likelihood of a wrong connection.
Compare POLARIZED PLUG.
unpolarized receptacle A receptacle into which a
plug can be inserted in two or more different
ways, thus increasing the likelihood of a wrong
connection. Also called UNPOLARIZED SOCKET.
Compare POLARIZED RECEPTACLE.
unpolarized relay A relay that always closes in
the same direction, regardless of the direction of
current in its coil. Also called nonpolarized
relay.
unpolarized socket A socket into which a component
or plug can be inserted in two or more different
ways, thus increasing the likelihood of
wrong connections. Also called UNPOLARIZED
RECEPTACLE.
unprotected antenna An outside antenna operated
without a lightning arrester or grounding
switch. Increases the risk of damage to equipment,
such as radio receivers and transmitters,
connected to the antenna. It also increases the
danger to personnel using the equipment.
unrationalized systems of units Collectively, the
absolute centimeter-gram-second (cgs) electrostatic
system of units, the absolute cgs electromagnetic
system of units, and the absolute
meter-kilogram-second (mks) system of units.
unreflected ray See UNREFLECTED WAVE.
unreflected wave 1. See DIRECT WAVE. 2. See
GROUND WAVE. 3. An electromagnetic wave that
penetrates the ionosphere and passes into space.
unregulated Not held to a constant value. For example,
an unregulated voltage is free to fluctuate
in value.
unregulated power supply A power supply whose
output current or voltage is not automatically
held to a constant value. Compare CONSTANT-
CURRENT SOURCE and CONSTANT-VOLTAGE
SOURCE.
uns Abbreviation of UNSYMMETRICAL.
unsaturated core A magnetic core operated below
the point of saturation (i.e., below the point at
which an increase in coil current produces no
further increase in magnetization of the core).
unsaturated logic A digital-logic scheme in which
the switching devices operate between the saturated
and cut-off conditions during either or both
of the high and low states.
unsaturated operation Operation of a device at a
point below saturation [i.e., below the point at
which (1) an increase in voltage produces no further
increase in current, or vice versa, or (2) an
increase in coil current produces no further increase
in magnetization of a core]. Compare
SATURATED OPERATION.