18WuD2x

filter transmission band • firing angle 285
filter transmission band See FILTER PASSBAND.
fin 1. A metal disk or plate attached to a component
for the purpose of radiating heat. 2. A projection
in an irregular heatsink.
final amplifier Also called output amplifier or
power amplifier. In a wireless transmitter, the
amplifier that boosts the signal power to the level
to be emitted over the airwaves. The input is
provided by the driver; the output is connected to
the system, to a transverter, or to a network cable
power amplifier. In some transmitters, the
output amplifier requires no tuning; in others,
adjustment of the output circuitry is necessary to
obtain proper coupling to the antenna system. In
a single-sideband (SSB) or amplitude-modulated
(AM) transmitter, all amplifiers following the
modulator must be linear. In transmitters intended
for use only in digital modes or for frequency
modulation (FM), power amplifiers need
not be linear.
final result A result displayed at the end of a data
processing operation. Compare INTERMEDIATE
RESULT.
finder The switch or group of relays that selects
the path for a call going through a telephone
switching system. Also called LINE FINDER.
fine adjustment Adjustment of a quantity in small
increments or as a smooth, continuous variation.
Compare COARSE ADJUSTMENT.
fine-chrominance primary See I SIGNAL.
fine frequency control A variable component,
such as a potentiometer or variable capacitor,
that permits a signal or response frequency to be
varied over a small increment; it is often used in
conjunction with a coarse frequency control.
Fine
control
10
pF
Coarse
control
365
pF
fine frequency control
To
osc.
fine-groove record See MICROGROOVE REC-
ORD.
fine index In computer operations, a secondary,
supplemental index used with a main, or gross,
index when the latter does not adequately detail
the differences between the items being indexed.
fine-motion planning The scheme used by a
robotic end effector (“hand”) to get in exactly the
correct position. It uses machine vision, tactile
sensors, pressure sensors, or high-precision displacement
transducers.
finger See FEELER, 1.
finger plethysmograph A device that senses and
records the resistance through the human finger
during various parts of the heart cycle.
finger rules See FLEMING’S LEFT-HAND RULE,
FLEMING’S RIGHT-HAND RULE, and RIGHT-
HAND RULE FOR WIRE.
finish lead The lead attached to the last turn of a
coil. Also called outside lead. Compare START
LEAD.
finished blank The end product in the crystal manufacturing
process, often including electrodes.
finishing The careful handwork and testing involved
in bringing a crystal blank to a condition
that is acceptable as finished, according to specifications.
finishing rate The rate of charging a battery, as
the battery approaches a full charge. Generally,
the finishing rate is less than the normal charging
rate.
finite Pertaining to that which has defined limits.
finite sample space In statistics, a sample space
having definite limits.
finite series A mathematical series having a limited
number of terms. Example: 1 + 0.1 + 0.01 +
0.001, a finite series containing four terms and
whose sum is equal to 1.111.
finned surface The irregular surface of a heatsink.
The ratio of surface area to volume is greater than
with a flat surface; this increases the cooling effectiveness
of the heatsink.
fins Metal vanes radiating from components that
dissipate large amounts of power as heat.
FIR Abbreviation of FAR INFRARED.
fire A transition from non-conduction to conduction
in an ionizing switching device.
fire control The aiming and firing of guns automatically
via radar and associated electronic systems.
firefighter robot A robotic device or system intended
to protect lives and property from fire.
Such a robot can be simple, such as an automatic
sprinkler system actuated via heat sensors
and/or smoke detectors. More sophisticated systems
might use autonomous or remotely controlled
androids that perform the same functions
as human firefighters.
Fire Underwriter’s regulations See NATIONAL
ELECTRIC CODE.
firing The pulse that initiates conduction in an
ionization switching device.
firing angle 1. For a magnetic amplifier, the angular
distance through which the input-voltage
vector rotates before the core is driven into
saturation. 2. For a silicon-controlled rectifier
(SCR), the point, as an angle (in degrees or
radians), along the control voltage half-cycle at
which the SCR fires.