18WuD2x

fader • fan-out 275
tomotive high-fidelity sound system, a control
that adjusts the volume of the front speaker set
and rear speaker set. Usually, this is a single
knob; increasing the front volume decreases the
rear volume, and vice-versa.
fading 1. Repeated increases and decreases of radio
communications signal amplitude at the reception
point. Fading of a radio wave results from
multiple propagation paths from transmitter to
receiver, causing the received waves to arrive in
constantly varying phase relationships. 2. In a
cell or battery power supply, a gradual loss of
power-delivering capability that occurs during
the discharge cycle.
TX
Earth
fading
Ionized
layer
RX
cent to 10 percent of its peak amplitude. Compare
RISE TIME.
false add A logic add (i.e., addition without carries).
false alarm 1. Improper operation of an electronic
security system, resulting in actuation of the
device when no breach of security has occurred.
2. In radar, the presence of a false echo that
causes the attendant circuits or personnel to act
as though an enemy target is present.
false error A condition in which a computer system
erroneously signals the existence of an error.
false precision See MISLEADING PRECISION.
false retrieval The incorrect specification of criteria
for information to be selected for retrieval so
that an unwanted item of data is selected. Also
called false drop.
family Any group of components, circuits, ratings,
or characteristics, classed together because of
some common or analogous feature or application.
Examples: IC family, family of curves, and
family of equations.
family of curves A group of curves plotted on the
same axes, that depict the performance of a circuit
or device at several levels of a third parameter (e.g.,
curves showing transistor collector current vs. collector
voltage for several levels of base current).
Collector
current,
milliamps
8
_
6 _
4 _
2 _
0 _
_
_
_
0 5
10
15
Collector voltage, volts
factory automation The use of robotic devices, to
the greatest extent possible, as laborers in manufacturing
plants.
Fahnestock clip A flat, sheet-metal spring clip for
holding a wire (usually in a temporary breadboard
setup).
Fahrenheit scale A temperature scale on which
the freezing point of water is 32 degrees, and the
boiling point of water is 212 degrees. Compare
ABSOLUTE SCALE and CELSIUS SCALE.
failsafe Pertaining to devices or circuits that, upon
failure, cause no damage or serious malfunction.
failsoft In a computer, a system in which operation
is maintained—even in the event of partial failure.
Efficiency is reduced but the computer does
not completely shut down.
failure The condition wherein a circuit, system, or
device is not operating correctly.
failure analysis 1. The process of determining the
failure rate for a component, system, or device.
2. The process of determining the cause of a
failure.
failure mode The particular way in which a failure
of equipment or a method occurs.
failure unit A unit of machine or device failure:
one failure per billion (10 9 ) hours of operation.
fall-in The time when synchronous speed is attained
in a synchronous motor.
falling characteristic A NEGATIVE RESISTANCE
characteristic.
fall time 1. Decay time. 2. The time required for
the amplitude of a pulse to decrease from 90 perfamily
of curves
Base
current,
microamps
150
100
50
25
0
_
fan antenna See DOUBLE-V ANTENNA.
fan-in 1. A number of inputs entering a common
input terminal. 2. In digital computer operations,
the number of inputs that can be accommodated
by a logic circuit. Compare FAN-OUT.
fan-in circuit A circuit having a number of input
lines entering a common input point. Also see
FAN-IN, 1.
fan-out 1. One common output terminal feeding a
number of output lines. 2. In digital computer