Page 275 - Electrical Engineering Dictionary

Faraday shield an electrostatic (E field) fast packet networks networks in which
shield made up of a conductive or partially packets are transferred by switching at the
conductive material or grid. A Faraday cage frame layer rather than the packet layer. Such
or screen room is effective for protecting in- networks are sometimes called frame relay
side equipment from outside radiated RF en- networks. Current thinking views frame re-
ergies. lay as a service, rather than transmission,
technology.
Faraday’s law one of Maxwell’s equa-
tions that describes the fundamental relation- fast reactor a reactor which maintains a
ship between induced voltage and a time- critical chain reaction with fast neutrons and
varying magnetic field. For a conducting which does not require a moderator.
coil, theinducedvoltageisproportionaltothe
time rate of change in the magnetic flux link- father wavelet the scaling function in the
ing the coil. This change may be produced coarsest resolution in wavelet analysis.
either by actual variation of field strength or
byrelativemotionbetweencoilandfield. See
fault (1) in hardware, a physical defect
also Maxwell’s equations.
or imperfection of hardware. Typical circuit
faults are shorts opens in conductor, defects
Faraday, Michael (1791–1867) Born:
in silicon, etc. See also disturbance.
Newington, Surrey, England
(2) in software, the manifestation of an
Faraday is best known as the greatest ex-
error.
perimental physicist of the 19th century. It
was Faraday who invented the electric mo-
fault avoidance a technique used to pre-
tor, generator, and transformer, and first de-
vent or limit fault occurrence (for example,
scribed electromagnetic induction and the
with signal shielding, fan-out limitation, and
laws of electrolysis. Faraday had no for-
power dissipation decrease).
mal schooling, although he attended many
lectures. The most inspirational of these lec-
fault confinement technique that limits
tureswerebythefamedchemistSirHumphry
the spread of fault effects to some area of
Davy. Faraday became Davy’s assistant and
the system and prevents propagation of these
thus began an extraordinary career as an ex-
effects to other areas.
perimentalist. Faraday’s contributions are
recognized by the use of his name as the unit
of electrical capacitance, the farad in the SI fault coverage the measure of test qual-
system, and the Faraday constant in electrol- ity expressed as the percentage of detected
ysis. faults.
farm See processor farm. faultdetection theprocessoflocatingdis-
tortions or other deviations from the ideal,
fast Fourier transform (FFT) a compu- typically during the process of automated vi-
tational technique that reduces the number sual inspection, e.g., in products undergoing
of mathematical operations in the evaluation manufacture.
of the discrete Fourier transform (DFT) to
N log N. fault indicator a small indicating unit
2
equipped with a permanent magnet and piv-
fast neutrons neutrons emitted from oting pointer which is hung on a transmission
fission reactions which travel at velocities line suffering intermittent faults of unknown
higher than the average velocity of atoms un- origin. After a fault occurs, fault indicators
der random thermal motion. are inspected. Each shows the presence and

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