Page 289 - Electrical Engineering Dictionary

tially constant over the entire range of load the aim of combining the benefits of a highly
currents. productive transfer line, and a highly flexible
job shop.
Fleming, John Ambrose (1849–1945)
Born: Lancaster, Lancashire, England flexure node standing wave pattern in
Fleming is best known as the inventor of loudspeakermembranecausedbyapplieden-
the thermionic diode valve, also known as the ergy.
Fleming valve. This valve was later adapted
by Lee DeForest into a form of vacuum tube flicker the apparent variation of lighting
he called the Audion Triode. Fleming was luminance over time to an observer.
an avid experimentalist as well as a solid the- (2) the apparent visual interruptions pro-
oretician. He began his studies under James duced in a TV picture when the field (one
Clerk Maxwell and ended up consulting for half of a TV frame) frequency is insuffi-
Edison, Swan, and Ferranti, as well as Mar- cient to completely synchronize the visual
coni. Thus Fleming can be considered one of images. Occurs when the field rate is too low
the earliest pioneers in the field of radio and and the biologic characteristic of the human
television electronics. eye known as the persistence of vision does
not give the illusion of continuous motion.
Fletcher-Powell algorithm an iterative Flicker is eliminated if the field rate exceeds
algorithm of Fletcher and Powell (1963) for 50 to 60 Hz.
finding a local minimum of the approxima- (3) repetitive sags and swells in the elec-
tion error. In its original form, the Fletcher- tric service voltage, often accompanied by
Powell algorithm performs an unconstrained periodic harmonic distortion.
minimization.
flicker fusion the perception by the hu-
flexible AC transmission system a trans- man visual system of rapidly varying lights
mission scheme in which each power line is (flicker) as being steady (fused). Flicker fu-
maintained at its optimal impedance, gener- sion is why fluorescent lights and scenes in
ally by means of thyristor-controlled series moviesandtelevisionappeartohaveconstant
compensators. illumination.

flexible link opposite to rigid link, is flicker noise occurs in solid-state devices
subject to elastic deformations of its struc- and vacuum tubes. Its power varies inversely
ture. Basic assumption is that its model is with frequency; therefore, it is also called
described by the so-called Euler–Bernoulli 1/f noise.
beam equations of motion in which of second
or higher order in the deformation variables flip-chip for microwave a packaging in-
are neglected. terconnection, in which the chips are bonded
with contact pads, face down by solder bump
flexible manipulator member of a class connection. The solder bumps support the
of robot manipulators with flexible links. See weight of the chip and control the height of
flexible link. the joint. It is a very good approach for high-
frequency packages.
flexible manufacturing systems (FMS)
manufacturing systems that deal with high- flip-flop a basic digital device capable of
level distributed data processing and auto- storing one bit of information (1 or 0). In
mated material flow using computer-control- an “edge-triggered” flip/flop, information is
led machine tools, robots, assembly robots stored in the device at the transition (positive
and automated material handling, etc., with or negative) of a clock-signal. A flip/flop is

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2000 by CRC Press LLC