18WuD2x

572 quartz resonator • quick-break fuse
quartz resonator See CRYSTAL RESONATOR.
quartz timepiece A watch or clock having as its
control element a time-determining quartz crystal.
quasi- A prefix meaning “to some extent” or “similar
to,” as in quasi-optical radio wave (a radio
wave that behaves like a light ray).
quasi-bistable circuit A trigger-operated multivibrator.
It operates as a flip-flop when the trigger
frequency is sufficiently high.
quasi-instruction In a computer program, a data
item appearing as an encoded instruction, but
that is not acted upon.
quasi-linear feedback system A system in which
the feedback elements are nearly linear, but not
entirely linear.
quasi-negative Pertaining to a voltage that is
negative, with respect to some other voltage, but
whose absolute polarity is positive. For example,
+0.5 volt is quasi-negative, with respect to
+5.5 volts.
quasi-optical Behaving like light. The term is used
to describe certain extremely short radio waves or
other radiations that, like light rays, follow lineof-sight
paths and can be directed, reflected, refracted,
or diffused.
quasi-optical path A line-of-sight path followed by
very short radio waves, such as microwaves.
quasi-positive Pertaining to a voltage that is positive,
with respect to some other voltage, but
whose absolute polarity is negative. For example,
–0.5 volt is quasi-positive, with respect to
–5.5 volts.
quasi-random A set of numbers considered to be
random, but chosen according to an algorithm.
quasi-rectangular wave A wave whose shape approaches
that of a rectangular wave, but that
possesses a small amount of tilt and/or curvature.
quasi-scientific A term that is sometimes applied
to the design of electronic systems or to the appraisal
of circuit behavior, using an intuitive,
rather than analytical approach.
quasi-sine wave A waveform that is not a perfect
sine curve, but is close enough to be considered
sinusoidal, for all practical purposes.
quasi-single sideband A modulated waveform that
somewhat resembles single sideband, in which
parts of both sidebands are present.
quasi-square wave A waveform that is not a perfect
square, but is close enough to be considered
square for all practical purposes. It is sometimes
applied to a rectangular wave when a square
wave is desired.
quasi-technical A term sometimes applied to qualitative
tests, as opposed to quantitative tests.
quaternary 1. Pertaining to a base-4 number
system. 2. Of an atom, joined to carbon atoms for
four bonds. 3. The fourth member of a 4-unit set.
Quebec Phonetic alphabet code word for the
letter Q.
Amplitude
+
−
quasi square wave
Time
quench 1. To suddenly bring to an end (e.g., to
quench an oscillation). 2. To cool quickly, as in
the quenching of a heated metal object. 3. To extinguish
the discharge in a gas tube.
quench capacitor A capacitor that prevents a
spark from arcing across an inductor when current
flow abruptly stops.
quench frequency See QUENCHING FRE-
QUENCY.
quenching action Typical operation of a superregenerative
circuit, in which regeneration is increased
to nearly the point of oscillation and then
reduced; this action is repeated at an ultrasonic
frequency and results in very high sensitivity.
Also see QUENCHING FREQUENCY, QUENCH
OSCILLATOR, and SUPERREGENERATIVE CIR-
CUIT.
quenching frequency The frequency at which regeneration
in a superregenerative circuit is increased
and decreased.
quench oscillator In some superregenerative circuits,
the separate ultrasonic oscillator that produces
the required quenching action.
quench resistor A resistor in a quenching network
that prevents a spark from occurring across an
inductor when current flow stops.
queue A list of data, steps in a process, or commands
awaiting execution in a specific order.
queuing theory A branch of mathematical electronics,
dealing with the optimum order in which
steps should be executed to obtain a particular
end result.
quibinary code In computer operations, a binarycoded
decimal system in which each decimal digit
is represented by seven bits occupying places
whose values are 8, 6, 4, 2, 0, 1, and 0.
quibinary decade circuit A decade counter consisting
of a ring-of-5, followed by a single binary
stage.
quick break An operating characteristic of a
switch, relay, or circuit breaker whereby the contacts
open rapidly—even when the actuating current
or mechanical force is slow-acting.
quick-break fuse A fuse in which the wire melts
and breaks almost instantly when the current
rating is exceeded. Also called quick-blow fuse.
Compare SLOW-BLOW FUSE.