18WuD2x

660 stray inductance • stylus friction
stray field
Field
interacts
with nearby
components
stray inductance Inherent inductance in a place
where it can be detrimental (e.g., inductance in
the coil of a wirewound resistor). Also see STRAY
COMPONENT.
stray resistance Inherent resistance in a place
where it can be detrimental, such as leakage resistance
in a dielectric, and wire resistance in an
inductor.
streaking In television or facsimile, a form of distortion
in which the image appears enlarged in
the horizontal, but not the vertical.
stress 1. See STRAIN. 2. See TENSION, 1. 3. The
force per unit area that produces STRAIN or TEN-
SION on a body.
stretch The amount by which a material being
measured with an electronic device increases in
surface dimensions. Compare SHRINK.
stretched string A long, thin wire or string that vibrates
at a certain frequency, causing standing
waves. It generally exhibits a specific fundamental
frequency and integral harmonics of this frequency.
As the wavelength is cut in half, the
frequency doubles.
strike To initiate a discharge, as in striking a gas
tube.
striking voltage See STARTING VOLTAGE.
string 1. In computer operations, a set of items in
a sequence determined by the order of keys. 2. In
a computer memory, a sequence of bits or characters.
3. Any group of series-connected components
or circuits.
string electrometer See BIFILAR ELECTROME-
TER.
string variable A string of characters, usually
forming a word or phrase, represented by a variable
name and character string symbol (BASIC’s
$, for example) in a computer program.
strip chart A longitudinal, as opposed to circular,
chart for graphic recording. In a rectilinear chart,
both coordinates are straight; in a curvilinear
chart, the crosswise coordinates are arcs.
strip core A ferromagnetic core material made from
a strip of the substance. The method of manufacture
results in superior ferromagnetic qualities,
but also imparts a polarization to the material.
strip fuse A fuse in which the fusible element is a
flat strip of low-melting-point metal. Compare
WIRE FUSE.
strobe 1. See ELECTRONIC FLASH, 1. 2. See
STROBOSCOPE.
strobe light 1. See ELECTRONIC FLASH, 1. 2. See
STROBOSCOPE.
Strobolume Trade name for a type of high-output
stroboscope.
stroboscope 1. An instrument that emits bright,
adjustable-rate flashes of light. When this light illuminates
an object that is rotating or vibrating
at a fixed period, and the flash rate is made to
match that period, the object seems to stand still
and can be examined for flaws or faulty operation
(and its speed can be measured). 2. A rotatable,
slotted disk for producing the effect defined in 1.
stroboscopic disk A rotatable disk with alternating
white and black radial regions, used in conjunction
with a strobe light for precise measurement of
the speed of a phonograph turntable.
strobotron A gas tetrode tube used as the flashing
light source in a stroboscope.
stroke speed See SCANNING FREQUENCY.
strong coupling See CLOSE COUPLING.
strontium Symbol, Sr. A metallic element of the alkaline-earth
group. Atomic number, 38. Atomic
weight, 87.62. It is used in some ceramic dielectrics,
such as barium-strontium titanate.
Strowger exchange A telephone system incorporating
Strowger switches.
Strowger switch A switch with one input and 100
individually selectable outputs. It is used with
telephone switching networks. The telephone dial
code causes a contact to move vertically and horizontally
in such a way that a particular output is
connected to the input. Each output has a
unique dial code and each dial code has a unique
output.
structured programming Computer programming
using a limited number of procedural sets, while
minimizing branches to make the program as
forward-going as possible. This allows it to be
easily modified or debugged.
STS switch See SPACE-TIME-SPACE SWITCH.
stub A (usually short) section of transmission line
that is patched onto a longer line for tuning or
impedance matching.
Stubs gauge See BIRMINGHAM WIRE GAUGE.
stub tuner A tuning unit consisting of a stub with
a short circuit that can be moved along the stub.
stub trap See INTERFERENCE STUB.
stub-type wavetrap See INTERFERENCE STUB.
stuffing bits In a digital communications system,
extra bits inserted into some words so that all the
words are the same length.
styli Plural of STYLUS.
stylus 1. The “needle” that conveys vibrations to or
from the disk in phonograph-disc recording or
playback. 2. One of the pins in the print head of
a dot-matrix printer.
stylus drag See NEEDLE DRAG.
stylus friction Rubbing of the stylus against the
record groove in phonograph-disc playback.