18WuD2x

staggered tuning • standard signal generator 653
successive stages to slightly different frequencies
to obtain flat-top response.
stagger tuning See STAGGERED TUNING.
stagger-wound coil See BASKET-WEAVE COIL
and SPIDERWEB COIL.
staircase circuit See STAIR-STEP CIRCUIT.
staircase generator A circuit or device for generating
a STAIR-STEP WAVE.
staircase wave See STAIR-STEP WAVE.
stair-step circuit A circuit that converts a series of
equal-amplitude pulses into a stair-step wave.
stair-step wave A nonsinusoidal wave characterized
by a multistep rise and a steep fall. It is so
called from its resemblance to the cross section of
a staircase.
broadcast bands range from 54 MHz to 806 MHz
in several sections, designated in channels from 2
through 69. Also see BROADCAST SERVICE, 1.
standard candle See CANDELA.
standard cell A highly refined primary cell used
to supply a precise direct-current voltage for
electronic measurements. The Weston standard
cell contains a mercury positive electrode, cadmium
amalgam negative electrode, and cadmium
sulfate electrolyte, and delivers 1.0183
volts at 20 degrees Celsius. Also see ZINC
STANDARD CELL.
stair-step wave
stall torque The torque produced when a motor
shaft is prevented from turning.
stalo Acronym for stabilized oscillator.
stand-alone photovoltaic system A solar-power
plant that uses large banks of rechargeable electrochemical
batteries, such as the lead–acid type,
to store electric energy as it is supplied by photovoltaics
during hours of bright sunshine. The energy
is released by the batteries at night or in
gloomy daytime weather. This system does not
depend on the electric utility companies. Although
this scheme offers independence from the
utility companies, a blackout will occur if the system
goes down. Compare INTERACTIVE PHOTO-
VOLTAIC SYSTEM.
standard 1. A precise specification governing the
dimensions and characteristics of a device or system
(e.g., military standard). 2. A highly accurate
physical or electrical quantity to which similar
quantities can be compared (e.g., standard frequency).
3. The device or system that produces a
standard quantity as defined in 2 (e.g., frequency
standard). 4. Having conventional and widely accepted
characteristics.
standard atmosphere Abbreviation, atm. Air pressure
at sea level (1.013 Pascals, or about 14.7
pounds per square inch). Also called ATMO-
SPHERE.
standard broadcast band Any of numerous frequency
bands allocated to conventional broadcast
stations. In the United States, the
amplitude-modulation (AM) radio broadcast band
extends from 535 to 1705 kHz, and the frequency-modulation
(FM) radio broadcast band
extends from 88 to 108 MHz. The television (TV)
standard deviation In statistical analysis, the
square root of the mean of squares of deviation
from the mean.
standard frequency A highly precise frequency to
which other frequencies can be compared for
identification or measurement.
standard-frequency oscillator A stable, precise
oscillator that delivers a standard frequency. Also
see PRIMARY FREQUENCY STANDARD and
SECONDARY FREQUENCY STANDARD.
standard-frequency signal A calibration and reference
signal that is broadcast on a standard frequency,
such as those transmitted on 2.5, 5, 10,
and 15 MHz by the National Bureau of Standards.
standard pitch The tone corresponding to the
frequency 440 Hz (in music, the note A above
middle C).
standard signal generator A (usually continuously
variable) high-grade generator of modulated
and unmodulated radio-frequency test
signals. A general-purpose instrument of this
type usually covers a wide range (e.g., 15 kHz to
100 MHz) in several tuning bands. For calibration,
a standard signal generator is referred to a
primary frequency standard or secondary frequency
standard.