18WuD2x

operating station • optical character reader 497
operating station In a computer installation, one
or more consoles for the control of a dataprocessing
system by an operator.
operating system Abbreviation, OS. In a computer,
a set of programs that oversee the functioning of
the hardware and application software. It works
with the basic input/output system (BIOS).
operating temperature The actual or recommended
temperature of a device during its operation.
operating-temperature range For a given device,
the spread between maximum and minimum values
of operating temperature.
operating time 1. The interval during which an
equipment is in operation. 2. The period corresponding
to OPERATING ANGLE.
operating-time characteristic For a coil-type relay,
the relationship between operating time and
operating power.
operating voltage The voltage required by a device,
or measured at the device, during its operation.
Compare IDLING VOLTAGE.
operation 1. The working of a circuit or device (i.e.,
its performance). 2. A process usually involving a
sequence of steps (e.g., a mathematical operation).
operational amplifier Also called an op amp. A
specialized linear integrated circuit (IC) that consists
of several transistors, resistors, diodes, and
capacitors, interconnected to produce gain over a
wide range of frequencies. A single amplifier can
comprise an entire IC, or an IC can contain several
amplifiers. The dual op amp and the quad op
amp are common variants. Some ICs contain one
or more amplifiers in addition to other circuits.
The devices can be used with resistance-capacitance
(RC) network combinations to build active
filters for use at audio frequencies.
operational differential amplifier An OPERA-
TIONAL AMPLIFIER preceded by a DIFFEREN-
TIAL AMPLIFIER.
operational readiness In statistical analysis, the
probability that a system will, at a certain time,
be correctly operating or ready to operate.
operational reliability Reliability determined empirically
from a study of the actual operation of a
device or system under controlled conditions.
Also called ACHIEVED RELIABILITY.
operational transconductance amplifier Abbreviation,
OTA. An integrated-circuit amplifier that
differs from the conventional operational amplifier
in that its output current is proportional to its
input-signal voltage.
operation code In computer operations, the part
of an instruction that specifies an operation.
operation decoder In a digital computer, the circuit
that reads an OPERATION CODE and directs
other circuitry in the execution of the code.
operation envelope See WORK ENVELOPE.
operation number In computer programming, a
number that indicates the position in the program
of a particular operation or subroutine.
operation part In a computer program, the part
of an instruction containing the OPERATION
CODE.
operation register In a digital computer, the register
that stores the operation code of an instruction.
operations research A branch of computer engineering,
devoted to the solution and/or optimization
of functions of many variables.
operation time The interval between the instant of
application of all voltages to a circuit, and the instant
when the current reaches a specified percentage
of its final steady value.
operator 1. A person who performs an operation
(see OPERATE, 1). 2. In mathematics, a symbol
indicating an operation (e.g., j, +, –, ×, etc.).
operator j See J OPERATOR.
opposition 1. The state of two quantities that are
180 degrees out of phase with each other. 2. A
state in which two effects or quantities operate
against each other in some manner (e.g., physically,
mathematically, electrically, etc.).
opt Abbreviation of OPTICAL.
Optacon An electronic aid for the blind. It has a
camera that scans printed matter and a device
that forms corresponding raised letters that can
be read, as would Braille, with the fingertips. The
name is a contraction of optical to tactile converter.
optical 1. Generating or sensing visible light.
2. Visible electromagnetic radiation in the range
of approximately 390 to 750 nanometers wavelength.
optical ammeter A type of OPTICAL PYROMETER
that measures the current flowing through the filament
of an incandescent lamp.
optical antenna A photosensitive device intended
for the reception of modulated-light or modulated-infrared
signals. Usually consists of a
convex lens or a concave reflector and a
semiconductor photodetector.
optical axis The z-axis of a quartz crystal (see
Z-AXIS, 4).
optical character reader A device that uses OPTI-
CAL CHARACTER RECOGNITION to discern
printed characters.