`
`off-peak period
`
`756
`
`ohmic contact
`
`off-peak period (watthour meters) The period of time during
`which the specified off-peak rate applies.
`(ELM) C12.13-1985s
`off-peak power Power supplied during designated periods of
`relatively low system demands. See also: generating station.
`(T&D/PE) [10]
`OFF period (1) (electron tube) The time during an operating
`cycle in which the electronic tube is nonconducting. See also:
`ON period.
`(Std100) [84]
`(2) (circuit switching element) (inverters) The part of an
`operating cycle during which essentially no current flows in
`the circuit switching element. See also: self-commutated in-
`verters.
`(IA) [62]
`off-road vehicle A vehicle specifically designed and equipped
`to traverse sand, swamps, muddy tundra, or rough mountain-
`ous terrain. Vehicles falling into this category are usually all
`wheel drive or tracked units. In some cases, units equipped
`with special air bag rollers having a soft footprint are utilized.
`Synonyms: all terrain vehicle; swamp buggy.
`(T&D/PE) 524-1992r
`offset (1) (transducer) The component of error that is constant
`and independent of the inputs, often used to denote bias.
`(C) 166-1977w, 165-1977w
`(2) (course computer) (electronic navigation) An automatic
`computer that translates reference navigational coordinates
`into those required for a predetermined course. See also: nav-
`igation.
`(AES/RS) 686-1982s, [42]
`(3) (pulse terminology) The algebraic difference between
`two specified magnitude reference lines. Unless otherwise
`specified, the two magnitude reference lines are the waveform
`baseline and the magnitude origin line. See also: waveform
`epoch.
`(IM/WM&A) 194-1977w
`(4) (A) (software) The difference between the loaded origin
`and the assembled origin of a computer program. Synonym:
`relocation factor. (B) (software) A number that must be
`added to a relative address to determine the address of the
`storage location to be accessed. This number may be the dif-
`ference defined in (A) or another number defined in the pro-
`gram. See also: self-relative address; relative address; base
`address; indexed address.
`(C) 610.12-1990
`(5) The octet position relative to the start of a Pre-Arbitrated
`(PA) segment used to carry an isochronous service octet for
`a particular Isochronous Service User (ISU).
`(LM/C) 8802-6-1994
`(6) (A) The measure of unbalance between halves of a sym-
`metrical circuit. (B) The change in input voltage needed to
`cause the output voltage of a linear amplifier to be zero.
`(C) The difference between the value or condition desired
`and that actually attained. (D) The difference between the
`address in a base register and the memory location of a datum.
`See also: relative address.
`(C) 610.10-1994
`(7) (as used in data acquisition) A predetermined value mod-
`ifying the actual value so as to improve the integrity of the
`system, for example, the use of a 4 mA signal to represent
`zero in a 4 mA to 20 mA system.
`(SWG/PE/SUB) C37.100-1992, C37.1-1994
`(8) (as applied to a distance relay) The displacement of the
`operating characteristic on an R-X diagram from the position
`inherent to the basic performance class of the relay. Note: A
`relay with this characteristic is called an offset relay.
`(SWG/PE/PSR) C37.100-1992, C37.90-1978s
`(9) See also: gain and offset.
`(IM/WM&A) 1057-1994w
`offset angle (lateral disk reproduction) (electroacoustics) The
`offset angle is the smaller of the two angles between the pro-
`jections into the plane of the disk of the vibration axis of the
`pickup stylus and the line connecting the vertical pivot (as-
`suming a horizontal disk) of the pickup arm with the stylus
`(SP) [32]
`point. See also: phonograph pickup.
`offset (outboard) bearing (air switch) A component of a
`switch-operating mechanism designed to provide support for
`a torsional operating member and a crank that provides re-
`ciprocating motion for switch operation.
`(SWG/PE) C37.100-1992
`
`offset, clipping See: clipping offset.
`offset course computer (navigation aid terms) An automatic
`computer which translates reference navigational coordinates
`into those required for a predetermined course.
`(AES/GCS) 172-1983w
`offset entry A read-only memory (ROM) entry that provides a
`24-bit offset value. The offset values specifies the location of
`a Control and Status Register (CSR) that provides a 32-bit
`parameter.
`(C/BA/MM) 896.10-1997, 896.2-1991w, 1212-1991s
`offset marker pole See: plumb marker pole.
`offset paraboloidal reflector See: paraboloidal reflector.
`offset paraboloidal reflector antenna A reflector antenna
`whose main reflector is a portion of a paraboloid that is not
`symmetrical with respect to its focal axis, and does not in-
`clude the vertex so that aperture blockage by the feed is re-
`duced or eliminated.
`(AP/ANT) 145-1993
`offset plan-position indicator (PPI) A PPI that has the zero
`position of the time base at a point other than the center of
`the display, thus providing the equivalent of a larger display
`for a selected portion of the coverage area. Synonym: off-
`center PPI.
`(AES) 686-1997
`offset voltage (1) (power supplies) A direct-current potential
`remaining across the comparison amplifier’s input terminals
`(from the null junction to the common terminal) when the
`output voltage is zero. The polarity of the offset voltage is
`such as to allow the output to pass through zero and the po-
`larity to be reversed. It is often deliberately introduced into
`the design of power supplies to reach and even pass zero-
`output volts.
`(AES) [41]
`(2) The driver offset voltage is the average dc voltage gen-
`erated by the differential driver;
`V ⫽ (V ⫹ V )/2.
`os
`oa
`ob
`
`(C/MM) 1596.3-1996
`offset waveform (pulse terminology) A waveform whose base-
`line is offset from, unless otherwise specified, the magnitude
`origin line.
`(IM/WM&A) 194-1977w
`OFF state (thyristor) The condition of the thyristor corre-
`sponding to the high-resistance low-current portion of the
`principal voltage-current characteristic between the origin
`and the breakover point(s) in the switching quadrant(s). See
`also: principal voltage-current characteristic.
`(IA) [12]
`OFF-state current (thyristor) The principal current when the
`thyristor is in the OFF state. See also: principal current.
`(IA) [12]
`OFF-state power dissipation (thyristor) The power dissipa-
`tion resulting from OFF-state current.
`(IA) [12]
`OFF-state voltage (thyristor) The principal voltage when the
`thyristor is in the OFF state. See also: principal voltage-cur-
`rent characteristic.
`(IA) [12]
`ohm (1) (general) The unit of resistance (and of impedance) in
`the International System of Units (SI). The ohm is the resis-
`tance of a conductor such that a constant current of one am-
`pere in it produces a voltage of one volt between its ends.
`(Std100) 270-1966w
`(2) (metric practice) The electric resistance between two
`points of a conductor when a constant difference of potential
`of one volt, applied between these two points, produces in
`this conductor a current of one ampere, this conductor not
`being the source of any electromotive force.
`(QUL) 268-1982s
`ohmic contact (1) (semiconductor) A contact between two ma-
`terials, possessing the property that the potential difference
`across it is proportional to the current passing through. See
`also: semiconductor.
`(AES) [41]
`(2) (charged-particle detectors) (x-ray energy spectrome-
`ters) A purely resistive contactƒone that has a linear voltage-
`current characteristic throughout its entire operating range.
`(NPS/ED/NID) 759-1984r, 325-1996, 216-1960w,
`301-1976s, 300-1988r
`
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