Page 117 - Electrical Engineering Dictionary

reactive power Q. The region of allowable and ground. The circuit finds application in
operation is determined by factors such as ro- capacitive sensors.
tor thermal limit, stator thermal limit, rated
power of prime mover (alternator operation), capacitive reactance the opposition of-
and stability torque limit. fered to the flow of an alternating or pulsating
current by capacitance measured in ohms.
capability list a list of capabilities, usu-
ally associated with a process, defining a set capacitively coupled current See
of objects and the modes of access permit- capacitively coupled field.
ted to those objects. Computer systems have
been designed to use capability lists to define capacitivelycoupledfield fieldappliedto
the memory environment for process execu- the affected limb by electrodes touching the
tion. skin (the current from the electrodes has both
displacement and conduction components).
capacitance the measure of the electri-
cal size of a capacitor, in units of farads. capacitor bank (1) an assembly at one
Thus a capacitor with a large capacitance location of capacitors and all necessary ac-
stores more electrons (coulombs of charge) cessories, such as switching equipment, pro-
at a given voltage than one with a smaller tective equipment, and controls, required for
capacitance. a complete operating installation.
In a multiconductor system separated by (2) a group of (typically 3) capacitors
nonconductive mediums, capacitance (C) mounted on an electric power line for volt-
is the proportionality constant between the age boosting or power factor correction.
charge (q) on each conductor and the volt-
age (V ) between each conductor. The total
equilibrium system charge is zero. Capac- capacitor-start induction motor (CSIM)
itance is dependent on conductor geometry, a single-phase induction motor with a ca-
conductor spatial relationships, and the ma- pacitor in series with its auxiliary winding,
terial properties surrounding the conductors. producing nearly a 90 phase difference be-
◦
Capacitors are constructed as two metal tween the main winding and the auxiliary
surfaces separated by a nonconducting elec- winding currents at starting. This results in
trolytic material. When a voltage is applied a high starting torque, so this motor is used
to the capacitor the electrical charge accumu- for hard-to-start loads. The auxiliary wind-
lates in the metals on either side of the non- ing and capacitor are removed from the cir-
conducting material, negative charge on one cuit by a centrifugal switch as the machine
side and positive on the other. If this mate- approaches operating speed.
rial is a fluid then the capacitor is electrolytic;
otherwise, it is nonelectrolytic. capacity miss a category of cache misses
denoting the case where the cache is not large
capacitance bridge a circuit that includes enough to hold all blocks needed during ex-
two branches which form a balanced drive ecution of a program. See also conflict miss,
(two sinusoidal voltage sources connected cold start miss.
in series with common point grounded) and
twocapacitancesconnectedinseriesbetween capacity region for a multiple termi-
free ends of the voltage sources. The detector nal communications system. The entire set
of current (virtual ground of an operational of rate-vectors for which there exist chan-
amplifier is a suitable choice) is connected nel codes such that the probability of mak-
between the common point of the capacitors ing a decoding error can be made arbitrar-

c
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