Page 161 - Electrical Engineering Dictionary

condition is met. For example, the instruc- (θ − ). Hence, the conduction angle θ cond is
tion JNZ TOP only jumps to TOP if the zero
flag is clear (the “not zero” condition). θ cond = θ + + θ sat + θ −

conditional statistic a statistic premised
on the occurrence of some event. The proba- conduction band the lowest energy band
bility of event E 1 given that E 2 has occurred that is not completely occupied by electrons
is denoted by p(E 1 |E 2 ). See also Bayes’ in a crystalline solid. See also valence band.
rule.
conduction current the drift of electrons
conditionally addressed ROM read- in a conductor (or of electrons and holes in a
only memory in which not every address can semiconductor).
be used to access a valid word. Usually im-
plemented from a PLA. conduction electron a free electron in
the conduction band of a semiconductor.
conductance (1) the reciprocal of resis-
tance. conductivity (1) the reciprocal of resis-
(2)acharacteristicthatdescribestheavail- tivity.
ability and the mobility of conduction elec- (2) a measure of a material’s ability to con-
trons within a material. The values range duct electrical current. Conductivity σ is the
from zero for a perfect insulator to infinity ratio of the conduction current to the electric
for a perfect conductor. The units are sie- field in Ohm’s Law:
mans.
(3) the ability of a substance to carry a J c = σE
thermodynamic flow, such as current, heat,
energy, etc.
conduit a pipe through which an electrical
conducted emission an RF current prop- cables are laid.
agated through an electrical conductor.
cone beam term describing the shape of
conducted noise unwanted electrical sig- the beam formed with an X-ray source and
nals that can be generated by power elec- beam restricter. Because the source is a finite
tronic switching circuits. Conducted noise distance from the target, beam divergence oc-
can travel through the circuit cables as curs because the photons in the beam are not
common-mode or differential mode currents travelling along truly parallel paths. Process-
andcaninterferewithcontrolcircuitsorother ing can be applied to correct for the beam
electronic equipment. shape during image reconstruction.

conduction angle the period during cone of protection a method used to de-
which a device is conducting, i.e., carrying termine the extent of protection to surround-
current. While the device could be a switch ing structures afforded by a tall, grounded
or any other electrical element, such as induc- structure like a steel tower. Proposed prior
tor, phase coil, capacitor, resistor, this term is to the "rolling ball" model, this method sug-
primarily applied to power electronic switch- gests that any structure which can fit within a
ing devices, which are gated to operate for right circular cone whose vertex is at the top
some fraction of a power cycle. of the tower will be protected from lightning
The conduction angle is the sum of the strikes by that tower. The angle of the cone’s
positive transition angle (θ + ), the saturation vertex is a matter of some controversy. See
angle (θ sat ), and the negative transition angle rolling ball.

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2000 by CRC Press LLC