Thus, the actuator saturates, that is, it has
“limited authority.”
saturation
(1) the failure of the output to
increase as fast as the input.
For example, often the current regulator
used in variable-speed drives is unable to
track the commanded current because of in-
sufficient voltage difference between the mo-
tor back EMF and the supply.
In an amplifier, saturation results in a re-
duction of gain in an amplifier or loss in an
absorber due the intensity of the signal being
amplified or absorbed.
In ferromagnetic circuits, the magnetic
flux initially increases linearly with the ap-
plied magnetomotive force (MMF), but even-
tually most of the domains in the ferromag-
netic material become aligned, and the rate of
increase in flux decreases as the MMF con-
tinues to increase. See figure below. See also
saturation flux density
.
Saturation effect in a ferromagnetic circuit.
(2) with respect to color, the amount or
purity of the color seen. A pure color is said
to be fully saturated, and the saturation de-
creases as white is added to the mix. The
color “pink,” for example is a less saturated
version of “red.”
saturation angle
the angular portion of
the time-based output signal (in degrees) over
which the device is saturated. It is always
less than or equal to the conduction angle,
since the device must conduct before it can
saturate.
saturation flux density
the maximum
value of intrinsic induction (
B
i
) beyond
which an increase in magnetizing field yields
no further improvement, indicating that all
magnetic moments in the material have been
aligned.
saturation intensity
the intensity of a
beam of light above which saturation ef-
fects become appreciable. See also
saturable
absorption
.
saturation magnetization
the magnetic
moment per unit volume of a material when
the magnetization in the sample is aligned
(saturated) by a large magnetic field.
saturation parameter
reciprocal of the
value of intensity for which the gain of an
amplifying medium or the loss of an absorb-
ing medium is reduced to one half of its un-
saturated value.
saturation polarization
the value to
which the externally measured electrical
dipole moment of a ferroelectric body tends
when subjected to an external electrical field
greater than the coercive field.
save instruction
an assembly language
instruction that saves information about the
currently executing process.
SAW
See
surface acoustic wave
.
SAW device
See
surface acoustic wave
device
.
saw-tooth coupler
transmission line cou-
pler consisting of two parallel transmission
lines placed in close proximity to one another.
The adjacent edges of the two transmission
lines are shaped in a notch or saw-tooth pat-
tern to equalize the phase velocity of the even
and odd mode voltage components.
c
2000 by CRC Press LLC