Dictionary of Electrical Engineering

Commonly used terms in the Electrical industry.

magnetic saturation
the condition in a magnetic material when an increase in the magnetizing force does not result in a useful increase in the magnetic induction of the material.
(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 insufficient voltage difference between the motor back EMF and the supply.

In an amplifier, saturation results in a reduction 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 applied magnetomotive force (MMF), but eventually most of the domains in the ferromagnetic material become aligned, and the rate of increase in flux decreases as the MMF continues 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 decreases 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 (Bi) beyond which an increase in magnetizing field yields no further improvement, indicating that all magnetic moments in the material have been aligned.
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 absorbing medium is reduced to one half of its unsaturated 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.