Dropout within the realm of
electronicsElectronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...
and
electrical engineeringElectrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical...
, has a number of uses.
It is the dropping away of a flake of magnetic material from
magnetic tapeMagnetic tape is a medium for magnetic recording, made of a thin magnetizable coating on a long, narrow strip of plastic. It was developed in Germany, based on magnetic wire recording. Devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders...
, leading to loss of signal, or a failure to properly read a
binaryThe binary numeral system, or base-2 number system, represents numeric values using two symbols, 0 and 1. More specifically, the usual base-2 system is a positional notation with a radix of 2...
characterIn computer and machine-based telecommunications terminology, a character is a unit of information that roughly corresponds to a grapheme, grapheme-like unit, or symbol, such as in an alphabet or syllabary in the written form of a natural language....
from
data storagethumb|200px|right|A reel-to-reel tape recorder .The magnetic tape is a data storage medium. The recorder is data storage equipment using a portable medium to store the data....
. In magnetic disk, tape, card, or drum systems, a dropout is a recorded signal with an
amplitudeAmplitude is the magnitude of change in the oscillating variable with each oscillation within an oscillating system. For example, sound waves in air are oscillations in atmospheric pressure and their amplitudes are proportional to the change in pressure during one oscillation...
less than a predetermined percentage of a
referenceReference is derived from Middle English referren, from Middle French rèférer, from Latin referre, "to carry back", formed from the prefix re- and ferre, "to bear"...
signal. On an
optical discIn computing and optical disc recording technologies, an optical disc is a flat, usually circular disc which encodes binary data in the form of pits and lands on a special material on one of its flat surfaces...
, it is an area of reduced or obscured
reflectivityIn optics and photometry, reflectivity is the fraction of incident radiation reflected by a surface. In general it must be treated as a directional property that is a function of the reflected direction, the incident direction, and the incident wavelength...
due to
fingerprintA fingerprint in its narrow sense is an impression left by the friction ridges of a human finger. In a wider use of the term, fingerprints are the traces of an impression from the friction ridges of any part of a human hand. A print from the foot can also leave an impression of friction ridges...
s,
scratchScratch may refer to:* A mark or indentation on a surface: Abrasion It may also refer to:- Recordings :* Scratch , by Kaela Kimura* Scratch , the soundtrack to the 2001 documentary Scratch...
es, or other damage. It may also be a
potential differenceVoltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...
between the input and output terminals of a
linear regulatorIn electronics, a linear regulator is a voltage regulator based on an active device operating in its "linear region" or passive devices like Zener diodes operated in their breakdown region...
, below which the regulator can not meet its specifications.
A dropout is also a momentary loss of signal in a
communications systemIn telecommunication, a communications system is a collection of individual communications networks, transmission systems, relay stations, tributary stations, and data terminal equipment usually capable of interconnection and interoperation to form an integrated whole...
, usually caused by
noiseIn common use, the word noise means any unwanted sound. In both analog and digital electronics, noise is random unwanted perturbation to a wanted signal; it is called noise as a generalisation of the acoustic noise heard when listening to a weak radio transmission with significant electrical noise...
,
propagationRadio propagation is the behavior of radio waves when they are transmitted, or propagated from one point on the Earth to another, or into various parts of the atmosphere...
anomalies, or system
malfunctionA malfunction is when something functions wrongly or does not function at all.Some types of malfunctions are:*Malfunction , malfunction of a parachute*Sexual malfunction, also called "sexual dysfunction"**See also dyspareunia...
s. For
analog signalAn analog or analogue signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. It differs from a digital signal in terms of small fluctuations in the signal which are...
s, a dropout is frequently gradual and partial, depending on the cause. For
digital signalA digital signal is a physical signal that is a representation of a sequence of discrete values , for example of an arbitrary bit stream, or of a digitized analog signal...
s, dropouts are more pronounced, usually being sudden and complete, due to the
cliff effectIn telecommunications, the cliff effect or brickwall effect describes the sudden loss of digital signal reception. Unlike analog signals, which gradually fade when signal strength decreases or electromagnetic interference or multipath increases, a digital signal provides data which is either...
. In
mobile telephonyMobile telephony is the provision of telephone services to phones which may move around freely rather than stay fixed in one location. Mobile phones connect to a terrestrial cellular network of base stations , whereas satellite phones connect to orbiting satellites...
, a dropout of more than a few
secondThe second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock....
s will result in a dropped call.