Qué (quién) es scanner generator - definición
![trunktracking]] scanner](https://commons.wikimedia.org/wiki/Special:FilePath/Uniden BCT-15 deck in bracket-left.jpeg?width=200 "trunktracking]] scanner")
![Copyright Law]] to scan a book by a third party who is not a copyright holder or a book owner. Therefore, in South Korea, book owners visit 'Scan Room' to scan books by themselves.](https://commons.wikimedia.org/wiki/Special:FilePath/2020-03-27 16.38.23 Scan Room in South Korea.jpg?width=200 "Copyright Law]] to scan a book by a third party who is not a copyright holder or a book owner. Therefore, in South Korea, book owners visit 'Scan Room' to scan books by themselves.")
![Belinograph]] BEP2V wirephoto machine by Edouard Bélin, 1930](https://commons.wikimedia.org/wiki/Special:FilePath/Belinograph BEP-2V - MfK Bern.jpg?width=200 "Belinograph]] BEP2V wirephoto machine by Edouard Bélin, 1930")
![Detroit News]]'' in the early 1990s.](https://commons.wikimedia.org/wiki/Special:FilePath/Photoshop goddess version 1.05 (3378276180).jpg?width=200 "Detroit News]]'' in the early 1990s.")
![sceyeX document camera.](https://commons.wikimedia.org/wiki/Special:FilePath/SilverCreations - model "sceyeX" 10MP Document Scanner 03-2013.jpg?width=200 "sceyeX document camera.")
![Hydroelectric power station at [[Gabčíkovo Dam]], [[Slovakia]]](https://commons.wikimedia.org/wiki/Special:FilePath/DSCN1028.JPG?width=200 "Hydroelectric power station at [[Gabčíkovo Dam]], [[Slovakia]]")
![Protesters at [[Occupy Wall Street]] using bicycles connected to a motor and one-way diode to charge batteries for their electronics<ref>[http://cityroom.blogs.nytimes.com/2011/10/30/with-generators-gone-wall-street-protesters-try-bicycle-power/ With Generators Gone, Wall Street Protesters Try Bicycle Power], Colin Moynihan, ''New York Times'', 30 October 2011; accessed 2 November 2011</ref>](https://commons.wikimedia.org/wiki/Special:FilePath/Day 47 Occupy Wall Street November 2 2011 Shankbone 15.JPG?width=200 "Protesters at [[Occupy Wall Street]] using bicycles connected to a motor and one-way diode to charge batteries for their electronics<ref>[http://cityroom.blogs.nytimes.com/2011/10/30/with-generators-gone-wall-street-protesters-try-bicycle-power/ With Generators Gone, Wall Street Protesters Try Bicycle Power], Colin Moynihan, ''New York Times'', 30 October 2011; accessed 2 November 2011</ref>")
![The [[Faraday disk]] was the first electric generator. The horseshoe-shaped magnet ''(A)'' created a magnetic field through the disk ''(D)''. When the disk was turned, this induced an electric current radially outward from the center toward the rim. The current flowed out through the sliding spring contact ''m'', through the external circuit, and back into the center of the disk through the axle.](https://commons.wikimedia.org/wiki/Special:FilePath/Faraday disk generator.jpg?width=200 "The [[Faraday disk]] was the first electric generator. The horseshoe-shaped magnet ''(A)'' created a magnetic field through the disk ''(D)''. When the disk was turned, this induced an electric current radially outward from the center toward the rim. The current flowed out through the sliding spring contact ''m'', through the external circuit, and back into the center of the disk through the axle.")
![alternating current generator]], c. 1900.](https://commons.wikimedia.org/wiki/Special:FilePath/Ferranti two-phase generator set (Rankin Kennedy, Electrical Installations, Vol III, 1903).jpg?width=200 "alternating current generator]], c. 1900.")
![Early [[Ganz]] Generator in [[Zwevegem]], [[West Flanders]], [[Belgium]]](https://commons.wikimedia.org/wiki/Special:FilePath/Generator-20071117.jpg?width=200 "Early [[Ganz]] Generator in [[Zwevegem]], [[West Flanders]], [[Belgium]]")
![The [[Athlone Power Station]] in [[Cape Town]], [[South Africa]]](https://commons.wikimedia.org/wiki/Special:FilePath/Greater Cape Town 12.02.2007 16-41-31.2007 16-41-33.JPG?width=200 "The [[Athlone Power Station]] in [[Cape Town]], [[South Africa]]")
![commutator]] needed for high power applications.](https://commons.wikimedia.org/wiki/Special:FilePath/High-Current Copper-Brush Commutated Dynamo.jpg?width=200 "commutator]] needed for high power applications.")
![kVA]] direct-driven power station AC alternator, with a separate belt-driven exciter generator.](https://commons.wikimedia.org/wiki/Special:FilePath/Murray Alternator with Belt-Driven Exciter.jpg?width=200 "kVA]] direct-driven power station AC alternator, with a separate belt-driven exciter generator.")
![[[Hippolyte Pixii]]'s dynamo. The commutator is located on the shaft below the spinning magnet.](https://commons.wikimedia.org/wiki/Special:FilePath/Wechselstromerzeuger Crop LevelAdj.jpg?width=200 "[[Hippolyte Pixii]]'s dynamo. The commutator is located on the shaft below the spinning magnet.")
Wikipedia
A scanner (also referred to as a radio scanner) is a radio receiver that can automatically tune, or scan, two or more discrete frequencies, stopping when it finds a signal on one of them and then continuing to scan other frequencies when the initial transmission ceases.
The term scanner generally refers to a communications receiver that is primarily intended for monitoring VHF and UHF landmobile radio systems, as opposed to, for instance, a receiver used to monitor international shortwave transmissions.
More often than not, these scanners can also tune to different types of modulation as well (AM, FM, WFM, etc.). Early scanners were slow, bulky, and expensive. Today, modern microprocessors have enabled scanners to store thousands of channels and monitor hundreds of channels per second. Recent models can follow trunked radio systems and decode APCO-P25 digital transmissions. Both hand held and desktop models are available. Scanners are often used to monitor police, fire and emergency medical services. Radio scanning serves an important role in the fields of journalism and crime investigation, as well as a hobby for many people around the world.
