Editing Watch (section)

==== Automatic watches ====
{{Main|Automatic watch}}
[[File:Jaeger-Lecoultre-p1000838.jpg|thumb|[[Automatic watch]]: An eccentric weight, called a rotor, swings with the movement of the wearer's body and winds the spring.]]
[[File:Grand Seiko Automatic Hi-Beat.jpg|thumb|upright|A [[Grand Seiko]] Automatic watch]]

A ''self-winding'' or ''automatic'' watch is one that rewinds the mainspring of a mechanical movement by the natural motions of the wearer's body. The first self-winding mechanism was invented for pocket watches in 1770 by Abraham-Louis Perrelet,<ref>{{cite web | url=http://www.worldtempus.com/fr/encyclopedie/index-encyclopedique/lhorlogerie-dans-le-monde/lhorlogerie-europeenne-en-chine-watches-wonders/ | title=Watchmaking in Europe and China: Watches & Wonders | work=[[Richemont]] | publisher=Worldtempus |archive-url=https://web.archive.org/web/20121011232012/http://www.worldtempus.com/fr/encyclopedie/index-encyclopedique/lhorlogerie-dans-le-monde/lhorlogerie-europeenne-en-chine-watches-wonders/ |archive-date=11 October 2012}}</ref> but the first "[[self-winding watch|self-winding]]", or "automatic", wristwatch was the invention of a British watch repairer named [[John Harwood (watchmaker)|John Harwood]] in 1923. This type of watch winds itself without requiring any special action by the wearer. It uses an eccentric weight, called a winding rotor, which rotates with the movement of the wearer's wrist. The back-and-forth motion of the winding rotor couples to a [[ratchet (device)|ratchet]] to wind the mainspring automatically. Self-winding watches usually can also be wound manually to keep them running when not worn or if the wearer's wrist motions are inadequate to keep the watch wound.

In April 2013, the [[Swatch Group]] launched the ''sistem51'' wristwatch. It has a mechanical movement consisting of only 51 parts,<ref>{{cite web|url=https://www.faz.net/aktuell/technik-motor/swatch-bringt-bunte-sistem51-auf-den-markt-13003950.html|title=Vollautomatisch vom Band|author=Monika Schramm|language=de|date=29 June 2014|website=Frankfurter Allgemeine Zeitung|access-date=24 September 2024}}</ref> including 19 [[jewel bearing|jewels]] and a novel self-winding mechanism with a transparent oscillating weight.<ref>{{cite web|url=https://www.watchtime.com/blog/monochrome-monday-our-review-of-the-swatch-sistem51/|title=Reviewing the Swatch Sistem51|author=Brice Goulard|website=WatchTime|date=4 May 2016|access-date=23 September 2024}}</ref> Ten years after its introduction, it is still the only mechanical movement manufactured entirely on a fully automated assembly line, including adjustment of the balance wheel and the escapement for accuracy by [[laser]].<ref>{{cite web|url=https://www.uhrenkosmos.com/swatch-sistem51-werk-und-konstruktionsweise/|title=Swatch Sistem51 – ein Uhrwerk mit System|author=Gisbert L. Brunner|language=de|date=19 October 2023|website=uhrenkosmos.com|access-date=23 September 2024}}</ref> The low parts count and the fully automated assembly make it an inexpensive automatic Swiss watch.<ref>{{cite web|url=https://www.hodinkee.com/articles/exclusive-hands-on-look-at-the-swatch-sistem51|title=An Exclusive Look At The Swatch Sistem51, A Revolutionary Mechanical Watch|author=Stephen Pulvirent|website=hodinkee.com|date=30 April 2013|access-date=23 September 2024}}</ref>