Watch
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For other uses, see Watch (disambiguation).
The Magma watch
The Magma watch
A watch is a timepiece that is made to be worn on a person, as opposed to a clock which is not. The term now usually refers to a wristwatch, which is worn on the wrist with a strap or bracelet. In addition COMPUTER REMINDER to the time, modern watches often display the day, date, month and year, and electronic watches may have many other functions.
Most inexpensive and medium-priced watches used mainly for timekeeping are electronic watches with quartz movements. Expensive, collectible watches valued more for their workmanship and aesthetic appeal than for simple timekeeping, often have purely mechanical movements and are powered COMPUTER REMINDER by springs, even though mechanical movements are less accurate than more affordable quartz movements.
Before the inexpensive miniaturization that became possible in the 20th century, most watches were pocket watches, which had covers and were carried in a pocket and attached to a watch chain or watch fob. Watches evolved in the 1600s from spring powered clocks, which appeared COMPUTER REMINDER in the 1400s.
Contents
[hide]
* 1 Parts
o 1.1 Movement
+ 1.1.1 Mechanical movements
+ 1.1.2 Electronic COMPUTER REMINDER movements
o 1.2 Power sources
o 1.3 Display
+ 1.3.1 Analog
COMPUTER REMINDER + 1.3.2 Digital
* 2 Functions
* 3 Types
o 3.1 Fashion
o 3.2 Computerized multi-function watches
o 3.3 For space travel
COMPUTER REMINDER o 3.4 For scuba diving
* 4 History
* 5 See also
* 6 References
* 7 External links
[edit] Parts
[edit] Movement
A Movement in watchmaking is the mechanism that measures the passage of time and displays the current time (and COMPUTER REMINDER possibly other information including date, month and day). Movements may be entirely mechanical, entirely electronic (potentially with no moving parts), or a blend of the two. Most watches intended mainly for timekeeping today have electronic movements, with mechanical hands on the face of the watch indicating the time.
[edit] Mechanical movements
Main article Mechanical watch.
COMPUTER REMINDER See also Self-winding watch.
Compared to electronic movements, mechanical watches are less accurate, often with errors of seconds per day, and they are sensitive to position and temperature. As well, they are costly to produce, they require regular maintenance and adjustment, and they are more prone to failure. Nevertheless, the "old world" craftsmanship of mechanical watches still COMPUTER REMINDER attracts interest from part of the watch-buying public.
Mechanical movements use an escapement mechanism to control and limit the unwinding of the watch, converting what would otherwise be a simple unwinding, into a controlled and periodic energy release. Mechanical movements also use a balance wheel together with the balance spring(also known as Hairspring) to control motion of the gear COMPUTER REMINDER system of the watch in a manner analogous to the pendulum of a pendulum clock. The tourbillon, an optional part for mechanical movements, is a rotating frame for the escapement which is intended to cancel out or reduce the effects of bias to the timekeeping of gravitational origin. Due to the complexity designing a tourbillon, they are very COMPUTER REMINDER expensive, and only found in "prestige" watches. The pin-lever, (also called Rosskopf) movement, after its inventor: Georges Frederic Roskopf, is a cheaper version of the fully levered movement which was manufactured in huge quanties by many Swiss manufacturers as well as Timex, until it was replaced by quartz movements.[1][2]
Tuning fork watches use a type of electromechanical movements. Introduced by Bulova in 1960, they use a tuning fork at a precise frequency (most often 360 hertz) to drive a mechanical watch. The task of converting electronically pulsed fork vibration into rotary movement is done via two tiny jeweled fingers, called pawls. Tuning fork watches were rendered obsolete when electronic quartz watches were developed, because quartz watches were cheaper to produce and even more accurate.
