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watch

  (wŏch) pronunciation

v., watched, watch·ing, watch·es.

v.intr.
  1. To look or observe attentively or carefully; be closely observant: watching for trail markers.
  2. To look and wait expectantly or in anticipation: watch for an opportunity.
  3. To act as a spectator; look on: stood by the road and watched.
  4. To stay awake at night while serving as a guard, sentinel, or watcher.
  5. To stay alert as a devotional or religious exercise; keep vigil.
v.tr.
  1. To look at steadily; observe carefully or continuously: watch a parade.
  2. To keep a watchful eye on; guard: watched the prisoner all day.
  3. To observe the course of mentally; keep up on or informed about: watch the price of gold.
  4. To tend (a flock, for example). See synonyms at tend2.
n.
  1. The act or process of keeping awake or mentally alert, especially for the purpose of guarding.
    1. The act of observing closely or the condition of being closely observed; surveillance.
    2. A period of close observation, often in order to discover something: a watch during the child's illness.
  2. A person or group of people serving, especially at night, to guard or protect.
  3. The post or period of duty of a guard, sentinel, or watcher.
  4. Any of the periods into which the night is divided; a part of the night.
  5. Nautical.
    1. Any of the periods of time, usually four hours, into which the day aboard ship is divided and during which a part of the crew is assigned to duty.
    2. The members of a ship's crew on duty during a specific watch.
    3. A chronometer on a ship.
    1. A period of wakefulness, especially one observed as a religious vigil.
    2. A funeral wake.
  6. A small portable timepiece, especially one worn on the wrist or carried in the pocket.
  7. A flock of nightingales. See synonyms at flock1.
phrasal verbs:

watch out

  1. To be careful or on the alert; take care.
watch over
  1. To be in charge of; superintend.

idioms:

watch it

  1. To be careful: had to watch it when I stepped onto the ice.
watch (one's) step
  1. To act or proceed with care and caution.
  2. To behave as is demanded, required, or appropriate.

[Middle English wacchen, from Old English wæccan, to watch, be awake.]


 
 
How Products are Made: How is a watch made?

Background

The oldest means of determining time is by observing the location of the sun in the sky. When the sun is directly overhead, the time is roughly 12:00 noon. A slightly later development, and one less subject to an individual's judgment, is the use of a sundial. During the daylight hours, sunlight falls on a vertical pole placed at the center of a calibrated dial, thus casting a shadow on the dial and providing the reader with a relatively accurate time reading.

The invention of the mechanical clock in the fourteenth century was a major advancement—it provided a more concise and consistent method of measuring time. The mechanical clock includes a complicated series of wheels, gears, and levers powered by a falling weights and with a pendulum (or later a wound-up spring). These pieces together moved the hand or hands on a dial to show the time. The addition of chimes or gongs on the hour, half hour, and quarter hour followed soon afterward. By the eighteenth century, smaller clocks for the home were available, and, unlike their predecessors, were closed and sealed in a case.

The more exacting the workmanship of the moving parts, the more accurate the clock was. From invention through to the middle of the twentieth century, developments in clock-making focused on making the moving parts work as accurately as possible. Developments in metal technology and in miniaturization, the lubrication of small parts, and the use of first, natural sapphires (and then artificial sapphires) at the spots that received the most stress (the jeweled movement) all became integral components of horological science. Small pocket watches, perhaps two to three inches (five to seven centimeters) in diameter, were available by the end of the nineteenth century. Mechanical wristwatches were an everyday item in the United States by the 1960s. And yet, the central problem faced by watch and clockmakers remained the same: mechanical parts wear down, become inaccurate, and break.

In the years immediately following World War II, interest in atomic physics led to the development of the atomic clock. Radioactive materials emit particles (decayed) at a known, steady rate. The parts of a mechanical clock that ratcheted to keep the time could be replaced by a device that stimulated the watch movement each time a particle was emitted by the radioactive element. Atomic clocks, incidentally, are still made and sold, and they are found to be consistently accurate.

With the development of the microchip in the 1970s and 1980s, a new type of watch was invented. Wristwatches that mixed microchip technology with quartz crystals became the standard; there are few non-quartz wristwatches made today. The microchip is utilized to send signals to the dial of the watch on a continual basis. Because it is not a mechanical device with moving parts, it does not wear out.

The use of quartz in watches makes use of a long-known type of electricity known as piezoelectricity. Piezoelectricity is the current which flows from or through a piece of quartz when the quartz is put under electrical and/or mechanical pressure (piezo is from the Greek verb meaning "to press"). A quartz watch uses the electricity from a piece of quartz subjected to the electricity from a battery to send a regular, countable series of signals (oscillations) to one or more microchips. (Electrical wall clocks, in contrast, use the regularity of wall current to keep track of time.)

The most accurate quartz watches are those in which the time appears in an electronically controlled digital display, produced via a light-emitting diode (LED) or a liquid crystal display (LCD). It is possible, of course, to have the microprocessor send its signals to mechanical devices that make hands move on the watch face, creating an analog display. But because the hands are mechanically operated through a portion of the watch known as a gear train, analogue watches usually are not as accurate as digitals and are subject to wear. Both types of watches achieve tremendous accuracy, with digital watches commonly being accurate to within three seconds per month.

Raw Materials

Electronic watches make use of many of the most modern materials available, including plastics and alloy metals. Cases can be made of either plastic or metal; watches with metal cases often include a stainless steel backing. Microchips are typically made of silicon, while LEDs are usually made of gallium arsenide, gallium phosphide, or gallium arsenide phosphide. LCDs consist of liquid crystals sandwiched between glass pieces. Electrical contacts between parts are usually made of a small amount of gold (or are goldplated); gold is an almost ideal electrical conductor and can be used successfully in very small amounts.

The Manufacturing
Process

This section will focus on quartz digital watches with LED displays. Although the assembly of such watches must be performed carefully and methodically, the most essential aspects of the manufacturing process are in the manufacture of the components.

Quartz

  • The heart of a quartz watch is a tiny sliver of quartz. The synthetically produced quartz is cut by the manufacturer with a diamond saw and shipped to the watchmaker to use. The production of "grown" quartz is a critical step in the process.

    Quartz, in a natural form, is first loaded into a giant kettle or autoclave (the same device used by doctors and dentists to sterilize instruments). Hanging from the top of the autoclave are seeds or tiny particles of quartz with the desired crystalline structure. An alkaline material is pumped into the bottom of the autoclave, and the autoclave is heated to a temperature of roughly 750 degrees Fahrenheit (400 degrees Celsius). The natural quartz dissolves in the hot alkaline liquid, evaporates, and deposits itself on the seeds. As it deposits itself, it follows the pattern of the crystalline structure of the seeds. After about 75 days, the chamber can be opened, and the newly grown quartz crystals can be removed and cut into the correct proportions. Different angles and thicknesses in the cutting lead to predictable rates of oscillation. The desired rate of oscillation for quartz used in wristwatches is 100,000 hertz or 100,000 oscillations per second.

  • To work most effectively, the piece of quartz needs to be sealed in a vacuum chamber of one sort or another. Most commonly, the quartz is placed into a sort of capsule, with wires attached to both ends so that the capsule can be soldered or otherwise connected to a circuit board.

The microchip

  • The electronic leads generated by a battery through the quartz (producing oscillations) will go to a microchip that serves as a "frequency dividing circuit." Microchip manufacture, like the quartz, is also carried out by the supplier to the watch manufacturer. An extensive and complex process, making microchips involves chemical and/or x-ray etching of a microscopic electronic circuit onto a tiny piece of silicon dioxide.
  • The oscillation rate of perhaps 100,000 vibrations/second is reduced to 1 or 60 or some other more manageable number of oscillations. The new pattern of oscillation is then sent to another microchip that functions as a "counter-decoder-driver." This chip will actually count the oscillations that it receives. If there are sixty oscillations per second, the chip will change the reading on an LED every second. After 3,600 oscillations (60 x 60), the counter will instruct the LED to change the reading for minutes. And, after 60 x 60 x 60 oscillations (216,000), the counter will change the hour reading.

Assembly

  • The entire set of crystal and microchips is set onto a circuit board. The board incorporates a space to hold the battery that supplies electricity to the quartz crystal and supplies the power for the LED display. Generally, the space for the battery is on the outside of the surface facing the back of the case. The battery can be replaced by removing the back of the watch, shaking out the old one, and dropping in the new battery.
  • The mechanism used for setting the watch is then connected. This mechanism involves two pins that extend beyond the case of the watch. One pin lets the counter circuit know which reading to reset—seconds, minutes, or hours. The second pin is pushed a number of times to bring the display to the desired reading.
  • The entire circuit board, along with a battery, is then closed into a case, and a wrist strap is attached.

Additional Watch Features

Because the microchips in a quartz watch are capable of holding large quantities of information, it is possible, from an engineering standpoint, to add other functions to a watch without much difficulty. An additional push button on the case connected to the counter circuit can provide alarms, tide information, and more. The microchip can just as easily be programmed to set the watch forward or back a defined amount at the push of a button, so that an owner can determine the time in another time zone, or perhaps have two, three, or more time zone times displayed successively.

Quality Control

All components of electronic watches are manufactured under a strict system of quality control. Quartz crystals, for example, have their frequencies tested before being used in a watch. Microchips must be made in a "clean room" environment with specially filtered air, since even the tiniest dust particles can render a chip useless. Microchips are examined carefully and are also bench tested for accuracy before use.

After a watch is manufactured, it is again tested before being shipped to market. In addition to its time-keeping accuracy, it is also subjected to a drop-test in which it must continue to operate properly after being dropped and otherwise abused; a temperature test; and a water test. While a watchmaker may, with proper testing and proof, claim that a watch is "water resistant" at certain, known specifications, it is inaccurate to say a watch is "waterproof because without particular specification that designation is meaningless.

Large watch companies make all of their own components, ensuring that product quality standards are in place at the earliest point in the manufacturing process.

The Future

Because today's electronic watches are by design so accurate, accuracy is not the only goal for which a watch manufacturer aims. Future changes in product will take advantage of other technologies from other fields such as the addition of a calculator function to a watch, or even the addition of a radio-transmitter that can send out a traceable signal if the wearer is lost or in trouble.

Where To Learn More

Books

Billings, Charlene W. Microchip: Small Wonder. Dodd, Mead & Company, 1984.

Carpenter, Alice B. Questions and Answers in Quartz Watch Repairing. American Watchmakers Institute, 1989.

Ford, Roger, and Oliver Strimpel. Computers: An Introduction. Facts On File, 1985.

Periodicals

Becker, Dan. "Crystal Oscillators," Electronics Now. January, 1993, pp. 45-54.

Beller, Miles. "Consumer Corner: The Ultrawatches," Los Angeles. September, 1986, p. 14.

"A Good Watch Is More Than Just a Pretty Face," Changing Times. March, 1981, pp. 72-74.

Hathaway, Bruce. "Circuitry Wizards and New Agers Alike Can Get Good Vibes from Quartz," Smithsonian. November, 1988, p. 83.

"Kit Report: Clock Module," Radio-Electronics. November, 1987, pp. 122-123.

Schmidt, Leon W. "Build The Hyper Clock," Radio-Electronics. February, 1992, pp. 33-41.

Wassef, Ayyam. "Quartz Time," The Unesco Courier. April, 1991, pp. 33-36.

[Article by: Lawrence H. Berlow]


 

A portable timepiece. Its operation may be described as mechanical, electromechanical, or electronic.

In the mechanical watch a mainspring in the barrel stores operating energy; the user retightens the spring daily by means of the winding stem. The wheel train advances at five increments per second under control by the escapement. From there the dial train turns the minute and hour hands across the watch face. See also Clock; Escapement; Gear train; Jewel bearing; Spring (machines).

Among the variety of features incorporated into modern watches are: self-winding mechanisms, substitution of an electrochemical cell for the mechanical mainspring, and several forms of electromechanical escapement in place of the balance-and-hairspring mechanism.

When solid-state electronic integrated circuits became available in quantity, the all-electronic watch became a commercial reality. In it an electrochemical cell supplies the energy. A chain of binary dividers triggered from a crystal oscillator develops a train of seconds pulses. These pulses drive a digital counter or sealer, which develops minute and hour pulses to activate the digital display. See also Digital counter; Integrated circuits; Oscillator; Piezoelectricity.

One form of readout uses a light-emitting diode (LED). Because illumination of the readout consumes most of the power in an electronic watch, a liquid crystal display (LCD) is used where low power consumption is a first consideration. See also Electronic display; Horology; Light-emitting diode; Liquid crystals.


 
Thesaurus: watch
also watch over

verb

  1. To look at or on attentively or carefully: eye, observe, regard, scrutinize, survey. Idioms: have one'skeep aneye on, keep tabs on. See awareness/unawareness, see/not see.
  2. To have the care and supervision of: attend, care for, look after, mind, minister to, see to, tend2. Idioms: keep an eye on, look out for, takecarechargeof, take under one's wing. See care for/neglect.

phrasal verb - watch out

    To be careful: beware, look out, mind. Idioms: be on guard, be on the lookout, keep an eye peeled, takecareheed,, awareness/unawareness, careful/careless.

phrasal verb - watch over

    To direct and watch over the work and performance of others: boss, overlook, oversee, superintend, supervise,, over/under.

noun

  1. The act of observing, often for an extended time: observance, observation, scrutiny. See awareness/unawareness, see/not see.
  2. The act of carefully watching: lookout, surveillance, vigil, vigilance. Idioms: watch and ward. See awareness/unawareness.
  3. A person or special body of persons assigned to provide protection or keep watch over, for example: guard, lookout, picket, protector, sentinel, sentry, ward. See awareness/unawareness, safety/danger.
  4. A limited, often assigned period of activity, duty, or opportunity: bout, go, hitch, inning (often used in plural), shift, spell3, stint, stretch, time, tour, trick, turn. See time.
  5. A watch over the body of a dead person before burial: wake1. See ritual.

 
Antonyms: watch

v

Definition: guard, protect
Antonyms: harm, hurt, neglect

v

Definition: look at
Antonyms: ignore, overlook, pass by


 

n. 1. an act or instance of carefully observing someone or something over a period of time: the security forces have been keeping a close watch on our activities.

2. a fixed period of duty on a ship, usually lasting four hours.

3. also starboard or port watch the officers and crew on duty during one such period.

4. a body of soldiers making up a guard.

5. (usually the watch) a watchman or group of watchmen who patrolled and guarded the streets of a town before the introduction of the police force.

See the Introduction, Abbreviations and Pronunciation for further details.

 

Portable timepiece designed to be worn on the wrist or carried in the pocket. The first watches appeared shortly after 1500, when the mainspring (see spring) was invented as a replacement for weights in driving clocks. The progressive miniaturization of electronic components in recent decades has made possible the development of all-electronic watches, in which the necessary transistors, resistors, capacitors, and other elements are all on one or several miniature integrated circuits, or chips. Such circuitry enables them to perform several timekeeping functions and also makes possible digital readouts of the time.

For more information on watch, visit Britannica.com.

 
small, portable timepiece usually designed to be worn on the person. Other kinds of timepieces are generally referred to as clocks. At one time it was generally believed that the first watches were made in Nuremburg, Germany, c.1500. However, there is now evidence that watches may have appeared at an earlier date in Italy. Early watches were ornate, very heavy, and made in a variety of shapes, e.g., pears, skulls, and crosses; the faces were protected by metal latticework. Watch parts were made by hand until c.1850, when machine methods were introduced by watch manufacturers in the United States. The introduction of machine-made parts not only cut manufacturing costs but increased precision and facilitated repairs. To insure the accuracy of a watch over a long period, bearings made of jewels (usually synthetic sapphires or rubies) are utilized at points subject to heavy wear. The mechanical watch contains a mainspring to drive the watch's mechanism. Part of the mechanism includes a hairspring and an oscillating balance wheel to control the rate at which the mechanism moves. The mainspring is wound by the wearer when he turns a knob outside the watch's casing. The automatic, or self-winding, watch has a mainspring that is wound by an oscillating weight, contained in the watch, that is set into motion by the movements of the wearer. The stopwatch can be stopped or started at will by pressing a tiny button on its edge and is used for timing such events as races. The electric watch, which was introduced by the Hamilton Watch Company in 1957, also uses a hairspring and a balance wheel to regulate the rate at which its mechanism moves, but it has no mainspring. In recent years sophisticated electronic watches have been developed. One type uses the vibrations of an electrically driven tuning fork to determine the rate at which a small motor drives the hands. In another type a crystal oscillator provides a signal that regulates this motion. In the most common type a quartz crystal oscillator is joined to digital counting and digital display circuits, thus eliminating all moving parts. See liquid crystal. Quartz watches with digital displays now account for nearly half of all watch production, since they are inexpensive to produce but are accurate to within several seconds per month. Electric and electronic watches are powered by tiny long-lasting batteries. See chronometer.

Bibliography

See C. Clutton and G. Daniels, Watches: A Complete History (3d ed. 1979); J. Zagoory and H. Chan, A Time to Watch: The Wrist Watch as Art (1985); E. Bruton, History of Clocks and Watches (1989).


 
Word Tutor: watch
pronunciation

IN BRIEF: To keep sight on. Also: A small clock worn on the wrist or carried in one's clothing.

pronunciation Everyone must take time to sit and watch the leaves turn. — Elizabeth Lawrence.

 
Wikipedia: watch


A watch is a timepiece or portable clock that displays the time and sometimes the day, date, month and year. In past centuries, these often took the form of pocket watches, which today are seldom carried or worn. In modern usage, watch is usually a contraction of wristwatch, a name for the most popular style of timekeeping device worn on the wrist.

Because most watches lack a striking mechanism, such as a bell or gong, to announce the passage of time, they are properly called timepieces rather than clocks.[citation needed]

Overview

The Magma - Early 21st Century Watch Design
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The Magma - Early 21st Century Watch Design

Today, the most common type of watch is the wristwatch, worn on the wrist and fastened with a watchband made of leather, nylon or other plastics (then called strap), metal links (called bracelet) or even ceramic. Before the inexpensive miniaturization that became possible in the 20th century, most watches were pocket watches, which had covers and were carried separately, often in a pocket and attached to a watch chain or fob. The most accurate watches have radio-controlled movements that are miniaturized, portable versions of radio clocks.

In the 21st century, technological advances in metallurgy, composite materials development and physical vapor deposition greatly influence watch design and manufacturing. Solid stainless steel, titanium, tungsten carbide, carbon fiber, high-tech ceramic and ion plating processes dominate a considerable market share of today's modern watch-making industry. Sapphire crystals are often incorporated to complement and enhance the durability of a quality watch.

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 by springs, even though mechanical movements are less accurate than inexpensive quartz movements.

Watch cases

Pocket timepieces

Main article: Pocket watch

In the 15th century, navigation and mapping increased the desire for portability in timekeeping. The latitude could be measured by looking at the stars, but the only way a ship could measure its longitude was by comparing the midday (high noon) time of the local longitude to that of a European meridian (usually Paris or Greenwich)—a time kept on a shipboard clock. However, the process was notoriously unreliable until the introduction of John Harrison's marine chronometer. For that reason, most maps from the 15th century through the 19th century have precise latitudes but distorted longitudes.

The first reasonably accurate mechanical clocks measured time with simple weighted pendulums, which are unworkable when irregular movement of the fulcrum occur whether at sea or in watches. The invention of a spring mechanism was crucial for portable clocks. In Tudor England, the development of "pocket-clockes" was enabled by the development of reliable springs and escapement mechanisms, which allowed clockmakers to compress a timekeeping device into a small, portable compartment.

In 1524, Peter Henlein created the first pocket watch.[1] It is rumored that Henry VIII (the portrait of Henry VIII at this link shows the medallion thought to be the back of his watch) had a pocket clock which he kept on a chain around his neck. However, these watches only had an hour hand—a minute hand would have been useless because of the inaccuracy of the watch mechanism. Eventually, miniaturization of these spring-based designs allowed for accurate portable timepieces (marine chronometers) which worked well even at sea.

In 1850, Aaron Lufkin Dennison founded Waltham Watch Company, which was the pioneer of the industrial manufacturing of pocket watches with interchangeable parts, the American System of Watch Manufacturing.

Breguet developed the first self-winding watch known as the perpetual in 1780.[2]

Parts

The first two are key mechanisms within any mechanical watch of classical design; the third is optional:

  1. The escapement – a mechanism that controls and limits the unwinding of the watch, converting what would otherwise be a simple unwinding, into a controlled and periodic energy release. The escapement does this by interlocking with a gear in a simple manner that switches between a "driven" and a "free" state, with abrupt locking at each end of the cycle. The escapement also for the same reason produces the ticking noise characteristic of mechanical watches.
  2. The balance wheel together with the balance spring(also known as Hairspring) – these form a simple harmonic oscillator, which controls the motion of the gear system of the watch in a manner analogous to the pendulum of a pendulum clock. This is possible because the moment of inertia of the balance wheel is fixed, and the wheel as a whole provides a regular motion of known period.
  3. The tourbillon – a rotating frame for the escapement. It is intended to cancel out or reduce the effects of bias to the timekeeping of gravitational origin, which might result from the watch being kept in a particular position for much of the day. It is technically very challenging to create a high quality tourbillon, and those made by specialists and found in prestige watches are often very highly valued.

NB: the pin-lever (also called Rosskopf) movement, as per the name of its inventor: Georges Frederic Roskopf: This cheaper version of the fully levered movement had been manufactured in huge quanties by many Swiss Manufacturers as well as Timex, has been replaced by Quartz movements. [3] [4]

Watch movements

A movement in watchmaking is the mechanism that measures the passage of time and displays the current time (and 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.

Mechanical movements

See also Self-winding watch.
Mechanical Omega 38.5 caliber on a Lepine Pocket Watch.
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Mechanical Omega 38.5 caliber on a Lepine Pocket Watch.

Purely mechanical watches are still popular, although they are most commonly seen among medium priced watches such as Fortis, Omega, Rolex and TAG Heuer and expensive watches like Patek Phillipe, Vacheron Constantin, Ulysse Nardin and Audemars Piguet. Their superb craftsmanship accounts for much of the attraction of purely mechanical watches. Compared to electronic movements, mechanical watches keep very poor time, often with errors of seconds per day. They are frequently sensitive to position and temperature, they are costly to produce, they require regular maintenance and adjustment, and they are more prone to failure.

Generally speaking, inexpensive and moderately priced timepieces with electronic movements now provide most users with timekeeping more accurate than the most expensive Rolex or Patek Phillipe. The most expensive, diamond encrusted Rolex contains a similar movement as its less expensive C.O.S.C rated brethren and all modern models can keep time to within 1 second a day. However, in recent times there has been less emphasis on one's watch for time precision as many people now carry multiple devices that will tell them the time accurately such as mobile phones, PDAs and laptops, these finely crafted mechanical watches have remained popular as precision time pieces and in many cases more so because of their aesthetic value as jewellery.

Tuning-fork movements

Tuning fork watches (introduced by Bulova in 1960) use a tuning fork at a precise frequency (most often 360 hertz) to drive a mechanical watch. Since the fork is used in place of a typical balance wheel, these watches naturally hum instead of tick.

The inventor, Max Hetzel, was born in Basel, Switzerland, and joined the Bulova Watch Company of Bienne, Switzerland, in 1948. Hetzel was the first to use an electronic device, a transistor, in a wristwatch. Thus, he developed the first watch that could be qualified as electronic. However, fork movements are actually more "electrical", like an old electrical wall clock, than electronic. The sweep second hand moves fluidly like that of an old electrical wall clock.

Such watches were also sold by Swiss watch companies under license of Bulova. In 1974, after leaving Bulova, Hetzel developed a different tuning fork drive for Omega Watches. The watch featured a cal. 1220 micromotor, and a tuning fork frequency of 720 hertz.[5] This development was obsolete compared to the newer electronic quartz watch which had become cheaper to produce and even more accurate.

Tuning fork movements are electromechanical. The task of converting electronically pulsed fork vibration into rotary movement is done via two tiny jeweled fingers, called pawls, one of which is connected to one of the tuning fork's tines. As the fork vibrates, the pawls precisely ratchet a tiny index wheel. This index wheel has over 300 barely visible teeth and spins more than 38 million times per year. The tiny electric coils that drive the tuning fork have 8000 turns of insulated copper wire with a diameter of 0.015 mm and a length of 90 meters. This amazing feat of engineering was prototyped in the 1950s.

Electronic movements

Electronic movements have few or no moving parts. Essentially, all modern electronic movements use the piezoelectric effect in a tiny quartz crystal to provide a stable time base for a mostly electronic movement: the crystal forms a quartz oscillator which resonates at a specific and highly stable frequency, and which can be used to accurately pace a timekeeping mechanism. For this reason, electronic watches are often called quartz watches. Most quartz movements are primarily electronic but are geared to drive mechanical hands on the face of the watch in order to provide a traditional analog display of the time, which is still preferred by most consumers.

The first prototypes of electronic quartz watches were made by the CEH research laboratory in Switzerland in 1962. The first quartz watch to enter production was the Seiko 35 SQ Astron, which appeared in 1969. Modern quartz movements are produced in very large quantities, and even the cheapest wristwatches typically have quartz movements.

The best quartz movements are significantly more accurate than the worst, but the difference is much smaller than that found between mechanical movements and quartz movements. Quartz movements, even in their most inexpensive forms, are an order of magnitude more accurate than purely mechanical movements. Whereas mechanical movements can typically be off by several seconds a day, an inexpensive quartz movement in a child's wristwatch may still be accurate to within 500 milliseconds per day—ten times better than a mechanical movement.

Quartz mechanisms usually have a resonant frequency of 32768 Hz, chosen for ease of use (being 215). Using a simple 15 stage divide-by-two circuit, this is turned into a 1 pulse per second signal responsible for the watch's keeping of time.

Recently, efforts have been made to combine the best features of quartz and mechanical movements. For example, the Seiko Spring Drive, introduced in 2005, uses a mainspring to power both a mechanical movement and, via a generator, a quartz regulator that controls it's speed. The result is claimed to be a timepiece that operates as a mechanical watch, but with quartz accuracy.


Radio-controlled movements

Some electronic quartz watches are able to synchronize (time transfer) themselves with an external time source. These sources include radio time signals directly driven by atomic clocks, time signals from GPS navigation satellites, the German DCF77 signal in Europe, WWVB in the US, and others. These watches are free-running most of the time, but periodically align themselves with the chosen external time source automatically, typically once a day.

Because these watches are regulated by an external time source of extraordinarily high accuracy, they are never off by more than a small fraction of a second a day (depending on the quality of their quartz movements), as long as they can receive the external time signals that they expect. Additionally, their long-term accuracy is comparable to that of the external time signals they receive, which in most cases (such as GPS signals and special radio transmissions of time based on atomic clocks) is better than one second in three million years. For all practical purposes, then, radio-controlled wristwatches keep near perfect time.

Movements of this type synchronize not only the time of day but also the date, the leap-year status of the current year, and the current state of daylight saving time (on or off). They obtain all of this information from the external signals that they receive. Because of this continual automatic updating, they never require manual setting or resetting.

A disadvantage of radio-controlled movements is that they cannot synchronize if radio reception conditions are poor. Even in this case, however, they will simply run autonomously with the same accuracy as a normal quartz watch until they are next able to synchronize.

Power sources

Springs

Traditional, purely mechanical watch movements generally use a wound spring as a power source. The spring must be rewound by the user periodically (usually once a day, or once every few days).

Self-winding watches

Main article: Automatic watch
Automatic watch: An eccentric weight called a rotor, swings with the movement of the wearer's body and winds the spring
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Automatic watch: An eccentric weight called a rotor, swings with the movement of the wearer's body and winds the spring

A self-winding mechanism is one that rewinds the mainspring (power spring) of a mechanical movement through some means other than explicit winding by the user.

The first self-winding mechanism, for fob-watches, was invented in 1770 by Abraham-Louis Breguet;[6] but the first "self-winding," or "automatic," wristwatch was the invention of a British watch repairer named John Harwood in 1923. This type of watch allows for a constant winding without special action from the wearer: it works by an eccentric weight, called a winding rotor, that rotates to the movement of the wearer's body. The back-and-forth motion of the winding rotor couples to a ratchet to automatically wind the watch. The spring drives an escapement, which consists of a lever that moves back and forth against a gear, keeping the gear moving at a specific number of times per second, usually four or five. That gear, in turn, drives all of the other gears of the watch that turn the hands on the dial.

Kinetic power

Some watches are powered by the movement of the wearer of the watch. Kinetic powered quartz watches make use of the motion of the wearer's arm turning a rotating weight, which in turn, turns a generator to supply power. The concept is similar to that of self-winding spring movements, except that electrical power is generated instead of mechanical motion alone.

Batteries

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Electronic watches require electricity as a power source. Some mechanical movements and hybrid electronic-mechanical movements also require electricity. Usually the electricity is provided by a replaceable battery. The first use of electrical power in watches was as substitute for the mainspring, in order to remove the need for winding. The first electrically-powered watch, the Hamilton Electric 500, was released in 1957 by the Hamilton Watch Company of Lancaster, Pennsylvania.

Batteries (strictly speaking cells) for watches are specially designed for their purpose. They are very small and provide tiny amounts of power continuously for very long periods (several years or more). In most cases, replacing the battery requires a trip to a watch-repair shop or watch dealer; this is especially true for watches that are designed to be water-resistant, as special tools and procedures are required to ensure that the watch remains water-resistant after battery replacement. Silver-oxide and lithium batteries are popular today; mercury batteries, formerly quite common, are no longer used, for environmental reasons. Cheap batteries may be alkaline, of the same size as silver-oxide but providing shorter life. Rechargeable batteries are used in some solar powered watches.

Light-powered watches

Some electronic watches are powered by light. A photovoltaic cell on the face (dial) of the watch converts light to electricity, which in turn is used to charge a rechargeable battery or capacitor. The movement of the watch draws its power from the rechargeable battery or capacitor. As long as the watch is regularly exposed to fairly strong light (such as sunlight), it never needs battery replacement, and some models need only a few minutes of sunlight to provide weeks of energy (as in the Citizen Eco-Drive).

Some of the early solar watches of the 1970s had innovative and unique designs to accommodate the array of solar cells needed to power them (Synchronar, Nepro, Sicura and some models by Cristalonic, Alba, Seiko and Citizen). As the decades progressed and the efficiency of the solar cells increased while the power requirements of the movement and display decreased, solar watches began to be designed to look like other conventional watches.[7]

Some critics point out that both the low cost of quartz watches and the extreme longevity of the newest lithium-ion batteries (said to be upwards of ten years in some watches) may make solar power, whilst an interesting technology, obsolete before it truly catches on. According to this view, battery-powered watches will become disposable items, so the purchaser will not care about the cost of replacing the battery. However, some purchasers may be persuaded by the ecological benefits of solar watches: less waste and lower energy input, not to mention the reduced hassle of not having to purchase a replacement watch every few years. In addition, the widespread use of watches as jewelry--worn as much for their aesthetic value as their timekeeping ability--makes the prospect of disposable watches less attractive.

Thermal power

A seldom used power source is the temperature difference between the wearer's arm and the surrounding environment (as applied in the Citizen Eco-Drive Thermo).

Displaying the time

There are two main ways in which watches display the time: analog and digital.

Analog display

Traditionally, watches have displayed the time in analog form, with a numbered dial upon which are mounted at least a rotating hour hand and a longer, rotating minute hand. Many watches also incorporate a third hand that shows the current second of the current minute. Watches powered by quartz have second hands that snap every second to the next marker. Watches powered by a mechanical movement have a "sweep second hand", the name deriving from its uninterrupted smooth (sweeping) movement across the markers, although this is actually a misnomer; the hand merely moves in smaller steps, typically 1/6 of a second, corresponding to the beat of the balance wheel. All of the hands are normally mechanical, physically rotating on the dial, although a few watches have been produced with “hands” that are simulated by a liquid-crystal display.

Analog display of the time is nearly universal in watches sold as jewelry or collectibles, and in these watches, the range of different styles of hands, numbers, and other aspects of the analog dial is very broad. In watches sold for timekeeping, analog display remains very popular, as many people find it easier to read than digital display; but in timekeeping watches the emphasis is on clarity and accurate reading of the time under all conditions (clearly marked digits, easily visible hands, large watch faces, etc.).

Digital display

Since the advent of electronic watches that incorporate small computers, digital displays have also been available. A digital display simply shows the time as a number, e.g., 12:40 AM instead of a short hand pointing towards the number 12 and a long hand pointing towards the number 8 on a dial.

The first digital watch, a Pulsar prototype in 1970, was developed jointly by Hamilton Watch Company and Electro-Data. John Bergey, the head of Hamilton's Pulsar division, said that he was inspired to make a digital timepiece by the then-futuristic digital clock that Hamilton themselves made for the 1968 science fiction film 2001: A Space Odyssey. On April 4, 1972 the Pulsar was finally ready, made in 18-carat gold and sold for $2,100 at retail. It had a red light-emitting diode (LED) display. Another early digital watch innovator, Roger Riehl's Synchronar Mark 1, provided an LED display and used solar cells to power the internal nicad batteries.[8] Most watches with LED displays required that the user press a button to see the time displayed for a few seconds, because LEDs used so much power that they could not be kept operating continuously. Watches with LED displays were popular for the next few years, but soon the LED displays were superseded by liquid crystal displays (LCDs), which used less battery power. The first LCD watch with a six-digit LCD was the 1973 Seiko 06LC, although various forms of early LCD watches with a four-digit display were marketed as early as 1972 including the 1972 Gruen Teletime LCD Watch, and the Cox Electronic Systems Quarza.[9][10]

Digital watches were very expensive and out of reach to the common consumer up until 1975, when Texas Instruments started to mass produce LED watches inside a plastic case. These watches, which first retailed for only $20, and then $10 in 1976, saw Pulsar lose $6 million and the brand sold to competitors twice in only a year, eventually becoming a subsidiary of Seiko and going back to making only analogue quartz watches.

From the 1980s onward, technology in digital watches vastly improved. In 1982 Seiko produced a watch with a small TV screen built in and Casio produced a digital watch with a thermometer and another watch that could translate 1,500 Japanese words into English. In 1985, Casio produced the CFX-400 scientific calculator watch. In 1987 Casio produced a watch that could dial your telephone number and Citizen revealed one that would react to your voice. In 1995 Timex release a watch which allowed the wearer to download and store data from a computer to their wrist. Since their apex during the late 1980's to mid 1990's high technology fad, digital watches have mostly devolved into a simpler, less expensive basic time piece with little variety between models.

Despite these many advances, almost all watches with digital displays today are not considered an impressive form of jewelry and most are seen as being in the category of simple timekeeping watches.

Expensive watches for collectors rarely have digital displays since there is little demand for them. Less craftsmanship is required to make a digital watch face and most collectors find that analog dials (especially with complications) vary in quality more than digital dials due to the details and finishing of the parts that make up the dial (thus making the differences between a cheap and expensive watch more evident).

Watch functions

All watches provide the time of day, giving at least the hour and minute, and usually the second. Most also provide the current date, and often the day of the week as well. However, many watches also provide a great deal of information beyond the basics of time and date.

Some watches include alarms.

Other elaborated and more expensive watches, both pocket and wrist models, also incorporate striking mechanisms or repeater functions, so that the wearer could learn the time by the sound emanating from the watch. This announcement or striking feature is an essential characteristic of true clocks and distinguishes such watches from ordinary timepieces.

Complicated watches

A complicated watch has one or more functionalities beyond the basic function of displaying the time and the date; such a functionality is called a complication. Two popular complications are the chronograph complication, which is the ability of the watch movement to function as a stopwatch, and the moonphase complication, which is a display of the lunar phase. Other more expensive complications include, Tourbillion, Perpetual calender, Minute repeater and Equation of time. A truly complicated watch has many of these complications at once(see Calibre 89 from Patek Phillipe for instance)

Among watch enthusiasts, complicated watches are especially collectible.

Chronographs and chronometers

The similar-sounding terms chronograph and chronometer are often confused, although they mean altogether different things. A chronograph is a type of complication, as explained above. A chronometer watch is an all-mechanical watch or clock whose movement has been tested and certified to operate within a certain standard of accuracy by the COSC (Contrôle Officiel Suisse des Chronomètres). The concepts are different but not mutually exclusive; a watch can be a chronograph, a chronometer, both, or neither.

Second display

Some watches includes a second 12-hour display for UTC (as Pontos Grand Guichet GMT).

Types of watch

Fashionable watches

At the end of the 20th century, Swiss watch makers were seeing their sales go down as analog clocks were considered obsolete. They joined forces with designers from many countries to reinvent the Swiss watch.

The result was that they could considerably reduce the pieces and production time of an analog watch. In fact it was so cheap that if a watch broke it would be cheaper to throw it away and buy a new one than to repair it. One of these Swiss watch manufacturers (today named The Swatch Group Ltd.) started a new brand, Swatch, and called graphic designers to redesign a new annual collection.

This is often used as a case study in design schools to demonstrate the commercial potential of industrial and graphic design.

Dual time watches

A dual time watch is designed for travellers, allowing them to see what time it is at home when they are elsewhere.

Collectible and jewelry watches

Wristwatches are often treated as jewelry or as collectible works of art rather than as timepieces. This has created several different markets for wristwatches, ranging from very inexpensive but accurate watches intended for no other purpose than telling the correct time, to extremely expensive watches that serve mainly as personal adornment or as examples of high achievement in miniaturization and precision mechanical engineering. Still another market is that of “geek watches”—watches that not only tell the time, but incorporate computers, satellite navigation, complications of various orders, and many other features that may be quite removed from the basic concept of timekeeping.

Most companies that produce watches specialize in one of these markets. Companies such as Patek Phillipe or Jaeger-LeCoultre specialize in watches as jewelry or fine mechanical devices. where as companies as Rolex, Omega, Tag Heuer and Breitling all make mass-produced watches, mostly done completely with machines. Companies such as Casio specialize in watches as timepieces or multifunctional computers. Since watches are considered by many to be both functional and attractive, there are many types and manufacturers to choose from.

Important collectible American made watches from the early 20th Century were the best available at any price. Leading watchmakers included Elgin, Gruen, Hamilton, and Illinois. Hamilton is generally considered as having the finest early American movements, while the art deco styling of The Illinois Watch Company was unsurpassed worldwide. Early Gruen Curvex models remain very desired for how they entwined form and function, and Elgin made more watches than anyone else.

Computerized multi-function watches

Many technological enhancements to wristwatches have been explored but most of them remained unnoticed. In 2005 for example, one company marketed an alarm wristwatch with an accelerometer inside that monitors the user's sleep and rings during one of his almost-awake phases.

A number of functionalities not directly related to time have also been inserted into watches. As miniaturized electronics became cheaper, watches have been developed containing calculators, video games, digital cameras, keydrives, GPS receivers and cellular phones.

In the early 1980s Seiko marketed a watch with a television in it, although at the time television receivers were too bulky to fit in a wristwatch, and the actual receiver and its power source were in a book-sized box with a cable that ran to the wristwatch. In the early 2000s, a self-contained wristwatch television receiver came on the market, with a strong enough power source to provide one hour of viewing.

These watches have not had sustained long-term sales success. As well as awkward user interfaces due to the tiny screens and buttons possible in a wearable package, and in some cases short battery life, the functionality available has not generally proven sufficiently compelling to attract buyers. Such watches have also had the reputation as ugly and thus mainly geek toys. Now with the ubiquity of the mobile phone in many countries, which have bigger screens, buttons, and batteries, interest in incorporating extra functionality in watches seems to have declined.

Several companies have however attempted to develop a computer contained in a wristwatch (see also wearable computer). As of 2005, the only programmable computer watches to have made it to market are the Seiko Ruputer, the Matsucom onHand, and the Fossil, Inc. Wrist PDA, although many digital watches come with extremely sophisticated data management software built in.

Spacewatches

The Omega Speedmaster, selected by US space agencies.
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The Omega Speedmaster, selected by US space agencies.

Zero gravity environment and other extreme conditions encountered by astronauts in space requires the use of specially tested watches.

On April 12th 1961 Yuri Gagarin wore a Poljot "Shturmanskie" (a transliteration of Штурманские which actually means "Navigator's") wristwatch during his historic first flight into space. The Shturmanskie was manufactured at the First Moscow Watch Factory (1-MChZ).

Since 1964, the watches of the First Moscow Factory have been marked by a trademark "ПОЛЕТ" and "POLJOT", which means "flight" in Russian and is a tribute to the number of many space trips their watches have accomplished.

In the late 1970s, Poljot launched a new chrono movement, the 3133. With a 23 jewel movement and manual winding (43 hours), it was a modified Russian version of the Swiss Valjoux 7734 of the early 1970s. Poljot 3133 were taken into space by astronauts from Russia, France, Germany and Ukraine. On the arm of V.V. Polyakov, a Poljot 3133 chronograph movement-based watch set a space record for the longest space flight in history.

During the 60s, a large range of watches were tested for durability and precision under extreme temperature changes and vibrations. The Omega Speedmaster was selected by U.S. space agencies.

TAG Heuer became the first Swiss watch in space thanks to an Heuer Stopwatch, worn by John Glenn in 1962 when he piloted the Friendship 7 on the first manned US orbital mission.

The Breitling Navitimer Cosmonaute was designed with a 24-hour dial to avoid confusion between AM and PM, which are meaningless in space. It was first worn in space by U.S. astronaut Scott Carpenter on May 24, 1962 in the Aurora 7 mercury capsule.[11]

Since 1994 Fortis is the exclusive supplier of manned space missions authorized by the Russian Federal Space Agency, with B-42 OFFICIAL COSMONAUTS models.

China National Space Administration (CNSA) astronauts wear the Fiyta[12] spacewatches.

FLIGHT-CERTIFIED BY NASA FOR ALL MANNED SPACE MISSIONS:

FLIGHT-QUALIFIED BY NASA FOR SPACE MISSIONS:

Mobile phones as pocket w