Automatic quartz

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Automatic quartz is a collective term describing watch movements that combine a self-winding rotor mechanism (as used in automatic mechanical watches) to generate electricity with a piezoelectric quartz crystal as its timing element. Such movements aim to provide the advantages of quartz and mechanical watches. Several manufacturers employ this technique.

1 Mode of operation
2 Applications
3 Critique
4 See also
5 External links

[edit] Mode of operation

Lorus watch with glass back, showing clearly the swinging pendulum and meshing gear and pinion of the Seiko Kinetic movement

A rotating pendulum inside the case is attached to a relatively large gear which meshes with a very small pinion. As the wearer moves, the pendulum turns and spins the pinion at a very high speed - up to 100,000 rpm. This is coupled to a miniature electrical generator which charges three or four small capacitors. If the watch is left unused the capacitors can store enough charge to power the watch for longer periods than a mechanical automatic, usually at least one month, six months for most models. Charge from the capacitor drives a conventional quartz watch mechanism accurate to 1-2 seconds per week.

[edit] Applications

[edit] Seiko

Japanese company Seiko pioneered the technique and released the first such watch in Germany in January 1988 and April of the same year in Japan (under the name Auto-Quartz) [1]. The watches had an average monthly rate of ±15 sec and provided 75 hours of continuous operation when fully powered. Early automatic quartz movements were called AGS (Automatic Generating System); in 1991 the company introduced the Kinetic brand name. Today Seiko offers a wide range of watches with various different Kinetic movements. The top of the line is the caliber 9T82, included in Sportura (international brand) and PROSPEX (only marketed in Japan) Collection. It's sold in limited volume at a price range of about $3000 USD which makes it one of the most expensive automatic quartz watches. Kinetic technology has also been used in some of Seiko's Pulsar and Lorus watches.

Technical advances by Seiko include

Kinetic Auto Relay, if the watch is stationary for 72 hours that stops the analog hands in order to conserve power during long periods of inactivity, and can maintain a record of the correct time for four years, as well as,
Kinetic Perpetual which is the first Kinetic calibre combining Kinetic technology, Auto Relay capabilities, and a perpetual calendar correct until February 28, 2100.

The different calibres of Kinetic watches are relatively large and heavy. Therefore, most Seiko Kinetic watches are only available in a men's size.

Movement calibers:

1M20
3M21 3M22
3M62
4M21
4M71
5J21* 5J22* (Auto Relay)
5J32* (Auto Relay)
5M22 5M23 5M25
5M42 5M43 5M45 5M47
5M62* 5M63* 5M65*
7D48* (Auto Relay, Perpetual Calendar)
7L22* (Auto Relay, Chronograph)
7M12 7M42
7M22 7M45
9T82* (Chronograph)
YT57* YT58*

(*) In use as of at Dec-2006

Implementation faults:

Some calibers have the backlash phenomena; tilting the watch from side to side occasionally caused the minute hand to fall around somewhere between half a minute and a full minute. It was confirmed by SEIKO and technically it is impossible to improve the situation by reassembling the watch.

Some watches made before year 2000 brought faulty capacitors in the ESU (Electricity Storage Unit). Newer models already bring a new lithium ion rechargeable cell. This cell, sometimes called a secondary battery, enabled the ESU to store more energy for a longer period of time. It also eliminated some capacitor related issues in some Kinetic models in the mid and late 1990s.

[edit] ETA

Swiss company ETA SA, part of the Swatch group, also manufactures automatic quartz movements, calling them Autoquartz. These are then used under the Swatch brand or sold to third-party companies. However, ETA has had little success to spur demand for the product and few watch models have so far been released (as of 2006).

Movement calibers:

204.901
204.911 (power reserve: 60 days)
205.711
205.911 (power reserve: 100 days)
205.961

Manufacturers who employ ETA movements: Tissot, Longines, Swatch, Omega (Omega Seamaster Omega-matic), Dugena (K-Tech), Invicta (9179), Hermes (Nomade), Roberge (Altaïr), Mido (Multifort), Bovet (Autoquartz calibre 11BQ01) and Cyma.

[edit] Citizen

Citizen, the second largest japanese watch company (after Seiko), also build an autoquartz-powered watch: the Citizen Promaster Eco-Duo Drive (released in December of 1998)[2]. Novel to this watch was the use of both mechanical power as well as a solar cell. This model was an attempt to enter higher-priced markets (at a cost of around $1000 USD) but the technology failed to attract consumer interest and Citizen has since stopped making use of the unique movement. No other autoquartz powered watch from Citizen is known, all other Eco Drive models only use solar power.

[edit] Ventura

Ventura is a small Swiss watch manufacturer claiming to be "the World's only manufacturer of automatic digital watches". Their VEN_99 movement is indeed the only watch combining autoquartz and digital readout of time (LCD) in one package. On offer are three models: the Sparc rx, fx and px. In late 2006 the company will start selling their new movement incorporating alarm which would make another exclusive feature. All hardware is genuinely designed and exclusively sold by Ventura.

[edit] Critique

As a result of the relatively complex mechanical parts used, such watches tend to be more expensive to manufacture. Automatic quartz watches can also require more maintenance due to the wear of mechanical parts. Replacing a battery may be more expensive than simply buying a cheap digital watch.
Although they are a hybrid of mechanical and electric parts and provide substantial advantages over entirely mechanical watches, these movements do rarely or never appeal to watch collectors and connoisseurs interested in higher-priced and up-market models which are nearly always mechanical.