The major component of a mechanical movement is the mainspring, a special gradually unwinding spring responsible for transmission of energy. The same way as in case of a quartz movement a mechanical movement has an oscillator for time keeping.
The oscillator of a mechanical movement is the balance wheel, a small wheel moving very quickly to and fro. In most watches produced at present day the balance wheel oscillates 28, 800 times per hour.
One more important component of the mechanical movement is the balance spring, also called the hairspring, a tiny delicate spring necessary for controlling oscillations of the balance wheel.
Mechanical movements are divided into two major groups - automatic, also called self-winding, and manual-wind, also known as hand-wound or wind-up.
Automatic Mechanical Movement
An automatic mechanism has a special fan-shaped rotor that is swinging on a pivot in response to the motion of the arm of the watch wearer. With help of the swinging rotor the watch's mainspring winds up and keeps the watch running. Many watches equipped with automatic movements have transparent case backs to allow the owner of the timepiece admire the spinning rotor.
So, owners of automatic watches do not have to regularly wind their timepieces - all they have to do is to remember to put the watch on the wrist and wear it for about 12 hours every day. This way the owner of an automatic mechanical watch provides the mechanism with enough motion to keep the mainspring wound. If an automatic timepiece is not worn for a few days, it stops running and its owner must wind it with help of a winding crown positioned on the side of the watch case.
Today watchmakers develop automatic movements that will keep an unworn watch running for a week or more. The are also electronically powered watch winders to keep the watch on. Watch winders rotate the timepiece for a few hours at a time, so an owner of the watch does not have to manually wind it or reset the time and date.
As for hand-wound watches, it is necessary to wind them up regularly, usually once a day, using the crown.
Quartz movements power the timepiece by electricity stored in a battery. The electricity is worked out by a tiny piece of quartz crystal oscillating at the rate of 32, 786 times per second.
The majority of timepieces equipped with a quartz movement feature analog time display, implying a dial with rotating hands. Other quartz watches feature digital displays, very often LCDs - liquid crystal displays - that are used in many types of electronic devices. You will also see quartz watches with both analog and digital time readouts for simultaneous display of different information. These watches are known as 'ana-digi.'
A lot of people are puzzled by the question a watch with which type of movement to buy. It is easier to make up your mind when you consider the factors mentioned below:
Watches equipped with quartz movements generally provide more accurate timekeeping. The accuracy is provided due to the faster and steadier oscillations of a quartz crystal than those of a balance wheel. A quartz timepiece usually gains or loses about 10 seconds monthly, while a mechanical watch gains or loses several minutes a month.
2. Winding or Changing the Battery
An owner of a quartz watch will never have to wind it. But it will be necessary to replace the battery from time to time. Silver oxide batteries serve for two-three years. As for long-life lithium batteries, they run for about a decade.
You will also find quartz watches equipped with batteries that are recharged by light, or by the wearer's arm-motion. Light enters a light-powered watch through its dial. Beneath the dial there is a special solar cell that transforms the light into electricity. The electricity created is stored in the cell. The 'motion-powered' quartz watch incorporates a tiny rotor spinning in response to motion and generating electricity.
Mechanical watch movements require cleaning and lubricating once in 3-5 years. Usually, a mechanical watch is accompanied by a booklet that specifies the necessary service intervals.
Quartz movements consist of fewer parts and are influenced by less stress as they are powered electronically rather than mechanically, so they do not need much attention. Sometimes, however, some dirt accumulates on the gears of an analog quartz movement, making the watch lose time. Then, it is necessary to take the watch to the service center to have the gears cleaned.
Revolution In Quartz Movements' Field
In the 1970-s the world of mechanical watchmaking had to face the appearance of quartz technology. The first quartz wristwatch, named the Astron, was produced by Seiko in 1969. Quartz watches became serious rivals to their mechanical forerunners as they offered supreme accuracy and convenience - they saved their owners from the necessity to wind the watch.
However, the battery-equipped quartz watches had their own disadvantage - a dead battery that had to be replaced by a watch repairer. Citizen, Seiko and the Swatch Group, the leading producers of quartz watches in the world, have invented a new revolutionary type of quartz watches. To recharge the battery, these watches use the motion of the wearer's arm or the light power.
The new generation of quartz watches provided three major advantages:
- convenience - the new-type quartz watch will never stop running unexpectedly. Its owner will not have to visit a watch repairer to have it equipped with a new battery.
- no need for maintenance - as there is no need to change the battery, there is no need to open the case. So the mechanism inside and the water-resistant seal are well-protected from any dust and dirt.
- environment-friendliness - there are no used batteries to throw away.
Seiko Kinetic Technology
The Seiko Company is the most experienced producer of the motion-powered quartz watches. Seiko developed the Kinetic technology generating electricity from arm-motion. The Kinetic system is based on a tiny rotor spinning at amazing speed - 10,000 to 100,000 revolutions a minute.
The motion of the rotor is generating voltage across a coil block. The system is also provided with the ESU (electrical storage unit), an extremely small component used for storing the electrical current that is released when it is necessary to power the watch.
The ESU stores electricity that powers the watch even when it is off the wrist of its owner. Fully charged Kinetic watches operate for 6 months when not worn. Seiko also introduced Kinetic Auto Relay watches that are devised to tell the precise time when off the wrist for the whole four years.
The Kinetic watch will stop when the ESU runs out of energy. To recharge it, it necessary to swing it gently from side to side to make the oscillating weight rotate and generate electricity. The second hand begins to move in one-second intervals and the watch has at store about three hours of power.
The Swatch Group and Citizen have developed and introduced their own motion-powered quartz movements. The Swatch Group has developed the Autoquartz technology. Citizen supplies its motion-powered movements to other brands, but does not use them for its own timepieces. The Japanese company is most experienced in producing light-powered watches.
In 1995 Citizen introduced its famous Eco-Drive series of watches powered by any type of light - natural, fluorescent and incandescent. The light passes through the dial of a watch and reaches a solar cell. The solar cell is produced from specially treated silicon semiconductor. The collision of the photons in the light and the surface of the cell results in the release of electrons.
The electrons are united into a current stored in a constantly refillable tiny reservoir - a 'secondary' energy cell. The created energy is used to power the timepiece. Citizen Eco-Drive watches have no battery as it is substituted by the energy cell.
Under normal conditions a light-powered watch will never stop running as it will be constantly recharged by any type of light. Even if the owner of a light-powered watch will keep it in complete darkness for months and years, some models will still provide perfect timekeeping due to the power stored in the secondary cell. The completely depleted cell will become 'full' after a few hours of being exposed to sunlight.