Quartz watch design and operation concept
Over several centuries, man managed to significantly improve mechanical wrist watches. By creating various complex design devices craftsmen achieved progress in accuracy movement up to + -5 seconds per day. But those watches were difficult in manufacture and, consequently, very expensive.
Electricity that increasingly intruded into all areas of human life, could not evade horology. With quartz technology advent, high-precision watches became available to every inhabitant of the world, and quality of watch now depends mainly on transfer line accuracy of operation, rather than people's skill and experience. Today the vast majority of watches produced in the world are related to quartz. What's their structure, how do they work and why more and more people prefer quartz watches?
In a nutshell
The main elements of quartz watches are electronic unit and stepping motor. Electronic unit sends impulse to an engine once per second, and the engine turns the arrow.
Stepper motor system
1. Winder
2. Stator
3. Rotor
4. Tribe rotor
5. Magnets
Quartz crystal, due to which watches received their name, provides a very high frequency stability of produced impulses, and therefore high accuracy movement.
Battery feeds electronic unit and motor and is designed for a few years of work and eliminates the need to start watch during this period. There is a unique combination of high accuracy and ease of use.
Sometimes they use a digital display instead of face with arrows. We call such watches electronic, but they are called quartz watches with digital indication all over the world. This name emphasizes that, firstly, a crystal oscillator is the basis of such watches, and secondly, information about time appears in the form of figures.
In fact, quartz watch is a mini-computer. Having programmed an electronic chip adequately, they are easily turned into a multifunctional device: chronograph, stopwatch, alarm clock, etc. And, unlike mechanical watch, their price is not growing so strongly.
Why watches need crystal
Quartz crystal has unique properties: while compression it generates an electrical pulse, and under the influence of electrical current quartz is compressed. Thus, you can make crystal constricting-releasing, i.e. fluctuate under the influence of electric current. Craftsmen achieve resonance frequency making 32768 hertz through size of crystal selection.
Quartz watches kinematic chain
1. Power source
2. Stepping motor
3. Gear wheel
4. Seconds wheel
5. Central wheel
6. Time wheel
7. Cam sleeve lever
8. Conversion tool
9. Conversion head
10. Reverse shaft
11. Jaw coupling
12. Brake lever
13. Centre wheel
14. Intermediate wheel
15. Quartz oscillator block
Quartz watch electronic unit consists of two parts. One part, a generator, produces electrical oscillations, which are stabilized by quartz crystal at its resonant frequency. Thus, we have a generator of electrical oscillations, frequency of these oscillations is very stable. We have to transform these even variations into even movement of arrows.
Generator produces 32768 electrical oscillations per second. This is approximately 10000 times greater than the number of balance oscillations in ordinary watches. No mechanical device can work at such speed. Therefore, another part of electronic circuit, called divisor, converts these vibrations into impulses with frequency of 1 hertz. These impulses are brought to stepper motor winding.
The engine consists of stator, winder and rotor - a permanent magnet, planted on the axle. After electrical impulse passes through a winder, there appears magnetic field, which rotates rotor half turn. The rotor rotates arrows through train of gears.
What's quartz durability?
Quartz watch wheel mechanism has the same resource as mechanical. Stepping motor is also very durable. Today we can find workable radios of the 20-ies, i.e., electronic component life is still long and not yet understood completely. And, theoretically, good quartz watches should not concede to mechanical in terms of longevity.
There is still no statistics for quartz watches "longevity", since they appeared only 30 years ago. But many electronic balance watches issued 40 years ago, work well run up to this day.
On the other hand, 100 years ago, watches were passed by inheritance, because it was extremely rare and expensive thing. Those days are gone; today we increasingly buy a new thing, not because an old one is damaged, but because it is obsolete. Quartz watches stand obsolescence term, delivering an owner minimum of hassle.
Mechanical watches are still more popular than quartz. But, according to foreign professionals projections, in the coming years the situation will drastically change, and, after 4-5 years proportion of quartz watches will be no less than 80% of the market.
Summary
Which watches are more precise?
Mechanical watch's accuracy depends on many factors: temperature, position, degree of click spring, parts wear, adjustment. Quartz watches are easier: frequency of impulses produced by crystal oscillator is almost constant. Engine and arrows represent just execution unit, their just should rotate on a command. If mechanical watches' good result is a deviation of + -20 seconds per day, and + -5 seconds is nearly the limit, most quartz watches provide accuracy of about + -20 seconds per month, and the best - up to + -5 seconds per year . Even cheap quartz watches are more precise than mechanical chronometer.
Why quartz watches arrangements are often plastic?
Most of the time all parts of mechanical watch remain under load a spring winder creates, and only during very short moments of time, when balance and anchor bracket allow escape wheel turning, the voltage is reduced. Large loads and high contact pressure require the use of solid materials, such as steel, brass, ruby. In quartz watches details are free most of the time. And only when stepping motor rotates wheels, details are loaded for a while. This allows using softer materials. Besides, stepper motor power is much lower than power, developed by clockwork spring. To make engine turning arrows, quartz mechanism details should be lighter, and friction - less. Plastics is lighter than steel, and a special selection of plastic allows reducing friction in a pair "plastic-plastic" several times, than in a pair "steel-brass", usually used in mechanics. In other words, use of plastic in quartz watch is preferable for many reasons.
By the way, Seiko, for example, patented composition of plastics used in machinery.
Why quartz watches usually contain no stones?
They are just needless. Contrary to popular belief, stones are used in mechanical watches not because they reduce friction, but because ruby is stronger and better withstand contact pressure. This pressure is very low in quartz watches.
Typically, quartz watches have one stone - stepper motor rotor bottom support. The point is that stator engine "pulls" rotor quite strong, and this support is the only place in watch, where contact pressure is relatively high.
Why quartz watches are cheaper?
Quartz watch accuracy movement is determined only by generator's parameters. Quartz watches require no fine manual tuning during assembling, they contain rather little details. This allows giving majority of manufacture and machinery assembly operations to automation. Naturally, the cost of those watches is lower.
Are quartz watches shockproof?
Quartz watches contain no parts sensitive to shocks, like balance axis in mechanical ones. Virtually all quartz watches are shockproof. They are almost non-sensitive to usual strokes that make mechanics incapacitate. However, we do not recommend experiments on their testing for strength.
Which watches have longer durability?
Many people say mechanical watches serve much longer than quartz. They remind examples aged a hundred or even two centuries. Well, how many watches released 100 - 200 years ago work today?
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