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A quartz clock is a timepiece that uses an electronic oscillator which is made up by a quartz crystal to keep precise time. This crystal oscillator creates a signal with very precise frequency. Usually some form of digital logic counts the cycles of this signal and provides a numeric time display, usually in units of hours, minutes, and seconds. Image File history File links Download high resolution version (2048x1536, 557 KB) en: clock. ...
Image File history File links Download high resolution version (2048x1536, 557 KB) en: clock. ...
Quartz is one of the most common minerals in the Earths continental crust. ...
A clock (from the Latin cloca, bell) is an instrument for measuring time. ...
An electronic oscillator is an electronic circuit that produces a repetitive electronic signal, often a sine wave or a square wave. ...
Quartz crystal In chemistry and mineralogy, a crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. ...
A crystal oscillator (sometimes abbreviated to XTAL on schematic diagrams) is an electronic circuit that uses the mechanical resonance of a physical crystal of piezoelectric material along with an amplifier and feedback to create an electrical signal with a very precise frequency. ...
Sine waves of various frequencies; the bottom waves have higher frequencies than those above. ...
A pocket watch, a device used to measure time Two distinct views exist on the meaning of time. ...
Explanation
Quartz Chemically, quartz is a compound called silicon dioxide. When a crystal of quartz is properly cut and mounted, it can be made to bend in an electric field. When the field is removed, the quartz will generate an electric field as it returns to its previous shape. This property is known as piezoelectricity. R-phrases R42 R43 R49 S-phrases S22 S36 S37 S45 S53 Flash point non-flammable Supplementary data page Structure and properties n, εr, etc. ...
Piezoelectricity is the ability of crystals to generate a voltage in response to applied mechanical stress. ...
Many materials can be formed into plates that will resonate. However, since quartz can be directly driven by an electric signal, no additional speaker or microphone is required.
Quartz has the further advantage that it does not change size much as temperature changes. Fused quartz is often used for laboratory equipment that must not change shape as the temperature changes. This means that a quartz plate's size will not change much with temperature. Therefore, the resonant frequency of the plate, which depends on the plate's size, will not change much, either. This means that a quartz clock will be relatively accurate as the temperature changes. Fig. ...
Fused quartz or fused silica are types of glass containing primarily silica in amorphous (non-crystalline) form. ...
Mechanism In modern quartz clocks, the resonator is tuning fork shaped, laser-trimmed or precision lapped to vibrate at 32,768 Hz. This frequency is exactly 215 Hz. A very simple electronic circuit can be built with a series of 15 divide-by-2 stages cascaded to get the base time of 1 second. In most clocks, the resonator is in a small can or flat package, about 4mm long. The reason 32,768Hz resonator has become so common is due to a compromise between the large physical size of low frequency crystals for watches and the large current drain high frequency resonators demand from watch batteries. During the 1970's the introduction of Metal Oxide Semiconductor (MOS) integrated circuits allowed a 12 month battery life from a single coin cell when driving either a mechanical stepper motor, indexing the second hand (Quartz Analogue), or a Liquid Crystal Display (LCD Digital). Light Emitting Diode, (LED) displays for watches have become rare due to their very high battery consumption. A tuning fork is a simple metal two-pronged fork with the tines formed from a U-shaped bar of elastic material (usually steel). ...
A LASER (from the acronym of Light Amplification by Stimulated Emission of Radiation) is an optical source that emits photons in a coherent beam. ...
The hertz (symbol: Hz) is the SI unit of frequency. ...
High frequency (HF) radio frequencies are between 3 and 30 MHz. ...
A resonator is a device or part that vibrates (or oscillates) with waves. ...
Type CR2032 watch battery (lithium anode, 3 V, 20. ...
The MOSFET, or Metal Oxide Semiconductor Field-Effect Transistor, is by far the most common field-effect transistor in both digital and analog circuits (The Metal in the name is an anachronism from early chips where gates were metal; modern chips use polysilicon gates, but are still called MOSFETs). ...
Integrated circuit showing memory blocks, logic and input/output pads around the periphery A monolithic integrated circuit (also known as IC, microchip, silicon chip, computer chip or chip) is a miniaturized electronic circuit (consisting mainly of semiconductor devices, as well as passive components) that has been manufactured in the surface...
The top electromagnet (1) is charged, attracting the topmost four teeth of a sprocket. ...
Reflective twisted nematic liquid crystal display. ...
Various light-emitting diodes (5 mm reds, 3 mm greens and yellows) A light-emitting diode (LED) is a semiconductor device that emits incoherent monochromatic light when electrically biased in the forward direction. ...
Since the introduction of the low current consumption microprocessor in the late 1970's, clocks and watches now contain a small, special-purpose computer with a program that counts the cycles, and translates them into an electrical form to drive the visible display. The use of computers in electronic timepieces has enabled a wealth of features, such as stop watches, perpetual calendars, multiple perpetual alarms that play tunes, and other features that would be impractical with simple electronic counters. A microprocessor (sometimes abbreviated µP) is a digital electronic component with transistors on a single semiconductor integrated circuit (IC). ...
A Lego RCX Computer is an example of an embedded computer used to control mechanical devices. ...
A stopwatch is a timepiece designed to measure the amount of time elapsed from a particular time when activated and when the piece is deactivated. ...
A perpetual calendar is a calendar which is good for a span of many years, such as the Runic calendar. ...
Accuracy The relative stability of the resonator and its driving circuit is much better than its absolute accuracy. Standard quality resonators of this type are warranted to have a long-term accuracy of about 6 parts per million at 31 °C, that is, a typical quartz wristwatch will gain or lose less than a half second per day at body temperature.
If a quartz wristwatch is "rated" by measuring it against an atomic clock's time broadcast, and worn on one's body to keep its temperature constant, the corrected time can easily be as accurate as 2 seconds per month, more than good enough to perform celestial navigation. A rate is a special kind of ratio, of two measurements with different units. ...
Atomic clock Chip-Scale Atomic Clock Unveiled by NIST An atomic clock is a type of clock that uses an atomic resonance frequency standard as its counter. ...
Table of geography, hydrography, and navigation, from the 1728 Cyclopaedia. ...
Some premium clock designs self-rate. That is, rather than just counting vibrations, their computer program takes the simple count, and scales it using a ratio calculated between an epoch set at the factory, and the most recent time the clock was set. These clocks usually have special instructions for changing the battery (the counter must not be permitted to stop), and become more accurate as they grow older. The word epoch can mean either an interval of time, or a particular point in time used as a reference point. ...
It is possible for a computerized clock to measure its temperature, and adjust for that as well. Both analog and digital temperature compensation have been used in high-end quartz watches. An analog or analogue signal is any continuously variable signal. ...
A digital system is one that uses discrete numbers, especially binary numbers, or non-numeric symbols such as letters or icons, for input, processing, transmission, storage, or display, rather than a continuous spectrum of values (an analog system). ...
Fine-tuning adjustment One practical issue for the mass-production of quartz oscillators was how to adjust their frequency without requiring a human operator to fine-tune them. Several automated methods were developed; in the most common one, the tuning fork as made has a small amount of metal on its ends, and runs slightly slower than rated frequency. An automatic machine then measures its frequency while using a laser to vaporize the metal on its ends, slowly raising its frequency, until it reaches the specified frequency; then it is sealed into a small can and is ready for use. A crystal oscillator is an electronic device that uses the mechanical resonance of a physical crystal of piezoelectric material to create an electrical signal with a very precise frequency. ...
Chronometers Quartz chronometers designed as time standards often include a crystal oven, to keep the crystal at a constant temperature. Some self-rate and include "crystal farms," so that the clock can take the centroid of a set of time measurements. A Crystal Oven is a temperature-controlled chamber used to maintain constant temperature of electronic crystals, in order to ensure stability of operation. ...
Centroid of a triangle In geometry, the centroid or barycenter of an object in -dimensional space is the intersection of all hyperplanes that divide into two parts of equal moment about the hyperplane. ...
History
 The first quartz clock, on display at the International Watchmaking Museum, in La Chaux-De-Fonds Warren Marrison, working for Bell Laboratories, developed the first quartz clock in Canada. Seiko produced the world's first quartz wristwatch, the Astron, in 1969. The inherent accuracy and low cost of production has resulted in the proliferation of quartz clocks and watches since that time. Quartz timepiece production has emerged from Asia, notably Hong Kong and Japan. Many traditional European clockmakers have continued to produce the less accurate but popular geared timepieces. Image File history File links Download high-resolution version (1429x2191, 408 KB) Work by Rama File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Quartz clock ...
Image File history File links Download high-resolution version (1429x2191, 408 KB) Work by Rama File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Quartz clock ...
Location within Switzerland La Chaux-de-Fonds is a city located in the Jura mountains in Switzerland. ...
Bell Telephone Laboratories or Bell Labs was originally the research and development arm of the United States Bell System, and was the premier corporate facility of its type, developing a range of revolutionary technologies from telephone switches to specialized coverings for telephone cables, to the transistor. ...
Seiko Corporation ) (TYO: 8050 ) is a Japanese watch company. ...
Astron may refer to: Astron Document Management(an RRD company) - Branches in asia(Chennai, Trivandrum & Colombo)-www. ...
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