Quartz Oscillator - Quartz Oscillator A Quartz Oscillator is the most common source of time and frequency signals. More than two billion (2 x 10^9) quartz oscillators are manufactured annually. Most are small devices built for wristwatches, clocks, and electronic circuits. However, quartz oscillators are also found inside test and measurement equipment, such as counters, signal generators, and oscilloscopes. A quartz crystal inside the oscillator is the resonator. It could be made of either natural or synthetic quartz, but all modern devices use synthetic quartz. The crystal strains (expands or contracts) when an electrical voltage is applied. When the voltage is reversed, the strain is reversed. This is known as the piezoelectric effect. Oscillation is sustained by taking a voltage signal from the resonator, amplifying it, and feeding it.
Quartz clock - Quartz clock A quartz clock is an electronic oscillator that uses a quartz filter to achieve very precise frequencies. Usually some form of digital logic counts these cycles and provides a numeric time display that a human can read. 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. 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.
Frequency synthesiser - system for generating any of a range of frequencies from a single fixed timebase or oscillator. They are found in many modern devices, including radio receivers, mobile telephones, radiotelephones, walkie-talkies, CB radios, Satellite receivers, GPS systems, etc. Before the invention of the frequency synthesiser, radio transmitters and receivers had to employ a separate crystal for each channel that the device could operate on. When the user changed channel, a new crystal was switched into the circuit. Since quartz crystals are highly precise they are therefore expensive to make, and in addition take up quite a large amount of space. Frequency synthesisers generate multiple channels from a single master crystal oscillator, and can generate hundreds of frequencies. This yields a huge cost and space saving. Almost all modern synthesisers operate on the.
Electronic filter - but are added to inductors and capacitors to determine the time-constants of the circuit, and therefore the frequencies to which it responds. At very high frequencies (above about 100 megahertz), sometimes the inductors consist of single loops or strips of sheet metal, and the capacitors consist of adjacent strips of metal. Other components can be added to LC filters to make them more precise. Filters are measured by their quality or "Q" factor. A filter is said to have a high Q if it selects or rejects a narrow range of frequencies compared with the absolute frequency at which it operates. Quality can be measured by the precision of a harmonic oscillator implemented with that type of device. Active Filters Filters can also be implemented using a combination of passive components.
Chronometer - clock based on a pair of counter-oscillating weighted beams connected by springs, whose motion was not influenced by gravity or the motion of a ship. His chronometers H1-H3 were all of this design but were large and heavy, and required to be suspended from a beam in a ship. He finally solved the problem with his H4 chronometer, essentially a large 5" diameter watch, winning a prize from the British Admiralty. His design used a temperature-compensated balance wheel. This method remained in use till microchips reduced the cost of a quartz clock to the point that electronic chronometers became commonplace. This is the paragraph where Thomas Ernshaw and the development of the practical spring detent escapement chronometer is discussed. Talking about chronometry without discussing Ernshaw is like talking about electricity without.
Clock generator - a simple symmetrical square wave to more complex arrangements. The basic parts that all clock generators share are a resonant circuit and an amplifier. The resonant circuit is usually a quartz piezo-electric oscillator, although simpler tank circuits and even RC circuits may be used. The amplifier circuit usually inverts the signal from the oscillator and feeds a portion back into the oscillator to maintain oscillation. The generator may have additional sections to modify the basic signal. The 8088 for instance, used a 2/3rds duty cycle clock, which required the clock generator to incorporate logic to convert the 50/50 duty cycle which is typical of raw oscillators..
Timeline of time measurement technology - - Second hand introduced 1737 - John Harrison presents the first stable nautical chronometer, thereby allowing for precise longitude determination while at sea 1928 - Joseph Horton and Warren Morrison build the first quartz crystal oscillator clock 1946 - Felix Bloch and Edward Purcell develop nuclear magnetic resonance 1949 - Harold Lyons develops an atomic clock based on the quantum mechanical vibrations of the ammonia molecule 2008 - Launch date for the Primary Atomic Reference Clock in Space. See also: clock.
Pilottone - after 800 feet or more. Pilottone provides such a system. The pilottone signal itself is very simple. On a given track of analogue tape medium, a pilottone-recording audio tape recorder (ATR) records a 60 Hz sine wave (Europeans record a 50 Hz sine wave.) This sine wave is generated in the recorder by a highly accurate quartz oscillator. This pilottone is recorded alongside the audio being recorded. This is useful because the pilottone is in effect an absolute record of how fast the tape was moving at the time the audio was recorded. When the tape is played back on a pilottone-reading tape player, it needs to only resolve the pilottone signal on the tape. The player has a quartz oscillator of its own, and when the operator hits play, the.
Pyrite - a very valuable ore), as well as arsenic, nickel, cobalt and copper. A mass of interwoven pyrite crystals, 11 cm (4.0 in) long Pyrite is the commonest of the sulfide minerals, and is found world-wide. It is found associated with other sulfides, or with oxides, in quartz veins, in sedimentary rock and metamorphic rock, in coal beds, and as the replacement mineral in fossils. Pyrites, interestingly, can show negative resistance, acting as radio detectors and have been used in oscillator circuits. Pyrite is used in the production of sulphur dioxide for the paper industry and in the manufacture of sulphuric acid, though not as much as it used to be. The name pyrite is from the Greek word meaning fire. because of the sparks that result when pyrite is struck with.
List of electronics topics - digital converter Angular misalignment loss Antenna Antenna blind cone Antenna effective area Antenna gain Antenna height above average terrain Antenna noise temperature Antenna theory aperiodic antenna aperture aperture illumination Aperture-to-medium coupling loss Apollo Guidance Computer Arithmetic and logical unit Armstrong oscillator ARRL Articulation score Astable Asynchronous communications system Asynchronous operation Asynchronous start-stop Atmospheric duct Atmospheric waveguide Attenuation Audible ringing tone Audio system measurements Automatic call distributor Automatic data processing Automatic Gain Control Automatic link establishment Automatic Number Identification Automatic sounding Automatic switching system Autovon Availability Available line Avalanche diode Azimuth B BCS theory Backplane Backward channel Balancing network Ball grid array Band gap Bandwidth compression Bare particular Baseband Battery (electricity) Baud rate Baudot code beam beam diameter beam divergence beam steering beamwidth Bel Bias biconical antenna billboard antenna Binaural recording Binary.
Quartz - Quartz Quartz is the most abundant mineral on earth (about 12% vol.), made of trigonal-crystallized silica (silicon dioxide, SiO2), with a hardness of 7 on the Mohs scale. The typical shape is six-sided prisms that end in six-sided pyramids, although these are often distorted, or so massive that only part of the shape is apparant from a mined specimin. Additionally a bed is a common form, particulaly for sub species such as amythyst, where the crystals grow up from a baserock, and thus only one termination pyramid is present. A geode consists of a hollow pebble (usually an approximatly spherical shape), with a hollow centre lined with a bed of crystals. Being one of the most common minerals, quartz goes by a bewlidering array of different.
Harmonic oscillator - Harmonic oscillator Table of contents showTocToggle("show","hide") 1 Introduction 2 Full Mathematical Definition 2.1 Simple Harmonic Oscillator 2.2 Driven Harmonic Oscillator 2.3 Damped Harmonic Oscillator 2.4 Damped, Driven Harmonic Oscillator 3 A Final Note on Mathematics Introduction A harmonic oscillator is any physical system that varies above and below its mean value with a characteristic frequency, f. Common examples of harmonic oscillators include pendulums, masses on springs, and RLC circuits. The following article discusses the harmonic oscillator in terms of classical mechanics. See the article quantum harmonic oscillator for a discussion of the harmonic oscillator in quantum mechanics. Full Mathematical Definition Most harmonic oscillators, at least approximately, solve the differential equation: where t is time, b is the damping constant, ωo is the characteristic angular frequency, and Aocos(ωt).
Hartley oscillator - Hartley oscillator Schematic Diagram The Hartley Oscillator is an LC oscillator that derives its feedback from magnetically coupled energy in a tapped coil. Hartley oscillator are inductively coupled variable frequency oscillators. Hartley oscillators may be series or shunt fed. Structure: One centre tapped inductor. One tuning capacitor. Advantages: Frequency simply varied by capacity net value in the tank circuit. Output amplitude remains constant (over the frequency range). Feedback ratio of inductor 1 to inductor 2 remains constant. Disadvantages: Harmonic content rich. Not suitable for a pure sine wave. See also: Colpitts oscillator Clapp oscillator Vackar oscillator Armstrong oscillator.
Fused quartz - Fused quartz Fused quartz is a man made mineral, manufactured principly from sands. It is non-crystaline, and in a high purity state is a useful material for high performance fluid and gas delivery. It's mechanical and thermal properties are superior to that of glass, priciply due to the purity (or, rather, the lack of impurities). For these reasons, it finds use in situations such as semiconductor fabrication and laboratory equiptment. See also: quartz, list of minerals Properties of Clear Fused Quartz (Based on information in Fused Quartz Catalogue Q-7A, General Electric Company) Density: 2.203 g/cm3 Hardness: 7 (Modified Scale); 5.3-6.5 (Mohs Scale) Tensile strength: 48.3 MPa Compressive strength: >1.1 GPa Bulk modulus: ~37 GPa Rigidity modulus: 31 GPa Young's modulus: 71.7 GPa Poisson's ratio: 0.16 Coefficient of.
Electronic oscillator - Electronic oscillator An electronic oscillator is an electronic circuit that produces a repetitive electronic signal, often a sine wave or a square wave. Table of contents showTocToggle("show","hide") 1 Types of Electronic Oscillator 1.1 Harmonic Oscillator 1.2 Relaxation Oscillator 2 See also Types of Electronic Oscillator There are two main types of electronic oscillator: the harmonic oscillator and the relaxation oscillator. Harmonic Oscillator The harmonic oscillator produces a sinusoidal output. The basic form of an harmonic oscillator is an electronic amplifier with the output attached to an electronic filter, and the output of the filter attached to the input of the amplifier. When the power supply to the amplifier is first switched on, the amplifier's output consists only of noise. The noise travels around the loop, being filtered.
Crystal oscillator - Crystal oscillator In telecommunication, a crystal oscillator (XO) is an oscillator in which the frequency is controlled by a piezoelectric crystal. Note 1: A crystal oscillator may require controlled temperature because its operating frequency is a function of temperature. Note 2: Types of crystal oscillators include voltage-controlled crystal oscillators (VCXO), temperature-compensated crystal oscillators (TCXO), oven-controlled crystal oscillators (OCXO), temperature-compensated-voltage controlled crystal oscillators (TCVCXO), oven-controlled voltage-controlled crystal oscillators (OCVCXO), microcomputer-compensated crystal oscillators (MCXO), and rubidium crystal oscillators (RbXO). Source: from Federal Standard 1037C.
Relaxation oscillator - Relaxation oscillator A relaxation oscillator is an oscillator in which a capacitor is charged gradually and then discharged rapidly. See also: RC oscillator multivibrator.
Rose quartz - Rose quartz Rose quartz is a type of quartz. An elephant carved in rose quartz, 4 inches (10 cm) long. It is not very popular as a faceted gem because its pink color is often too pale and the stones are always cloudy. When rose quartz is cut in cabochons, or rounded into beads for necklaces or carved, it is far more effective..
Quantum harmonic oscillator - Quantum harmonic oscillator The quantum harmonic oscillator is a quantum mechanical analogue of the classical harmonic oscillator. It is one of the most important problems in quantum mechanics, because (i) a simple exact solution exists, and (ii) a wide variety of physical situations can be reduced to this. In particular, a system near an equilibrium configuration can often be described in terms of one or more harmonic oscillators. The following discussion of the quantum harmonic oscillator relies on the article Mathematical formulation of quantum mechanics. Table of contents showTocToggle("show","hide") 1 One-dimensional Harmonic Oscillator 1.1 Hamiltonian and energy eigenstates 1.2 Ladder operator method 1.3 Natural length and energy scales 2 N-dimensional Harmonic Oscillator 3 Related problems 3.4 Anharmonic oscillator 3.5 Coupled Harmonic Oscillators One-dimensional Harmonic Oscillator Hamiltonian and energy.
Quartz Hill, California - Quartz Hill, California Quartz Hill is a town located in Los Angeles County, California. As of the 2000 census, the town had a total population of 9,890. Geography \nQuartz Hill is located at 34°39'8" North, 118°13'14" West (34.652194, -118.220647)1. According to the United States Census Bureau, the town has a total area of 9.9 km² (3.8 mi²). 9.9 km² (3.8 mi²) of it is land and none of it is covered by water. Demographics \nAs of the census of 2000, there are 9,890 people, 3,450 households, and 2,639 families residing in the town. The population density is 999.6/km² (2,591.9/mi²). There are 3,644 housing units at an average density of 368.3/km² (955.0/mi²). The racial makeup of the town is 81.47% White, 4.99% African American, 1.13% Native American,.
