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Quartz is one member of a family of crystals that experience the piezoelectric effect.The piezoelectric effect has found applications in high power sources, sensors, actuators, frequency standards, motors, etc., and the relationship between applied voltage and mechanical deformation is well known; this allows probing an acoustic resonance by electrical means.
Mechanical boxed Marine Chronometer used on Queen Victoria's royal yacht, made about 1865 Omega 4.19 MHz (4 194 304 = 2 22 high frequency quartz resonator) Ships Marine Chronometer giving an autonomous accuracy of less than ± 5 seconds per year, French Navy issued,1980
A crystal oscillator is an electronic oscillator circuit that uses a piezoelectric crystal as a frequency-selective element. [1] [2] [3] The oscillator frequency is often used to keep track of time, as in quartz wristwatches, to provide a stable clock signal for digital integrated circuits, and to stabilize frequencies for radio transmitters and receivers.
Crystal oscillators can be manufactured for oscillation over a wide range of frequencies, from a few kilohertz up to several hundred megahertz.Many applications call for a crystal oscillator frequency conveniently related to some other desired frequency, so hundreds of standard crystal frequencies are made in large quantities and stocked by electronics distributors.
Quartz clocks and quartz watches are timepieces that use an electronic oscillator regulated by a quartz crystal to keep time. This crystal oscillator creates a signal with very precise frequency , so that quartz clocks and watches are at least an order of magnitude more accurate than mechanical clocks .
The full LCD display of the omega Chronograph rendered the Chrono-Quartz obsolete, at the same time changes in design and fashion moved towards slimmer and smaller watches, by comparison the 1620 range of watches was at least 1/3rd smaller than the bulky Chrono-Quartz.
A graphing calculator is a class of hand-held calculator that is capable of plotting graphs and solving complex functions. While there are several companies that manufacture models of graphing calculators, Hewlett-Packard is a major manufacturer.
Given a system transforming a set of inputs to output values, described by a mathematical function f, optimization refers to the generation and selection of the best solution from some set of available alternatives, [1] by systematically choosing input values from within an allowed set, computing the value of the function, and recording the best value found during the process.