Sample-and-hold Amplifier
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Sample-and-hold Amplifier
In electronics, a sample and hold (also known as sample and follow) circuit is an analog device that samples (captures, takes) the voltage of a continuously varying analog signal and holds (locks, freezes) its value at a constant level for a specified minimum period of time. Sample and hold circuits and related peak detectors are the elementary analog memory devices. They are typically used in analog-to-digital converters to eliminate variations in input signal that can corrupt the conversion process.Kefauver and Patschke, p. 37. They are also used in electronic music, for instance to impart a random quality to successively-played notes. A typical sample and hold circuit stores electric charge in a capacitor and contains at least one switching device such as a FET (field effect transistor) switch and normally one operational amplifier.Horowitz and Hill, p. 220. To sample the input signal, the switch connects the capacitor to the output of a buffer amplifier. The buffer ampl ...
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Volatile Memory
Volatile memory, in contrast to non-volatile memory, is computer memory that requires power to maintain the stored information; it retains its contents while powered on but when the power is interrupted, the stored data is quickly lost. Volatile memory has several uses including as primary storage. In addition to usually being faster than forms of mass storage such as a hard disk drive, volatility can protect sensitive information, as it becomes unavailable on power-down. Most general-purpose random-access memory (RAM) is volatile. Types There are two kinds of volatile RAM: dynamic and static. Even though both types need continuous electrical current to retain data, there are some important differences between them. Dynamic RAM (DRAM) is very popular due to its cost-effectiveness. DRAM stores each bit of information in a different capacitor within the integrated circuit. DRAM chips need just one single capacitor and one transistor to store each bit of information. This makes ...
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Modular Synthesizer
Modular synthesizers are synthesizers composed of separate modules for different functions. The modules can be connected together by the user to create a patch. The outputs from the modules may include audio signals, analog control voltages, or digital signals for logic or timing conditions. Typical modules are voltage-controlled oscillators, voltage-controlled filters, voltage-controlled amplifiers and envelope generators. History The first modular synthesizer was developed by German engineer Harald Bode in the late 1950s. The 1960s saw the introduction of the Moog synthesizer and the Buchla Modular Electronic Music System, created around the same period. The Moog was composed of separate modules which created and shaped sounds, such as envelopes, noise generators, filters, and sequencers, connected by patch cords. The Japanese company Roland released the Roland System 100 in 1975, followed by the System 700 in 1976 and the System 100m in 1979. In the late 19 ...
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Synthesizer
A synthesizer (also synthesiser or synth) is an electronic musical instrument that generates audio signals. Synthesizers typically create sounds by generating waveforms through methods including subtractive synthesis, additive synthesis and frequency modulation synthesis. These sounds may be altered by components such as filters, which cut or boost frequencies; envelopes, which control articulation, or how notes begin and end; and low-frequency oscillators, which modulate parameters such as pitch, volume, or filter characteristics affecting timbre. Synthesizers are typically played with keyboards or controlled by sequencers, software or other instruments, and may be synchronized to other equipment via MIDI. Synthesizer-like instruments emerged in the United States in the mid-20th century with instruments such as the RCA Mark II, which was controlled with punch cards and used hundreds of vacuum tubes. The Moog synthesizer, developed by Robert Moog and first so ...
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Display Motion Blur
In modern displays, motion blur is an unwanted artifact caused primarily by: # Retinal blur resulting from your eyes ''continuously'' tracking ''discrete'' movement. While your eyes move, the object you're tracking remains stationary throughout each frame, causing it to "smear". This does not happen in real life where both move continuously. # Slow pixel response times, which lead to visible ghosting or smearing. The faster the motion, the more pronounced the effect is. Cause Displays work by rapidly showing frames, each one slightly different from the previous, thereby creating the illusion of movement. Let's take a normal computer monitor with a resolution of 1920×1080 and a refreshrate of 60 Hz. If an object were to move across the display in 2 seconds, there would be 60×2 = 120 "steps", each one translated by 1920÷120 = 16 pixels. Your eyes, however, would not start and stop, over and over again to track the object, quickly moving the fovea to the "new" positio ...
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Sample And Hold DSCF0028
Sample or samples may refer to: * Sample (graphics), an intersection of a color channel and a pixel * Sample (material), a specimen or small quantity of something * Sample (signal), a digital discrete sample of a continuous analog signal * Sample (statistics), a subset of a population – complete data set People * Sample (surname) * Samples (surname) Places * Sample, Kentucky, unincorporated community, United States * Sampleville, Ohio, unincorporated community, United States * Hugh W. and Sarah Sample House, listed on the National Register of Historic Places in Iowa, United States Music * Sample (music), to reuse a portion of a sound recording in another recording, or the portion reused * "Sample" (Sakanaction song) * "Sample", a song by No-Man from ''Flowermix'' * The Samples, a band from Boulder, Colorado Other uses * USS ''Sample'' (FF-1048), a frigate in the U.S. Navy * The Sample, a defunct department store in Buffalo, New York, U.S. * SAMPLE history, a ...
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IEEE Jun-ichi Nishizawa Medal
In 2002, the Institute of Electrical and Electronics Engineers (IEEE) added a new award to its already existing program of awards. Each year, one or more nominees are honored with a medal in the name of Jun-ichi Nishizawa, considered to be the ''father of Japanese microelectronics''. Nishizawa was professor, director of two research institutes and the 17th president at Tohoku University, Sendai, Japan, and contributed important innovations in the fields of optical communications and semiconductor devices, such as laser and PIN diodes and static induction thyristors for electric power applications. This medal is awarded by the IEEE on a yearly basis to nominees in the fields of materials science Materials science is an interdisciplinary field of researching and discovering materials. Materials engineering is an engineering field of finding uses for materials in other fields and industries. The intellectual origins of materials sci ... and device technologies. Sponsor of ...
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Thin-film Transistor
A thin-film transistor (TFT) is a special type of field-effect transistor (FET) where the transistor is made by thin film deposition. TFTs are grown on a supporting (but non-conducting) substrate, such as glass. This differs from the conventional bulk metal-oxide-semiconductor field-effect transistor (MOSFET), where the semiconductor material typically ''is'' the substrate, such as a silicon wafer. The traditional application of TFTs is in TFT liquid-crystal displays. Design and manufacture TFTs can be fabricated with a wide variety of semiconductor materials. Because it is naturally abundant and well understood, amorphous or polycrystalline silicon were (and still are) used as the semiconductor layer. However, because of the low mobility of amorphous silicon and the large device-to-device variations found in polycrystalline silicon, other materials have been studied for use in TFTs. These include cadmium selenide, metal oxides such as indium gallium zinc oxide (IGZO) or ...
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Greyscale
In digital photography, computer-generated imagery, and colorimetry, a greyscale (more common in Commonwealth English) or grayscale (more common in American English) image is one in which the value of each pixel is a single sample representing only an ''amount'' of light; that is, it carries only intensity information. Grayscale images, are black-and-white or gray monochrome, and composed exclusively of shades of gray. The contrast ranges from black at the weakest intensity to white at the strongest. Grayscale images are distinct from one-bit bi-tonal black-and-white images, which, in the context of computer imaging, are images with only two colors: black and white (also called ''bilevel'' or '' binary images''). Grayscale images have many shades of gray in between. Grayscale images can be the result of measuring the intensity of light at each pixel according to a particular weighted combination of frequencies (or wavelengths), and in such cases they are monochroma ...
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Pixel
In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a Raster graphics, raster image, or the smallest addressable element in a dot matrix display device. In most digital display devices, pixels are the smallest element that can be manipulated through software. Each pixel is a Sampling (signal processing), sample of an original image; more samples typically provide more accurate representations of the original. The Intensity (physics), intensity of each pixel is variable. In color imaging systems, a color is typically represented by three or four component intensities such as RGB color model, red, green, and blue, or CMYK color model, cyan, magenta, yellow, and black. In some contexts (such as descriptions of camera sensors), ''pixel'' refers to a single scalar element of a multi-component representation (called a ''photosite'' in the camera sensor context, although ''wikt:sensel, sensel'' is sometimes used), while in yet ...
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Active Matrix
Active matrix is a type of addressing scheme used in flat panel displays. It is a method of switching individual elements of a flat panel display, known as pixels. Each pixel is attached to a transistor and capacitor that ''actively'' maintain the pixel state while other pixels are being addressed, in contrast with the older passive matrix technology in which each pixel must maintain its state passively, without being driven by circuitry. Active matrix technology was invented by Bernard J. Lechner at RCA, using MOSFETs (metal–oxide–semiconductor field-effect transistors). Active matrix technology was first demonstrated as a feasible device using thin-film transistors (TFTs) by T. Peter Brody, Fang Chen Luo and their team at the Thin-Film Devices department of Westinghouse Electric Corporation in 1974, and the term was introduced into the literature in 1975. Given an ''m'' × ''n'' matrix, the number of connectors needed to address the display is ''m'' +&nbs ...
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Liquid Crystal
Liquid crystal (LC) is a state of matter whose properties are between those of conventional liquids and those of solid crystals. For example, a liquid crystal can flow like a liquid, but its molecules may be oriented in a common direction as in a solid. There are many types of LC Phase (matter), phases, which can be distinguished by their Optics, optical properties (such as Texture (crystalline), textures). The contrasting textures arise due to molecules within one area of material ("domain") being oriented in the same direction but different areas having different orientations. An LC material may not always be in an LC state of matter (just as water may be ice or water vapour). Liquid crystals can be divided into three main types: thermotropic, lyotropic, and #Metallotropic liquid crystals, metallotropic. Thermotropic and lyotropic liquid crystals consist mostly of organic molecules, although a few minerals are also known. Thermotropic LCs exhibit a phase transition into the L ...
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