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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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
