Displacement receiver

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A displacement receiver is a device that responds to or is sensitive to directed distance (displacement).

Examples of displacement receivers include carbon microphones, strain gauges, and pressure sensors or force sensors, which, to within an appropriate scale factor, respond to distance.

Carbon microphone

The carbon microphone, also known as carbon button microphone, button microphone, or carbon transmitter, is a type of microphone, a transducer that converts sound to an electrical audio signal. It consists of two metal plates separated by granules of carbon. One plate is very thin and faces toward the speaking person, acting as a diaphragm. Sound waves striking the diaphragm cause it to vibrate, exerting a varying pressure on the granules, which in turn changes the electrical resistance between the plates. Higher pressure lowers the resistance as the granules are pushed closer together. A steady direct current is passed between the plates through the granules. The varying resistance results in a modulation of the current, creating a varying electric current that reproduces the varying pressure of the sound wave. In telephony, this undulating current is directly passed through the telephone wires to the central office. In public address systems it is amplified by an audio amplifier. The frequency response of the carbon microphone, however, is limited to a narrow range, and the device produces significant electrical noise.

Strain gauge electronic component

A strain gauge is a device used to measure strain on an object. Invented by Edward E. Simmons and Arthur C. Ruge in 1938, the most common type of strain gauge consists of an insulating flexible backing which supports a metallic foil pattern. The gauge is attached to the object by a suitable adhesive, such as cyanoacrylate. As the object is deformed, the foil is deformed, causing its electrical resistance to change. This resistance change, usually measured using a Wheatstone bridge, is related to the strain by the quantity known as the gauge factor.

Pressure sensor

A pressure sensor is a device for pressure measurement of gases or liquids. Pressure is an expression of the force required to stop a fluid from expanding, and is usually stated in terms of force per unit area. A pressure sensor usually acts as a transducer; it generates a signal as a function of the pressure imposed. For the purposes of this article, such a signal is electrical.

In music, certain music keyboards can be considered displacement receivers in the sense that they respond to displacement, rather than velocity (as is more commonly the case).

Examples of displacement-responding sensors include the mechanical action of tracker organs, as well as the force-sensing resistors found in music keyboards that had polyphonic aftertouch capability. Polyphonic aftertouch is no longer a feature of presently manufactured keyboards, but certain older models such as the Roland A50 featured a pressure sensing resistor, similar in principle-of-operation to a carbon microphone, in each key.

Tracker action

Tracker action is a term used in reference to pipe organs and steam calliopes to indicate a mechanical linkage between keys or pedals pressed by the organist and the valve that allows air to flow into pipe(s) of the corresponding note. This is in contrast to "direct electric action" and "electro-pneumatic action", which connect the key to the valve through an electrical link or an electrically assisted pneumatic system respectively, or "tubular-pneumatic action" which utilizes a change of pressure within lead tubing which connects the key to the valve pneumatic.

Pipe organ wind instrument that produces sound by driving pressurized air (called wind) through pipes selected via a keyboard

The pipe organ is a musical instrument that produces sound by driving pressurized air through the organ pipes selected via a keyboard. Because each pipe produces a single pitch, the pipes are provided in sets called ranks, each of which has a common timbre and volume throughout the keyboard compass. Most organs have multiple ranks of pipes of differing timbre, pitch, and volume that the player can employ singly or in combination through the use of controls called stops.

Musical keyboard musical instrument part

A musical keyboard is the set of adjacent depressible levers or keys on a musical instrument. Keyboards typically contain keys for playing the twelve notes of the Western musical scale, with a combination of larger, longer keys and smaller, shorter keys that repeats at the interval of an octave. Depressing a key on the keyboard makes the instrument produce sounds—either by mechanically striking a string or tine, plucking a string (harpsichord), causing air to flow through a pipe organ, striking a bell (carillon), or, on electric and electronic keyboards, completing a circuit. Since the most commonly encountered keyboard instrument is the piano, the keyboard layout is often referred to as the piano keyboard.

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In the broadest definition, a sensor is a device, module, or subsystem whose purpose is to detect events or changes in its environment and send the information to other electronics, frequently a computer processor. A sensor is always used with other electronics.

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Preamplifier Circuit that prepares a signal for amplification

A preamplifier is an electronic amplifier that converts a weak electrical signal into an output signal strong enough to be noise-tolerant and strong enough for further processing, or for sending to a power amplifier and a loudspeaker. Without this, the final signal would be noisy or distorted. They are typically used to amplify signals from analog sensors such as microphones and pickups. Because of this, the preamplifier is often placed close to the sensor to reduce the effects of noise and interference.

Yamaha CS-80 synthesizer

The Yamaha CS-80 is a polyphonic analog synthesizer released in 1976. It supports true 8-voice polyphony as well as a primitive (sound) settings memory based on a bank of micropotentiometers, and exceptionally complete performer expression features, such as a layered keyboard that was both velocity-sensitive and pressure-sensitive ("after-touch") but unlike most modern keyboards the aftertouch could be applied to individual voices rather than in common, and a ribbon controller allowing for polyphonic pitch-bends and glissandos. This can be heard on the Blade Runner soundtrack by Vangelis, in which CS-80 is featured prominently, as well as the composer's soundtrack for the film Chariots of Fire, and the bassline of Peter Howell's interpretation of 1980 theme tune to BBC sci-fi show Doctor Who.

Kurzweil Music Systems company that produces electronic musical instruments

Kurzweil Music Systems is an American company that produces electronic musical instruments. It was founded in 1982 by Stevie Wonder (musician), Raymond Kurzweil (innovator) and Bruce Cichowlas.

Keyboard expression is the ability of a keyboard musical instrument to respond to change tone or other qualities of the sound in response to velocity, pressure or other variations in how the performer depresses the keys of the musical keyboard. Expression types include:

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Korg DW-8000

The Korg DW-8000 synthesizer was an eight-voice polyphonic hybrid digital-analog synthesizer 61-note keyboard instrument released in 1985. By the time of its launch Korg had already begun a common trend in 1980s synthesizer design: using numerical codes to access or change parameters with the Korg Poly-61, which was widely regarded as the company's first 'knobless' synthesizer. This was a move away from the heavily laden, complex control panels of earlier designs.

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The Fantom-X (Xa/X6/X7/X8/XR) is a music workstation/synthesizer produced by Roland Corporation. It was introduced in 2004 as an upgrade from the Fantom S series. The Fantom-X competes with the Korg Triton/Triton Extreme, the Yamaha Motif ES and other similar large-scope keyboards such as the discontinued Alesis Fusion. In 2008 it was succeeded by the Fantom-G, which was devised to compete with the new Korg and Yamaha flagship keyboards.

Ultrasonic transducer

Ultrasonic transducers or ultrasonic sensors are a type of acoustic sensor divided into three broad categories: transmitters, receivers and transceivers. Transmitters convert electrical signals into ultrasound, receivers convert ultrasound into electrical signals, and transceivers can both transmit and receive ultrasound.

Sonic Palette

The Sonic Palette is a MIDI controller type musical instrument. It consists of an 84 force sensor note surface, placed within a body that is wearable with a guitar strap. The body also contains various other controls including two additional force sensors, a tactile switch, and two potentiometers.

A velocity receiver is a sensor that responds to velocity rather than absolute position. For example, dynamic microphones are velocity receivers. Likewise, many electronic keyboards used for music are velocity sensitive, and may be said to possess a velocity receiver in each key. Most of these function by measuring the time difference between switch closures at two different positions along the travel of each key.

Capacitive displacement sensor

Capacitive displacement sensors “are non-contact devices capable of high-resolution measurement of the position and/or change of position of any conductive target”. They are also able to measure the thickness or density of non-conductive materials. Capacitive displacement sensors are used in a wide variety of applications including semiconductor processing, assembly of precision equipment such as disk drives, precision thickness measurements, machine tool metrology and assembly line testing. These types of sensors can be found in machining and manufacturing facilities around the world.

MEMS magnetic field sensor

A MEMS magnetic field sensor is a small-scale microelectromechanical systems (MEMS) device for detecting and measuring magnetic fields (Magnetometer). Many of these operate by detecting effects of the Lorentz force: a change in voltage or resonant frequency may be measured electronically, or a mechanical displacement may be measured optically. Compensation for temperature effects is necessary. Its use as a miniaturized compass may be one such simple example application.