Electrostatic pickup

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An electrostatic pickup converts mechanical motion to an electrical signal by means of varying electrical capacitance. This type of pickup, in which the moving plate is a vibrating metal reed, is used in some types of electronic pianos and organs as an inexpensive method of generating tones.

Capacitance ability of a body to store an electrical charge

Capacitance is the ratio of the change in an electric charge in a system to the corresponding change in its electric potential. There are two closely related notions of capacitance: self capacitance and mutual capacitance. Any object that can be electrically charged exhibits self capacitance. A material with a large self capacitance holds more electric charge at a given voltage than one with low capacitance. The notion of mutual capacitance is particularly important for understanding the operations of the capacitor, one of the three elementary linear electronic components.

Pickup (music technology) transducer that captures or senses mechanical vibrations produced by musical instruments

A pickup is a transducer that captures or senses mechanical vibrations produced by musical instruments, particularly stringed instruments such as the electric guitar, and converts these to an electrical signal that is amplified using an instrument amplifier to produce musical sounds through a loudspeaker in a speaker enclosure. The signal from a pickup can also be recorded directly.

Electronic piano

An electronic piano is a keyboard instrument designed to simulate the timbre of a piano using analog circuitry.

Contents

Principle of operation

The electrostatic pickup consists of a capacitor with one stationary plate and one moving plate. The moving plate is typically a steel or brass reed, anchored at one end and free to vibrate at the other end. Another fixed plate is suspended near the vibrating reed, but is electrically insulated. A high voltage is applied between the stationary and moving plates to produce an electric field. The motion of the moving plate induces a varying current through the capacitor formed by the reed and the fixed plate. [1]

Capacitor electrical component used to store energy for a short period of time

A capacitor is a passive two-terminal electronic component that stores electrical energy in an electric field. The effect of a capacitor is known as capacitance. While some capacitance exists between any two electrical conductors in proximity in a circuit, a capacitor is a component designed to add capacitance to a circuit. The capacitor was originally known as a condenser or condensator. The original name is still widely used in many languages, but not commonly in English.

The capacitance of the pickup is changed by the motion of the moving plate. As a result of the changing capacitance, a varying current flows into or out of the plates as needed to maintain the proper charge for the new amount of capacitance. This current produces a varying voltage across an external resistor which is amplified to produce a usable output signal.

Wurlitzer "Model 44" Electrostatic Reed Organ Wurlitzer Model 44 Electrostatic Reed Organ.png
Wurlitzer "Model 44" Electrostatic Reed Organ

Variations

The shape, size and position of the fixed plate relative to the reed has an effect on the capacitance change as a function of the reed's instantaneous position during its travel. This allows different combinations of overtones to be generated from a single reed by placing several fixed plates in different locations, as seen in Wurlitzer electrostatic organs.

Overtone

An overtone is any frequency greater than the fundamental frequency of a sound. Using the model of Fourier analysis, the fundamental and the overtones together are called partials. Harmonics, or more precisely, harmonic partials, are partials whose frequencies are numerical integer multiples of the fundamental. These overlapping terms are variously used when discussing the acoustic behavior of musical instruments. The model of Fourier analysis provides for the inclusion of inharmonic partials, which are partials whose frequencies are not whole-number ratios of the fundamental.

Wurlitzer American company of music boxes and instruments

The Rudolph Wurlitzer Company, usually referred to as simply Wurlitzer, is an American company started in Cincinnati in 1853 by German immigrant (Franz) Rudolph Wurlitzer. The company initially imported stringed, woodwind and brass instruments from Germany for resale in the U.S. Wurlitzer enjoyed initial success largely due to defense contracts to provide musical instruments to the U.S. military. In 1880, the company began manufacturing pianos and eventually relocated to North Tonawanda, New York, and quickly expanded to make band organs, orchestrions, nickelodeons and pipe or theatre organs popular in theatres during the days of silent movies.

The electrostatic pickup used in the Hohner Pianet N electric piano has a fixed plate mounted at a 90 degree angle to the reed, while the fixed plates used in Wurlitzer electrostatic organs are parallel to the reed. The position of the fixed plate in the Pianet is such that the capacitance changes most dramatically when the reed is in the upper portion of its travel. The result is a large second-harmonic content in the resulting signal, similar to that produced by a fuzz box distortion pedal.

The Pianet is a type of electro-mechanical piano built by the Hohner company of Trossingen, West Germany, from the early 1960s to the early 1980s. The designer of the early Pianet models was Ernst Zacharias, basing the mechanism closely on a 1920s design by Lloyd Loar. The Pianet was a variant of the earlier reed-based Hohner electric piano the Cembalet which, like the Pianet, was intended for home use. Hohner offered both keyboards in their range until the early 1970s. The Pianet production consisted of two distinctly different mechanism groups with characteristically different sound. The first group, lasting from introduction to 1977, had ground stainless steel reeds, a pick-up using variable capacitance, and leather faced activation pads. The second group from 1977 until the end of production used rolled spring-steel reeds, electro-magnetic pick-ups, and moulded silicone rubber activation pads.

Distortion (music) form of audio signal processing giving "fuzzy" sound

Distortion and overdrive are forms of audio signal processing used to alter the sound of amplified electric musical instruments, usually by increasing their gain, producing a "fuzzy", "growling", or "gritty" tone. Distortion is most commonly used with the electric guitar, but may also be used with other electric instruments such as bass guitar, electric piano, and Hammond organ. Guitarists playing electric blues originally obtained an overdriven sound by turning up their vacuum tube-powered guitar amplifiers to high volumes, which caused the signal to distort. While overdriven tube amps are still used to obtain overdrive in the 2010s, especially in genres like blues and rockabilly, a number of other ways to produce distortion have been developed since the 1960s, such as distortion effect pedals. The growling tone of distorted electric guitar is a key part of many genres, including blues and many rock music genres, notably hard rock, punk rock, hardcore punk, acid rock, and heavy metal music.

See also

Wurlitzer electric piano

The Wurlitzer electronic piano, commonly called the Wurly is an electric piano manufactured and marketed by Wurlitzer from the mid-1950s to the early 1980s. The sound is generated by striking a metal reed with a hammer, which induces an electric current in a pickup; although conceptually similar to the Rhodes piano, the sound is different.

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Electrometer scientific instrument to measure electric charge or electrical potential difference

An electrometer is an electrical instrument for measuring electric charge or electrical potential difference. There are many different types, ranging from historical handmade mechanical instruments to high-precision electronic devices. Modern electrometers based on vacuum tube or solid-state technology can be used to make voltage and charge measurements with very low leakage currents, down to 1 femtoampere. A simpler but related instrument, the electroscope, works on similar principles but only indicates the relative magnitudes of voltages or charges.

Microphone a device that converts sound into an electrical signal

A microphone, colloquially nicknamed mic or mike, is a transducer that converts sound into an electrical signal.

A transducer is a device that converts energy from one form to another. Usually a transducer converts a signal in one form of energy to a signal in another.

Electric piano musical instrument used by many of the great musicians such as Ray Charles

An electric piano is an electric musical instrument which produces sounds when a performer presses the keys of the piano-style musical keyboard. Pressing keys causes mechanical hammers to strike metal strings, metal reeds or wire tines, leading to vibrations which are converted into electrical signals by magnetic pickups, which are then connected to an instrument amplifier and loudspeaker to make a sound loud enough for the performer and audience to hear. Unlike a synthesizer, the electric piano is not an electronic instrument. Instead, it is an electro-mechanical instrument. Some early electric pianos used lengths of wire to produce the tone, like a traditional piano. Smaller electric pianos used short slivers of steel to produce the tone. The earliest electric pianos were invented in the late 1920s; the 1929 Neo-Bechstein electric grand piano was among the first. Probably the earliest stringless model was Lloyd Loar's Vivi-Tone Clavier. A few other noteworthy producers of electric pianos include Baldwin Piano and Organ Company and the Wurlitzer Company.

Electronic component basic discrete device or physical entity in an electronic system used to affect electrons or their associated fields

An electronic component is any basic discrete device or physical entity in an electronic system used to affect electrons or their associated fields. Electronic components are mostly industrial products, available in a singular form and are not to be confused with electrical elements, which are conceptual abstractions representing idealized electronic components.

Comb drive

Comb-drives are actuators, often used as linear actuators electrostatic forces that act between two electrically conductive combs. Comb drive actuators typically operate at the micro- or nanometer scale and are generally manufactured by bulk micromachining or surface micromachining a silicon wafer substrate.

Variable capacitor capacitor whose capacitance may be intentionally and repeatedly changed mechanically or electronically. Variable capacitors are often used in L/C circuits to set the resonance frequency

A variable capacitor is a capacitor whose capacitance may be intentionally and repeatedly changed mechanically or electronically. Variable capacitors are often used in L/C circuits to set the resonance frequency, e.g. to tune a radio, or as a variable reactance, e.g. for impedance matching in antenna tuners.

Capacitor types

Capacitors are manufactured in many forms, styles, lengths, girths, and from many materials. They all contain at least two electrical conductors separated by an insulating layer. Capacitors are widely used as parts of electrical circuits in many common electrical devices.

Differential capacitance in physics, electronics, and electrochemistry is a measure of the voltage-dependent capacitance of a nonlinear capacitor, such as an electrical double layer or a semiconductor diode. It is defined as the derivative of charge with respect to potential.

In electrical engineering, capacitive sensing is a technology, based on capacitive coupling, that can detect and measure anything that is conductive or has a dielectric different from air.

Applications of capacitors

Capacitors have many uses in electronic and electrical systems. They are so ubiquitous that it is rare that an electrical product does not include at least one for some purpose.

Cembalet

The Cembalet is a type of electro-mechanical piano built by the Hohner company of Trossingen, West Germany from the late-1950s to the early 1970s. The designer of the Cembalet was Ernst Zacharias. The Cembalet was a reed-based electric piano intended for home use. It was the first keyboard produced by Hohner as a piano-like instrument rather than an instrument having the sustained note of an organ. It was adopted by popular musicians for recording and performance in the early 1960s due to its portability and ability to be amplified by electronic means.

Guitar wiring electrical wiring in guitars

Guitar wiring refers to the electrical components, and interconnections thereof, inside an electric guitar. It most commonly consists of pickups, potentiometers to adjust volume and tone, a switch to select between different pickups, and the output socket. There may be additional controls for specific functions; the most common of these are described below.

Supercapacitor Electrochemical capacitor that bridges the gap between electrolytic capacitors and rechargeable batteries

A supercapacitor (SC) is a high-capacity capacitor with capacitance values much higher than other capacitors that bridge the gap between electrolytic capacitors and rechargeable batteries. They typically store 10 to 100 times more energy per unit volume or mass than electrolytic capacitors, can accept and deliver charge much faster than batteries, and tolerate many more charge and discharge cycles than rechargeable batteries.

Most of the terms listed in Wikipedia glossaries are already defined and explained within Wikipedia itself. However, glossaries like this one are useful for looking up, comparing and reviewing large numbers of terms together. You can help enhance this page by adding new terms or writing definitions for existing ones.

References

Benjamin Franklin Miessner was an American radio engineer and inventor. He is most known for his electronic organ, electronic piano, and other musical instruments. He was the inventor of the Cat's whisker detector.

The Institute of Radio Engineers (IRE) was a professional organization which existed from 1912 until December 31, 1962. On January 1, 1963 it merged with the American Institute of Electrical Engineers (AIEE) to form the Institute of Electrical and Electronics Engineers (IEEE).

  1. US 2542611,Zuck, Victor,"Pickup for Electric Organs",issued Feb. 20, 1951