FACTOID # 26: Delaware is the latchkey kid capital of America, with 71.8% of households having both parents in the labor force.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Amplifier" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Amplifier

Generally, an amplifier is any device that changes, usually increases, the amplitude of a signal. The "signal" is usually voltage or current. Amplifier are an alternative rock band from Manchester, England. ... This article is about devices that perform tasks. ... In the fields of communications, signal processing, and in electrical engineering more generally, a signal is any time-varying quantity. ...


In popular use, the term today usually refers to an electronic amplifier, often as in audio applications. The relationship of the input to the output of an amplifier — usually expressed as a function of the input frequency — is called the transfer function of the amplifier, and the magnitude of the transfer function is termed the gain. A related device that emphasizes conversion of signals of one type to another (for example, a lightsignal in photons to a DC signal in amperes) is a transducer, or a sensor. However, a transducer does not amplify power. The term amplifier as used in this article can mean either a circuit (or stage) using a single active device or a complete system such as a packaged audio hi-fi amplifier. ... “Sound recorder” redirects here. ... A transfer function is a mathematical representation of the relation between the input and output of a linear time-invariant system. ... In electronics, gain is usually taken as the mean ratio of the signal output of a system to the signal input of the system. ... For other uses, see Light (disambiguation). ... In modern physics the photon is the elementary particle responsible for electromagnetic phenomena. ... Direct current (DC or continuous current) is the continuous flow of electricity through a conductor such as a wire from high to low potential. ... For other uses, see Ampere (disambiguation). ... This article is about transducers in engineering. ... Not to be confused with censure, censer, or censor. ... In physics, power (symbol: P) is the rate at which work is performed or energy is transmitted, or the amount of energy required or expended for a given unit of time. ...

Contents

Figures of merit

The quality of an amplifier can be characterized by a number of specifications, enumerated below.


Gain

The gain of an amplifier is the ratio of output to input power or amplitude, and is usually measured in decibels. (When measured in decibels it is logarithmically related to the power ratio: G(dB)=10 log(Pout/Pin)). In electronics, gain is usually taken as the mean ratio of the signal output of a system to the signal input of the system. ... This article is about the mathematical concept. ... For other uses, see Decibel (disambiguation). ... Look up logarithm in Wiktionary, the free dictionary. ...


Bandwidth

The bandwidth (BW) of an amplifier is the range of frequencies for which the amplfier gives "satisfactory performance". The "satisfactory performance" may be different for different applications. However, a common and well-accepted metric are the half power points (i.e. frequency where the power goes down by half its peak value) on the power vs. frequency curve. Therefore bandwidth can be defined as the difference between the lower and upper half power points. This is therefore also known as the −3 dB BW. Bandwidths for other response tolerances are sometimes quoted (−1 dB, −6 dB etc.). The half power point of an electronic amplifier stage is that frequency at which the output power has dropped to half of its mid-band level. ... The half power point of an electronic amplifier stage is that frequency at which the output power has dropped to half of its mid-band level. ...


A full-range audio amplifier will be essentially flat between 20 Hz to about 20 kHz (the range of normal human hearing.) In minimalist amplifier design, the amp's usable frequency response needs to extend considerably beyond this (one or more octaves either side) and typically a good minimalist amplifier will have −3 dB points < 10 and > 65 kHz. Professional touring amplifiers often have input and/or output filtering to sharply limit frequency response beyond 20 Hz-20 kHz; too much of the amplifier's potential output power would otherwise be wasted on infrasonic and ultrasonic frequencies, and the danger of AM radio interference would increase. Modern switching amplifiers need steep low pass filtering at the output to get rid of high frequency switching noise and harmonics. Infrasound is sound with a frequency too low to be detected by the human ear (less than approximately 20 hertz). ... Ultrasound is sound with a frequency greater than the upper limit of human hearing, approximately 20 kilohertz. ... Electromagnetic interference (also called EMI, Radio Frequency Interference, and RFI) is electromagnetic radiation which is emitted by electrical circuits carrying rapidly changing signals, as a by-product of their normal operation, and which causes unwanted signals (interference or noise) to be induced in other circuits. ... Block diagram of a basic switching or PWM (Class-D) amplifier. ...


Efficiency

Efficiency is a measure of how much of the input power is usefully applied to the amplifier's output. Class A amplifiers are very inefficient, in the range of 10–20% with a max efficiency of 25%. Class B amplifiers have a very high efficiency but are impractical because of high levels of distortion (See: Crossover distortion). In practical design, the result of a tradeoff is the class AB design. Modern Class AB amps are commonly between 35–55% efficient with a theoretical maximum of 78.5%. Commercially available Class D switching amplifiers have reported efficiencies as high as 97%. Amplifiers of Class C-F are usually known to be very high efficiency amplifiers. The efficiency of the amplifier limits the amount of total power output that is usefully available. Note that more efficient amplifiers run much cooler, and often do not need any cooling fans even in multi-kilowatt designs. The reason for this is that the loss of efficiency produces heat as a byproduct of the energy lost during the conversion of power. In more efficient amplifiers there is less loss of energy so in turn less heat. Crossover distortion is a type of distortion which is caused by switching between devices driving a load. ... Block diagram of a basic switching or PWM (Class-D) amplifier. ...


Linearity

An ideal amplifier would be a totally linear device, but real amplifiers are only linear within certain practical limits. When the signal drive to the amplifier is increased, the output also increases until a point is reached where some part of the amplifier becomes saturated and cannot produce any more output; this is called clipping, and results in distortion. For other uses, see Distortion (disambiguation). ...


Some amplifiers are designed to handle this in a controlled way which causes a reduction in gain to take place instead of excessive distortion; the result is a compression effect, which (if the amplifier is an audio amplifier) will sound much less unpleasant to the ear. For these amplifiers, the 1 dB compression point is defined as the input power (or output power) where the gain is 1 dB less than the small signal gain.


Linearization is an emergent field, and there are many techniques, such as feedforward, predistortion, postdistortion, EER, LINC, CALLUM, cartesian feedback, etc., in order to avoid the undesired effects of the non-linearities. Linearization in mathematics and its applications in general refers to finding the linear approximation to a function at a given point. ... Feed-forward is a term describing a kind of system which reacts to changes in its environment, usually to maintain some desired state of the system. ... Predistortion is a technique used to improve the linearity of radio transmitter amplifiers. ... The efficiency of air conditioners are often (but not always) rated by the Seasonal Energy Efficiency Ratio (SEER). ...


Noise

This is a measure of how much noise is introduced in the amplification process. Noise is an undesirable but inevitable product of the electronic devices and components. It is measured in either decibels or the peak output voltage produced by the amplifier when no signal is applied. This article is about noise as in sound. ...


Output dynamic range

Output dynamic range is the range, usually given in dB, between the smallest and largest useful output levels. The lowest useful level is limited by output noise, while the largest is limited most often by distortion. The ratio of these two is quoted as the amplifier dynamic range. More precisely, if S = maximal allowed signal power and N = noise power, the dynamic range DR is DR = (S + N ) /N.[1] For other uses, see Dynamic range (disambiguation). ... This article is about noise as in sound. ...


Slew rate

Slew rate is the maximum rate of change of output variable, usually quoted in volts per second (or microsecond). Many amplifiers are ultimately slew rate limited (typically by the impedance of a drive current having to overcome capacitive effects at some point in the circuit), which may limit the full power bandwidth to frequencies well below the amplifiers frequency response when dealing with small signals. In electronics, the slew rate is a nonlinear effect in amplifiers. ... In electronics, the slew rate is a nonlinear effect in amplifiers. ...


Rise time

The rise time, tr, of an amplifier is the time taken for the output to change from 10% to 90% of its final level when driven by a step input. For a Gaussian response system (or a simple RC roll off), the rise time is approximated by: In electronics, when approximating a voltage or current step function, rise time (also risetime) refers to the time required for a signal to change from a specified low value to a specified high value. ... In control theory the unit step response is the response of a dynamic system to the Heaviside step function. ... GAUSSIAN is a computational chemistry software program, first written by John Pople. ...


tr * BW = 0.35, where tr is rise time in seconds and BW is bandwidth in Hz. This article is about the unit of time. ... This article is about the SI unit of frequency. ...


Settling time and ringing

Time taken for output to settle to within a certain percentage of the final value (say 0.1%). This is usually specified for oscilloscope vertical amplifiers and high accuracy measurement systems. Ringing refers to an output that cycles above and below its final value, leading to a delay in reaching final value quantified by the settling time above. In electrical circuits, ringing is an unwanted oscillation of a voltage or current. ...


Overshoot

In response to a step input, the overshoot is the amount the output exceeds its final, steady-state value. In control theory the unit step response is the response of a dynamic system to the Heaviside step function. ...


Stability factor

Stability is a major concern in RF and microwave amplifiers. The degree of an amplifiers stability can be quantified by a so-called stability factor. There are several different stability factors, such as the Stern stability factor and the Linvil stability factor, which specify a condition that must be met for the absolute stability of an amplifier in terms of its two-port parameters. Look up stability in Wiktionary, the free dictionary. ... RF may mean: RF, the IATA code for Florida West International Airways RF, NYSE ticker symbol for Regions Financial Corporation Royalty free Rf or RF may stand for: Radio frequency Volumetric flow rate/rate of flow (Rf) RF connectors, electrical connectors designed to work at radio frequencies Red Faction, a... This article is about the type of Electromagnetic radiation. ...


Electronic amplifiers

Main article: Electronic amplifier

There are many types of electronic amplifiers, commonly used in radio and television transmitters and receivers, high-fidelity ("hi-fi") stereo equipment, microcomputers and other electronic digital equipment, and guitar and other instrument amplifiers. Critical components include active devices, such as vacuum tubes or transistors. A brief introduction to the many types of electronic amplifier follows. The term amplifier as used in this article can mean either a circuit (or stage) using a single active device or a complete system such as a packaged audio hi-fi amplifier. ... Antenna tower of Crystal Palace transmitter, London A transmitter is an electronic device which, usually with the aid of an antenna, propagates an electromagnetic signal such as radio, television, or other telecommunications. ... In radio terminology, a receiver is an electronic circuit that receives a radio signal from an antenna and decodes the signal for use as sound, pictures, navigational-position information, etc. ... This article is about audiophile sound systems. ... For other uses, see Guitar (disambiguation). ... An instrument amplifier is an electronic amplifier designed for use with an electric or electronic musical instrument, such as an electric guitar. ... An electrical circuit consists of various components or devices or elements, which may be active or passive. ... Structure of a vacuum tube diode Structure of a vacuum tube triode In electronics, a vacuum tube, electron tube, or (outside North America) thermionic valve or just valve, is a device used to amplify, switch or modify a signal by controlling the movement of electrons in an evacuated space. ... Assorted discrete transistors A transistor is a semiconductor device, commonly used as an amplifier or an electrically controlled switch. ...


Power amplifier

The term "power amplifier" is a relative term with respect to the amount of power delivered to the load and/or sourced by the supply circuit. In general a power amplifier is designated as the last amplifier in a transmission chain (the output stage) and is the amplifier stage that typically requires most attention to power efficiency. Efficiency considerations lead to various classes of power amplifier: see power amplifier classes. The term amplifier as used in this article can mean either a circuit (or stage) using a single active device or a complete system such as a packaged audio hi-fi amplifier. ...


Vacuum tube (valve) amplifiers

Main article: valve amplifier

According to Symons, while semiconductor amplifiers have largely displaced valve amplifiers for low power applications, valve amplifiers are much more cost effective in high power applications such as "radar, countermeasures equipment, or communications equipment" (p. 56). Many microwave amplifiers are specially designed valves, such as the klystron, gyrotron, traveling wave tube, and crossed-field amplifier, and these microwave valves provide much greater single-device power output at microwave frequencies than solid-state devices (p. 59).[2] A valve amplifier (UK and Aus. ... Reflex klystron Type 2K25 or 723 A/B. The threaded adjustment rod on the right side allows the position of the reflector to be adjusted (by compressing the reflex cavity), and thus the natural resonant frequency of the device. ... Gyrotrons are high powered electron tubes which emit a millimeter wave beam by bunching electrons with cyclotron motion in a strong magnetic field. ... A traveling wave tube (TWT) is an electronic device used to produce high-power radio frequency signals. ... A crossed-field amplifier (CFA) is a specialized vacuum tube, frequently used as a microwave amplifier in very-high-power transmitters. ...


Transistor amplifiers

The essential role of this active element is to magnify an input signal to yield a significantly larger output signal. The amount of magnification (the "forward gain") is determined by the external circuit design as well as the active device. Assorted discrete transistors A transistor is a semiconductor device, commonly used as an amplifier or an electrically controlled switch. ... A bipolar junction transistor (BJT) is a type of transistor. ... Mission Cyrus 1 Hi Fi integrated audio amplifier An audio amplifier is an electronic amplifier that amplifies low-power audio signals (signals composed primarily of frequencies between 20 hertz to 20,000 hertz, the human range of hearing) to a level suitable for driving loudspeakers and is the final stage... The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is by far the most common field-effect transistor in both digital and analog circuits. ...


Many common active devices in transistor amplifiers are bipolar junction transistors (BJTs) and metal oxide semiconductor field-effect transistors (MOSFETs). A bipolar junction transistor (BJT) is a type of transistor. ... The MOSFET, or Metal-Oxide-Semiconductor Field-Effect Transistor, is by far the most common Field effect transistor in both digital and analog circuits. ... The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is by far the most common field-effect transistor in both digital and analog circuits. ...


Applications are numerous, some common examples are audio amplifiers in a home stereo or PA system, RF high power generation for semiconductor equipment, to RF and Microwave applications such as radio transmitters.


Transistor-based amplifier can be realized using various configurations: for example with a bipolar junction transistor we can realize common base, common collector or common emitter amplifier; using a MOSFET we can realize common gate, common source or common drain amplifier. Each configuration has different characteristic (gain, impedance...). Figure 1: Basic NPN common base circuit (neglecting biasing details). ... Typical common collector or emitter follower circuit. ... Common emitter amplifier, voltage divider bias (CEVDB) circuit configuration A common emitter is a type of electronic amplifier stage based on a bipolar transistor in series with a load element such as a resistor. ... Common gate amplifier A common-gate amplifier is one of the common configurations of FET electronic amplifier. ... Common source amplifier with input bias and capacitively coupled input and output. ... Figure 1: Basic N-channel common source circuit (neglecting biasing details). ...


Operational amplifiers (op-amps)

An operational amplifier is a solid state integrated circuit amplifier which employs external feedback for control of its transfer function or gain. Op-amp ICs (some single, some dual) in 8-pin dual in-line packages (DIPs) An operational amplifier, usually referred to as an op-amp for brevity, is a DC-coupled high-gain electronic voltage amplifier with differential inputs[1] and, usually, a single output. ... Typical instrumentation amplifier schematic An instrumentation amplifier is a type of differential amplifier that has been specifically designed to have characteristics suitable for use in measurement and test equipment. ... In electronics, gain is usually taken as the mean ratio of the signal output of a system to the signal input of the system. ...


Fully differential amplifiers (FDA)

A fully differential amplifier is a solid state integrated circuit amplifier which employs external feedback for control of its transfer function or gain. It is similar to the operational amplifier but it also has differential output pins. An fully differential amplifier, usually referred to as an FDA for brevity, is a DC-coupled high-gain electronic voltage amplifier with differential inputs and differential outputs. ... In electronics, gain is usually taken as the mean ratio of the signal output of a system to the signal input of the system. ...


Video amplifiers

These deal with video signals and have varying bandwidths depending on whether the video signal is for SDTV, EDTV, HDTV 720p or 1080i/p etc.. The specification of the bandwidth itself depends on what kind of filter is used and which point (-1 dB or -3 dB for example) the bandwidth is measured. Certain requirements for step response and overshoot are necessary in order for acceptable TV images to be presented.


Oscilloscope vertical amplifiers

These are used to deal with video signals to drive an oscilloscope display tube and can have bandwidths of about 500 MHz. The specifications on step response, rise time, overshoot and aberrations can make the design of these amplifiers extremely difficult. One of the pioneers in high bandwidth vertical amplifiers was the Tektronix company. Tektronix is a United States corporation that is currently a major presence in the test, measurement, and measuring industry. ...


Distributed amplifiers

Main article: Distributed Amplifier

These use transmission lines to temporally split the signal and amplify each portion separately in order to achieve higher bandwidth than can be obtained from a single amplifying device. The outputs of each stage are combined in the output transmission line. This type of amplifier was commonly used on oscilloscopes as the final vertical amplifier. The transmission lines were often housed inside the display tube glass envelope. Distributed amplifiers are a very resourceful example of distributed circuit design that incorporate transmission line theory into traditional amplifier design in order to arrive at an amplifier with a larger gain-bandwidth product than is realizable by conventional circuits. ... A transmission line is the material medium or structure that forms all or part of a path from one place to another for directing the transmission of energy, such as electromagnetic waves or acoustic waves, as well as electric power transmission. ... Illustration showing the interior of a cathode-ray tube for use in an oscilloscope. ...


Microwave amplifiers

Travelling wave tube (TWT) amplifiers

Main article: Traveling wave tube

Used for high power amplification at low microwave frequencies. They typically can amplify across a broad spectrum of frequencies; however, they are usually not as tunable as klystrons. A traveling wave tube (TWT) is an electronic device used to produce high-power radio frequency signals. ...


Klystrons

Main article: Klystron

Very similar to TWT amplifiers, but more powerful and with a specific frequency "sweet spot". They generally are also much heavier than TWT amplifiers, and are therefore ill-suited for light-weight mobile applications. Klystrons are tunable, offering selective output within their specified frequency range. Reflex klystron Type 2K25 or 723 A/B. The threaded adjustment rod on the right side allows the position of the reflector to be adjusted (by compressing the reflex cavity), and thus the natural resonant frequency of the device. ...


Musical instrument (audio) amplifiers

An audio amplifier is usually used to amplify signals such as music or speech. An instrument amplifier is an electronic amplifier designed for use with an electric or electronic musical instrument, such as an electric guitar. ... Mission Cyrus 1 Hi Fi integrated audio amplifier An audio amplifier is an electronic amplifier that amplifies low-power audio signals (signals composed primarily of frequencies between 20 hertz to 20,000 hertz, the human range of hearing) to a level suitable for driving loudspeakers and is the final stage...


Other amplifier types

Carbon microphone

One of the first devices used to amplify signals was the carbon microphone (effectively a sound-controlled variable resistor). By channeling a large electric current through the compressed carbon granules in the microphone, a small sound signal could produce a much larger electric signal. The carbon microphone was extremely important in early telecommunications; analog telephones in fact work without the use of any other amplifier. Before the invention of electronic amplifiers, mechanically coupled carbon microphones were also used as amplifiers in telephone repeaters for long distance service. Carbon microphone from Western Electric telephone. ... An ideal resistor is a component with an electrical resistance that remains constant regardless of the applied voltage or current flowing through the device. ... For other uses, see Carbon (disambiguation). ... Plain old telephone service, or POTS, are the services available from analogue telephones prior to the introduction of electronic telephone exchanges into the public switched telephone network. ... For other uses, see Repeater (disambiguation). ...


Magnetic amplifier

Main article: magnetic amplifier

A magnetic amplifier is a transformer-like device that makes use of the saturation of magnetic materials to produce amplification. It is a non-electronic electrical amplifier with no moving parts. The bandwidth of magnetic amplifiers extends to the hundreds of kilohertz. The magnetic amplifier is an electromagnetic device for amplifying electrical signals. ... For other uses, see Transformer (disambiguation). ... Bandwidth is the difference between the upper and lower cutoff frequencies of, for example, a filter, a communication channel, or a signal spectrum, and is typically measured in hertz. ...


Rotating electrical machinery amplifier

A Ward Leonard control is a rotating machine like an electrical generator that provides amplification of electrical signals by the conversion of mechanical energy to electrical energy. Changes in generator field current result in larger changes in the output current of the generator, providing gain. This class of device was used for smooth control of large motors, primarily for elevators and naval guns. This article is about machines that produce electricity. ...


Field modulation of a very high speed AC generator was also used for some early AM radio transmissions.[1] See Alexanderson alternator. AM broadcasting is radio broadcasting using Amplitude Modulation. ... Alexanderson Alternator in the Grimeton VLF transmitter. ...


Johnsen-Rahbek effect amplifier

The earliest form of audio amplifier was Edison's "electromotograph" loud-speaking telephone, which used a wetted rotating chalk cylinder in contact with a stationary contact. The friction between cylinder and contact varied with the current, providing gain. Edison discovered this effect in 1874, but the theory behind the Johnsen-Rahbek effect was not understood until the semiconductor era. Edison is the last name of a famous United States inventor: Thomas Edison Other people known by the name Edison: Charles Edison – son of Thomas Edison and Governor of New Jersey Edison Chen – popular Hong Kong teen idol Edison Carter, character in the television show Max Headroom A number of...


Mechanical amplifiers

Mechanical amplifiers were used in the pre-electronic era in specialized applications. Early autopilot units designed by Elmer Ambrose Sperry incorporated a mechanical amplifier using belts wrapped around rotating drums; a slight increase in the tension of the belt caused the drum to move the belt. A paired, opposing set of such drives made up a single amplifier. This amplified small gyro errors into signals large enough to move aircraft control surfaces. A similar mechanism was used in the Vannevar Bush differential analyzer. An autopilot is a mechanical, electrical, or hydraulic system used to guide a vehicle without assistance from a human being. ... Elmer Ambrose Sperry (born October 12, 1860 in Cincinnatus, New York; died June 16, 1930 in Brooklyn, New York) was an inventor and entrepreneur. ... Vannevar Bush (March 11, 1890 – June 30, 1974) was an American engineer and science administrator, known for his political role in the development of the atomic bomb, and the idea of the memex—seen as a pioneering concept for the World Wide Web. ... The differential analyser was a mechanical analog computer invented by Vannevar Bush in 1927. ...


Optical amplifiers

Main article: Optical amplifier

Optical amplifiers amplify light through the process of stimulated emission. An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. ... For other uses, see Light (disambiguation). ... In optics, stimulated emission is the process by which, when perturbed by a photon, matter may lose energy resulting in the creation of another photon. ...


Miscellaneous types

  • There are also mechanical amplifiers, such as the automotive servo used in braking.
  • Relays can be included under the above definition of amplifiers, although their transfer function is not linear (that is, they are either open or closed).
  • Also purely mechanical manifestations of such digital amplifiers can be built (for theoretical, didactical purposes, or for entertainment), see e.g. domino computer.
  • Another type of amplifier is the fluidic amplifier, based on the fluidic triode.

Small R/C servo mechanism 1. ... This article is about the vehicle component. ... Relay as used in cars A relay is an electromechanical switch that uses an electromagnet to open or close one or many sets of contacts. ... For other uses, see Linear (disambiguation). ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Fluidics is science and technology of the application of a fluid or compressible medium to transmit energy and signals. ... The fluidic triode is an amplification device that uses a fluid to convey the signal. ...

References

  1. ^ Verhoeven CJM, van Staveren A, Monna GLE, Kouwenhoven MHL and Yildiz E (2003). Structured electronic design: negative feedback amplifiers. Boston/Dordrecht: Kluwer Academic, p. 10. ISBN 1-4020-7590-1. 
  2. ^ Robert S. Symons (1998). "Tubes: Still vital after all these years". IEEE Spectrum 35 (4): 52–63. 

See also

Electronics Portal
Wikimedia Commons has media related to:
Hi-Fi amplifiers
Image File history File links Nuvola_apps_ksim. ... Image File history File links Commons-logo. ... “Attenuator” redirects here. ... The term amplifier as used in this article can mean either a circuit (or stage) using a single active device or a complete system such as a packaged audio hi-fi amplifier. ... A negative feedback amplifier, or more commonly simply a feedback amplifier, is an amplifier which uses a negative feedback network, generally for improving performance (gain stability, linearity, frequency response etc. ... An instrument amplifier is an electronic amplifier designed for use with an electric or electronic musical instrument, such as an electric guitar. ... The low noise amplifier (LNA) is a special type of electronic amplifier or amplifier used in communication systems to amplify very weak signals captured by an antenna. ... An example of a typical high-end stereo preamplifier. ... In control theory the unit step response is the response of a dynamic system to the Heaviside step function. ...

  Results from FactBites:
 
Description datasheet search, AMPLIFIER datasheet, AMPLIFIER datasheets, AMPLIFIER data sheets ::: ALLDATASHEET ::: (198 words)
Amplifiers(845) Amplifier (24) AMPLIFIER  (12) AMPLIFIER   (10) AMPLIFIER    (8) Amplifier:(5) AMPLIFIERS (5) amplifier.
0.1- 6 GHz 3 V, 14 dBm Amplifier
AMPLIFIER Amplifier AMPLIFIER GHz AMPLIFIER dBm AMPLIFIER Power AMPLIFIER HBT AMPLIFIER for AMPLIFIER MMIC
ESP Amplifier Basics - How Audio Amps Work (3926 words)
In the case of a speaker, the power amplifier must be capable of providing a voltage and current sufficient to cause the speaker cone(s) to move.
An amplifier - or an element of an amplifying device - is presented with the input signal, and compares it to a "small scale replica" of the output signal.
In many designs, one part of the complete amplifier circuit (usually the input stage) acts as an error amplifier, and supplies exactly the right amount of signal to the rest of the amp to ensure that there is no difference between the input and output signals, other than amplitude.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m