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Linear Amplifier
A linear amplifier is an electronics, electronic circuit whose output is proportional to its input, but capable of delivering more power (physics), power into a Electrical load, load. The term usually refers to a type of radio-frequency (RF) power amplifier, some of which have output power measured in kilowatts, and are used in amateur radio. Other types of linear amplifier are used in Sound, audio and laboratory equipment. Linearity refers to the ability of the amplifier to produce signals that are accurate copies of the input. A linear amplifier responds to different frequency components independently, and tends not to generate harmonic distortion or intermodulation distortion. No amplifier can provide perfect linearity however, because the amplifying devices—Transistor, transistors or vacuum tubes—follow nonlinear transfer function and rely on circuitry techniques to reduce those effects. There are a number of Electronic amplifier#Power amplifier classes, amplifier classes p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OM2000+ Innenansicht
''Om'' (or ''Aum''; ; , ISO 15919: ''Ōṁ'') is a polysemous symbol representing a sacred sound, seed syllable, mantra, and invocation in Hinduism. Its written form is the most important symbol in the Hindu religion. It is the essence of the supreme Absolute, consciousness,James Lochtefeld (2002), "Om", ''The Illustrated Encyclopedia of Hinduism'', Vol. 2: N-Z, Rosen Publishing. , page 482Om . ''Merriam-Webster'' (2013), Pronounced: \ˈōm\ ''Ātman (Hinduism), Ātman,'' ''Brahman,'' or the cosmic world.David Leeming (2005), ''The Oxford Companion to World Mythology'', Oxford University Press, , page 54Hajime Nakamura, ''A History of Early Vedānta Philosophy'', Part 2, Motilal Banarsidass, , page 318Annette Wilke and Oliver Moebus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Push–pull Output
A push–pull amplifier is a type of electronic circuit that uses a pair of active devices that alternately supply current to, or absorb current from, a connected load. This kind of amplifier can enhance both the load capacity and switching speed. Push–pull outputs are present in Transistor-transistor logic, TTL and CMOS digital logic circuits and in some types of electronic amplifier, amplifiers, and are usually realized by a complementary pair of transistors, one dissipating or ''sinking'' current from the load to ground or a negative power supply, and the other supplying or ''sourcing'' current to the load from a positive power supply. A push–pull amplifier is more efficient than a single-ended Power amplifier classes#Class A, "class-A" amplifier. The output power that can be achieved is higher than the continuous dissipation rating of either transistor or tube used alone and increases the power available for a given supply voltage. Symmetrical construction of the two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feed Forward (control)
A feed forward (sometimes written feedforward) is an element or pathway within a control system that passes a controlling signal from a source in its external environment to a load elsewhere in its external environment. This is often a command signal from an external operator. In control engineering, a feedforward control system is a control system that uses Sensor, sensors to detect disturbances affecting the system and then applies an additional input to minimize the effect of the disturbance. This requires a mathematical model of the system so that the effect of disturbances can be properly predicted. A control system which has only feed-forward behavior responds to its control signal in a pre-defined way without responding to the way the system reacts; it is in contrast with a system that also has feedback, which adjusts the input to take account of how it affects the system, and how the system itself may vary unpredictably. In a feed-forward system, the control variable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negative Feedback
Negative feedback (or balancing feedback) occurs when some function (Mathematics), function of the output of a system, process, or mechanism is feedback, fed back in a manner that tends to reduce the fluctuations in the output, whether caused by changes in the input or by other disturbances. Whereas positive feedback tends to instability via exponential growth, oscillation or chaos theory, chaotic behavior, negative feedback generally promotes stability. Negative feedback tends to promote a settling to List of types of equilibrium, equilibrium, and reduces the effects of perturbations. Negative feedback loops in which just the right amount of correction is applied with optimum timing, can be very stable, accurate, and responsive. Negative feedback is widely used in Mechanical engineering, mechanical and electronic engineering, and it is observed in many other fields including biology, chemistry and economics. General negative feedback systems are studied in Control engin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doherty Amplifier
The Doherty amplifier is a modified class B radio frequency amplifier invented by William H. Doherty of Bell Telephone Laboratories Inc in 1936. Whereas conventional class B amplifiers can clip on high input-signal levels, the Doherty power amplifier can accommodate signals with high peak-to-average power ratios by using two amplifier circuits within the one overall amplifier to accommodate the different signal levels. In this way, the amplifier achieves a high level of linearity while retaining good power efficiency. In Doherty's day, within the Western Electric product line, the eponymous electronic device was operated as a linear amplifier with a driver which was modulated. In the 50,000-watt implementation, the driver was a complete 5,000-watt transmitter which could, if necessary, be operated independently of the Doherty amplifier and the Doherty amplifier was used to raise the 5,000-watt level to the required 50,000-watt level. The amplifier was usually configured as a gro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class-D Amplifier
A class-D amplifier, or switching amplifier, is an electronic amplifier in which the amplifying devices (transistors, usually MOSFETs) operate as electronic switches, and not as linear gain devices as in other amplifiers. They operate by rapidly switching back and forth between the supply rails, using pulse-width modulation, pulse-density modulation, or related techniques to produce a pulse train output. A simple low-pass filter may be used to attenuate their high-frequency content to provide analog output current and voltage. Little energy is dissipated in the amplifying transistors because they are always either fully on or fully off, so efficiency can exceed 90%. History The first class-D amplifier was invented by British scientist Alec Reeves in the 1950s and was first called by that name in 1955. The first commercial product was a kit module called the X-10 released by Sinclair Radionics in 1964. However, it had an output power of only 2.5 watts. The Sinclair X-20 in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrode
A tetrode is a vacuum tube (called ''valve'' in British English) having four active electrodes. The four electrodes in order from the centre are: a thermionic cathode, first and second grids, and a plate electrode, plate (called ''anode'' in British English). There are several varieties of tetrodes, the most common being the screen-grid tube and the beam tetrode. In screen-grid tubes and beam tetrodes, the first grid is the control grid and the second grid is the screen grid. In other tetrodes one of the grids is a control grid, while the other may have a variety of functions. The tetrode was developed in the 1920s by adding an additional grid to the first amplifying vacuum tube, the triode, to correct limitations of the triode. During the period 1913 to 1927, three distinct types of tetrode valves appeared. All had a normal control grid whose function was to act as a primary control for current passing through the tube, but they differed according to the intended function of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4CX250B
A beam tetrode, sometimes called a beam power tube, is a type of vacuum tube or vacuum tube, thermionic valve that has two grids and forms the electron stream from the cathode into multiple partially collimated beams to produce a low potential space charge region between the anode and screen grid to return anode secondary emission electrons to the anode when the anode potential is less than that of the screen grid.Winfield G. Wagener, (May 1948"500-Mc. Transmitting Tetrode Design Considerations" ''Proceedings of the I.R.E.'', pp. 612, 617. Retrieved 10 June 2021 Beam tetrodes are usually used for power amplifier, amplification, from audio frequency to radio frequency. The beam tetrode produces greater output power than a triode or pentode with the same anode supply voltage. The first beam tetrode marketed was the Marconi N40, introduced in 1935.Editors, (Feb. 1935"New Output Tetrode" ''Electronics'', vol. 8 no.2, p. 65. Retrieved 10 June 2021K. R. Thrower, (2009) ''British Radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonlinear System
In mathematics and science, a nonlinear system (or a non-linear system) is a system in which the change of the output is not proportional to the change of the input. Nonlinear problems are of interest to engineers, biologists, physicists, mathematicians, and many other scientists since most systems are inherently nonlinear in nature. Nonlinear dynamical systems, describing changes in variables over time, may appear chaotic, unpredictable, or counterintuitive, contrasting with much simpler linear systems. Typically, the behavior of a nonlinear system is described in mathematics by a nonlinear system of equations, which is a set of simultaneous equations in which the unknowns (or the unknown functions in the case of differential equations) appear as variables of a polynomial of degree higher than one or in the argument of a function which is not a polynomial of degree one. In other words, in a nonlinear system of equations, the equation(s) to be solved cannot be written as a lin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class-C Amplifier
In electronics, power amplifier classes are letter symbols applied to different power amplifier An audio power amplifier (or power amp) amplifies low-power electronic audio signals, such as the signal from a radio receiver or an electric guitar pickup, to a level that is high enough for driving loudspeakers or headphones. Audio power a ... types. The class gives a broad indication of an amplifier's Electrical efficiency, efficiency, linearity and other characteristics. Broadly, as you go up the alphabet, the amplifiers become more efficient but less linear, and the reduced linearity is dealt with through other means. The first classes, A, AB, B, and C, are related to the time period that the active amplifier device is passing current, expressed as a fraction of the period of a signal waveform applied to the input. This metric is known as conduction angle (\theta). A class-A amplifier is conducting through the entire period of the signal (\theta=360°); class-B only for one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class-B Amplifier
In electronics, power amplifier classes are letter symbols applied to different Amplifier#Power_amplifiers, power amplifier types. The class gives a broad indication of an amplifier's Electrical efficiency, efficiency, linearity and other characteristics. Broadly, as you go up the alphabet, the amplifiers become more efficient but less linear, and the reduced linearity is dealt with through other means. The first classes, A, AB, B, and C, are related to the time period that the active amplifier device is passing current, expressed as a fraction of the period of a signal waveform applied to the input. This metric is known as conduction angle (\theta). A class-A amplifier is conducting through the entire period of the signal (\theta=360°); class-B only for one-half the input period (\theta=180°), class-C for much less than half the input period (\theta 180°); each one of the two active elements conducts more than half of the time. Class-AB is widely considered a good compromise f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Tube
A vacuum tube, electron tube, thermionic valve (British usage), or tube (North America) is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. It takes the form of an evacuated tubular envelope of glass or sometimes metal containing electrodes connected to external connection pins. The type known as a thermionic tube or thermionic valve utilizes thermionic emission of electrons from a hot cathode for fundamental Electronics, electronic functions such as signal amplifier, amplification and current Rectifier, rectification. Non-thermionic types such as vacuum phototubes achieve electron emission through the photoelectric effect, and are used for such purposes as the detection of light and measurement of its intensity. In both types the electrons are accelerated from the cathode to the anode by the electric field in the tube. The first, and simplest, vacuum tube, the diode or Flem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
