Am de facut o lucrare de licentza si nu ma prea pricep.. rog dc sunt specialisti pe aicea in ale electrici sa atasheze cateva lincuri utile cu documentatia necesara pt amplificatoare audio si crector de ton !! Necesit 60 de pagini si nu stiu cum sa le scot !! Multzumesc
QUOTE (cataramaru @ May 27 2008, 08:20) 
Am de facut o lucrare de licentza si nu ma prea pricep.. rog dc sunt specialisti pe aicea in ale electrici sa atasheze cateva lincuri utile cu documentatia necesara pt amplificatoare audio si crector de ton !! Necesit 60 de pagini si nu stiu cum sa le scot !! Multzumesc
Daca necesitezi 60 de pagini si ai numai 2 scrise, incluzind prima pagina din Softpedia, incearca sa le tragi la Xerox: le bagi pe-o parte si le scoti pe alta.
Aicisa daca am vrea sa-ti dam 60 de pagini s-ar necesita cel putin doi specialisti: unul in amplificatoare si unul in corector de ton.
Am eu o lucrare , dar de 62 de pagini ,daca tu crezi ca te-ar putea ajuta la necesitate lasa-mi mesaj pe privat, impreuna cu-n cantec la moda, in interpretarea si la alegerea ta: Ajutati-ma si pe mine cu un ban, muzica Metrorex, versurile cu rima desperecheata sau Mamelor din lumea-ntreaga, muzica si versuri RATB, autobaza Filaret.
nu am cerut proiect gata facut !! pur si simplu am cerut niste lincuri pe care sa le studiez .. si scuza'ma dc team ofensat cu problemele mele ! Ms mult o sa ma descurc si singur !!
Cateva idei aplicabile si in cazul de fata gasesti aici:
http://forum.softpedia.com/index.php?showt...=amplificatoare
Pentru a ajunge la o norma de 60 de pagini, unele pagini din proiect pot contine scheme, altele imagini cu diverse produse...
http://forum.softpedia.com/index.php?showt...=amplificatoare
Pentru a ajunge la o norma de 60 de pagini, unele pagini din proiect pot contine scheme, altele imagini cu diverse produse...
Daca chiar vrei sa aprofundezi fenomenul si nu doar sa compilezi referate iti recomand o carte poate usor depasita (necesita completari la partea moderna audio - vezi mosfeturi noi si integrate, precum si clasa D), dar pe care o consider si acum interesanta. Tot de pe forum am ajuns sa aflu de existenta ei si am gasit-o in talcioc la un mosulica - miroase si acum a tigari - imi imaginez ce e in camera lui... Partea practica e cam subtire, dar teoria e destul de buna. Poti sa completezi cu ce gasesti pe net la capitolul scheme.
Ar trebui sa o gasesti la biblioteci - poate e si de vanzare pe net pe undeva:
L. Festila, E. Simion, C. Miron - Amplificatoare audio si sisteme muzicale
Editura Dacia, Cluj Napoca, 1990
Cine cunoaste alte lucrari mai bune e binevenit sa ma completeze, as fi chiar bucuros - si eu vreau sa stiu mai multe despre tot ce tine de audio.
Ar trebui sa o gasesti la biblioteci - poate e si de vanzare pe net pe undeva:
L. Festila, E. Simion, C. Miron - Amplificatoare audio si sisteme muzicale
Editura Dacia, Cluj Napoca, 1990
Cine cunoaste alte lucrari mai bune e binevenit sa ma completeze, as fi chiar bucuros - si eu vreau sa stiu mai multe despre tot ce tine de audio.
Cateva materiale despre amplificatoare:
http://www.bcae1.com/ampclass.htm
http://sound.westhost.com/class-a.htm
Click pentru a vizualiza atașamentul
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http://www.irf.com/technical-info/appnotes/an-1071.pdf
http://legwww.epfl.ch/~decurnex/Circuits+S...p%20by%20IR.pdf
QUOTE
Classes of Amplifiers
Amplifiers do not actually increase the strength of an electronic signal. What happens instead, the signal is copied and enlarged. There are different schemes for amplifying the signal. There are different classes of amplifiers. These classes are A, AB, and C. There have been some special classes such as G, created by Hatachi. Class H created by Soundcraftsman. Class D for the so-called digital amps and Class T for Tripath's digital amplifiers.
Class A amplifiers use one or more transistors that conduct during both the positive and negative cycles of the signal. This Class of amplifier has the lowest distortion but it is very inefficient and generates a lot of heat. A Class A amplifier requires that the amplifier generate the full current no matter what the output is. If you were simply listening to FM or watching a movie, the amplifier would be consuming as much power as if you had it turned up to full volume.
In order to increase efficiency, Class B amplifiers use one transistor to conduct the positive portion of the waveform and another transistor to conduct the negative portion of the waveform. 99% of all audio amplifiers today are Class B. Class B amplifier can be built today so that its distortions are well below what the human ear can detect and nearly to the point where it is unmeasurable.
Many amplifiers call themselves Class A/B. In reality, very few are. Early Class B amplifiers had a problem known as switching delay. In a class B design, a transistor works 50% of the cycle while another transistor works 50% of the cycle. In early class B amplifiers, there was a distortion created between the time the devices were switching back and forth. Some people referred to this distortion as notch distortion because there was a notch appearance on an oscilloscope between the two waveforms.
Class A/B was created to leave the transistor conducting while the second transistor was conducting. This created an overlap between the two signals. The problem with this approach is that it created its own distortion called gumming. This means that the signal would get a little fatter where the two devices were both conduction.
Today, if you look at a properly designed Class B amplifier on a scope, you will see no switching distortion.
Class D amps are sometimes called digital amplifiers. There is really no such thing today as a digital amplifier. A Class D amplifier uses transistors that are either switched on or off to represent positive or negative values. The transistors are either on or off. The advantage of such a system is that it is highly efficient and generates very little heat. The disadvantage is that there can be a distortion caused between the switching of the positive and negative transistors as the positive and negative transistors can not be on at the same time.
Many Class D amplifiers are finding their way into Subwoofers. They are inexpensive to build and the logic is that the switching distortion is not important in a subwoofer.
Class T amps are a more refined switching amplifier developed by Tripath. It uses signal processing to eliminate the switching distortion of Class D. nOrh is currently working with parts from Tripath to determine the sonic merits using the Tripath parts. Our current view is that advantage to using Class T and Class D amps is not to achieve better sound than can currently be achieved with standard A or A/B amplifiers. Rather it is an attempt to create a lower priced amplifier that offers good performance.
It is important to remember that classes of amplifiers do not describe quality but rather topology.
Amplifiers do not actually increase the strength of an electronic signal. What happens instead, the signal is copied and enlarged. There are different schemes for amplifying the signal. There are different classes of amplifiers. These classes are A, AB, and C. There have been some special classes such as G, created by Hatachi. Class H created by Soundcraftsman. Class D for the so-called digital amps and Class T for Tripath's digital amplifiers.
Class A amplifiers use one or more transistors that conduct during both the positive and negative cycles of the signal. This Class of amplifier has the lowest distortion but it is very inefficient and generates a lot of heat. A Class A amplifier requires that the amplifier generate the full current no matter what the output is. If you were simply listening to FM or watching a movie, the amplifier would be consuming as much power as if you had it turned up to full volume.
In order to increase efficiency, Class B amplifiers use one transistor to conduct the positive portion of the waveform and another transistor to conduct the negative portion of the waveform. 99% of all audio amplifiers today are Class B. Class B amplifier can be built today so that its distortions are well below what the human ear can detect and nearly to the point where it is unmeasurable.
Many amplifiers call themselves Class A/B. In reality, very few are. Early Class B amplifiers had a problem known as switching delay. In a class B design, a transistor works 50% of the cycle while another transistor works 50% of the cycle. In early class B amplifiers, there was a distortion created between the time the devices were switching back and forth. Some people referred to this distortion as notch distortion because there was a notch appearance on an oscilloscope between the two waveforms.
Class A/B was created to leave the transistor conducting while the second transistor was conducting. This created an overlap between the two signals. The problem with this approach is that it created its own distortion called gumming. This means that the signal would get a little fatter where the two devices were both conduction.
Today, if you look at a properly designed Class B amplifier on a scope, you will see no switching distortion.
Class D amps are sometimes called digital amplifiers. There is really no such thing today as a digital amplifier. A Class D amplifier uses transistors that are either switched on or off to represent positive or negative values. The transistors are either on or off. The advantage of such a system is that it is highly efficient and generates very little heat. The disadvantage is that there can be a distortion caused between the switching of the positive and negative transistors as the positive and negative transistors can not be on at the same time.
Many Class D amplifiers are finding their way into Subwoofers. They are inexpensive to build and the logic is that the switching distortion is not important in a subwoofer.
Class T amps are a more refined switching amplifier developed by Tripath. It uses signal processing to eliminate the switching distortion of Class D. nOrh is currently working with parts from Tripath to determine the sonic merits using the Tripath parts. Our current view is that advantage to using Class T and Class D amps is not to achieve better sound than can currently be achieved with standard A or A/B amplifiers. Rather it is an attempt to create a lower priced amplifier that offers good performance.
It is important to remember that classes of amplifiers do not describe quality but rather topology.
http://www.bcae1.com/ampclass.htm
http://sound.westhost.com/class-a.htm
Click pentru a vizualiza atașamentul
Click pentru a vizualiza atașamentul
Click pentru a vizualiza atașamentul
Click pentru a vizualiza atașamentul
Click pentru a vizualiza atașamentul
http://www.irf.com/technical-info/appnotes/an-1071.pdf
http://legwww.epfl.ch/~decurnex/Circuits+S...p%20by%20IR.pdf
Aceasta este o versiune simplificată a paginii originale. Pentru a vizita versiunea originala click aici.