Donde Puedo Encontrar Fotos De Nails

Tipos de amplificadores

Amplifier Class A (CLASS-A AMPLIFIER)

output current circulates throughout the cycle input signal in a single transistor. The bias current of transistor output is high and constant throughout the process, whether or not there is audio output. The distortion introduced is very low, but performance will also be low, being always below 50%. This means that half of the current amplified by the transistor is dissipated as heat.

class B amplifier (CLASS-B AMPLIFIER)

During a half cycle current flows and is amplified by a transistor, and for another half cycle circulates and is amplified by one transistor, allowing a break for a half cycle every and a working transistor and power dissipation. In addition, no current flows through the output transistors when no audio signal.

The problem is that it occurs so-called "crossover distortion", as in the first half cycle when the signal voltage falls below 0.6 V (voltage bias about base-emitter junction of a BJT) , depolarizes the BJT and leaves to amplify which also occurs when the other half cycle, the tension is not yet reached the 0.6 V. In summary, in the case of a sinusoidal 1.2 V would not amplified, although this is not the best way to define it. Class AB Amplifier (CLASS-AB AMPLIFIER)

Same case as the amplifier B only that there is a small stream circulates constantly through the 2 transistors, that greatly reduces polarized called crossover distortion. " As with Class A amplifiers, there is a constant bias current, but relatively low, avoiding crossover distortion (hence its name: AB). In the case of audio amplifiers are most often used reaching less than 0.01% distortion (THD = 0.01%)

Class C Amplifier (CLASS-C AMPLIFIER)

single output current flows for less than half cycle of input signal. And then the output is complemented with a circuit composed of capacitors and inductors (tank circuit). Class C

works for a narrow frequency band and is very appropriate radio equipment. This is due to the resonance phenomenon which is generated at the output of the amplifier is tuned (inductive and capacitive impedance are canceled at a rate previously calculated), but does not work above 180 degrees cycle, the amplifier generates output a full cycle signal to the fundamental frequency signal.

sound is not used for its high level of distortion and that its operation is not intended for large-signal amplifiers or large power.

Class D Amplifier (CLASS-D AMPLIFIER)

This kind of operation uses pulse signals (digital), which are lit by a short interval and off during a long interval. The use of digital technology makes it possible to get a signal that varies over the complete cycle to produce output from many parts of the input signal. The main advantage of class D operation, the amplifier is turned on (using power) only for short intervals and the overall efficiency can be very high. It consists of 4 transistors, running 2 at a time, cutting or clipping. Finally, define the aggregate efficiency power amplifier, as the ratio of ac output power between the dc power that is fed to the amplifier. It means that much energy becomes ac dc. Amplifiers

Class G (Class E and F do not produce commercial models).

incorporate several power lines that are activated progressively as the input voltage increases to greater efficiency.

These teams provide a better output of Class AB amplifiers, but with a smaller size.

Posted by: Emmanuel Angel