Saturday, July 12, 2014

Amplifier

Amplifier generates a new voltage in the same shape as the input voltages.  The input is amplified as the output is usually higher.

The gain of the amplifier is the ratio of its output and input

Gain (A) = Vout/Vin

Amplifier essentially takes an DC source and covert it to a AC output based on the same of a smaller AC input.  Efficiency of an amplifier indicates how well this DC-AC conversion is

%Eff = (Power-out/Power-in) * 100%

Lost power is usually converted to heat.  Efficient is sometime traded off for better linearity, fidelity and lower distortion of the signal.

Another property of amplifier is frequency response.  This indicate the range of frequency that an amplifier covers.  DC amplifier covers only frequency up to a few hundred Hz.  Audio amplifier covers frequency up to 20kHz

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