Ludicrous Blog » power amplifiers http://sitetodd.com sea bloggers INC Tue, 07 Sep 2010 05:37:35 +0000 en hourly 1 Power Amplifier – Last Stage of Multistage amplifier http://sitetodd.com/2009/09/30/power-amplifier-%e2%80%93-last-stage-of-multistage-amplifier/ http://sitetodd.com/2009/09/30/power-amplifier-%e2%80%93-last-stage-of-multistage-amplifier/#comments Wed, 30 Sep 2009 17:04:02 +0000 http://sitetodd.com/?p=190 As stated earlier, a power amplifier is the last stage of multistage amplifier. The previous stage develop sufficient gain and the input signal level or amplitude of a power amplifier is large of the order of few volts. The h-parameter analysis is applicable to small signal amplifiers and not valid for power amplifiers as power amplifiers are largely signal amplifiers. Hence the analysis of power amplifiers is carried out graphically by drawing a load line on the output characteristics of the transition used in it.

The power amplifiers have to feed the loads like loud speakers, having low impedance values. For maximum power transfer to the load, the impedance matching the output impedance of the power amplifiers must be small. Hence common collector or emitter follower circuit is very common in power amplifiers, which has very low output impedance. The common emitter circuit with step down transformer for impedance matching is also commonly used in power amplifiers.

The power amplifiers developing power at audio frequency range are called audio frequency power amplifiers.

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