Power Amplifier

 Power Amplifier

 

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An amplifier is electronic equipment that can boost the amplitude of voltage, current, or power that is sent by an input signal. It takes in a weak electrical signal or waveform and then uses an external power source to duplicate a comparable waveform that is much stronger at the output.

An electrical amplifier that is intended to enhance the amount of power that is output by a particular input signal is known as a power amplifier. The strength of the input signal is amplified until it reaches a level that is sufficient to drive loads of output devices such as speakers, headphones, RF transmitters, and so on. A power amplifier, in contrast to an amplifier that amplifies voltage or current, is expected to force loads directly and serves as the last block in an amplifier chain. It is necessary for the signal that is sent into a power amplifier to be stronger than a certain threshold. Therefore, the raw audio/RF signal is not supplied as input to the power amplifier; rather, it is first enhanced using current/voltage amplifiers as a pre-amplifier, and once the required adjustments have been made to it, it is then sent as input to the power amplifier. 

Power amplifiers are further classified into three main categories like DC power amplifiers, RF Power Amplifiers, and Audio power amplifiers. An audio power amplifier is a device that boosts the strength of an existing audio signal so that it may be heard more clearly. An audio power amplifier may provide an output that is anything from a few milliwatts to hundreds of watts. This category includes the amplifiers that are used in the speaker driving circuitries of various electronic devices such as TVs, mobile phones, etc. Long-distance wireless communications use modulated waves. The transmission range relies on the signal strength delivered to the antenna. Antennas need hundreds of kilowatts of electricity for FM broadcasting. Radio Frequency Power amplifiers boost the power of modulated waves to the needed transmission distance. DC power amplifiers increase PWM signals. Electronic control systems that operate motors or actuators with high-power signals employ them. They amplify microcontroller input and send it to DC motors or Actuators.

There are several approaches to designing circuits for a power amplifier. Each of the designed circuits has its own unique operating and output properties, which set it apart from the others. Power Amplifier Classes are used to separate the features and behavior of various power amplifier circuits. Within these Power Amplifier Classes, letter symbols are allocated to designate the mode of operation. They may generally be split up into two different types. Power amplifiers that are intended to amplify analog signals fall into one of four categories: A, B, AB, or C. Power amplifiers that are intended to amplify Pulse Width Modulated (PWM) digital signals are under the D, E, F, etc. categories. The power amplifiers that are used in audio amplifier circuits are the ones that are used the most often, and they fall into one of four classes: A, B, AB, or C.

Audio power amplifiers are utilized in practically all consumer electronics, including headphone drivers, microwave ovens, TVs, mobile phones, and Entertainment systems  Switching power amplifiers drive most commercial and industrial systems like servos and DC motors. High power amplifiers provide cellular or FM signals to consumers. Power amplifiers boost data transmission speeds and usefulness. Satellite communication equipment also uses them.