Power amplifier is a special electronicA device designed to convert a small-power electrical signal that comes from a source into a more powerful signal. Indeed, to control electroacoustic transducers, for example, headphones or loudspeakers, a powerful source signal without distortion is needed, and the source often cannot provide the necessary signal power or distorts it with undesirable effects.
Power amplifier can be as independenta separate device with its own panel and control system, and be an internal element of a device and be soldered into a hybrid circuit. This device is the latest link in any sound amplification circuit.

Power amplifier can be distinguished by its areaapplication. Usually there are two main areas of use: household and professional. You can also separate them according to the execution schemes for a single-ended and push-pull power amplifier. Single-ended work in the so-called linear gain mode. In this mode, the current flows through the transistor for a full period.
Power amplifier is in absolutely anyinstrument or device that reproduces sound signals of the widest frequency spectrum. Since the primary signal, which is read, initially usually has a rather insignificant power, it is necessary to use amplifiers to transfer it to other devices. Such devices can be found in any mobile phone, tape recorder, in computers and laptops, and even in children's toys that can talk (which have speakers). In such household appliances use household amplifiers. The purpose of such devices is to amplify the electrical signal to the values of the sound range that the average person in the human mind is capable of perceiving (usually it is from 15 to 22 kilohertz). It should be noted that with age the range is significantly reduced (mostly its upper limit falls), the hearing becomes less sensitive - and most people of age are not able to perceive sounds at a frequency of more than 16-17 kilohertz.

In industry are widespreadprofessional amplifiers, for example, such a device as a broadcasting power amplifier. It is used for sound alerts in office buildings, industrial large enterprises and open spaces, stadiums and entertainment centers. Their purpose is to amplify and transmit a sound signal for the organization of broadcasting (signal transmission) at various large objects.

The appearance of such a device as an amplifierpower, can be very diverse and vary greatly depending on its application and purpose. There may also be specific differences in the design. For example, a sound power amplifier has a special system for playback, protection from water and moisture, and a permanent ventilation system. All this in total provides a much longer term for the operation of sound-amplifying equipment under conditions of maximum loads.