Base Amplifier

Amplifiers Uses And Its Applications

What is an Amplifier? • An amplifier, or (informally) amp is an electronic device that increase the power of a signal. • It does this by taking energy from a power supply and controlling the output to match the input signal shape but with a larger amplitude. In this sense, an amplifier modulates the output of the power supply to make the output signal stronger than the input signal.

Function of an amplifier Amplifiers may be classified by their function or output characteristics. These functional descriptions usually apply to complete amplifier systems or sub-systems and rarely to individual stages. •

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A wideband amplifier has a precise amplification factor over a wide frequency range, and is often used to boost signals for relay in communications systems. A narrowband amp amplifies a specific narrow range of frequencies, to the exclusion of other frequencies. An RF amplifier amplifies signals in the radio frequency range of the electromagnetic spectrum, and is often used to increase the sensitivity of a receiveror the output power of a transmitter.[7] An audio amplifier amplifies audio frequencies. This category subdivides into small signal amplification, and power amps that are optimised to drivingspeakers, sometimes with multiple amps grouped together as separate or bridgeable channels to accommodate different audio reproduction requirements. Frequently used terms within audio amplifiers include: – Preamplifier (preamp), which may include a phono preamp with RIAA equalization, or tape head preamps with CCIR equalisation filters. They may include filters or tone control circuitry. – Power amplifier (normally drives loudspeakers), headphone amplifiers, and public address amplifiers. – Stereo amplifiers imply two channels of output (left and right), though the term simply means "solid" sound (referring to three-dimensional)—soquadraphonic stereo was used for amplifiers with four channels. 5.1 and 7.1 systems refer to Home theatre systems with 5 or 7 normal spacial channels, plus a subwoofer channel.

Further Amplifiers •

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Buffer amplifiers, which may include emitter followers, provide a high impedance input for a device (perhaps another amplifier, or perhaps an energy-hungry load such as lights) that would otherwise draw too much current from the source. Line drivers are a type of buffer that feeds long or interference-prone interconnect cables, possibly with differential outputs through twisted pair cables. A special type of amplifier - originally used in analog computers - is widely used in measuring instruments for signal processing, and many other uses. These are called operational amplifiers or op-amps. The "operational" name is because this type of amplifier can be used in circuits that perform mathematical algorithmic functions, or "operations" on input signals to obtain specific types of output signals. Modern op-amps are usually provided as integrated circuits, rather than constructed from discrete components. A typical modern op-amp has differential inputs (one "inverting", one "non-inverting") and one output. An idealized op-amp has the following characteristics: – Infinite input impedance (so it does not load the circuitry at its input) – Zero output impedance – Infinite gain – Zero propagation delay The performance of an op-amp with these characteristics is entirely defined by the (usually passive) components that form a negative feedback loop around it. The amplifier itself does not effect the output. All real-world op-amps fall short of the idealised specification above—but some modern components have remarkable performance and come close in some respects.

Applications of Amplifier • A power amplifier is a piece of equipment designed to drive a speaker system. They are used in numerous industries and can be found powering everything from the surround sound system at your local movie theater to public address systems used in concerts, supermarkets and train stations. From professional to personal use, there are many applications for a power amplifier.