It is device which is used to increase the voltage, current, or the power of a particular signal. They are now commonly used in various electronics media and wireless communication devices and also for broadcasting the signals. It is the widely used electronic device in the world and a basic building block of a various electronic circuits. Basically its work is to increase the power of a signal thereby making it stronger than the given input.
There are simply two types of amplifiers as power amplifiers and weak signal amplifiers. The former used in wireless receivers and the later one used in wireless transmitters and in higher audio devices. Power output and efficiency are the two major key points while considering amplifiers.
Types of Amplifiers are termed as:-
This type of amplifier takes the given current signal as input and produces the signal of higher value current. It has a very low input impedance and high output impedance. Its performance depends on the impeding signal of an input device.
This type of amplifier takes the given voltage signal as input and produces the signal of higher value of voltage. It has a very low input impedance and high output impedance. Its performance depends on the impeding signal of an input device.
It is an amplifier that makes the given output current as according to the changing input voltage.
These amplifiers are also called the tuned amplifiers because the frequency of the operation is fully govern by the tuned circuit, but this circuit may or may not be adjustable due to the purpose of the amplifier. Bandwidth is relatively wide or narrow depends on the usage, it has low input resistance. It has a very low noise performance which makes them very special.
This type amplifier handles the frequency level in the range of 20 to 100 kilo-Hertz, Because of this factor they are also known as ultrasonic amplifiers. . They are used in ultrasonic cleaning of objects, detection of a fatigue level of a metal, ultrasonic scanning etc.
They are the special type of wide ban amplifiers used specifically for signals that are to be applied to cathode Ray tubes (CRT) or to other video devices. The video signal generated by these amplifiers carries all the picture information in TV, video and radar system. Their bandwidth depends upon their uses.
They are special type of amplifier than can be used with any other type of amplifiers discussed above. They are generally placed between other two circuits, to prevent the meeting of operation of two circuit’s .They don’t amplify the signal but they have very high input impedance and low output impedance. Therefore they can be used as a matching impedance device. They ensure that the signals not attenuated between the two circuits. So their output is same amplitude as of their input.
An idealistic amplifier must has the properties like higher bandwidth signal, No Noise, should have the ration maximum between the input and output signals , has stability in its performance and should be highly efficient. The other two important considerations that need to be observed are power output and linearity.