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.
Here we will define you about the classes of Amplifier. But when defining the power amplifiers then there are mainly four type of class amplifier are present for highly signal production as class A, class B, class AB and class D, each of them having a slight different operational profile which can impact the sound to the listeners.
This class is the most linear class among the other classes of amplifier because the output signal is the representation of what was truly imputed. In this class the output device bears electricity for the complete cycle and produces the waveform entirely. They run at full potential for all the time so they become hot quickly. Electricity flows constantly at all the time, this continuous signal is known as bias. Class A mostly inefficient of all the amplifiers. They usually waste power in the form of heat, they can be very large, heavy, and they need to be operated at the continuous ventilation. But despite of all these things they are used widely because sound is clear and more linear contains much lower level of distortion.
In this class the affirmative and non affirmative signals are deal by different chunks of the circuit. The output device ay continuously switched on and off. The input wave has to be big to make it switched on for a long time, so this is almost opposite of the class A amplifier. We need at least two output mechanisms with this amplifier, so that each side intensifies half of the signal generated by the amplifier. Both have to be switched on for exactly one and a half cycle. But these amplifiers run calmly than class A however the sound status is not pure. They can be less expensive; there is lot of traverse noise distortion as each output device turned on and off for each signal cycle.
This amplifier combines the properties of both class A and class B amplifiers. It has the sound quality as in case of class A and productivity as similar to class B amplifiers. Most modern amplifiers have this type of designing. There are enough current flows through each of the output device to keep it operational. The output signal bias is lay down so that the current flows in a certain output device, brings it under more than the half signal cycle and less than the full cycle. Because of many advantages over the class A and class B amplifiers it is mostly used in the devices of popular amplifier design.
This is also called the digital amplifier or we can say them switching amplifiers. Some of the class D amplifiers runs in faithful digital mode while other not. Here the output appliances are promptly switched between on and off condition for not less than twice the total cycle. They can be switched on and off for millions of times in a second depends on the switching frequency, but in practical case this number is closer to 85-90 %. A pulse width modulation technology is used with these types of amplifiers. They are generally used for sub woofer applications or non high constancy devices.