Working and Operation of Amplifier

An Amplifier or an operational amplifier (op-amp) circuit is commonly used in the automation, control and other electronic circuits of marine applications. The applied input signal is normally a voltage or a current signal. The purpose of an amplifier is to produce an output signal larger than that of the input signal.

Purpose of Amplifier

As the name suggest, the purpose of an amplifier or an op amp is to amplify or increase the input signal to produce an output signal, which is much larger than that of the input, with a similar waveform as that of the input. The main change in the output signal will be the increase in the power level. This additional power is supplied by a D.C voltage, which is externally provided. The output signal is controlled by the input signal in an amplifier.

Operation of Amplifier Circuit

The input of the amplifier consists of differential input voltage V+ input and V-input and this difference in the voltage is amplified to produce a larger output. The op-amp equation can be given by:

V o/p = [(V+)- (V-)] x A o/l

Where A o/l - is open loop gain of the amplifier. In an op-amp the magnitude of A o/l is very large which gives a larger output even when the input differential is small.

Other important properties;

1. It has a high output gain.
2. It has high input and low output impedance.
3. Bandwidth is in very high range.

Applications of Amplifier Circuit

An amplifier circuit is popularly used in marine electrical/ electronic circuits and applications such as:

1. It is used to amplify audio signal (loudspeaker, VHF).
2. It is used as voltage and current regulator.
3. It is used as analog to digital 
4. converter and vice-versa.
5. It is used as a servo amplifier in motors.
6. The output signal from amplifier is supplied to a relay in a circuit.