Whatever the name, the subject of our discussion is the amplifier. Hearing the word amplifier, one can understand what it does. Whose job is to increase. This means that if you put a small kitten on one side, it will turn out to be a big kitten on the other side. But since we are studying electronics, we have to define it with electronics.
In electronics, an amplifier is an electronics device that if we give any small signal or voltage at one end, we get an amplified signal or voltage at the other end. And the most popular of these amplifiers is the operational amplifier or op-amp. The reason for this name is that this amplifier has some mathematical operations on the signal as well as amplification. Such as: addition, subtraction, multiplication, division, integration, subtraction etc.
The most widely used amplifier among these amplifiers is the LM741 amplifier. Whose pin diagram is shown below. The voltage we input at the inverting and non-inverting ends of this IC will be multiplied by the output edge. How many times do I need, if I want to get exactly that, then I need to control this magnification. And we can do this control work with RC circuit between input and output. By increasing or decreasing the values of R and C I can get my desired magnification.
And in this way we can multiply any small signal or voltage by using only one IC in the circuit. Usually the voltage we get through networking or wireless switches is much less. Many times this voltage may not be enough to turn our relay on. Then we can increase our voltage with the help of it. Again, we can use the LM-741 to amplify the smaller ECG signal inside us.
Jeion Ahmed
B.Sc. in EEE CUET
