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An operational amplifier is an active element designed to perform mathematical operations like addition , subtraction , multiplication , division , differentiation and integration . operation amplifier (Op – Amp ) can be used for AC as will as DC.
An op amp is a multistage direct coupled amplifier.
Amplifier is an electronic device that can increase the power of signal.
Op Amp –
An operational amplifier is a DC coupled high gain (voltage , current, power).
An op amp for short is fundamentally a voltage amplifying device designed to be used with external feedback components such as register and capacitors between its output and input terminal.
V+ : non – inverting input
V- : inverting input
Vout : output
Vs+ : positive power supply
Vs- : negative power supply
V – (inverting input) –
Which terminal is response for gain.
V + (non inverting) –
Which terminal is same property shown like inverting terminals but their polarity become different.
V out –
In op amp case output is taken between the two terminals .
op amp works on dual power supply.
Direct Coupled Amplifier –
A DC amplifier that is it should have high gain.
It is type of amplifier in which the o/p of stage of the amplifier is coupled to the input of the next stage in such a way to permit signals with zero frequency at referred to as direct current to pass F input to output .
1. When V in = 0 then first transistor Q1 will not working because it will reverse biased ,
but Q2 transistor become forward biased to we get direct coupling capacitor then output remains high.
2. When V in = 1 Then first transistor Q1 will be working
but Q2 also be response. So above working we can say that transistor output remain very high it the input voltage remain high frequency .
Drawbacks of DC opmp –
1. The output of a direct coupled amplifier will be a DC voltage in addition to alternating voltage , wherever applicable.
2. The output also changes with age/time and change in supplying voltage.
The above effects , arising even in absence of on input therefore , lead to an o/p which is unwanted.
3. In the DC opmp circuit gives high gain so it reduces noise.
There are several advantages of using this type of amplifier including.
- Simple circuit arrangement as there are minimum number of components.
- For above reason also quite inexpensive.
- Can be used to amplify zero and low frequency signal.