Fundamental Physics/Electronics/Electronics Amplifier

Electronics Amplifier

Electronics amplifier is an electronics device that provides voltage amplification . Electronics amplifier has a transfer function

$H={\frac {v_{o}}{v_{i}}}=\pm A$

With

A - Amplification factor

the positive sign - means positive amplification . The circuit that provides positive amplification is called Non-inverting amplifier

the negative sign - means negative amplification . The circuit that provides negative amplification is called Inverting amplifier

DC Amplifier

Non-inverting amplifier

Using Op amp to provide positive amplification

${\frac {v_{o}}{v_{i}}}=1+{\frac {R_{2}}{R_{1}}}$

With $R_{2}=AR_{1}$ . $v_{o}=Av_{i}$

Using Transistor to provide positive amplification

${\frac {v_{o}}{v_{i}}}=({\frac {R_{2}}{R_{2}+R_{1}}})({\frac {R_{4}}{R_{3}}})$

With $R_{1}=0.R_{4}=AR_{3}$ . $v_{o}=Av_{i}$

Using Transformer to provide positive amplification

${\frac {v_{o}}{v_{i}}}={\frac {N_{2}}{N_{1}}}$

With $N_{2}=AN_{1}$ . $v_{o}=Av_{i}$

Inverting amplifier

Using Op amp to provide positive amplification

${\frac {v_{o}}{v_{i}}}=-{\frac {R_{2}}{R_{1}}}$

With $R_{2}=AR_{1}$ . $v_{o}=-Av_{i}$

Using Transistor to provide positive amplification

${\frac {v_{o}}{v_{i}}}={\frac {R_{2}}{R_{2}+R_{1}}}{\frac {R_{4}}{R_{3}}}$

With $R_{1}=0.R_{4}=(A+1)R_{3}$ . $v_{o}=-Av_{i}$

Using Transformer to provide positive amplification

${\frac {v_{o}}{v_{i}}}=-{\frac {N_{2}}{N_{1}}}$

With $N_{2}=AN_{1}$ . $v_{o}=-Av_{i}$