Question
What is meant by –ve feed and +ve feed back
Explain the
characteristic of –ve feed back.
-ve feedback
When the feed back
energy is [voltage or current] is out of phase with the input signal and thus opposuite it, it is called a –ve
feed back. it reduces gain of amplifier.
Advantages
Reduction
in distortion.
Stability in gain
Increased
band width.
Improved I/p and O/p impedance.
Positive feed back
When the feed back
energy is in phase with the input signal and thus aids it, it is called
positive feed back.
Positive feed back
increases gain of amplifier.
Disadvantages
Increased
distortion and un-stability
On important use
of +ve feed back is in oscillation
If +ve feed back is sufficiently large it leads to oscillation.