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Clipping circuits

Here, i am going to explain the working and output waveforms of shunt(parallel) clipping circuits using diodes and resistors.
Clipping circuit is commonly used to clippoff, any part of an input waveform (either positive or negetive) at any levels.



Principle used in Shunt clippers using DIODES

The basic principle used in diode clippers is that, The diode conducts only in one direction (Forward biased) and it blocks current when reverse biased.

ie; When the input wave makes the diode forward biased , it will conducts the current and it will goes to ground but it will appears across the output.
By using diode clipper, we can be able to clip the wave at any levels, by furnishing an additional voltage source.


POSITIVE CLIPPER


clipping circuits




clipping circuits





The fig. Shows the circuit diagram and output waveform of positive clipper.
In the fig. I am neglected the voltage drop across diode during forward bias, due to the cutin voltage of diode( which may vary according to the diodes we used ). If we are going to consider this drop which will appears on output during conduction hence on the waveform.





NEGETIVE CLIPPER



clipping circuits





clipping circuits






The fig. shows the circuit diagram and output waveform of negetive clipper. Similarly in positive clipper it will works on negetive side too.
Having only one difference that the diode is connected just opposite to that of positive clipper.






POSITIVE CLIPPER AT 3 VOLTS.




clipping circuits





clipping circuits





The fig. Shows the circuit diagram and waveform of the positive clipper at 3V. Till 3V the diode is in reverse bias so the output is present.
After that the input waveform exceeds 3v the diode get in forward biases and the wave clipped off. If we are considering the voltage drop of 0.6v the output may clipped at the level of 3+0.6 volts =3.6v




NEGETIVE CLIPPER AT 3 VOLTS.



clipping circuit






clipping circuits





The fig. Shows the circuit diagram and output waveform of negetive clipper at 3v. The working is similar to that of positive clipper at 3v.
Except that the diode and cell is just connected in opposite. So the negetive going wave at -3v is clipped



Some tricks to learn about CLIPPING CIRCUITS

¤ Look for the anode(positive) of diode in the circuit diagram, if it is in upperside, the top portion of the wave get clipped off.

¤ check whether the diode is connected in series with cell, if yes it will clipped at a level equal to the sum of voltage source and the diode drop.

¤ By using these tricks, you can easily draw the output waveform of any clipping circuits and viceversa.


Got Confused? Comment it here i will solve soon.

Post a Comment

  1. I have a doubt.it is about +ve clipper. u told that during biased condition diode will conducts the current and it will goes to the ground. then how can it appears across output.If it is a wrong question.sorry

    ReplyDelete
    Replies
    1. Its The Voltage Difference that appears. The Ground sort of indicates that the Charges are Moving. If we want current to Flow there must be a High potential, And a Low Potential. The Current Will Flow From a High Potential to a Low Potential. Vpp is a High Potential, And Ground is a Low Potential. If There is No Ground and Both Ends Are Vpp. Then there is No high or low Potential, because both Potentials Are equal, So Current Wouldn't Flow.
      Hope it helps somehow :P

      Delete
  2. sry during FB condition,diode will conducts,then ???

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