Filter design

Discussion in 'The Projects Forum' started by syedali, Jun 10, 2014.

  1. syedali

    Thread Starter New Member

    Jun 2, 2014
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    I have design a filter using 1mh choke and 1nf capacitor but still there is 2volts ripples at the output and i need 0.14v ripples at the output. how can i suppress these ripples.
     
  2. Papabravo

    Expert

    Feb 24, 2006
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    What kind of filter? Schematic please.
    What is your input to the filter?
    What is the maximum ripple that you can tolerate?
     
  3. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    What frequency/voltage/current?
     
  4. wmodavis

    Well-Known Member

    Oct 23, 2010
    737
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    Filters do not eliminate noise or ripple they only reduce the amplitude of them.

    How much they are reduced is subject to an appropriately designed filter taking into account the input signal and output requirements. You have neither said what the input to the filter is nor the output requirements of the filter nor which filter configuration you are using - only given the value of two components.

    Guess why there are so many types of filters.
     
  5. syedali

    Thread Starter New Member

    Jun 2, 2014
    11
    0
    I have design a filter using 1mh choke and 1nf capacitor but still there is 2volts ripples at the output and i need 0.14v ripples at the output. how can i suppress these ripples.

    Filter Type: LC filter
    Input: DC with ripples of 2 volts
    ripples that can tolerate at the output: 0.14 volts
    Input/Output : voltage
     
  6. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    Sounds like you are building rectifier.

    Filter is whole different thing.
     
  7. syedali

    Thread Starter New Member

    Jun 2, 2014
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    So what should I do to reduce the input ripples of 2volts to 0.14v at the output
     
  8. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    Use a smoothing capacitor.
     
  9. syedali

    Thread Starter New Member

    Jun 2, 2014
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    If the input voltage is 27 volts with ripple voltage of 2V. then what should be the value of smoothing capacitor to reduce the ripples up to 0.14v
     
  10. MrChips

    Moderator

    Oct 2, 2009
    12,442
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    Google ripple voltage:

    http://en.wikipedia.org/wiki/Ripple_(electrical)

    For a full-wave rectifier:

    Vpp = I/2fC

    For a half-wave rectification:

    Vpp = I/fC

    where

    Vpp is the peak-to-peak ripple voltage
    I is the current in the circuit
    f is the frequency of the ac power
    C is the capacitance
     
  11. syedali

    Thread Starter New Member

    Jun 2, 2014
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    The input voltage of 27v having the ripples of 2 volts comes from the solar panel and it is DC not AC. IF the input is DC then what should be the formula of smoothing capacitor to reduce the ripples up to 0.14 volts
     
  12. MrChips

    Moderator

    Oct 2, 2009
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    Maybe the sun is rippling?
     
  13. wmodavis

    Well-Known Member

    Oct 23, 2010
    737
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    With filters of any kind it is very important if not essential to know the frequency of the desired signal. And of the undesired signal. Do you know what those are in your case?
     
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