Is this value fine for blocking capacitor?

Discussion in 'General Electronics Chat' started by Gordon Freeman, Sep 9, 2016.

  1. Gordon Freeman

    Thread Starter New Member

    Sep 6, 2016
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    Im designing CE amplifier and I calculated the coupling capacitor C1 using the cutoff frequency equation and it turns out I need 0,2mcF with 2221ohm input impedance and 300Hz frequency. Is this value fine? I mean,
     
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    How did it work on the breadboard? Only 5 parts - it should only take a few minutes.

    Or, how did it work in the simulator? LTSpice, TI-TINA can simulate and show the frequency response.

    The simulators are free from Linear Technologies and Texas Instruments.
     
    Last edited: Sep 9, 2016
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  3. AlbertHall

    Well-Known Member

    Jun 4, 2014
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    I don't understand your value "0,2mcF"
    If your lowest frequency of interest is 300Hz then you should generally calculate the capacitor value to give the -3dB at 1/0th of that frequency - 30Hz - which for 2221Ω I make 2.39uF
     
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  4. Gordon Freeman

    Thread Starter New Member

    Sep 6, 2016
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    Hmm, didn't know about those simulators. I will try them, thanks!
    I haven't yet tested the circuit, I meant in my question if I should trust the values I receive from calculating the capacitance this way, because I know this is the way (C=1/2пf*Zin), and yet as a beginner I have doubts.
     
  5. Gordon Freeman

    Thread Starter New Member

    Sep 6, 2016
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    Ahh, correct!
    Oh and 1/0th means 1/10 right?
     
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  6. AlbertHall

    Well-Known Member

    Jun 4, 2014
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    :oops: Sorry, yes 1/10
     
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  7. Gordon Freeman

    Thread Starter New Member

    Sep 6, 2016
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    Thank you!
     
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