dumb question

Discussion in 'Homework Help' started by mattm, Aug 10, 2009.

  1. mattm

    Thread Starter Member

    Aug 5, 2009
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    If you increase the resistance in a RLC series curcuit will it give you broader tuning at the resonant frequency?
     
  2. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
    2,039
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    Yep. And lower Q
     
  3. ELECTRONERD

    Senior Member

    May 26, 2009
    1,146
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    But that should increase impedance, shouldn't it? Which you don't want to have too high of a impedance.
     
  4. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
    2,039
    287

    At precise resonance, the ONLY impedance you'll see is the resistance.

    Depending on the application, you don't always have a choice of the resistance. An antenna is a perfect example. An antenna is electrically equivalent to a series resonant circuit. The radiation resistance is pretty well determined by the physical size of the antenna. And actually, for an antenna, it's GOOD to have a high radiation resistance, which generally lowers the Q of the circuit.

    In any case, the Q is determined by X/R, so all other things being equal, a larger L/C ratio wil result in a narrower bandwidth (for a simple series circuit).

    Eric
     
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