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DC choke filter

  1. Sep 6, 2009 #1
    Can a DC choke (inductor) filter be used in a resonant circuit with a capacitor? If connected in series with a capacitor will the two resonate, or will the signal passed be half wave? I thought all inductors can be interchangeable but some have certain applications such as DC applications.
  2. jcsd
  3. Sep 6, 2009 #2
    Depends on the type of choke. Some chokes are just plain inductors, others have magnetic cores that absorb certain range of frequencies.
  4. Sep 6, 2009 #3


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    Chokes used for filtering DC have a gap in the core so the DC doesn't saturate the core. Otherwise, they are just inductors.

    For example, if you put a 8 Henry inductor in series with 0.879 uF you would get resonance at 60 Hz. Or put it in series with 0.22 uF and it would resonate with 120 Hz.

    This would be pretty dramatic in a power supply with a 120 Hz component from a full wave rectifier. It would produce a big increase in hum when the function of the choke is normally to reduce hum.
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