Beginner question about LC filters

Discussion in 'General Electronics Chat' started by turkeybuzzard, Mar 24, 2011.

  1. turkeybuzzard

    Thread Starter New Member

    Mar 23, 2011
    Hi -- I'm trying to understand how LC band-stop filters work and hope someone might be able to help:

    Here's the circuit:

    1. If the AC source is at frequency f and the Rs are equal resistance and each F is an LC parallel band stop filter tuned to frequency f, then are the currents across all three resistors the same (at all frequencies)? Is the oscillating current inside each F the same? Symetry would suggest that all the LC filters behave the same and all the resistors behave the same, right?

    Thanks for your thoughts,
  2. Wendy


    Mar 24, 2008
    Welcome to AAC.

    This should have been in the general electronics chat, as it is electronics, not physics.

    A moderator will be along shortly and move it. Please do not start a second thread, as one of the two similar threads will have to be closed.

    Filters are a deep subject, the math can be highly complex, and leans heavily on the square root of -1 (called an imaginary number, and is denoted by j .

    I don't know your math background, or how far your studies have gone.

    Ignore the resistors for the moment, calculate the impedance for a series LC circuit and a parallel LC circuit at resonance. The calculate the voltages across each component (this has elements of a trick question, the answers will surprise) on the series LC at resonance.
    Last edited: Mar 24, 2011