Resonance - AAC ebook

Discussion in 'Electronics Resources' started by JStitzlein, Feb 24, 2011.

  1. JStitzlein

    Thread Starter Member

    Dec 6, 2010
    Hi All,

    Question about this paragraph from the book -

    If we assume that both components are subjected to a sudden application of voltage (say, from a momentarily connected battery), the capacitor will very quickly charge and the inductor will oppose change in current, leaving the capacitor in the charged state and the inductor in the discharged state

    I'm confused why the cap can hold a charge while the inductor is discharged even if both are loads to the sudden pulse of battery source.

    From what i've read, is it because the cap draws much more current, acting more of a "short"?

    If the battery were kept there longer, charging both elements fully, would it just do nothing and not oscillate?
    Last edited: Feb 24, 2011
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    The capacitor gets charged, but can't hold it once the battery is removed from circuit, as there is a discharge path through the inductor.
  3. JStitzlein

    Thread Starter Member

    Dec 6, 2010
    Yes, but both elements are powered equally at the same time as a load.
  4. Wendy


    Mar 24, 2008
    Caps charge fast, inductors don't. When you put a cap across power it acts like a dead short, surging several amps.

    Coils on the other hand, resist current flow, in a mirror image to how caps act. When a coil is charge it is the one carrying several amps, but it takes time.
  5. JStitzlein

    Thread Starter Member

    Dec 6, 2010
    This was my best guess, but i'm still curious to know what would happen if the battery were held there for a longer period of time. The cap would eventually charge, then the inductor would carry a magnetic field -

    After the switch is released both elements would ideally hold their charge, but because of cap&inductive resistances, they would eventually lose charge.

    I can't visualize what would happen next with both elements losing charge over time and supplying each other with energy, an oscillation with less amplitude?