lc circuit

Discussion in 'Wireless & RF Design' started by Lightfire, Mar 1, 2012.

  1. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
    690
    21
    ok.

    im just wondering if the values of capacitor and inductors must be the same. or the inductor must have greater value than capacitor.

    coz it says that capacitor charge came zero after it transfer it to the inductor.:D

    thnx
     
  2. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    It has to do with reactance. Capacitors and inductors resist the flow of AC electricity similar (well, no too similar) the way a resistor slows the flow of DC electricity.

    As the frequency changes, so does the reactance (which is similar to ohms). The frequency where the reactance of AC for both the coil and the capacitor is the resonant frequency.

    If you really want to understand the concepts you are going to have to read. There is no other way to learn this stuff. You can ask more informed question as you go, but this site has a text book attached.
     
  3. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
    690
    21
    is the standard unit for LC circuit ---

    pf for cap and nh for ind

    ok

    1/2π√(240,000nh x 384pf)

    meaning 60,318.58hz? what??

    thnx
     
  4. debjit625

    Well-Known Member

    Apr 17, 2010
    790
    186
    For AC any LC circuit will offer some reactance (opposition to current change),and its measured in ohms like resistance.In real life any LC circuit will also offer some resistance with the reactance.And the combination of this resistance and reactance is called impedance,its also measured in ohms.

    You could find more about this here : http://www.allaboutcircuits.com/vol_2/index.html

    Good Luck
     
  5. debjit625

    Well-Known Member

    Apr 17, 2010
    790
    186
    Its the formula to find out the resonant frequency of a LC tank circuit.
    f = {1\over {2\pi \sqrt{LC}}}
    The values for inductance L is in Henries ,Capacitor C in Farads and frequency in Hertz.

    You cant put nano henrys and pico farads in the equation...you have to convert them to henry and farad before you plug them into the equation.
    384 pf = 384 /1000000000000 = 0.000000000384 farads
    240,000 nh = 240000 / 1000000000 = 0.00024 henries

    That gives around 524529Hz


    Good Luck
     
    Last edited: Mar 3, 2012
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