How much charge can a capacitor hold?

Discussion in 'General Electronics Chat' started by impaJah, Aug 3, 2012.

  1. impaJah

    Thread Starter New Member

    Aug 2, 2012
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    Is there a way to calculate how many coulombs of charge a given capacitor can store given a certain time interval that can be derived from its farad rating? For instance, how many coloumbs can a 47uf cap hold after 2ns of 3 volts? What about a 1uf? Or a 500pf?

    If it can't be derived from it's rating, is there another convenient way to figure this out?
     
  2. MrChips

    Moderator

    Oct 2, 2009
    12,447
    3,363
    The charge Q in coulombs is the capacitance C in Farads multiplied by the voltage in Volts.

    Q = C x V

    For example, 1μF x 5V = 5 μC
     
  3. impaJah

    Thread Starter New Member

    Aug 2, 2012
    18
    0
    Thank you MrChips!!!
     
  4. crutschow

    Expert

    Mar 14, 2008
    13,028
    3,237
    The capacitor voltage (Vc) after an interval of time is determined by the voltage charging source (Vs) and any resistance (R) in series between the voltage charging source and the capacitor (C). The capacitor voltage will rise exponentially after the voltage is applied and will be equal to Vc = Vs(1 - e^{-t/RC}) where t is the elapsed time.

    From the capacitor voltage you can then calculate the charge using the formula MrChips gave you.
     
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