parallel capacitors

Discussion in 'General Electronics Chat' started by js60611, Nov 12, 2009.

  1. js60611

    Thread Starter New Member

    Nov 12, 2009
    3
    0
    Hello,
    First time here but probably not my last, I'm sure. I need to know how do you find for current across capacitors in parallel? For some reason i am not seeing or finding this anywhere. I'm sure its user error but I need to know this. For example: 2 capacitors 0.1uf in parallel with 5.99ma. I know this splits and will be 5.99 when current exits. I've tried current divider formula but this comes up with a crazy answer or user error which is always my first thought. I am drawing a blank can someone help with a formula since capacitor values will not always be same.
    Thanks,
    JS
     
  2. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
    2,039
    287

    You don't actually have current "across" capacitors, you have current THROUGH them.

    However, you can figure out the current through parallel capacitors by figuring out the susceptance of each capacitor. Susceptance(B)= 2*pi*f*C, where f is in Hertz and C is capacitance. You can now just add the susceptances of each capacitor to obtain total susceptance. If you take the INVERSE of susceptance, you have reactance. You can then use the reactance version of Ohm's law to get current: I=E/X.

    If you need the INDIVIDUAL currents you just take the reciprocal of each susceptance, and use ohm's law again.


    Eric
     
  3. pilko

    Active Member

    Dec 8, 2008
    213
    20
    Actually, current does not pass through a capacitor, but flows to or from the plates.
     
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