Combination Capacitor Circuits

Key Questions

  • Question #dd1e3

    For capacitors in parallel:

    farside.ph.utexas.edu

    The total capacitance C_(TOT is given by:

    C_(TOT)=C_1+C_2

    Since C_(TOT)=Q/V the total can be found from Q=C_(TOT)V where V is the voltage drop across the capacitors.

    For capacitors in series:

    farside.ph.utexas.edu

    1/C_(TOT)=1/C_1+1/C_2

    So Q=C_(TOT)V

    Michael · 1 · Jan 4 2015
  • What are some examples of combinations of capacitors?

    Series, parallel and combinations of series and parallel/

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    There are four examples of combinations in the diagram. The following points show how to calculate the total capacitance of each combination.
    1. Series
    The equivalent capacitance, C , of the combination is worked out as follows:

    1/C=1/C_1+1/C_2+1/C_3
    or
    C=1/(1//C_1+1//C_2+1//C_3)

    Total capacitance decreases in series.

    2. Parallel
    C=C_1+C_2+C_3

    Total capacitance increases in parallel.

    3. "Parallel in series"

    1/C=1/C_1+1/(C_2+C_3)

    4. "Series in parallel"

    C=1/(1//C_1+1//C_2)+C_3

    Example with numbers based on combination 4.

    C_1=200muF, C_2=400muF, C_3=400 muF

    C=1/(1//(200*10^(-6))+1//(400*10^(-6)))+(400*10^(-6))

    ⇒C=1/7500+400*10^-6=133*10^-6+400*10^-6

    C=533muF

    Daniel W. · 1 · Dec 14 2014

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