Question

What are some examples of combinations of capacitors?

Answer 1

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`

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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`