Charging Capacitors: How Does Series Ckt Work?

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SUMMARY

In a series circuit with multiple capacitors, each capacitor accumulates the same charge, but the potential difference across each varies inversely with their capacitance. The formula for the equivalent capacitance in series is 1/Cnew = 1/C1 + 1/C2, resulting in a total capacitance that is always less than or equal to the smallest capacitor in the series. Capacitors with lower capacitance will reach their maximum potential difference first, potentially failing before those with higher capacitance can fully charge. Continuous current flow can lead to premature failure of lower-capacitance capacitors.

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From my understanding, if I connect a capacitor to a power source, given enough time the capacitor will be fully charged and no current goes through the circuit. What if I have two or multiple capacitors connected in series? Do they all get charged at the same time? What if they have different capacitance? Does the capacitor with the lowest capacitance get charged first? And if it does get charged, there shouldn't be any current going through, so does that mean the other capacitors with higher capacitance won't get full charge? I'm a bit lost.
 
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What happens is that the capacitors essentially form one big capacitor with the following capacitance:

1/Cnew = 1/C1 + 1/C2

Meaning, the resulting capacitance is always smaller or equal than the smallest capacitor in the series.
 
Because they are in series, the capacitors will each accumulate the same charge. Because they have different capacitance, this means that the potential difference across each will be different -- in inverse proportion to their capacitance.

A "fully charged" capacitor is one that has as much charge (and therefore as much potential difference) as it can hold without failing. So yes, this will mean that the capacitors with the higher capacitance will have a lower potential difference and will likely not yet be near their failure point and so will not be "fully charged".

If you keep pumping current through the circuit you will cause the capacitors with lower capacitance to fail before the capacitors with a greater capacitance can reach their full charge.
 
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jbriggs444 said:
Because they are in series, the capacitors will each accumulate the same charge. Because they have different capacitance, this means that the potential difference across each will be different -- in inverse proportion to their capacitance.

A "fully charged" capacitor is one that has as much charge (and therefore as much potential difference) as it can hold without failing. So yes, this will mean that the capacitors with the higher capacitance will have a lower potential difference and will likely not yet be near their failure point and so will not be "fully charged".

If you keep pumping current through the circuit you will cause the capacitors with lower capacitance to fail before the capacitors with a greater capacitance can reach their full charge.
Ah ok! That makes sense! Something clicked! Thanks very much!
 

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