Series and parallel capacitors
When capacitors are connected in series, the
total capacitance is less than any one of the series
capacitors' individual capacitances. If two or more
capacitors are connected in series, the overall effect is
that of a single (equivalent) capacitor having the sum total
of the plate spacings of the individual capacitors. As we've
just seen, an increase in plate spacing, with all other
factors unchanged, results in decreased capacitance.
Thus, the total capacitance is less than any
one of the individual capacitors' capacitances. The formula
for calculating the series total capacitance is the same
form as for calculating parallel resistances:
When capacitors are connected in parallel,
the total capacitance is the sum of the individual
capacitors' capacitances. If two or more capacitors are
connected in parallel, the overall effect is that of a
single equivalent capacitor having the sum total of the
plate areas of the individual capacitors. As we've just
seen, an increase in plate area, with all other factors
unchanged, results in increased capacitance.
Thus, the total capacitance is more than any
one of the individual capacitors' capacitances. The formula
for calculating the parallel total capacitance is the same
form as for calculating series resistances:
As you will no doubt notice, this is exactly
opposite of the phenomenon exhibited by resistors. With
resistors, series connections result in additive values
while parallel connections result in diminished values. With
capacitors, it's the reverse: parallel connections result in
additive values while series connections result in
diminished values.
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