Elenco Basic Electronic Experiments - Manual (Page 21)

EXPERIMENT #9: SMALL DOMINATES LARGE - CAPACITORS IN SERIES
Take a look at the schematic, it is almost the same circuit as the last experiment except that now there are two capacitors
in series. What do you think will happen? Connect the circuit according to the schematic and Wiring Diagram and press
the switch several times to see if you are right.
Looking at the water diagram and the name of this experiment should have made it clear - the smaller 10 μF will dominate
(control) the response since it will take less time to charge up. As with resistors, you could change the order of the two
capacitors and would still get the same results (try this if you like). Notice that while resistors in series add together to
make a larger circuit resistance, capacitors in series combine to make a smaller circuit capacitance. Actually, capacitors
in series combine the same way resistors in parallel combine (using the same mathematical relationship given in
Experiment 4). For this experiment, 10
μF and 100μF in series perform the same as a single 9.1μF.
In terms of our water pipe analogy, you could think of capacitors in series as adding together the stiffness of their rubber
diaphragms.
21
+9V
3.3k Ω 10k Ω
100 μF
CAPACITOR
10 μF
+
-
+
-