A capacitor stores energy in an electric field between two conductive plates separated by an insulating material (the dielectric). When you apply voltage, charge accumulates on the plates. Remove the voltage, and the stored charge can flow back out.
Capacitance is measured in farads (F). Most capacitors in the experiments are in the picofarad (pF) to microfarad (µF) range.
In the experiments
Capacitors appear in two roles in the Open Energy experiments:
-
As part of an LC tank circuit — paired with an inductor to create a resonant circuit at a specific frequency
-
As energy storage — in back-EMF recovery circuits, a capacitor captures the energy spike from an inductor and holds it for measurement
Some experiments also study ferroelectric capacitors — special capacitors whose dielectric material has a non-linear relationship between voltage and stored charge. The non-linearity makes them interesting for the same reason saturating ferrite cores are interesting: they break the linear assumptions that conventional circuit analysis depends on.