I'm trying to self learn electronics and to that end have been studying capacitors and I came across the following
A capacitor’s ability to store energy as a function of voltage (potential difference between the two leads) results in a tendency to try to maintain voltage at a constant level. In other words, capacitors tend to resist changes in voltage drop. When voltage across a capacitor is increased or decreased, the capacitor ”resists” the change by drawing current from or supplying current to the source of the voltage change, in opposition to the change
I can't understand the wording here, so if anyone can answer the following questions I'll be really grateful.
- Does this resisting to the voltage happen while charging or only after capacitor been fully charged?
- What exactly happens if the voltage drops in the source
- What exactly happens if the voltage increased in the source.
EDIT Let me see if i got this correct. Lets say a capacitor is connected to a 5v source in series where the capacitor and the voltage source are ideal
- the capacitor starts charging up and the voltage across it increases
- the current through the capacitor increases as the voltage across it increases
- when voltage across the capacitor reaches 5v the current stop flowing through the capacitor
- if the voltage of the source drops to 4V, then capacitor will discharge some current opposite the current flow from the source
- this will reduce the net current flowing through the capacitor and thus reducing the voltage across it to 4V.
- after the voltage across the capacitor reaches 4v current again will stop flowing through the capacitor
- now if the voltage of the source increases to 7V the capacitor will start to charge again and current flowing through the circuit will increase.
when the voltage across the capacitor reached 7V then current will again stop flowing
is my understanding correct? if so does that mean that a ideal capacitor can charge it self upto infinity or is there a max limit