Plain English Meaning
A small part in an electrical circuit that holds an electrical charge for a short time and then releases it. Think of it as a tiny, fast rechargeable reservoir for electricity.
Full Definition
An electrical component that stores energy in an electric field by holding opposite electrical charges on two conductive plates separated by an insulating material called a dielectric. A capacitor opposes changes in voltage, can block direct current while allowing alternating current to pass, and releases its stored charge back into the circuit when needed.
Context Anchor
Seen in aircraft electrical system maintenance, radio and instrument circuits, and ignition-system discussions.
Derivation
From the Latin 'capacitas,' meaning 'capacity' or 'ability to hold.' The name describes exactly what the part does — it has the capacity to hold an electrical charge.
Why Pilots Care
Capacitors are found in ignition systems, radios, and many avionics units. A failed capacitor is a common cause of rough magneto operation, radio noise, or instrument faults, so the term comes up often in squawks and maintenance discussions.
Analogy
A capacitor is like a small spring in an electrical circuit. It compresses (stores energy) when voltage is applied, and pushes back (releases energy) when the voltage drops.
Intuition Check
A capacitor is not a battery. A battery stores chemical energy for longer use; a capacitor stores electric charge for short, quick use in a circuit.
Example Sentence 1
The mechanic traced the magneto's rough running to a failed capacitor and replaced it during the 100-hour inspection.
Example Sentence 2
During preflight checks a technician measures the capacitor to confirm it holds charge properly for the electrical system.