Definition
A capacitor designed so that a localized breakdown in its dielectric does not permanently disable it. When a small area of the dielectric fails under voltage stress, the resulting arc vaporizes the thin metal film electrode around the fault, isolating the damaged spot and allowing the capacitor to continue operating with only a tiny loss of capacitance.
Plain English
A capacitor that repairs itself when a small spot inside it fails. The damaged area burns clear and the rest of the capacitor keeps working normally.
Context Anchor
Seen in aircraft electrical equipment and maintenance descriptions, especially where capacitors are used in power circuits or to smooth unwanted electrical noise.
Derivation
Self-healing describes the action: the capacitor heals its own internal damage without outside intervention. The name reflects the practical behavior of the metallized-film construction that makes this possible.
Why Pilots Care
Provides greater reliability in critical aircraft circuits by reducing the chance of sudden capacitor failure during flight.
Intuition Check
Do not read “healing” as a complete repair of any damage. Here it means only that a very small internal short can clear itself by burning away a tiny area around the fault.
Example Sentence 1
The radio's power supply uses self-healing capacitors, so a brief voltage spike rarely takes the unit out of service.
Example Sentence 2
During the preflight check the technician confirmed the inverter circuit used self-healing capacitors rated for continuous engine vibration.