Definition
A fixed-value capacitor that uses a thin film of Mylar (polyester) as the dielectric material between its conductive plates. Mylar capacitors are valued for their stability, low cost, and resistance to moisture, and are commonly used in aircraft electronic equipment for filtering, coupling, and timing applications.
Plain English
A small electrical part that stores electrical energy briefly, using a thin sheet of plastic film as the insulating layer inside it. The plastic film, called Mylar, is what makes this type of capacitor stable and reliable.
Context Anchor
Seen in aircraft electrical system, radio, instrument, and maintenance discussions where individual electronic parts are identified or replaced.
Derivation
Mylar is a trade name registered by DuPont for a strong, thin polyester film developed in the 1950s. 'Capacitor' comes from the Latin 'capacitas,' meaning 'capacity to hold' -- in this case, the capacity to hold an electrical charge.
Why Pilots Care
These capacitors offer stable performance across temperature changes and are common in aircraft radios and navigation equipment, where failure can cause signal loss or instrument malfunction.
Intuition Check
Do not think of Mylar here as just shiny balloon material. In this term, Mylar means the thin plastic insulating film used inside the electrical part.
Example Sentence 1
The avionics technician replaced a failed Mylar capacitor in the radio's power supply circuit.
Example Sentence 2
During preflight checks, the avionics technician inspected the Mylar capacitors in the navigation unit for signs of degradation.