Definition
A designation indicating that a piece of electrical equipment is designed to operate on either alternating current (AC), in which the flow of electrons periodically reverses direction, or direct current (DC), in which the flow of electrons moves in one direction only.
Plain English
A label on electrical gear meaning it works whether the power source pushes current back and forth (AC) or steadily in one direction (DC).
Context Anchor
Seen in aircraft electrical-system descriptions, instrument power requirements, chargers, converters, and maintenance references.
Derivation
AC stands for alternating current — current that alternates direction. DC stands for direct current — current that flows directly in one direction. The slash between them simply means 'either/or.'
Why Pilots Care
Understanding AC/DC capability helps pilots recognize power compatibility during ground operations and electrical troubleshooting.
Intuition Check
Ac/Dc is not one single type of power. It is shorthand for two different types of electrical current: AC and DC.
Example Sentence 1
The portable test light is labeled Ac/Dc, so the technician can use it on either the 28-volt DC bus or the 115-volt AC bus.
Example Sentence 2
Preflight checks confirmed the system accepted both AC and DC input without issue.