Definition
A method used in electrical instruments to slow and steady the movement of a pointer or moving element by means of small circulating electric currents. A conductive disc or sector attached to the moving element passes through the field of a permanent magnet. As it moves, the magnet induces tiny swirling currents (eddy currents) in the disc. These currents produce their own magnetic field that opposes the motion, smoothly resisting rapid swings and bringing the pointer to rest without overshooting or oscillating.
Plain English
A way of stopping an instrument's needle from bouncing around. A metal disc moves near a magnet, which creates a gentle braking effect that smooths out the motion so the reading settles quickly and steadily.
Context Anchor
Seen in descriptions of analog electrical instruments, especially when explaining how a gauge pointer is kept smooth and steady.
Derivation
Eddy comes from Old Norse 'iða', meaning a swirl or whirlpool. It describes the way the induced electric currents loop and circulate within the metal disc, just like water swirling in a small pool. Damping comes from the older sense of 'damp' meaning to deaden or muffle — here it means to take the energy out of unwanted motion.
Why Pilots Care
Smooth, non-oscillating instrument readings allow pilots to interpret engine and system parameters accurately without distraction or misreading during flight.
Analogy
It acts like a light, invisible brake on the instrument needle: not stopping it, just keeping it from overshooting and wobbling.
Intuition Check
Do not read eddy as air turbulence here, and do not read damping as making something wet. Here, current means electric flow, and damping means reducing unwanted motion.
Example Sentence 1
Eddy current damping in the moving-coil meter prevents the pointer from oscillating after a sudden change in current.
Example Sentence 2
During preflight, the pilot noted the steady needle movement provided by eddy current damping in the electrical instruments.