Definition
An electrical component, essentially a coil of wire wound on an iron core, that opposes changes in alternating current by introducing inductive reactance into the circuit. A reactor stores energy briefly in its magnetic field and releases it back, which limits current flow and shifts the timing between voltage and current in AC systems.
Plain English
A coil used in an AC electrical circuit to slow down or smooth out changes in current. It works like an electrical shock absorber, resisting sudden surges.
Context Anchor
Seen in aircraft electrical system descriptions, especially AC power, lighting, and voltage-control circuits.
Derivation
From the Latin 're-' (back) and 'agere' (to act) -- literally 'to act back.' A reactor 'acts back' against changes in the current flowing through it, which is exactly how inductive reactance behaves.
Why Pilots Care
Pilots don't operate reactors directly, but understanding that they limit and smooth AC current helps when reading electrical system diagrams or troubleshooting AC power issues during training.
Analogy
A reactor is a little like a shock absorber for changing electrical current. It does not stop the current completely; it resists sudden changes so the circuit behaves more steadily.
Intuition Check
Do not read “reactor” here as a nuclear reactor. In this context, it means an electrical coil that resists changes in current.
Example Sentence 1
The reactor in the AC circuit limited the current surge when the load was switched on.
Example Sentence 2
A faulty reactor allowed voltage spikes that damaged several avionics units.