コイル

こいる
noun
coil (especially an electrical coil)
technicaltoolelectronics
1. coil (electrical or wire wound in loops)
A length of wire (usually copper) wound in loops, used in electrical circuits, motors, transformers, and electromagnets. Also refers to other coiled objects such as heating coils.
Current flows through the coil.
There is a coil inside the motor.
銅線(どうせん)()いてコイル(つく)った
I wound copper wire to make a coil.
When you bring a magnet near a coil, a voltage is generated.

コイル is a loanword from English "coil," used in physics and engineering for a wound length of wire and, by extension, for similarly shaped objects.

Common collocations

  • コイル(): to wind a coil
  • コイル()れる: the coil breaks (e.g., burns out)
  • 電磁(でんじ)コイル: electromagnetic coil
  • 一次(いちじ)コイル / 二次(にじ)コイル: primary coil / secondary coil (in transformers)
  • イグニッションコイル: ignition coil (in engines)

Scope notes

  • The Japanese term is largely restricted to electrical/mechanical contexts. For "hair coiled in curls" or other figurative uses common in English, Japanese tends to use ()() (curly hair) or other native expressions.
  • For coils of rope or hose, Japanese typically uses () or とぐろ instead.

Related words

Domain: Common in physics class, electrical engineering, and automotive contexts.