Primary drive coil
The primary drive coil was an important piece of propulsion technology used aboard .

In 2154, while attempting to reach a subspace corridor, Enterprise had its primary drive coil disabled by the attacking Kovaalans, forcing Commander Tucker to shut down the port impulse engine. ()

See also
Driver coil
Plasma coil
Resonator coil
Transwarp coil 
Warp coil
Primary warp coil
Teraphasic coil
Propulsion technology