The driver coil is a stage in 24th century impulse drive, using energy from the impulse fusion reactors to envelop the starship in a low-energy subspace field intended to lighten the relative mass of the vessel it encompasses. This significantly reduces the mass burden on the impulse drive, allowing for unprecedented rates of acceleration.
In 2370 in the mirror universe, the impulse driver coil on Benjamin Sisko's starship was offline. (DS9: "Crossover")
While inside the nucleogenic cloud being in 2371, the USS Voyager lost its rear driver coil assembly. (VOY: "The Cloud")
The Kazon destroyed the Voyager's driver coil assembly in their attack on the ship in late 2372. (VOY: "Basics, Part I")
In 2373, Miles O'Brien ordered the driver coils of the USS Defiant to be configured for impulse speed. (DS9: "For the Uniform")
The Delta Flyer II possessed accelerated driver coils, which were admired by Irina in 2377. (VOY: "Drive")