A distributor is an enclosed rotating shaft uised in spark-ignition internal combustion ingines that hae mechanically-timed ignition. The distributor's main function is tae route seicontar, or heich voltage, current frae the ignition coil tae the spark plugs in the correct firing order, an for the correct amount o time. Except in magneto seestems, the distributor an aa houses a mechanical or inductive breaker switch tae open an close the ignition coil's primary circuit.
The first reliable battery operated ignition wis developed bi Dayton Engineering Laboratories Co. (Delco) an introduced in the 1910 Cadillac. This ignition wis developed bi Charles Kettering an wis considered a wonder in its day. Atwater Kent invented his Unisparker ignition seestem aboot this time in competeetion wi the Delco seestem. Bi the end o the 20t century mechanical ignitions war disappearing frae automotive applications in favour o inductive or capacitive electronic ignitions, fully controlled bi ingine control units (ECU), rather than directly timed tae the ingine's crankshaft speed.