Pick-Up Coil: Description and Operation

Distributor Assembly:

PURPOSE
Electronic mechanism used to switch coil primary circuit "ON" and "OFF," inducing high coil voltage to fire spark plugs.

LOCATION
Inside distributor assembly.

OPERATION
As the signal rotor turns with the distributor shaft, protrusions on the rotor (one for each cylinder) pass close to the pick-up coil, causing a disruption in the coil's magnetic field. This disruption is the signal used by the igniter (a transistorized switching device) to disconnect the primary coil circuit ground connection and induce high voltage from the coil secondary windings. To control ignition timing advance, the relationship between signal rotor and pick-up coil varies with engine rpm (centrifugal advance mechanism) and load (vacuum advance mechanism).

CONSTRUCTION
Pick-up coil and igniter are combined as a single unit and incorporated into the distributor assembly.