Distributor: Description and Operation

Distributor With Integral Coil (Typical):

Distributor Components (Typical):

The distributor with an integral coil combines all ignition components in one unit. The coil is in the cap and connects through a resistance brush to the rotor.

The distributor has an internal magnetic pick-up assembly which contains a permanent magnet, a pole piece with internal teeth, and a pick-up coil. When the teeth of the timer core, rotating inside the pole piece, line up with the teeth of the pole piece, an induced voltage in the pick-up coil signals the electronic module to trigger the coil primary circuit. The primary current decreases and a high voltage of up to 35,000 volts is induced in the ignition coil secondary winding. This voltage is directed through the rotor and secondary leads to fire the spark plugs. The capacitor in the distributor is for radio suppression.

The magnetic pick-up assembly is mounted over the main bearing on the distributor housing. The assembly is made to rotate by the vacuum control unit., thus providing vacuum advance. The distributor shaft is mounted on the camshaft at the rear of the engine. The force of rotation moves the advance weights against the springs, and provides centrifugal advance to the timer core.