Pick-Up Coil: Description and Operation

Crank Angle Sensor:

When the distributor shaft rotates, a fluctuating magnetic field is generated due to changes in the air gap between the pick-up coil and signal rotor. As a result, an alternating current (AC) voltage is induced in the pick-up coil. This induced AC voltage peaks when a ridge on the signal rotor is adjacent to the ridge on the pick-up coil. When the voltage peaks this signals the ignition module to break the primary circuit of the coil. The capacitor in the distributor is for radio noise suppression.