The universal distributor (12127)
operates using a Hall effect vane switch assembly which:
Causes the ignition coil (12029)
to be switched off and on by the powertrain control module (PCM) (12A650)
and ignition control module (ICM) (12A297).
The vane switch is an encapsulated package consisting of a Hall sensor
on one side and a permanent magnet on the other side.
A rotary vane cup, made of ferrous metal, is used to trigger the signal
OFF and ON.
When the window of the vane cup is between the magnet and the Hall effect
device, a magnetic flux field is completed from the magnet through the Hall
effect device and back to the magnet.
As the vane passes through this opening, the flux lines are shunted
through the vane and back to the magnet.
During this time, a voltage is produced as the vane passes through the
opening.
When the vane clears the opening, the window edge causes the signal to go
to zero volts.
The signal is then used by the PCM for crankshaft position sensing and
the computation of the desired spark advance based on engine demand and
calibration.
The conditioned spark advance and voltage distribution is accomplished
through a conventional distributor rotor (12200)
, distributor cap (12106)
and ignition wires.
