TFI IV

Distributor (Typical) - Exploded View:

This distributor directs high voltage to the spark plugs and supplies crankshaft position and frequency information to the control module using a Profile Ignition Pick-up.

Hall Effect Device:

The universal distributor operates by using a Hall Effect vane switch assembly, which causes the ignition coil to be switched off and on by the EEC IV and TFI-IV modules. The vane switch consists of a Hall Sensor on one side and a permanent magnet on the other.

Rotary Vane Cup:

A rotary vane cup is used to trigger the signal off and on.

Figure 7 - Magnetic Flux Field:

When the window of the vane cup is between the magnet and the Hall Effect device, a magnetic field is completed from the magnet through the Hall Effect device and back to the magnet.

Hall Effect Device Response To Vane:

As the vane passes through this opening, the flux lines are shunted through the vane and back to the magnet. At 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 EEC system for Crankshaft position Sensing and the Desired Spark Advance based on engine demand and calibration. The spark advance and voltage distribution is accomplished through a conventional rotor, cap and ignition wires.