Transmission Speed Sensor: Description and Operation

Pulse Generators:

PURPOSE
The Pulse Generators, A and B, consist of a permanent magnet and a pickup coil that measure the input RPM to the transmission after the torque converter.

OPERATION
Pulse Generator A
The outer circumference of the of the kickdown drum has 4 holes drilled in it. As the drum rotates, the holes are moved past the pulse generator, causing a fluctuation in the magnetic field within the pulse generator. These fluctuations are transmitted through the pick up coil as an electrical signal.

Pulse Generator B
The transfer driven gear has a number of gear teeth. As the gear rotates, the teeth are moved past the pulse generator, causing a fluctuation in the magnetic field within the pulse generator. These fluctuations are transmitted through the pick up coil as an electrical signal.