Crankshaft Position (CKP) Sensor 24X

24X Crankshaft Position Sensor:

PURPOSE
The 24X crankshaft position sensor is used to improve idle spark control at engine speeds up to approximately 1250 RPM. A concentric interrupter ring mounted to the rear of the crankshaft balancer has blades and windows that, with crankshaft rotation, either block the magnetic field or allow it to reach the 24X crankshaft position sensor. The 24X crankshaft position sensor contains a hall-effect switch. The interrupter ring has 24 evenly-spaced same-width blades and windows and the 24X crankshaft sensor produces 24 "ON-OFF" pulses per crankshaft revolution. The 24X and the 3X crankshaft position sensors react similarly. The 24X signal is used for better resolution at a calibrated RPM.

OPERATION
The magnet and Hall-effect switch are separated by an air gap. A Hall-effect switch reacts like a solid-state switch, grounding a low-current signal voltage when a magnetic field is present. When the magnetic field is shielded from the switch by a piece of steel placed in the air gap between the magnet and the switch, the signal voltage is not grounded. If the piece of steel (called an interrupter) is repeatedly moved in and out of the air gap, the signal voltage will appear to go "ON-OFF-ON-OFF-ON-OFF." Compared to a conventional mechanical distributor, this "ON-OFF" signal is similar to the signal that a set of breaker points in the distributor would generate as the distributor shaft turned and the points opened and closed.