Engine RPM sensor

ENGINE RPM SENSOR

This sensor is secured to the crankcase: the flywheel is in one piece with a crankshaft crank.

Operating principle

The sensor consists of a tubular casing (1) which contains a permanent magnet (3) and an electrical winding (2): As a result of the flywheel teeth passing, the magnetic flow created by the magnet (3) undergoes fluctuations produced by the variation in the gap. These fluctuations produce an electro-motive force in the winding (2) where an alternately positive (tooth opposite the sensor) and negative (gap opposite the sensor) voltage is produced: see paragraph on "signal management"). The peak sensor output voltage value, all things being equal, depends on the distance between the sensor and the tooth (gap).

Wiring connector

The sensor winding resistance can be measured by disconnecting the connector and connecting an ohmmeter to the sensor terminals Resistance: 570±57 ohm at 20°C