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General Discussion Area / Re: Camshaft and Crankshaft Sensors
« on: 15 January 2008, 13:39:12 »
CPS's are normally variable reluctance, in that a coil of wire is wound round a magnet and then timing marks cut into the flywheel pass by the tip of the magnet.
As ferrous metal comes close to the magnet it causes the magnetic flux around the magnet to temporarily collapse, inducing a current in the coil.
As the metal moves away again, the magnet begins to re-establish the field and the current reverses. The fact that the current reversal happens at a very precise point on the flywheel's rotation, and that it can be detected easily using a zero crossing detector makes this a very accurate way of establishing the engine's crank angle.
The sensor is also cheap and robust - in 99% of vehicles. Perhaps not in V6 Omegas, although that's more of a wiring issue.
Kevin
As ferrous metal comes close to the magnet it causes the magnetic flux around the magnet to temporarily collapse, inducing a current in the coil.
As the metal moves away again, the magnet begins to re-establish the field and the current reverses. The fact that the current reversal happens at a very precise point on the flywheel's rotation, and that it can be detected easily using a zero crossing detector makes this a very accurate way of establishing the engine's crank angle.
The sensor is also cheap and robust - in 99% of vehicles. Perhaps not in V6 Omegas, although that's more of a wiring issue.
Kevin
I mean Car... 
