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Magnetic-Sensing Technologies for Powertrain Applications
Published June 19, 1997 by ISATA - Dusseldorf Trade Fair in United Kingdom
Event: ISATA 1997
Passive camshaft and crankshaft position sensors based on Lenz's law are being replaced by active sensors for improved performance. Active sensors provide a signal-conditioned output capable of interfacing directly with the engine control computer. They do not exhibit errors as a function of output loading and can sense a wide variety of targets without adjustment of sensor geometry. Contacting potentiometric rotary position sensors are being replaced by non-contacting rotary position sensors for throttle position sensing and drive-by-wire applications to eliminate issues associated with wear.
Four magnetic-sensing technologies: the Hall effect, geometric magnetoresistance, anisotropic magnetoresistance and giant magnetoresistance are reviewed for automotive applications such as camshaft and crankshaft sensors and rotary position sensing. The principle of operation of each is described, along with examples of sensor configurations, performance and candidate applications.