A New Generation of Contactless Magnetic Position Sensors

Magnetic position sensors have several advantages which make them attractive for automotive applications: they are contactless (there is no mechanical wear-out), insensitive to dirt, low cost and MMT has been a leader in the development of solutions based on measurement of magnetic field amplitude based on Hall effect. In this paper, we will present a new generation of position sensors. This new development is based on the direction measurement of the magnetic field generated by a diametrically magnetized magnet [1]. We will focus on through shaft 360°angular sensors and linear sensors adapted to large displacements [10...200 mm]. In the following article, first the rotary sensor principle is explained and then its derivative. The basic design considerations are explained through examples of automotive applications and more particularly through examples of powertrain transmission sensors.