Patent ID: 9316482
Filing Date: 2016-04-19
CPC Classification: G01B,G01D,G01L

Claim Text:
1. A magnetic device for detecting the absolute position of a rotating input shaft, the device comprising: a main rotor comprising a main magnet secured to the input shaft effecting a travel of n times 360°, n being greater than 1, and a driving member of a motion converter; at least one first magnetosensitive probe delivering, over a magnetic angle of 360°, a signal proportional to a direction of a magnetic field generated by the main magnet to derive a measurement of absolute position of the input shaft; a secondary magnet having two magnetic poles and effecting a travel of around 360° under effect of the rotation of the input shaft via the motion converter; and at least one second magnetosensitive probe delivering, over a magnetic angle of around 360°, a signal proportional to the direction of a magnetic field generated by the secondary magnet and able to derive therefrom a measurement of absolute position of the secondary magnet; the second probe and the secondary magnet constituting a position sensor of epsilon precision, expressed as a percentage; the secondary magnet being substantially positioned within a height H defined by upper and lower planes of the main rotor; and the main magnet being multipole and having P pairs of poles, where P is greater than 1 and less than an integer part of 36/T, with  where T is a minimum period, expressed in degrees, of the main magnet, and Hyst is an amplitude of a hysteresis of the detection device, expressed in degrees and referred to the input shaft.