Patent ID: 7283826

Claim:
Magnetic sensor to determine the position of a cellular phone ( 2 ) in linear movement along an axis of translation (T), the sensor comprising: a magnetic circuit within which at least a magnetic induction (I 1 , I 2 ) is created along a direction perpendicular to the axis; a measuring cell fitted to a magnetic circuit, sensitive to the value of the magnetic induction flux and capable of measuring the variations in the value of the magnetic induction flux consecutive with the reluctance variations of the magnetic circuit in order to determine the linear position of the cellular phone ( 2 ) along the axis of translation (T); and a single delimiting fixed magnetic circuit between two fixed pole parts, comprising: a variable air gap ( 4 ) within which at least a magnetic induction (I 1 , I 2 ) is created that extends along a length parallel to the axis of translation (T) and at least equal to the travel to be measured (C) of the cellular phone, the variable air gap ( 4 ) being capable of allowing the linear movement of the cellular phone ( 2 ) which is equipped with means ( 5 ) for modifying the reluctance of said variable air gap, mechanically independent of said sensor; and a measurable air gap ( 7 ) to which the measuring cell is fitted.