Patent ID: 7073391

Claim:
A force sensor, comprising, a force measurement cell ( 1 ) that has a Hall element, wherein the force measurement cell ( 1 ) includes at least one bending bar ( 2 , 3 ), which on the basis of the exertion of force to be detected exerts an influence on the magnetic field In the region of a magnetic-field-Sensitive sensor element ( 6 ) of the farce measurement cell ( 1 ); wherein the sensor element comprises a Hall element ( 8 ), retained on the at least one bending bar ( 2 , 3 ), which element can be deflected by the force exerted on the bending bar ( 2 , 3 ) within the field of a permanent magnet ( 4 ) disposed in relatively stationary fashion; wherein a magnetic diagnosis field in the region of the Hall element ( 6 ) can be generated, the field lines of which are located in the plane of the Hall element ( 6 ) without influencing the measurementent; wherein the force measurement cell ( 1 ) is employed for detecting the forces on a vehicle seat of a motor vehicle; and wherein the voltage supply of a coil ( 7 ) for generating the diagnosis field in the plane of the Hall element ( 6 ) is effected by means of an alternating voltage, modulated up to the supply voltage of the Hall element ( 6 ), a diode (D) or a capacitor is connected in series in a supply line for the coil ( 7 ).