Circuit arrangement for determination of rotational angle position of rotor in electromotor for operating e.g. seat in motor car, has device part for adjusting signal offset depending on amplified signal and comprising voltage source

摘要

The arrangement (10) has a measurement circuit (12) for providing a signal (Uim) based on measurement of motor current (Im) and/or a motor voltage (Um) of an electromotor (M). An amplifier (14) i.e. operational amplifier, amplifies the signal with an adjustable signal offset to produce an amplified signal (Us). An evaluating device (16) evaluates ripple of the amplified signal to determine current position of the rotor of the electromotor. A device part (16-3) adjusts the offset depending on the amplified signal and comprises a voltage source that is coupled with circuit nodes and resistors. An independent claim is also included for a method for determining current position i.e. rotational angle position, of a rotor in an electromotor.