Electronically controllable braking amplifier

摘要

The invention relates to an electronically controllable brake booster (21) comprising a vacuum chamber (23) and a pressure chamber (24) which are separated from one another by a movable wall (22). The invention also comprises a control valve assembly (26) which can be actuated by an electromagnetic actuating device (26) and can be adjusted by a pressure differential between the pressure and vacuum chambers. According to a current (I) flowing through the electromagnetic actuating device (26), the control valve assembly occupies a stopping position (II) in which the current (I) lies in a region between a higher value (I build-up) and a lower value (I reduction) such that the control valve assembly does not abandon the stopping position (II). Said control valve assembly also occupies a first pressure change position (I) in which the current is greater than the higher value (I build-up), and a second pressure change position (III) in which the current is less than the lower value (I reduction). The invention is characterized in such a way that the current value (I) at which the respective transition actually occurs is detected during a transition of the control valve assembly from the stopping position (II) to the first or the second pressure (III) change position or during a transition of said assembly from the first or the second pressure change position (III) to the stopping position (II). Said detected current value (I) is used for prescribing the higher value (I build-up) and or the lower value (I reduction) of the currents which define the stopping position (II) for a future corresponding transition of the control valve assembly.