Patent ID: 8262875

Claim:
A sensor arrangement, comprising: at least one electrode; a sensor element dependent on a sensor event in terms of its profile, at the at least one electrode; a drive circuit, to provide an electric current source at a constant magnitude as a predetermined electric current, the at least one electrode being at least one of charged and discharged with the predetermined electric current; a comparator unit, to compare the electrical voltage provided by the sensor element with a reference voltage, and to provide a comparison result; a voltage source, to provide the reference voltage to the comparator, the voltage source being coupled to the comparator unit; an evaluation circuit that receives an output signal from the comparator unit, to determine a time duration required for the at least one of charging and discharging of the electrode, from at least one of a predetermined voltage to the reference voltage and from the reference voltage to the predetermined voltage, the time duration representing at least one of whether or not a sensor event has taken place and the extent to which a sensor event has taken place at the sensor element; a switch unit, configured to invert a flow direction of the current from the drive circuit, the switch unit being connected between the drive circuit and the comparator unit, the electrode being charged or discharged depending on the switch state; and a control unit for controlling the switch unit such that, by way of the switch unit, with changeover of the switch unit, the electrode is repeatedly at least one of charged from the predetermined voltage to the reference voltage and discharged from the reference voltage to the predetermined voltage, wherein the sensor element is connected between the switch unit and the comparator.