Patent ID: 8879231

Claim:
A sensor system for a magnetic bearing, comprising: two actuator coils; two clocked power output stages; a current sensor for detection of currents with a ripple current on them, in the actuator coils; and a sensor interface, wherein: the clocked power output stages each provide a pulse-width-modulated output voltage whose pulse width is shortened or lengthened by small amounts, in a predetermined sequence such that a mean duty ratio of the pulse-width-modulated output voltage remains unchanged; pulse widths of the clocked power output stages are modulated with a fixed phase relationship with respect to one another; a signal from the current sensor is mathematically linked in the sensor interface, and is supplied to a rectifier circuit which operates synchronized to a time profile of the predetermined sequence of modulation of the pulse width; and, a time delay, which can be varied by means of a phase shift, exists between the predetermined sequence of the modulation of the pulse width and a clock of synchronous rectification.