INDUCTOR AND METHOD FOR VARYING THE MAGNETIC PERMEABILITY OF AN INDUCTOR

There is provided an inductor (5) having a coil (10) enclosing at least a part of a core (15, 20, 70, 90). A sensor (40) senses a current when flowing in the coil (10). The core comprises a first part (15), and a second part (20, 70, 90) comprising a movable metal part mounted relative to the first part (15) of the core such that the second movable metal part (20, 70, 90) is separated from the first part (15) of the core by an air gap (25, 30). A least a portion of the second part (20, 70, 90) is arranged to move relative to the first part (15), thereby to vary the magnetic permeability of the core (15, 20, 70, 90), according to an output of the sensor (40). In this way, if the output of the sensor (40) indicates an onset of saturation of the core (15, 20, 70, 90), the magnetic permeability of the core (15, 20, 70, 90) may be reduced by such movement. A method for varying the magnetic permeability of an inductor core (15, 20, 70, 90) is also provided.