A rotary switch includes an operating member, a magnet member, and a magnetic sensor. The system comprises an image capture device for capturing a stereo image pair of the object, the image pair comprising a first image and a second image of the object. 1, methods of screening for potassium channel activators and inhibitors using biologically active Kv10 subfamily members such as Kv10. The sensing system also includes a magnetic flux influencing element configured to influence magnetic field components associated with the alternating pole magnetic domains of the magnetic encoder to reduce magnetic field components associated with the first axis. Whilst changing between performance levels, the further circuits are capable of supporting intermediate levels of operation and the processor exploits these by operating at those intermediate levels pending the final target level being reached.