Abstract: A level sensor includes a first transducer generating a first signal, a second transducer generating a second signal, and a processor configured to switch operation between a first mode and a second mode. In the first mode, the first transducer generates the first signal and the second transducer senses a reflection of the first signal from a surface. In the second mode, the second transducer generates the second signal and the first transducer senses a reflection of the second signal from a reference target. The processor determines a distance to the surface.

Abstract: A sensor having a first array of N magnetic pole pairs, where N is a positive number, and a second array of M magnetic pole pairs, arranged substantially in parallel to the first array, where M is a positive number different from N, such as N?1 or N+1. A first magnetic pole in the second array is aligned with a first magnetic pole in the first array. The remaining magnetic poles in the second array are arranged such that each one of them is positioned with respect to at least one pole in the first array to form a magnetic field with an angular orientation with respect to the two poles. This arrangement of magnetic pole pairs can be used to measure absolute position. A third array of M magnetic pole pairs may be arranged substantially in parallel with the second array. The second and third arrays of magnetic pole pairs may be used to measure relative position between the two arrays.

Abstract: A circuit with two terminals that receive an input current. The circuit includes a sensor, and a controller to generate a modulated signal. The circuit also includes a flyback circuit that receives the modulated signal. The flyback circuit generates a first output voltage based on the modulated signal, shunts or redistributes at least a portion of the input current, and enables the controller to regulate the input current in proportion to the modulated signal.