Abstract: A radial position sensor includes a rotating element configured to rotate about an axis of rotation, which subject to displacement. The displacement from a first position to a second position can be represented by polar coordinates, e.g., (?, ?), where ? is a distance and ? is an angle. The sensor also includes a non-rotating emitting element configured to provide a plurality of electromagnetic fields and a non-rotating receiving element configured to receive the plurality of electromagnetic fields. The plurality of electromagnetic fields are electromagnetically coupled to the non-rotating receiving element through the rotating element. The electromagnetic coupling varies in dependence on the radial position of the axis of rotation of the rotating element. The non-rotating receiving element produces an output signal in response to the amount of coupling of the plurality of electromagnetic fields, and so the output signal is an indication of the radial position of the axis of rotation.

Abstract: A system and method for controlling multiple cooling fans is presented. The circuitry for directly driving each of the motors is removed from the motor casings, thus increasing air flow and reducing replacement costs should a motor fail. The system includes a common processor for centrally controlling the speeds of the motors and monitoring the performance of each of the multiple motors.

Abstract: Embodiments of the present invention provide an integrated air-mover and position sensor for an electric motor. One or more fins may be attached to a position sensor and adapted to generate a movement of air when the position sensor rotates with a rotor shaft. Such an arrangement not only allows the position sensor to sense positions of the electric motor, but also provides air-cooling functions for cooling the motor driver efficiently, thus improving product reliability. The position sensor may be an optical encoder or a capacitive sensor. Alternatively, one or more fins may be disposed within the electric motor and attached directly onto a rotor shaft of the electric motor to create a movement of air for cooling the motor driver directly and efficiently.

Abstract: A radial position sensor includes a rotating element configured to rotate about an axis of rotation, which subject to displacement. The displacement from a first position to a second position can be represented by polar coordinates, e.g., (?, ?), where ? is a distance and ? is an angle. The sensor also includes a non-rotating emitting element configured to provide a plurality of electromagnetic fields and a non-rotating receiving element configured to receive the plurality of electromagnetic fields. The plurality of electromagnetic fields are electromagnetically coupled to the non-rotating receiving element through the rotating element. The electromagnetic coupling varies in dependence on the radial position of the axis of rotation of the rotating element. The non-rotating receiving element produces an output signal in response to the amount of coupling of the plurality of electromagnetic fields, and so the output signal is an indication of the radial position of the axis of rotation.

Abstract: A system and method for controlling multiple cooling fans is presented. The circuitry for directly driving each of the motors is removed from the motor casings, thus increasing air flow and reducing replacement costs should a motor fail. The system includes a common processor for centrally controlling the speeds of the motors and monitoring the performance of each of the multiple motors.

Abstract: Angular position detection sensors include a capacitive sensor embodiment and an inductive sensor embodiment. A non-rotating excitation element is electromagnetically coupled to a non-rotating receiver element. The electromagnetic coupling is varied by an electrically passive, rotating element disposed between the non-rotating excitation element and the non-rotating receiver element. Excitation signals applied to the non-rotating excitation element are electromagnetically coupled to the non-rotating receiver element, producing a single output signal directly indicative of the angular position of the rotating element.

Abstract: A controller for brush less DC motors includes an angular position sensor and control logic to detect the phase difference between a target position signal and a current angular position signal. The detected phase difference is the basis for generating motor drive control signals to position the rotor of the motor to the target position.