Abstract: An apparatus for measuring the circumferential distribution of temperature in a fluid, comprising a plurality of sensor ladders, each incorporating a plurality of temperature sensors, wherein a first one of the sensor ladders partially overlaps a second one of the sensor ladders, part of the first sensor ladder not overlapping the second sensor ladder.

Abstract: A position sensor system for use in sensing the position of a component located within a housing and disposed, at least in part, within a fluid, the system comprising a first acoustic position sensor operable to transmit a first acoustic signal through the fluid and to sense a reflection of the first acoustic signal from a first surface to derive a first position signal, a second acoustic position sensor operable to transmit a second acoustic signal through the fluid and to sense a reflection of the second acoustic signal from a second surface to derive a second position signal, and means operable, using the first and second position signals, to derive a position signal indicative of the position of the component within the housing.

Abstract: A fault tolerant electric drive system comprises an alternator, a motor controller and an electric motor, wherein the alternator and motor each have a plurality of corresponding independent phase windings, the motor controller having a plurality of independent phase drives corresponding to the phase windings, and a plurality of independent electric drive phases is defined by connecting each corresponding phase winding of the alternator and motor to a corresponding phase drive of the motor controller.