Abstract: An ophthalmic illumination system includes planar shapes serially positioned in a path for a collimated beam, along an optical axis. The shapes are rotationally symmetric with one another relative to the optical axis. Each shape has a central rotational axis intersecting the optical axis. Generally wedge-shaped segments of the shapes are spaced apart around and converge at the optical axis to provide generally wedge-shaped apertures to the beam between the segments. The shapes are rotatable on the rotational axes along the optical axis to assume a plurality of configurations to vary intensity of the beam. The beam can fill spatial modes at substantially all radii of the optical fiber entrance pupil.

Abstract: A magnetoinductive flowmeter incorporates an electromagnetic circuit with at least one coil and a minimum of two detachably interconnected components of a magnetic material. One of the components features a resiliently deformable spring section that presses against the other component. The result is an easy-to-assemble magnetoinductive flowmeter that can be manufactured with substantial production tolerances.

Abstract: The present invention provides a position sensor which is suitable for use in a piston and cylinder assembly. The position sensor includes a movable field modifying member which is operable to vary the inductance of a sensor winding, whereby the position of the field modifying member relative to the sensor winding can be determined by monitoring the inductance of the sensor winding. The position sensor also includes a compensation winding which is arranged to have a common coupling with the field modifying member whereby a signal output from the compensation winding can be used to compensate for variations in the signal level output by the sensor winding caused by, for example, temperature variations of the system.

Abstract: The present invention provides a position sensor which is suitable for use in a piston and cylinder assembly. The position sensor includes a movable field modifying member which is operable to vary the inductance of a sensor winding, whereby the position of the field modifying member relative to the sensor winding can be determined by monitoring the inductance of the sensor winding. The position sensor also includes a compensation winding which is arranged to have a common coupling with the field modifying member whereby a signal output from the compensation winding can be used to compensate for variations in the signal level output by the sensor winding caused by, for example, temperature variations of the system.

Abstract: The lasing output of a laser diode (1) is controlled by the current through the diode (1). The laser diode (1) is driven by a switched mode drive circuit in which a pulsed signal is applied to a smoothing circuit, typically including a capacitor C and an inductor L, arranged to provide a smoothed output voltage whose magnitude depends on the pulse width of the drive signal.