Abstract: A current sensor arrangement comprises plural sensor elements arranged around a center point, each of the sensor elements having a plane of zero sensitivity to uniform magnetic fields. A first one (202) of the sensor elements has a first angular separation (X1) relative to the center point from a second, adjacent sensor element (204) and a second angular separation (X2) relative to the center point from a third, adjacent sensor element (206). The first angular separation is less than the second angular separation. An intercept (I13) of the planes of the first and third sensor elements is located outside a triangle formed by the center point and the first and third sensor elements and an intercept (I12) of the planes of the first and second sensor elements is located inside a triangle formed by the center point and the first and second sensor elements.

Abstract: A solenoid actuator is described. The solenoid actuator comprises an armature, pole piece(s), electromagnet coil(s) arranged, in response to energisation, to cause travel of the armature between first and second positions along a direction of travel, permanent magnet(s) positioned and orientated for latching the armature in at least the first position when the armature is in the first position and spring(s) arranged to bias the armature. The solenoid actuator can be operated to provide partial lift.

Abstract: A short travel solenoid actuator (44) is disclosed which comprises at least one pole piece (47, 48), an armature (51), an electromagnet coil (46) arranged, in response to energisation, to actuate the armature between first and second positions. A permanent magnet (52) is positioned and orientated so as to latch the armature in the first and second positions when the armature is in the first and second positions respectively. A spring (53) is arranged to bias the armature.

Abstract: A magnetic latching actuator operable to control the movement of at least a first contact and second contact between a closed position in which the contacts physically engage each other and an open position in which the contacts are spaced from each other. The magnetic latching actuator includes first and second stationary permanent magnets oriented such that the first magnetic field created by the first magnet and the second magnetic field created by the second magnet are in opposite directions. An actuation coil surrounds both the first and second magnets. Current is supplied to the actuation coil in a first direction to create a first magnetic field or a second direction to create a second actuation magnetic field opposite the first actuation magnetic field. A yoke is movable relative to the first and second magnets to cause the first and second contacts to move between the open and closed positions.

Abstract: A sensor for use in detecting a time-varying current in a conductor (106) comprises plural sets of two oppositely-configured sensor elements (104-1 . . . 104-6) arranged around a sensing volume having a central axis, the sensor elements (104-1A, 104-1B) of each set being provided substantially in a common plane that does not intersect the central axis, and each set having a different common plane, the sensor elements of each set being arranged such that a normal (N) of their common plane at a point between central parts of sensor elements lies on a plane (P) that is radial to the central axis of the sensing volume.

Abstract: A current sensor arrangement comprises plural sensor elements arranged around a centre point, each of the sensor elements having a plane of zero sensitivity to uniform magnetic fields. A first one (202) of the sensor elements has a first angular separation (X1) relative to the centre point from a second, adjacent sensor element (204) and a second angular separation (X2) relative to the centre point from a third, adjacent sensor element (206). The first angular separation is less than the second angular separation. An intercept (I13) of the planes of the first and third sensor elements is located outside a triangle formed by the centre point and the first and third sensor elements and an intercept (I12) of the planes of the first and second sensor elements is located inside a triangle formed by the centre point and the first and second sensor elements.

Abstract: A smart responsive electrical load (10) is operatively connectable to an electricity supply network (20). The smart responsive electrical load (10) comprises an electrical power-consuming device (30) and a control arrangement (40) for controlling a supply of electrical power from the network (20) to the device (30). The control arrangement (60, 110, 150, 160, 170) is operable to impose a variable time delay (tp) before supplying electrical power to the device (30) after a request for power to be provided to the device (30). The variable time delay (tp) is a function of a state of the network (20), for example its frequency (f) and/or its voltage amplitude (V). Optionally, the device (30) is a battery charger, for example for use with a rechargeable electric vehicle. Beneficially, the smart responsive load (10) is supplied with electrical power from a population of micro-generation devices (500) operable to provide supply network response.

Abstract: A magnetic latching actuator operable to control the movement of at least a first contact and second contact between a closed position in which the contacts physically engage each other and an open position in which the contacts are spaced from each other. The magnetic latching actuator includes first and second stationary permanent magnets oriented such that the first magnetic field created by the first magnet and the second magnetic field created by the second magnet are in opposite directions. An actuation coil surrounds both the first and second magnets. Current is supplied to the actuation coil in a first direction to create a first magnetic field or a second direction to create a second actuation magnetic field opposite the first actuation magnetic field. A yoke is movable relative to the first and second magnets to cause the first and second contacts to move between the open and closed positions.

Abstract: An optical switch comprises one or more input ports for directing an optical beam into the switch; dispersive means configured to receive said optical beam and which spatially separate the optical beam into individual wavelength components which are routed to an actuator; wherein the actuator is in the form of an array of elongate movable fingers for selectively interfering with individual wavelength components and means are provided to direct optical beams to selected one or more output ports.

Abstract: An inductive power transfer system comprises a primary unit 10, having a primary coil 12 and an electrical drive unit 14 which applies electrical drive signals to the primary coil so as to generate an electromagnetic field. The system also comprises at least one secondary device 30, separable from the primary unit and having a secondary coil 32 which couples with the field when the secondary device is in proximity to the primary unit. A control unit 16 causes a circuit including said primary coil to operate, during a measurement period, in an undriven resonating condition. In this condition the application of the drive signals to the primary coil by the electrical drive unit is suspended so that energy stored in the circuit decays over the course of the period. A decay measurement unit 18 takes one or more measures of such energy decay during the measurement period.

Abstract: An optical switching device, comprises an optical switch and an optical connector receiving means mateable with a connector., means for effectuating switching by engaging a connector in said receiving means, characterised in that said switching effectuating means acts or is acted upon once a connector is sufficiently engaged in the receiving means for optical communication with the connector to occur.

Abstract: An optical switch comprises an input array of optical elements spaced from an output array of optical elements, means to direct radiation beams and a further array of optical elements optically located between the inputs and outputs, wherein the pitch of the optical elements of said further array of optical elements is inferior to the pitch of the input and/or output array of optical elements.

Abstract: An optical element positioning arrangement comprises a reflective optical element, actuators, flexures located between the actuators and said optical element, the arrangement being configured so that when a first actuator is actuated any displacement generated is transmitted via a flexure to said optical element and provided that a second actuator's displacement defers from the displacement of the first, the optical element is caused to swing, characterised in that the actuators are spaced relative to one another and placed substantially parallel to one another.

Abstract: An optical connector (10) comprises at least one optical guide (12) for carrying optical radiations; a total internal reflection surface (11) upon which, in use, said radiations impinge, so that the radiation in the optical guide is reflected by said surface towards an optical element (14) of the connector and means enabling the connector (10) to interlock with any other optical connector which is appropriately matingly configured.

Abstract: An optical beam steering arrangement, comprises: a moveable optical element; actuating means for causing the movement of said element; a connecting means between said element and said actuating means for transmitting movement from said actuating means to said element; and flexure means which carry said optical element and are compliant with the displacement of said optical element.

Abstract: A flexure arrangement, suitable for use with or as part of, e.g., an optical beam steering arrangements, and intended for supporting and transmitting movement to any appropriate element, the arrangement including a first flexure to which movement is applied, a second flexure which attaches the arrangement to any appropriate supporting structure, structure linking the first flexure to the second flexure and structure for receiving any appropriate element, the first and second flexure being appropriately spaced so that any movement applied to the first flexure is amplified by the flexure arrangement.

Abstract: An optical switch comprises an optical input (902) and an optical output (904), the switch further comprising a wavelength selective switch element (912) for directing light of a selected wavelength between the input (902) and the optical output (904), wherein the switch element is tuneable to a plurality of different wavelengths. By having tuneable switch elements, the switch can be made having fewer elements and therefore more compact.

Abstract: Articles for use with security documents are disclosed which include planchettes and security threads that comprise a plastic substrate having at least one security feature employing soft magnetic metal located thereon. Preferred articles comprise at least two security features where a first security feature is made up of an optionally repeating pattern of soft magnetic metal adapted to generate a signal or a series of signals in an interrogation field applied by a detection system for remote detecting and optionally for remote reading or identifying the article. A second security feature is a public security feature that comprises magnetic and/or non-magnetic metal formed indicia. The first and second security features of this invention can be coextensive features.

Abstract: An antipilferage tag is disclosed which includes a resonant circuit adapted to receive an RF signal and to transmit a response signal when interrogated by said RF signal. The tag includes circuit components constituted by or fabricated from a metallized layer supported by a dielectric material.

Abstract: An electroacoustic transducer comprises a pair of active piezo electric membranes and a sleeve closed at its ends by the membranes to a form an enclosed rear volume of air. A case accomodates the assembly of sleeve and membranes and provides an enclosed front volume of air between its inner wall and the assembly. An opening in the case to the outside forms a sound pressure output. Each membrane comprises a sandwich of two active piezo layers on a substrate material. Very small thicknesses of the substrate and active piezo layers provides for a correct impedance match to the acoustic load in the ear when used in hearing aids.