Abstract: A motor includes a rotor having a pattern of permanent magnetic portions, and a stator disposed proximate to the rotor. In some arrangements, a stator housing of the stator has a segmented backplane formed of a plurality of metal segments in electrically non-conducting (or non-electrically conductive) thermal contact to provide for heat transfer from the forcer coils to a separate stator mounting structure while minimizing eddy currents and associated effects in the stator housing. In some arrangements, the stator housing of the stator has a coil-housing portion for holding the coils and a distinct mounting portion for attaching the stator to a separate support structure, the coil-housing portion being of an electrically non-conductive material effective to provide for heat transfer from the forcer coils to the mounting portion while avoiding eddy currents and associated effects in at least the coil-housing portion of the stator housing.

Abstract: A power converter comprising an active power factor correction (APFC) circuit. A first compensation circuit provides a first compensation signal to the APFC circuit. A second compensation circuit provides a second compensation signal to the APFC circuit. A load demand sensing circuit receives a load demand signal to switch on the second compensation circuit to provide the second compensation signal. There is also provided a controller for a power converter, with the controller comprising a first compensation circuit for providing a first compensation signal to an active power factor correction (APFC) circuit, and a second compensation circuit for providing a second compensation signal to the APFC circuit. The controller also comprises a load demand sensing circuit for receiving a load demand signal to switch on the second compensation circuit to provide the second compensation signal.

Abstract: A power converter comprising an inverter for receiving a supply power and providing an alternating output. An output rectifier receives the alternating output and provides a rectified output to a load. An output winding receives the rectified output, and a sensing winding is inductively coupled to the output winding and provides a sensing output. A controller receives the sensing output and provides a control signal to the inverter for controlling the alternating output. A related method of converting power is also provided.

Abstract: A controller for a power converter having at least a first switch and a second switch. Each switch is a transistor with a collector terminal, an emitter terminal, and a base terminal. The controller is connectable to the base terminals of the first and second switches to provide a base current to the base terminals of the first and second switches, and connectable to the emitter terminals of the first and second switches to provide a short-circuit between the base and emitter terminals of the first and second switches. The controller also comprises a timing circuit for controlling the provision of the base current and the short-circuit in a sequence. An associated method is also provided.

Abstract: A power converter circuit (1) and an associated method of converting an AC power supply. The power converter circuit (1) comprises: a supply rectifier circuit (2) for rectifying an AC supply power to generate a rectified supply power; an inverter circuit (3) for receiving the rectified supply power to generate an inverted supply power; a load rectifier circuit (4) for rectifying the inverted supply power to generate a rectified load power for supplying a load current to a load (5); and a charge pump circuit (6) driven by the load current to pump additional charge to the rectified supply power.

Abstract: There is provided a current control circuit for a power converter. The power converter has a primary circuit for receiving a supply current across a first supply rail and a second supply rail. There is a primary connection in the primary circuit. The power converter also has a secondary circuit providing an output current. There is a secondary connection in the secondary circuit. The secondary connection is connected to the primary connection. A controller controls one or more switches in the primary circuit to control the output current. The nature of the power converter is such that it has a reactive circuit which produces a reactive current. The current control circuit comprises a current sensing circuit connected to bypass or cancel the reactive current. The controller is connected to the current sensing circuit and controls the one or more switches based on a signal current sensed by the current sensing circuit.

Abstract: A power converter circuit (1) and an associated method of converting an AC power supply. The power converter circuit (1) comprises: a supply rectifier circuit (2) for rectifying an AC supply power to generate a rectified supply power; an inverter circuit (3) for receiving the rectified supply power to generate an inverted supply power; a load rectifier circuit (4) for rectifying the inverted supply power to generate a rectified load power for supplying a load current to a load (5); and a charge pump circuit (6) driven by the load current to pump additional charge to the rectified supply power.

Abstract: There is provided a current control circuit for a power converter. The power converter has a primary circuit for receiving a supply current across a first supply rail and a second supply rail. There is a primary connection in the primary circuit. The power converter also has a secondary circuit providing an output current. There is a secondary connection in the secondary circuit. The secondary connection is connected to the primary connection. A controller controls one or more switches in the primary circuit to control the output current. The nature of the power converter is such that it has a reactive circuit which produces a reactive current. The current control circuit comprises a current sensing circuit connected to bypass or cancel the reactive current. The controller is connected to the current sensing circuit and controls the one or more switches based on a signal current sensed by the current sensing circuit.

Abstract: A power converter circuit and an associated method of converting an AC power supply. The power converter circuit comprises: a supply rectifier circuit (2) for rectifying an AC supply power to generate a rectified supply power; an inverter circuit (3) for receiving the rectified supply power to generate an inverted supply power; a load rectifier circuit (4) for rectifying the inverted supply power to generate a rectified load power for supplying a load current to a load (5); and a boost circuit (6) driven by the load current to provide a boosted voltage to the rectified supply power.

Abstract: A power converter circuit and an associated method of converting an AC power supply. The power converter circuit comprises: a supply rectifier circuit (2) for rectifying an AC supply power to generate a rectified supply power; an inverter circuit (3) for receiving the rectified supply power to generate an inverted supply power; a load rectifier circuit (4) for rectifying the inverted supply power to generate a rectified load power for supplying a load current to a load (5); and a boost circuit (6) driven by the load current to provide a boosted voltage to the rectified supply power.

Abstract: A rotor having a plurality of laminations joined together and mountable on a shaft for rotation relative to a stator of a rotary electric machine arrangement has a solid section that surrounds an opening within which the shaft is receivable. The solid section includes an outside diameter, magnet receiving voids, and steps delimiting a plurality of pole spans from flux directing features at sides of each of the pole spans. Adjacent flux directing features between adjacent pole spans are disposed on opposite sides of scalloped areas or other such recesses, permitting cooling air flow past the rotor. The invention also concerns a lamination usable together with additional laminations to provide such a rotor, as well as an arrangement, such as an AC motor, generator, or motor/generator, including a stator and such a rotor.

Abstract: This invention generally relates to a bootstrap circuit for a switch mode power supply, a controller for a switch mode voltage converter, a switch mode flyback converter comprising the bootstrap circuit, a switch mode forward converter comprising the bootstrap circuit, and a method of bootstrapping a switch mode power converter. The bootstrap circuit comprises: a current bleed impedance (Rht1) to bleed current from an input power supply (VH+); circuitry to deliver current from the input power supply (VH+) via the current bleed impedance (Rht1) to the base of a power switch (Q1) such that the power switch (Q1) is operable to amplify the current delivered from the internal power supply; a passive circuit (Dst) to provide the amplified current to a reservoir capacitor (Cdd); and the passive circuit element (Dst) further to substantially block reverse current flow from the supply input (Vdd) to the emitter of the power switch (Q1).

Abstract: A current sensing system for sensing an output current of a Switch Mode Power Supply (SMPS), the SMPS including a magnetic energy storage device for transferring power from an input side to an output side of the SMPS, the current sensing system comprising: a flux model system to generate a waveform representing a magnetic flux in said magnetic energy storage device; and an output current model system to generate an output current sensing signal responsive to said magnetic flux waveform.

Abstract: This invention relates to Switch Mode Power Supply (SMPS) controllers, especially analogue controllers employing a combination of Pulse Width Modulation (PWM) and Pulse Frequency Modulation (PFM). We describe a switch mode power supply (SMPS) controller circuit for controlling a power switching device of said SMPS, the circuit including: a current input to receive a feedback signal current dependent upon an output voltage of said SMPS; a ramp generator circuit coupled to said current control input to generate responsive to said feedback current signal consecutive first and second voltage ramps, one rising the other falling; and a control output responsive to said voltage ramps from said voltage ramp generator to provide a drive signal for controlling said power switching device.

Abstract: A system for designing and ordering a stent graft is described. The system includes a user interface for designing and ordering the stent graft, and a centralised data processor remote from and in communication with the user interface for processing and storing entered information. The user interface further includes a selection portion for selecting a stent graft design and a design portion for entering a plurality of design parameters related to the stent graft design. A verification portion is also provided to verify details of a completed stent graft design with an ordering portion to order the completed stent graft design. In one embodiment the verification portion includes the capability to display a 3-dimensional view of the completed stent graft design.

Abstract: We describe a switch mode power supply (SMPS) controller employing a combination of pulse frequency and pulse width modulation. The controller employs a “gear box” control scheme using two complementary control loops, one for real-time control of the SMPS using PFM and a second using a PWM control scheme which monitors the switching frequency and, at defined operating points, adjusts the pulse width up or down through a set of pre-determined values. This can be considered analogous to the gearbox of a motor vehicle with the SMPS pulse width, switching frequency and output power roughly corresponding to the vehicle's gear ratio, engine speed and road speed respectively.

Abstract: A flexible cover system for truck and trailer beds. The cover system includes first and second frameworks. A flexible cover is suspended between the frameworks by developing tension in the cover. Tensioning force is preferably applied to the cover using tension frames connected near the ends of the cover. Such tension can be developed using tensioning winches. A cover suspension member extends between the frameworks and can be detached at one or both ends to allow better access during loading. The cover has ribs connected to the cover at spaced locations. A framework can be collapsed or otherwise repositioned on the bed to improve access for loading and unloading. The invention also includes methods for converting the cover systems between closed and retracted conditions.

Abstract: A method and apparatus for inducing a localised optical transmission loss in an optical fiber cable is described, which is particularly well suited for use with optical time-domain reflectometry (OTDR) equipment to aid in locating faults in an optical fiber cable. A small portion of the optical fiber cable is cooled, such as by immersion in a cryogenic liquid like liquid nitrogen, and fibres in the cooled cable portion exhibit localised optical transmission loss which can be detected as a point loss (26) with the OTDR trace (24). The technique of inducing the point loss is non-invasive, and the localised transmission loss disappears when the cable portion returns to the ambient temperature, without damage to the cable.