Isis Innovation Limited

Salunda Limited

Magma Global Limited

Other

John Francis Gregg

Martin Peter William Jones

Alan David Parker

Charles Alexander Tavner

Mazhar Ali Bari

Alexy Davison Karenowska

Martin Roy Harrison

Peter Wherritt

Philip Samuel Pickles

Patricia Dresel Sparks

Martin Peter Jones

Mazhar Bari

A fluid conduit comprises a wall defining a fluid flow path and a confinement feature within the wall and being configured to confine energy within a cavity, wherein at least a portion of the fluid flow path extends through the cavity. The confinement feature may be configured to confine electromagnetic energy. The fluid conduit may comprise an oscillator defined by the cavity and a positive feedback arrangement. The fluid conduit may be configured for sensing a property of a fluid present in or flowing through the fluid conduit or for use in sensing a property of a fluid present in or flowing through the fluid conduit.

Fluid conduit

A fluid conduit () comprises a wall () defining a fluid flow path () and a confinement feature () within the wall () and being configured to confine energy within a cavity (), wherein at least a portion of the fluid flow path () extends through the cavity (). The confinement feature () may be configured to confine electromagnetic energy. The fluid conduit () may comprise an oscillator defined by the cavity () and a positive feedback arrangement (). The fluid conduit () may be configured for sensing a property of a fluid present in or flowing through the fluid conduit () or for use in sensing a property of a fluid present in or flowing through the fluid conduit (). More specifically, the present invention deals with a microwave cavity sensor wherein the cavity member () is embedded in the wall () of the fluid conduit (), the wall () including a composite region ().

A wind turbine and generator arrangement comprises a turbine that drives a self-excited induction generator via a shaft and mechanical gearbox. The induction generator includes an electrical circuit that includes a variable capacitance and a variable resistance. The variable capacitance may be constituted by a fixed capacitor and a triac under the control of a controller, or by a bank of capacitors switched by a relay under control of the controller. The variable resistance includes a triac controlled resistor or a bank of relay-switched resistors which constitute heating elements for heating domestic hot water. In use the generator frequency and voltage are allowed to 'float' while the optimal generator power output is maintained, but adjusting the impedance of the electrical circuit as the wind speed varies.

Electricity generator

Target sensor comprising: sensor probe having a resonance frequency that changes as the separation of the sensor probe and a target changes. Oscillator arranged to apply a radio frequency (RF) signal to the sensor probe, the oscillator having: control circuitry configured to regulate the frequency of the RF signal applied to the sensor probe to below the resonance frequency of the sensor probe. Detector arranged to detect an electrical characteristic of the oscillator that varies with the impedance of the sensor probe indicating an interaction of the sensor probe with the target.

Target sensor

An electrical, magnetic or electromagnetic delay line self oscillator is described with a delay line arrangement, an oscillator control circuitry, and a frequency selection impedance connecting the delay line arrangement and the oscillator control circuitry and presenting an impedance to the delay line arrangement. The oscillator control circuitry includes an amplifier, a non linear amplitude control element (N-LACE) such as an active device with a negative differential conductance that provides an output amplitude has a negative second derivative with respect to an input signal, and a driver. The modal characteristics of electromagnetic delay lines can thus be exploited across a wide range of instrumentation applications, and a means is provided to enhance the achievable functionality and/or performance of the instrumentation without the need for expensive additional electrical hardware or electronics.

Delay-line self-oscillator

Apparatus comprising: a radio frequency (RF) Robinson oscillator comprising: a resonator comprising a sensor rhumbatron, the sensor rhumbatron comprising a cavity member, the cavity member having a re-entrant boss member, the re-entrant boss member being arranged to project into a cavity portion of the cavity member; a feedback element arranged to provide positive radio frequency (RF) feedback to the cavity member thereby to increase a quality factor Q of the cavity member, the feedback element having first and second terminals coupled to the cavity member, the apparatus being operable to cause the oscillator to oscillate at a resonant frequency; and an output arranged to provide a signal that varies according to a value of at least one electrical parameter of the oscillator, said at least one electrical parameter being selected from amongst an electromagnetic loss and a resonant frequency.

Microwave cavity sensor

There is described a position sensor comprising a sensor electromagnetic field generator, a screen arranged to confine the sensor electromagnetic field, and an output. The output is arranged to provide a signal which varies in dependence upon an amount of flux compression of the electromagnetic field resulting from the presence of the screen. The amount of flux compression is related to a position of the screen in relation to the sensor electromagnetic field generator. There is also described a method of detecting a relative position of an electromagnetic field generator and a screen.

Electromagnetic field-based position sensor

A position and electromagnetic field sensor is provided. The sensor relies upon an oscillator such as a Robinson marginal oscillator to generate an rf or microwave electromagnetic field. As an inhomogeneously shaped object, such as a metallic toothed wheel, for example, moves through the resultant field, the field experiences a change in electric or magnetic susceptibility. This in turn causes energy losses in the oscillator the magnitude of which can be output as a d.c. signal related thereto. To detect non-moving objects which nevertheless generate an electromagnetic field or have attached to them a source thereof, the sensor also includes a giant or colossal magnetoresistive structure located adjacent the oscillator coil, the structure having an imaginary magnetic susceptibility which is strongly dependent upon the magnitude and direction of the field generated by or at the object to be sensed.

Position and electromagnetic field sensor

A spin transistor () comprises a spin injector () formed of a ferromagnetic material and constituting the emitter () of a three-terminal device, a spin filter () also formed of a ferromagnetic material and constituting a collector (), and a semiconductor base () region. A tunnelling barrier () is formed of an insulating metal oxide such as aluminium oxide between the emitter () and the base (). The tunnelling barrier () reduces the degree of spin depolarization as carriers are injected into the base (), and permits selection of spin injection energy. In preferred embodiments, a second tunnelling barrier () may be formed between the base () and the collector (). A method of manufacture is also provided.

Spin transistor

A spin transistor is a hybrid magnetic/semiconductor transistor in which a magnetically controllable barrier is provided between a semiconductor base and collector to control the diffusion of charge carriers to the collector. With the spin transistor, the charge carrier populations are distinguished by the direction of the spin or magnetic moment of the carriers instead of the electronic charge. A spin injector is used to spin polarize the charge carrier population so that the population has a selected magnetic moment which population may or may not be enabled to flow to the collector via the magnetic barrier. The spin transistor utilizes the electronic characteristics of a conventional semiconductor transistor in combination with a carrier flow controlled by magnetic moment to maximize gain.

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Oxford, United Kingdom

John Francis Gregg