Cambridge Semiconductor Limited

Power Integrations, Inc.

Other

Saitek Limited

The Stanley Works

Perkinelmer Las, Inc.

Genomic Solutions Inc.

Aseptika Ltd

B.d.g. El S.r.l.

Paul Thomas Ryan

David Michael Garner

Vinod A Lalithambika

Russell Jacques

Johan Piper

Devarahandi Indika Mahesh De Silva

Catriona McKay

Kevin Andrew Auton

Kevin Auton

David Byatt

Antonius Jacobus Johannes Werner

Manoj Bhasin

Simon George-Kelso

Joe Michael Leisten

Charles W Wyatt-Millington

Colin P Wiseman

Eric K Tse

Carlo K Lo

Vinay Sajip

Jim Lindop

Kelvin R Davis

Sergei M Schurov

David John Wigley

Luigi Mazzani

Sergei Mikhailovich Schurov

We describe a user exercise-tolerance measuring pulse oximeter system, for determining the exercise tolerance or capacity of a user undergoing exercise, the system comprising: a wireless fingerband comprising an optical sensor to provide an oxygen saturation signal, a chargeable power supply, and a wireless transmitter/receiver; a motion detector to provide a user motion signal; and a signal processor coupled to said wireless fingerband to data from said optical sensor, and coupled to said motion detector; wherein said signal processor is configured to: process a combination of said oxygen saturation signal and said user motion signal to determine exercise tolerance data, wherein said exercise tolerance data is dependent upon said oxygen saturation signal and a level of exertion of said user determined from said user motion signal; and to time or count a period or quantity of user motion or movements, during said exercise, identified by said motion detector, to determine said level of exertion; to measure a degree of oxygen desaturation of blood of said user due to said exercise; and to output an exercise tolerance parameter; wherein said exercise tolerance data comprises said exercise tolerance parameter; and wherein said exercise tolerance parameter is a function of both said degree of desaturation and said level of exertion.

Medical devices and related methods

A controller for use in a power converter includes a first terminal to provide a turn on signal to initiate turning on of a power switch and a second terminal to provide a turn off signal to initiate turning off the power switch. A detection circuit is coupled to detect a turn off time delay. The turn off time delay is the duration of time between an initiating of a turn off of the power switch by the turn off signal and an actual turn off of the power switch. A control circuit is coupled to control the turn on signal to regulate the turn off delay time to a target time value. The control circuit controls the turn on signal by controlling an amount of charge delivered to turn on the power switch.

Storage time control

The invention generally relates to switch mode power converters (SMPCs). and methods for providing supplementary base drive to a bipolar transistor of an SMPC, and more particularly to a switching control circuit for a SMPC, a said SMPC having an inductive component coupled to receive power from an input to the SMPC, a bipolar transistor coupled to control current flow in the inductive component, an auxiliary power rail, a charge store for supplying power via the auxiliary rail to a switching control circuit for driving the bipolar transistor, and a bootstrap circuit for bleeding current from the input to the bipolar transistor to thereby provide an amplified current to the charge store, the switching control circuit comprising: a base current line for coupling to a base terminal of a said bipolar transistor, an emitter current line for coupling to an emitter terminal of a said bipolar transistor, an auxiliary line for coupling to a said auxiliary power rail, and at least one reference line for coupling to a reference voltage; a base current switch configured to controllably couple a base current source to the base current line; an emitter current switch configured to controllably couple the emitter current line to a said reference line; a bootstrap element for bleeding current from the emitter current line to the auxiliary line, the bootstrap element further operable to block a said current according to a current or voltage bias; a base discharge switch configured to controllably bleed current from the base current line to a said reference line; and a supplementary base drive line for coupling to a series circuit comprising a supplementary base drive resistor and current control element coupled in series, a said series circuit for bleeding current from a said input to a said base terminal, a said current control element for blocking current flow from a said bootstrap circuit to a said supplementary base drive resistor.

BJT drive scheme

A switch mode power converter (SMPC) includes a switching control system to control the turn off time delay of a switching device. The SMPC also has an inductive component including an input winding to receive power from an input and a switching device to conduct input winding current. The switching control system applies turn on and turn off signals to the switching device. The turn off signal initiates turning off of the switching device and a sensing signal from a further winding inductively coupled to the input winding is detected to indicate an end of a turn off time delay or duration. The turn on signal for a subsequent switching cycle of the SMPC device is controlled to regulate the turn off delay time.

The present invention generally relates to powering a switching controller of a switch mode power converter (SMPC), and more particularly to a method of providing power to a switching controller of a SMPC, to a charging circuit for supplying charge to a charge store for providing power to a switching controller of a SMPC, and to an SMPC comprising such a circuit. A method of providing power to a switching controller of a switch mode power converter (SMPC), the SMPC having: an inductive component having a winding coupled to receive power from an input to said SMPC; a switching circuit comprising first and second switching transistors, said first transistor coupled in series between said winding and said second transistor; a switching controller to control switching of said second transistor; and a charge store to provide power to said switching controller, the method comprising: flow of current from said winding through said first transistor; and diverting said current through a conduction path to said charge store.

Auxiliary recharge

We describe a resonant discontinuous power converter including a magnetic energy storage device, and a bipolar junction transistor (BJT) switch having a collector terminal coupled to repetitively switch power from the input on and off to said magnetic energy storage device such that power is transferred from the input to the output. During an off-period of said BJT switch a voltage on said magnetic energy storage device and on said collector terminal of said BJT is at least partially resonant. The power converter includes a voltage clamping circuit to clamp a base voltage on a base terminal of said BJT during a resonant portion of said off-period to limit an excursion of a collector voltage on said collector terminal of said BJT towards or beyond an emitter voltage of said BJT during said resonant portion of said off-period, in particular to inhibit reverse bias of a base emitter junction of the transistor.

Power converters

We describe a switch mode power supply having a power input, a switch, a transformer, and a power output. The transformer has a primary winding coupled to said power input via said switch, and a secondary winding coupled to said power output. The transformer further comprises an auxiliary winding and a coupling structure capacitatively coupled to said secondary winding of said transformer; wherein said coupling structure does not comprise a shield or screen between said primary and secondary windings. The switch mode power supply further comprises a coupling capacitor connected between said coupling structure and said auxiliary winding to provide a noise suppression voltage from said auxiliary winding to said secondary winding to at least partially cancel a common mode noise voltage on said secondary winding from unshielded coupling from said primary winding.

Noise reduction systems and methods for unshielded coupling of switch mode power supply

We describe a switching power converter comprising a bipolar switching device (BJT or IGBT) switching an inductive load, and including a closed-loop control system. The control system comprises a voltage sensing system to sense a voltage on a collector terminal of the switching device and provide a voltage sense signal; a controller; and a drive modulation system coupled to an output of the controller for modulating a drive to the control terminal of said bipolar switching device responsive to a controller control signal; wherein said controller is configured to monitor changes in the sensed voltage during a period when said switching device is switched on and to control said drive modulation system to control the degree of saturation of said bipolar switching device when the device is switched on and hence improve turn-off times.

Bipolar transistor drivers

This invention relates to control techniques and controllers for resonant discontinuous forward power converters (RDFCs). A method of controlling a resonant discontinuous forward converter (RDFC), said converter including a transformer with primary and secondary matched polarity windings and a switch to, in operation, cyclically switch DC power to said primary winding of said transformer, said converter further having a DC output coupled to said secondary winding of said converter, said method comprising: sensing a primary winding signal during an on period of said switch, said primary winding signal representing a current in said primary winding; comparing said sensed primary winding signal with a threshold value; and controlling one or both of an on and off duration of said switch in response to said comparison.

Forward power converter controllers

This invention relates to control techniques and controllers for resonant discontinuous forward power converters (RDFCs). A controller for a resonant discontinuous forward converter (RDFC), said converter including a transformer with primary and secondary matched polarity windings and a switch to, in operation, cyclically switch DC power to said primary winding of said transformer, said converter further having a DC output coupled to said secondary winding of said converter, said controller having a primary sense input to sense a primary winding signal, said primary winding signal representing a voltage across said primary winding or across an additional winding coupled to said primary winding, and wherein said controller is configured to switch on said switch in response to detection of a reduction in a rate of change of said primary winding signal below a threshold, adjacent a substantially minimum value in an operational cycle of said sensed primary winding signal to convey power to said DC output.

This invention relates to control techniques and controllers for resonant discontinuous forward power converters (RDFCs). A method of controlling a resonant discontinuous forward converter (RDFC), said converter including a transformer with primary and secondary matched polarity windings and a switch to, in operation, cyclically switch DC power to said primary winding of said transformer, said converter further having a DC output coupled to said secondary winding of said converter, said method comprising: sensing a transformer signal, said transformer signal representing a voltage across a winding of said transformer or a resonant current in a winding of said transformer; calculating a resonance period of said RDFC from said sensed transformer signal; and controlling an off duration of said switch in response to said calculated resonance period such that a sub-harmonic oscillation in said resonant voltage across said primary winding is reduced.

An assay device in which to carry out a fluid-phase chemical assay, comprising means for supporting a test substrate, a sample chamber for receiving a fluid sample and at least one fluid control device for controlling the movement of fluid into and/or out of the sample chamber, wherein the fluid control device comprises a fluid outlet chamber in fluid communication with the sample chamber, and a displaceable flexible diaphragm the displacement of which alters the volume of the outlet chamber so as to allow and/or restrict fluid flow between the outlet and sample chambers. The invention also provides assay apparatus incorporating such a device, an assay station for use as part of such apparatus, a fluid control unit for use as part of the assay device and a method of conducting an assay which may involve the use of such apparatus and devices.

Chemical assays

A system for automated excision of one or more samples from a sample media, including by using a device for electronically capturing one or more traits of samples in the media, using a microprocessor linked to the device to analyze the captured traits by comparison to reference databases, identifying samples of interest at location coordinates in the sample media, and automatically excising and processing the samples through the use of a novel robotic excision tool.

Method and apparatus for automated excision of samples from two-dimensional electrophoresis gels

An apparatus and method for chemical processing of multiple mixtures is disclosed. The apparatus provides selective purging of a liquid-phase of the mixtures. The apparatus can be used for processing many different types of mixtures under a wide variety of processing conditions, including but not limited to protein digestions, and is particularly well suited for processes requiring solid-liquid contacting. The apparatus includes an array of vessels or wells for containing the mixtures. The wells have openings that generally define a surface. A perforated plate and a film are disposed above the openings of the wells. The film is sandwiched between the perforated plate and the surface defined by the openings of the vessels, covering and sealing the vessels. A probe is used to perforate the film and to pressurize the vessels, which drives liquid out of the wells via through-holes formed in their bottoms.

Growing community of inventors

Cambridgeshire, United Kingdom

Paul Thomas Ryan