General Electric Company

John Andrew Mallick

Gerald Burt Kliman

Manoj Ramprasad Shah

Glenn A Forman

Sharbel E Noujaim

Eike Richter

Philippe L Jacob

Robert Louis Steigerwald

William A Edelstein

Eddy Benjamin Boskamp

Sayed-Amr A El-Hamamsy

John Norton Park

Ronald Dean Watkins

Charles S Korman

John F Schenck

Israel S Jacobs

Waseem A Roshen

George M Rosenberry, Jr

Randy Otto John Giaquinto

Thomas A Nondahl

Sang Bing Lee

A method for evaluating core stack pressure includes: positioning a magnetic yoke near the core, the magnetic yoke being wound by an excitation winding; supplying current to the excitation winding to inject magnetic flux into the core; measuring a signal resulting from the injected magnetic flux; and using the measured signal to evaluate the core stack pressure. A system for implementing the method includes the magnetic yoke; a current supply for supplying the current; a sensor for measuring the signal; and a computer for using the measured signal to evaluate core stack pressure.

Method and system for evaluating core stack pressure

A method for detecting core faults includes (a) positioning a magnetic yoke near at least one tooth of the core, the magnetic yoke being wound by a winding; (b) supplying current to the winding to inject magnetic flux into the at least one tooth of the core; (c) measuring a signal resulting from the injected magnetic flux; and (d) using the measured signal to detect core faults.

Method and system for detecting core faults

A quadrature coil suitable for use with an open frame MRI system provides crossing pairs of arrays of parallel conductor elements, respectively. Compact configuration is provided through use of an isolating circuit for incorporating parasitic capacitances at the resonance frequency of the coil into a blocking parallel resonance. Termination of the parallel conductor elements may be accomplished by equal impedance node connectors formed from branching pairs of conductors or a triangular least resistance connection form. RF shields are provided by pairs of conductive sheets containing eddy current reducing slots aligned with the parallel conductors elements of the coil.

Radio frequency coil for open magnetic resonance imaging system

A sensing coil affixed to the outside of an induction motor housing uses flux signals from the motor to measure motor speed. In particular, components of the rotor current are measured and compared to analysis from stator fundamentals and sidebands to determine the true rotor frequency which can then be used to determine the motor speed. A shield and/or a compensating coil can optionally be used to filter out extraneous signal noise.

Non-intrusive speed sensing for induction motors

A high frequency, high density, low profile magnetic circuit component includes a magnetic core having a first magnetic layer and a second magnetic layer with a conductive layer deposited therebetween, each magnetic layer being a multilayer structure comprised of alternating magnetic and insulating films. The magnetic films are anisotropic and are driven along their magnetic hard axis in order to reduce excess eddy current losses. To reduce fringing field eddy current losses, a distributed air gap is structured in the magnetic layers. The magnetic core has a distributed air gap formed therein in order to minimize eddy current losses in the conductive layer. The conductive layer has a conductive material patterned on a insulating substrate and is situated between the first and second magnetic layers such that the conductive material extends beyond the peripheries of the first and second magnetic layers, thereby maximizing the amount of magnetic material that is driven in the hard axis.

High frequency, high density, low profile, magnetic circuit components

Power is transferred from a stationary power supply to a rotational gantry in a computer tomography (CT) system through a rotary transformer arranged in a ring configuration with an inner diameter that is sufficiently large to receive a patient. The rotary transformer has a toroidal rotor core and a toroidal stator core arranged either concentrically with an air gap extending radially therebetween or side-by-side with an air gap extending axially therebetween. A resonant inverter provides ac power to the rotary transformer which, in turn, drives a high-voltage tank circuit coupled to a x-ray tube, the tank circuit and x-ray tube being mounted on a rotational gantry. Advantageously, this is a contactless power transfer system which eliminates conventional brush and slip ring arrangements and moreover avoids the need for mounting the inverter to rotate with the CT gantry.

Contactless power transfer system for a rotational load

A system and method for noiseless measurement of a biomagnetic field uses magnetic field magnitude and gradient measurement at a reference point together with mathematical extrapolation techniques to provide an effectively infinite order gradiometer response from a lower order physical gradiometer. Such a system has the advantages of potentially lower cost, higher accuracy, and easier adjustment and balancing.

Noise cancellation method in a biomagnetic measurement system using an

The plural-phase clocking signal used in a subsampling time-domain digital filter is partially blanked to generate a sparse clocking signal for a clocked data latch that decimates the output signal from the digital filter, to supply it at a subsampling rate as compared to the sampling rate of input signal to the filter. The blanking signal is generated from a counter that counts occurrences of pulses in the plural-phase clocking signal, which counter comprises a ripple-carry adder and another clocked data latch arranged to accumulate successive unit values. This procedure guarantees correct timing of clocking signal for the output latch vis-a-vis the plural-phase clocking signal used in the preceding time-domain digital filter despite the time taken for carry ripplethrough in the counter adder. Digital hardware is conserved by blanking only one phase of the plural-phase clocking signals.

Subsampling time-domain digital filter using sparsely clocked output

Instantaneous trip capability is provided to an electronic circuit breaker, which is of the type that generates trip signals by accumulating squares of power line current samples and thresholds the accumulation results. Samples of power line current are taken directly from the current transformer and analog-to-digital converter cascade generating them. The analog-to-digital converter is of an oversampling type, using a delta-sigma modulator. The samples are threshold detected against a prescribed threshold value without previous squaring, integration and detection. The threshold detector result is checked for two consecutive overcurrent indications before an instantaneous trip signal is generated.

Electronic circuit breaker using digital circuitry having instantaneous

A magnetic wedge for use in toothed stators holds the stator windings in the slots formed between the teeth of the stator. The magnetic slot wedge comprises a stack of magnetic material with a width corresponding to the width of the slot. The laminations each have central bridge portions connecting a first and second magnetic region, the bridge portion saturating during machine operation. The bridge and the first and second magnetic regions define an opening which, when the laminations are stacked, form a channel having a narrowed entrance. A fiberglass rod fits inside the channel and provides axial stiffness to the stacked laminations which clamp on the fiberglass rod.

Magnetic slot wedge with low average permeability and high mechanical

A homopolar inductor-alternator machine is constructed to have lower transient rectances by the incorporation of a current conducting ring concentric with the axis of the rotor and positioned on the rotor and/or the stator. The conducting ring helps prevent time varying fluxes from inducing eddy current flow in the high permeability rotor steel and unlaminated stator flux return path (back iron). The conducting ring acts upon the transient fluxes which occur in the DC flux path of the machine.

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Scotia, NY, United States of America

John Andrew Mallick