Bose Corporation

Gsi Group Corporation

Gsi Lumonics Corporation

Other

Surface Logix, Inc.

Michael B Nussbaum

Timothy W Sheen

Daniel Scott Pearce

Manoel Soares

Kenneth B Delpapa

David C Brown

Felix Stukalin

Joseph Taher Mossoba

Andrew Ferencz

Thomas A Froeschle

George Nichols

Jay N Teixeira

Michael R Shannon

Enoch Kim

Gregory Kirk

Bradley L Hunter

Charles R Barker, Iii

Remco Terwal

Kurt A Pelsue

Raymond O England

Adam Christopher Broders

Zoran Coric

Edward L Kelley

Christopher J Perkins

Aaron Raphel

Rocco Casagrande

Evelyn Wang

Joseph F Deck

Alvaro Kaplan

Steven D Owen

Ali Mohammadpour

Laura J Schroeder

Frederick A Stewart

Fredrick A Stewart

Evghenii Onoicenco

Anthony G Esposito

Jr John Michael Kitchura

Alfred G Giombetti

The technology described in this document can be embodied in an apparatus that includes at least four magnetic cores, wherein each core is for supporting an inductor of a filter circuit. Each of the cores include a first section, and a second section separated from the first section by an adhesive layer. The apparatus also includes an air-core structure to store magnetic energy, the air-core structure including a set of focusing projections that define a hollow cavity. The individual focusing projections of the set are disposed on different sides of the hollow cavity to focus magnetic field from the at least four magnetic cores through the hollow cavity.

Magnetic structures for filtering amplifier outputs

An example method for controlling a circuit may include determining an input signal in a circuit, the input signal comprising distortion; determining a fundamental component of the input signal; determining an error of the input signal using the input signal and the fundamental component; determining a distortion metric using the error; and controlling the circuit as a function of the distortion metric.

Adjustment of circuit operations in response to AC line distortion

An example circuit may include an inductor; a low-frequency sensor connected to the inductor; a high-frequency sensor connected to the inductor; and an integrator connected to the low-frequency sensor and the high frequency sensor, comprising one or more resistive devices and one or more capacitive devices, wherein the integrator is characterized by a time constant that varies as a function of the inductance of the inductor. The inductor may, for example, be part of a switched-mode power supply or an amplifier.

Current sensor

Example circuitry includes: a transformer circuit having first windings and second windings, where the second windings are magnetically orthogonal to the first windings; first transistors to provide a first voltage to a load, where each of the first transistors is responsive to a first control signal that is based on a first signal through a first winding; second transistors to provide a second voltage to the load, where each of the second transistors is responsive to a second control signal that is based on the first through the first winding, and where the first and second control signals cause the first transistors to operate in a different switching state than the second transistors; and control circuitry responsive to signals received through the second windings to control the first transistors and the second transistors to operate in a same switching state.

Gate drive circuit

An apparatus includes: a power supply circuit including at least a first stage having a push-pull circuit topology, the first stage including at least one transformer that isolates a primary side of the first stage from a secondary side of the first stage; a clamp circuit coupled to a center tap of the transformer, the clamp circuit including a first element that stores energy, and a second element that controls a flow of current between the center tap of the transformer and the first element; and a control module receiving power from the clamp circuit. The control module is configured to provide control signals to one or more elements of the power supply circuit.

Managing leakage inductance in a power supply

Circuits and techniques for improving power converter efficiencies and controllability are disclosed. For example, a first converter stage includes a push-pull circuit topology and an isolating element including a magnetizing inductance for isolating a primary side of the first converter stage from a secondary side of the first converter stage. The magnetizing inductance may vary as a function of a current flowing in the primary side of the first converter stage. For example, the isolating element can be a transformer with a stepped gap core and have a varying magnetizing inductance profile.

Power supply with switching converter

A power supply injects a series of 'tickle' pulses into a pulse width modulated (PWM) controller to induce the controller to generate PWM pulses at a minimum switching frequency, preferably one that is super-sonic (especially for audio applications). The switching frequency may also be selected or controlled such that it avoids resonances in the power supply. The 'tickle' pulses may be clocked by the same clock that times the PWM controller, and they may be shaped to help ensure that the power supply maintains some regulation during low-load conditions.

Power supply with tickle pulse injection

An audio power amplifier includes a first and a second amplification unit, each including a switching voltage amplifier, an output filter, a current compensator, an inner current feedback loop feeding a measurement of current measured at the output inductor back to a summing input of the current compensator, a voltage compensator coupled to the summing input of the current compensator, and an outer voltage feedback loop. A controlled signal path provides the output of the voltage compensator of the first amplification unit to the current compensator of the second amplification unit. The first and second amplification units are operable with separate loads, in parallel driving a common load, or across a bridge-tied-load. A second pair of amplification units may be added and operated together with the first pair to drive a single speaker with a parallel pair of amplifiers on each side of a bridge-tied-load.

Versatile audio power amplifier

A power conversion device includes a magnetic core; and a plurality of windings surrounding portions of the magnetic core, including a first set of windings defining a first magnetic flux path, a second set of windings defining a second magnetic flux path magnetically orthogonal to the first magnetic flux path, and a third set of windings. Each winding of the third set of windings is configured to be excitable via both the first flux path and the second flux path.

Power converter using orthogonal secondary windings

An apparatus for driving speakers includes user-configurable amplifier cells for driving selected speakers, a synchronous rectifier circuit, and a control system. Each cell connects between power rails. The rectifier circuit provides current on the rails for consumption by the cells. The current depends on the configuration. The control system implements a model of the rectifier circuit and cells and uses it to control an audio input signal in response to information concerning electrical outputs of the amplifier cells. This indirectly limits current drawn from the synchronous rectifier circuit.

Power supply with rectifier protection

An electrical apparatus to sense current through a load includes a first input terminal having a first input voltage relative to a reference, a second input terminal having a second input voltage relative to the reference, a first load terminal of the load having a first load voltage relative to the reference, a second load terminal of the load having a second load voltage relative to the reference, a first current sensing element connected between the first input terminal and the first load terminal and a second current sensing element connected between the second input terminal and the second load terminal. A first sense voltage is determined by a relationship between the first input voltage and the second load voltage and a second sense voltage is determined by a relationship between the second input voltage and the first load voltage.

Audio system with synthesized positive impedance

A method for pulse width modulation control of a multiple phase drive includes identifying at least one phase from the plurality of phases for the drive as eligible for clamping to one of a plurality of extreme power supply voltages, selecting a phase of the eligible phases having a largest magnitude driving current, determining a first offset signal as a difference between a control signal level for the selected phase and an extreme control signal level corresponding to one of the extreme power supply voltages, limiting a rate of change of the first offset signal to form a second offset signal, and determining a modified control signal for each of the phases for the drive including forming for each of a plurality of the phases a combination of the second offset signal and a control signal level for the phase to determine the modified control signal for the phase.

Rate limited common mode control for pulse-width modulation drives

Growing community of inventors

Newton, MA, United States of America

Michael B Nussbaum