Gm Global Technolgoy Operations, Inc.

Sonos, Inc.

Samsung Electronics Co., Ltd.

Raytheon Company

Hrl Laboratories, LLC

Taiyo Yuden Co., Ltd.

Braxton Engineering, Inc.

James Lazar

Mark Polomski

Lateef A Kajouke

Keming Chen

Joe Anthony Ortiz

Robert F Stiffler

Philip C Todd

James Michio Nagashima

Hasan Sharifi

Jongchan Kang

Ara K Kurdoghlian

Scott D Downer

Pascal M Brunet

Harris P Moyer

One embodiment provides a system comprising a single DC voltage source and a Class-D amplifier comprising at least one DC/DC converter operated by the single DC voltage source. The amplifier is configured to receive an input signal for power amplification, and generate, via the at least one DC/DC converter, a DC output voltage that approaches or exceeds a DC supply voltage from the single DC voltage source. A gain of the amplifier is a ratio of the output voltage level to the input signal. A steady-state operating point of the at least one DC/DC converter is zero output.

Boost amplifier

One embodiment provides a method for nonlinear control of a loudspeaker. The method comprises determining a target displacement of a diaphragm of a speaker driver of the loudspeaker based on a physical model of the loudspeaker and a source signal for reproduction via the speaker driver. The method further comprises determining, based on the target displacement, a corrected drive signal that compensates for action of reluctance force on the speaker driver during the reproduction of the source signal, and transmitting the corrected drive signal to a power amplifier connected to the loudspeaker. The power amplifier drives the speaker driver based on the corrected drive signal. Audio distortion generated by the speaker driver during the reproduction of the source signal is reduced based on the power amplifier output, via the corrected drive signal.

Reluctance force compensation for loudspeaker control

A circuit for driving a switched transistor comprises: a level shifter comprising at least one transistor, the level shifter configured to convert an input pulse to a pulse having a greater voltage swing than the input pulse and shift a voltage level of the converted pulse; and a pulse shaping filter coupled between the level shifter and the gate of the switched transistor, the pulse shaping filter tuned to cancel or reduce an impedance of the gate of the switched transistor. The switched transistor and/or the at least one transistor are a GaN High Electron Mobility Transistor (HEMT).

Circuit for driving switched transistor and filter, circulator and correlator including the same

One embodiment provides a system for nonlinear control of a loudspeaker. The system comprises a current source amplifier connected to the loudspeaker, and a controller connected to the current source amplifier. The controller is configured to determine a target displacement of a diaphragm of the speaker driver based on a source signal for reproduction via the loudspeaker, determine a control current based on the target displacement of the diaphragm and a first physical model of the loudspeaker, and transmit a control current signal specifying the control current to the current source amplifier. The current source amplifier outputs the control current to drive the speaker driver based on the control current signal. An actual displacement of the diaphragm during the reproduction of the source signal is controlled based on the control current, via the control current signal.

Nonlinear control of loudspeaker systems with current source amplifier

Techniques for providing multiple power supplies in electronic devices are disclosed. According to one aspect of the present invention, an appropriate power supply is provided only to accommodate a volume setting. In other words, there are at least two power supplies, one with a low voltage and the other with a high voltage. The high voltage power supply is only applied when there is a need to accommodate a volume setting. Thus the power consumption of the amplifiers is well controlled. As a result, the designs of the device and heat dissipation therein can be simplified and lowered in cost.

Power supplies

A high-power laser system includes a plurality of cascaded diode drivers, a pump source, and a laser element. The diode drivers are configured to generate a continuous driver signal. The pump source is configured to generate radiated energy in response to the continuous driver signal. The laser element is disposed downstream from the pump source and is configured to generate a laser beam in response to stimulation via the radiated energy. The high-power laser system further includes an electronic controller configured to output at least one driver signal that operates the plurality of diode drivers at a fixed frequency. The at least one driver signal operates a first cascade diode driver among the plurality of diode drivers 90 degrees out of phase with respect to a second cascade diode driver among the plurality of diode drivers.

Laser diode driver with variable input voltage and variable diode string voltage

Multi-tier power supply for audio amplifiers

A circuit that has one or more control units that divide a load into two or more load groups, with each load group comprised of at least one load element. The one or more control units directing power from a power source to one or more of the load groups based on voltage variations in an output of the power source, load grouping, and operational parameters of the load elements. The circuit further includes one or more pass stages that regulate current flow from the power source to the load groups.

Source and multiple loads regulator

A power conversion circuit includes a current section, a transformer, and a voltage section. The current section includes inductors configured to produce a boosted output voltage from a voltage sourse when then current section is operating in a forward direction. The transformer includes a primary winding electrically coupled to the secondary winding and configured to drive a load. The voltage section includes a pluralaty of balancing switchtes configured to actively driven to provide a DC voltage to the load. The balancing switches balance energy between the current section and the voltage section when the power conversion circuit is the load and operating in the forward direction.

Stable power conversion circuits

A DC-DC converter comprises an input circuit that stores inductive energy that includes a first switch that releases the stored inductive energy. A transformer includes a primary winding that communicates with the input circuit and a secondary winding. An output circuit communicates with the secondary winding and that includes first and second output conductors and a first diode that communicates with one end of the secondary winding and the first output conductor. A second diode communicates with one end of the secondary winding and the second output conductor. A third diode communicates with an opposite end of the secondary winding and the first output conductor. A fourth diode communicates with an opposite end of the secondary winding and the second output conductor. A first capacitor is connected in parallel to the third diode. A second capacitor is connected in parallel to the fourth diode.

DC converter circuit with overshoot protection

An active filtering method and apparatus for controlling a current generator that sources/sinks an APF current for compensating polluting harmonics on a power line connecting a power source and a load. A feedback loop regulates the APF current by sensing the current output of the current generator and the current flowing through the load. The feedback loop controls the current generator to force the APF current to track a current command signal to effectively limit the APF current to a safe value within the limitations of a particular design.

Current control method and apparatus for active power filters

A DC/DC converter includes a first leg and a second leg. A controller employs hard switching in the first leg to reduce the conduction loss. The controller employs zero voltage in the second leg to reduce the switching loss.

Growing community of inventors

Moorpark, CA, United States of America

James Lazar