Qing Chen

US Patent:

6618274, Sep 9, 2003

Filed:

Oct 9, 2001

Appl. No.:

09/973218

Inventors:

Jeffrey John Boylan - Richardson TX
Qing Chen - Plano TX
Jin He - Plano TX
Del Ray Hilburn - Mesquite TX

Assignee:

Innoveta Technologies - Plano TX

International Classification:

H02M 3335

US Classification:

363 17, 363 2106, 363 2114, 363 26, 363 65, 363 89

Abstract:

A control scheme for a synchronous rectifier converter that avoids disabling the synchronous rectifiers entirely. Rather than disable the synchronous rectifier altogether to stop the flow of reverse current in light-load, startup, or shutdown conditions, the duty cycle of the synchronous rectifier is modified such that forward current is always allowed to flow through the synchronous rectifier, but the synchronous rectifier is turned off before the reverse current flow reaches a pre-determined level. This is accomplished by operating the converter in a partially synchronous mode of operation during light-load, startup, or shutdown conditions. Whether the circuit is in a light-load, startup, or shutdown condition is determined by a circuit characteristic of the converter that is sensed by the controller, such as average output current. The desired changeover point from fully-synchronous mode to the partially synchronous mode is set to a predetermined level of output current for the converter. The predetermined level is set based on the particular power system in which the invention is implemented.

US Patent:

6728118, Apr 27, 2004

Filed:

Nov 13, 2002

Appl. No.:

10/293722

Inventors:

Qing Chen - Plano TX
Victor Ke-Ji Lee - Plano TX

Assignee:

Innoveta Technologies, Inc. - Plano TX

International Classification:

H02M 3335

US Classification:

363 24, 363 98

Abstract:

The invention presents a highly efficient, tightly regulated DC-to-DC converter which can be used in various applications, especially multiple output converters. The converter uses a buck converter to produce an intermediate bus voltage. A current-fed double ended circuit, such as bridge or push-pull circuit, couples to the buck converter to provide power to outputs. The double ended circuit operates at about 50% duty. The secondary output filter inductor is not required. With 50% duty cycle operation, the secondary rectifiers are easily controlled by either a self-driven or an external driven circuit. The secondary windings can also be stacked up to simplify the transformer design. In addition, bias voltages needed for control circuitry can also be obtained by adding extra windings to the power transformer and extra rectifier devices.

US Patent:

D507247, Jul 12, 2005

Filed:

Jun 17, 2002

Appl. No.:

29/162517

Inventors:

Qing Chen - Plano TX, US
Randy Thomas Heinrich - Rockwall TX, US
Del Ray Hilburn - Mesquite TX, US
Victor Ke-Ji Lee - Plano TX, US

Assignee:

TDK Innoveta Inc. - Richardson TX

International Classification:

1303

US Classification:

D13182

US Patent:

20030080723, May 1, 2003

Filed:

Mar 6, 2002

Appl. No.:

10/091788

Inventors:

Qing Chen - Plano TX, US
Jin He - Plano TX, US
Del Hilburn - Mesquite TX, US
Victor Lee - Plano TX, US

International Classification:

G01R023/165

US Classification:

324/076290

Abstract:

Compared with the prior art, the invention offers several extra benefits in addition to providing a dc current signal from a sensed peak current signal. First, the control switch is referenced to the ground, and therefore floating drive for the series switch in the prior art is not necessary. Second, the peak current signal is always available regardless of the status of the control switch. By separating the peak and average current signals, the converter can be better controlled and both peak current mode control and current sharing control can be optimized. Finally, referencing the peak current and average current signals to the different grounds provides freedom to implement different control schemes.

US Patent:

20120054184, Mar 1, 2012

Filed:

Aug 22, 2011

Appl. No.:

13/214720

Inventors:

Mohammad Mehedy Masud - Dallas TX, US
Latifur Rahman Khan - Plano TX, US
Bhavani Marienne Thuraisingham - Dallas TX, US
Qing Chen - Plano TX, US
Jing Gao - Urbana IL, US
Jiawei Han - Urbana IL, US

Assignee:

BOARD OF REGENTS, THE UNIVERSITY OF TEXAS SYSTEM - Austin TX

International Classification:

G06F 7/00
G06F 17/00

US Classification:

707737, 707E17091

Abstract:

Systems and methods for data classification and novel data class detection are provided. In one illustrative embodiment, a system or method for detecting a novel class includes receiving a data stream comprising a plurality of data points, and identifying a set of filtered outliers, in the plurality of data points, that are outside of a decision boundary. A cohesion and a separation for the set of filtered outliers may be determined. A novel class may be detected using the cohesion and the separation of the set of filtered outliers, and the novel class may include the set of filtered outliers.

US Patent:

58779477, Mar 2, 1999

Filed:

Jul 30, 1997

Appl. No.:

8/903407

Inventors:

Qing Chen - Plano TX
Victor Ke-Ji Lee - Plano TX

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H02H 7125
H02H 7122
H02M 75387

US Classification:

363 53

Abstract:

For use in a power converter having a rectifier coupled to an output thereof, a snubber circuit including an energy storage device coupled to the rectifier that moderates a voltage across the rectifier and a method of moderating the voltage. In one embodiment, the snubber circuit includes: (1) a first switch that regulates a voltage across the energy storage device, (2) an inductor, coupled to the first switch, that provides a discharge path for energy stored in the energy storage device when the first switch is conducting and (3) a second switch that recovers energy stored in the inductor to the output when the first switch is not conducting. The snubber circuit thereby reduces voltage stress across the rectifier during a current limit mode of operation.

US Patent:

62979728, Oct 2, 2001

Filed:

May 10, 2000

Appl. No.:

9/567881

Inventors:

Qing Chen - Plano TX

International Classification:

H02M 545

US Classification:

363 37

Abstract:

A dual input power supply, a method of operating the power supply and a telecommunications power plant incorporating the power supply or the method. In one embodiment, the power supply includes: (1) a single stage power converter, coupled to an input of the power supply, configured to receive primary power subject to interruption and provide therefrom DC power to a DC bus; (2) an output power stage, coupled to the DC bus, configured to condition the DC power for delivery to an output of the power supply; and (3) a backup power stage, couplable to a backup power source and having an output coupled to the DC bus, configured to provide backup power during the interruption, the single stage power converter configured to restrict a reverse flow of the backup power therethrough during the interruption.

US Patent:

58748261, Feb 23, 1999

Filed:

Oct 29, 1997

Appl. No.:

8/960633

Inventors:

Qing Chen - Plano TX
Del Ray Hilburn - Mesquite TX
Ashraf Wagih Lotfi - Rowlett TX

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H02M 706

US Classification:

323222

Abstract:

A boost converter module, a method of manufacturing the module and a power converter employing one or more of the same. In one embodiment, the boost converter module includes: (1) a power switch, (2) first and second snubber diodes series-coupled between the power switch and a converter output, (3) a snubber capacitor and a boost diode series-coupled across the second snubber diode and (4) an encapsulant substantially surrounding the power switch, the first and second snubber diodes, the snubber capacitor and the boost diode to join the power switch, the first and second snubber diodes, the snubber capacitor and the boost diode into an integrated package, the integrated package having: (4a) a control input coupled to the power switch, (4b) a power input coupled to the power switch, (4c) a snubber inductor input, coupled to a node between the snubber capacitor and the boost diode and (4d) a power output coupled to the converter output.