Trung T Nguyen

US Patent:

6522190, Feb 18, 2003

Filed:

Oct 31, 2001

Appl. No.:

09/999103

Inventors:

Randhir Singh Malik - Cary NC
Trung Minh Nguyen - Durham NC
William Hemena - Raleigh NC

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H03K 1762

US Classification:

327408, 327 63, 307 64

Abstract:

The present invention provides a highly efficient power supply with redundant multiple input voltage sources. The power supply uses switching transistors, specifically MOSFETs, to create paths for current from one of the voltage sources to the load. The switching transistors are switched either âonâ or âoffâ by comparators which compare the output from the voltage sources. These comparators allow the highest voltage source to provide power to the load, and keep the other switching transistors âoffâ that connect the common load to other voltage sources. Because the switching transistors have lower conduction losses than diodes in conventional power supplies, the power supply in accordance with the present invention is more efficient.

US Patent:

7679217, Mar 16, 2010

Filed:

Dec 28, 2007

Appl. No.:

11/966432

Inventors:

Cecil C. Dishman - Raleigh NC, US
Eino A. Lindfors - Raleigh NC, US
Randhir S. Malik - Cary NC, US
Trung M. Nguyen - Morrisville NC, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H02J 9/00

US Classification:

307 64, 307 87

Abstract:

An apparatus, system, and method are disclosed for a high efficiency redundant power system. First and second power supplies are connected in parallel to power a load. Each power supply includes a primary stage and a regulator stage. Each primary stage regulates voltage on an internal bus that is input for each regulator stage. Each regulator stage regulates a regulated bus connected to the load. A power meter detects power provided to the load and determines if the provided power is below a predefined power threshold. A regulator control module shuts down the regulator stage of the first power supply after the provided power falls below the predefined power threshold so the second power supply powers the load and the primary stage of the first power supply remains operational. A recovery module starts up the regulator stage of the first power supply after failure of the second power supply.

US Patent:

7698585, Apr 13, 2010

Filed:

Jul 10, 2008

Appl. No.:

12/170983

Inventors:

Randhir S. Malik - Cary NC, US
Trung M. Nguyen - Durham NC, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1/32

US Classification:

713320, 713300, 323246

Abstract:

An apparatus, system, and method is provided for reducing idle power in a power supply. The apparatus includes a connection module to determine whether a load is connected to the output terminal of the power supply. Also included is an idle module that turns off the power supply for an idle interval when the connection module determines that a load is not connected to the output. A monitor module turns on the power supply for a monitor interval when the idle interval ends. During the monitor interval, the connection module determines whether the load has been connected to the output terminal of the power supply. An activation module turns on the power supply if the connection module determines, during the monitor interval, that the load has been connected to the power supply. If the load has not been connected, another idle interval is initiated.

US Patent:

7724487, May 25, 2010

Filed:

Jul 10, 2008

Appl. No.:

12/171086

Inventors:

Cecil C. Dishman - Raleigh NC, US
Randhir S. Malik - Cary NC, US
Trung M. Nguyen - Durham NC, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H02H 3/00
H02H 3/08
H02H 9/02
H02H 9/08

US Classification:

361 82, 361 84, 361 931, 361 939

Abstract:

An apparatus, system, and method are disclosed for preventing reverse current in a switching power supply. An electrical connector receives an input current from an electric source. An input current limiting module substantially prevents the input current from reaching a switching power supply when the input current is flowing in a reverse direction. A voltage reduction module reduces an input voltage of the switching power supply to a switching voltage when the input current is flowing in a forward direction. A switching module closes a switch in response to the voltage reduction module providing the switching voltage. The switch provides the input current a lower impedance path to the switching power supply than does the input current limiting module.

US Patent:

7908505, Mar 15, 2011

Filed:

Sep 28, 2007

Appl. No.:

11/864613

Inventors:

Randhir S. Malik - Cary NC, US
Cecil C. Dishman - Raleigh NC, US
Ted A. Howard - Cary NC, US
Eino A. Lindfors - Raleigh NC, US
Trung M. Nguyen - Morrisville NC, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1/30

US Classification:

713340, 713300, 713330, 714 47, 714 48

Abstract:

An apparatus, system, and method are disclosed for event, time, and failure state recording in a power supply. Disclosed is a power supply that receives AC voltage as an input and provides regulated DC voltage as an output; a microcontroller integrated into the power supply that regulates output voltage and monitors, records, and reports operating conditions of the power supply; and a non-volatile solid-state storage that can be repeatedly read from, written to, and erased by the microcontroller and integrated within the microcontroller such that only a single address is needed to access both the microcontroller and the solid-state storage, the solid-state storage configured to store operating data received from the microcontroller, the operating data including the recorded operating conditions of the power supply.

US Patent:

7979727, Jul 12, 2011

Filed:

Dec 28, 2007

Appl. No.:

11/966512

Inventors:

Cecil C. Dishman - Raleigh NC, US
Randhir S. Malik - Cary NC, US
Trung M. Nguyen - Morrisville NC, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 11/30

US Classification:

713324, 713320, 713340

Abstract:

An apparatus, system, and method are disclosed for a power supply that is efficient in both high and low power conditions. An integrated power supply regulates current on a regulated bus to maintain a regulated bus voltage under varying load conditions. The integrated power supply includes a first power supply rated to provide full load power to the load and second power supply rated to provide power at levels below a minimum power threshold. The second power supply includes switching elements that have lower switching losses than switching elements of the first power supply. A sensing module measures power. A switching module starts up the second power supply and shuts down the first power supply if the measured power falls below the minimum power threshold, and starts up the first power supply and shuts down the second power supply if the measured power rises above the minimum power threshold.

US Patent:

8120300, Feb 21, 2012

Filed:

Dec 30, 2008

Appl. No.:

12/346365

Inventors:

C. Charles Dishman - Raleigh NC, US
Ted A. Howard - Cary NC, US
Randhir S. Malik - Cary NC, US
Trung M. Nguyen - Morrisville NC, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G05D 23/00
H02H 7/08
H05K 7/20

US Classification:

318471, 318708, 318564, 361688, 361695

Abstract:

An apparatus, system, and method are disclosed for fault tolerant cooling in a redundant power system. The apparatus receives power from a common power bus to power one or more power supply fans. The apparatus detects a non-functioning redundant power supply. The apparatus receives a fan control signal within a non-functioning redundant power supply. In addition, the apparatus uses the received fan control signal to synchronize a fan speed of a power supply fan within the non-functioning redundant power supply. The fan speed is synchronized with at least one fan control signal of a power supply fan within a functioning redundant power supply. Thus, the power supply fans of a non-functioning power supply continue to operate and are synchronized with power supply fans in functioning power supplies.