Professional Records
License Records
Hien T. Bui
License #:
CPT.009533 - Expired
Issued Date:
Apr 16, 2010
Expiration Date:
Jun 30, 2013
Type:
Certified Pharmacy Technician
Hien Bui Phones & Addresses
-
San Jose, CA
-
2012 Jackson St, Sioux City, IA 51104 (712) 279-0027 (712) 279-0047
Business Records
Name / Title
Company / Classification
Phones & Addresses
BOBA TEA CAFE, INC
Publications
Us Patents
On-Time Control For Constant Current Mode In A Flyback Power Supply
View pageUS Patent:
7443700, Oct 28, 2008
Filed:
May 7, 2007
Appl. No.:
11/745299
Inventors:
Liang Yan - Campbell CA, US
Junjie Zheng - Santa Clara CA, US
John Kesterson - San Jose CA, US
Xiaoyan Wang - Pleasanton CA, US
Hien Bui - San Jose CA, US
Junjie Zheng - Santa Clara CA, US
John Kesterson - San Jose CA, US
Xiaoyan Wang - Pleasanton CA, US
Hien Bui - San Jose CA, US
Assignee:
iWatt Inc. - Los Gatos CA
International Classification:
H02M 3/335
US Classification:
363 2101, 363 2108, 363 2116
Abstract:
A primary side sensing power control system and method for constant current control that utilizes a relationship that involves the measured reset-time from the previous cycle to determine the primary side peak current and off-time for the next cycle. This control mechanism does not need the knowledge of input voltage or magnetizing inductance. Therefore, it removes the sensitivities of input voltage and magnetizing inductance to the output current limit. Furthermore, it uses a time measurement instead of a voltage measurement for the current calculation which in many cases is easier to perform.
Dynamic Drive Of Switching Transistor Of Switching Power Converter
View pageUS Patent:
8576586, Nov 5, 2013
Filed:
Sep 28, 2007
Appl. No.:
12/678690
Inventors:
Junjie Zheng - Santa Clara CA, US
Jun Zheng - Shenzhen, CN
Andrew Kwok-Cheung Lee - Santa Clara CA, US
John William Kesterson - San Jose CA, US
Allan Ming-Lun Lin - Pleasanton CA, US
Hien Huu Bui - San Jose CA, US
Carrie Seim - Campbell CA, US
Yong Li - Campbell CA, US
Jun Zheng - Shenzhen, CN
Andrew Kwok-Cheung Lee - Santa Clara CA, US
John William Kesterson - San Jose CA, US
Allan Ming-Lun Lin - Pleasanton CA, US
Hien Huu Bui - San Jose CA, US
Carrie Seim - Campbell CA, US
Yong Li - Campbell CA, US
Assignee:
iWatt Inc. - Campbell CA
International Classification:
H02M 3/335
H02M 3/337
H02M 3/338
H02M 3/337
H02M 3/338
US Classification:
363 2113, 363 2117, 363 2118
Abstract:
A switching power converter comprises a transformer (), a switch () coupled to the transformer (), and a switch controller () coupled to the switch () for generating a switch drive signal () to turn on or off the switch (). The drive current of the switch drive signal () is adjusted dynamically according to line or load conditions within a switching cycle and/or over a plurality of switching cycles. The magnitude of the drive current can be dynamically adjusted within a switching cycle and/or over a plurality of switching cycles, in addition to the pulse widths or pulse frequencies of the drive current.
Adaptively Controlled Soft Start-Up Scheme For Switching Power Converters
View pageUS Patent:
8582329, Nov 12, 2013
Filed:
Mar 30, 2011
Appl. No.:
13/076157
Inventors:
Xiaolin Gao - Santa Clara CA, US
Yong Li - San Jose CA, US
Hien Huu Bui - San Jose CA, US
Fuqiang Shi - Cupertino CA, US
Yong Li - San Jose CA, US
Hien Huu Bui - San Jose CA, US
Fuqiang Shi - Cupertino CA, US
Assignee:
iWatt Inc. - Campbell CA
International Classification:
H02M 3/335
US Classification:
363 2116, 363 2118, 363 97
Abstract:
A switching power converter provides regulated voltage to a load according to a desired regulation voltage. The switching power converter includes a transformer coupled to a switch and a switch controller for generating a control signal to control switching. The switch controller monitors a sensed voltage representing the output voltage of the switching power converter. The switch controller controls switching of the switch to operate the switching power converter in a continuous conduction mode while the sensed output voltage indicates that the output voltage is less than a first threshold voltage. The switch controller controls switching of the switch to operate the switching power converter in a discontinuous conduction mode while the sensed output voltage is above the first threshold voltage.
Valley-Mode Switching Schemes For Switching Power Converters
View pageUS Patent:
20100165672, Jul 1, 2010
Filed:
Dec 18, 2009
Appl. No.:
12/642261
Inventors:
Yong Li - San Jose CA, US
Hien Huu Bui - San Jose CA, US
Junjie Zheng - Santa Clara CA, US
John William Kesterson - San Jose CA, US
Hien Huu Bui - San Jose CA, US
Junjie Zheng - Santa Clara CA, US
John William Kesterson - San Jose CA, US
Assignee:
IWATT INC. - Los Gatos CA
International Classification:
H02M 3/335
US Classification:
363 2116
Abstract:
An improved valley-mode switching (VMS) scheme and circuitry for implementing the improved VMS switching scheme in a switch-mode power converter are disclosed. For a given switching cycle, a desired switch turn-on time is determined based on a pulse width modulation, pulse frequency modulation, or other suitable power converter control scheme. Also, one or more times corresponding to local minimums (valleys) are predicted for the voltage across a power switch of the switching power converter. The power switch is turned on at a valley immediately subsequent or otherwise subsequent to the desired switch time determined according to the power converter control scheme. Thus, the improved VMS scheme enables low-voltage switch operation to reduce switching loss and EMI noise without restricting the control scheme of the power converter.
Adaptive Bipolar Junction Transistor Gain Detection
View pageUS Patent:
20130242625, Sep 19, 2013
Filed:
Mar 13, 2012
Appl. No.:
13/419329
Inventors:
Liang Yan - Milpitas CA, US
Clarita C. Poon - Pleasanton CA, US
Hien Huu Bui - San Jose CA, US
Chuanyang Wang - Cupertino CA, US
Andrew Kwok-Cheung Lee - Union City CA, US
John William Kesterson - Seaside CA, US
Clarita C. Poon - Pleasanton CA, US
Hien Huu Bui - San Jose CA, US
Chuanyang Wang - Cupertino CA, US
Andrew Kwok-Cheung Lee - Union City CA, US
John William Kesterson - Seaside CA, US
Assignee:
IWATT INC. - Campbell CA
International Classification:
H02M 1/36
US Classification:
363 49
Abstract:
A power converter that controls a collector current of a bipolar junction transistor (BJT) by controlling the base current to the BJT after having determined the gain of the BJT. A gain detection block determines a gain of the BJT during a first mode. A current calculation block generates a current setting for the base current based on the gain of the BJT determined by the gain detection block during a second mode distinct from the first mode. In some embodiments, the power converter may be included in a LED lamp system.
Dynamic Drive Of Switching Transistor Of Switching Power Converter
View pageUS Patent:
20130279209, Oct 24, 2013
Filed:
Jun 18, 2013
Appl. No.:
13/920914
Inventors:
Jun Zheng - Santa Clara CA, US
Andrew Kwok-Cheung Lee - Union City CA, US
John William Kesterson - Seaside CA, US
Allan Ming-Lun Lin - Pleasanton CA, US
Hien Huu Bui - San Jose CA, US
Carrie Seim - Campbell CA, US
Yong Li - San Jose CA, US
Andrew Kwok-Cheung Lee - Union City CA, US
John William Kesterson - Seaside CA, US
Allan Ming-Lun Lin - Pleasanton CA, US
Hien Huu Bui - San Jose CA, US
Carrie Seim - Campbell CA, US
Yong Li - San Jose CA, US
International Classification:
H02M 3/335
US Classification:
363 2112
Abstract:
The drive current of the switch in a switching power converter is adjusted dynamically according to line or load conditions within a switching cycle and/or over a plurality of switching cycles. The magnitude of the switch drive current can be dynamically adjusted within a switching cycle and/or over a plurality of switching cycles, in addition to the pulse widths or pulse frequencies of the switch drive current.
Hybrid Adaptive Power Factor Correction Schemes For Switching Power Converters
View pageUS Patent:
20140022829, Jan 23, 2014
Filed:
Jul 18, 2012
Appl. No.:
13/552567
Inventors:
Fuqiang Shi - Oak Park IL, US
Xiaolin Gao - Santa Clara CA, US
Hien Huu Bui - San Jose CA, US
Yong Li - San Jose CA, US
John William Kesterson - Seaside CA, US
Xiaolin Gao - Santa Clara CA, US
Hien Huu Bui - San Jose CA, US
Yong Li - San Jose CA, US
John William Kesterson - Seaside CA, US
Assignee:
IWATT, INC. - Campbell CA
International Classification:
H02M 7/04
US Classification:
363 84
Abstract:
The embodiments disclosed herein describe a method of a controller of a switching power converter that provides a configurable power factor control method for the switching power converter. In one embodiment, the controller combines power regulation control methods of constant on-time control and constant power control to adjust the power factor of the switching power converter.
Adaptive Gate Drive For A Power Switch Transistor In A Switching Power Converter
View pageUS Patent:
20220224217, Jul 14, 2022
Filed:
Jan 8, 2021
Appl. No.:
17/145186
Inventors:
- Campbell CA, US
Vijay KANAGALA - Campbell CA, US
Hien BUI - Campbell CA, US
Vijay KANAGALA - Campbell CA, US
Hien BUI - Campbell CA, US
International Classification:
H02M 1/08
H02M 3/335
H03K 17/042
H02M 1/44
H02M 3/335
H03K 17/042
H02M 1/44
Abstract:
A gate drive control circuit is provided that charges a gate voltage of a power switch transistor during a power switch transistor on-time period. During a first portion of the on-time period, the gate drive control circuit charges the gate voltage through a relatively-low resistance. During a second portion of the on-time period, the gate drive control circuit charges the gate voltage through a relatively-high resistance. Finally, during a third portion of the on-time period, the gate drive control circuit charges the gate voltage through another relatively-low resistance.