Mingliang Chen

US Patent:

8125798, Feb 28, 2012

Filed:

Jul 1, 2008

Appl. No.:

12/217052

Inventors:

Steven Huynh - Sunnyvale CA, US
Jian Yang - Thousand Oaks CA, US
Mingliang Chen - Sterrett AL, US

Assignee:

Active-Semi, Inc.

International Classification:

H02M 3/335

US Classification:

363 2112, 363 2118, 363 97, 363147

Abstract:

A self-oscillating flyback converter includes a controller integrated circuit housed in a 3-pin package. A switch control terminal is coupled to the base of an inductor switch that controls the current through a primary inductor of the converter. The controller IC adjusts the on time of the switch such that output current remains constant in constant current mode and output voltage remains constant in constant voltage mode. A signal received on a switch control terminal turns the switch off and provides an indication of the output current when the switch is on. A signal received on a feedback terminal powers the controller IC and provides an indication of the output voltage when the switch is off. The controller IC is grounded through a ground terminal. The flyback converter transitions from critical conduction mode to discontinuous conduction mode at light loads to prevent its efficiency from deteriorating at high switching frequencies.

US Patent:

51343568, Jul 28, 1992

Filed:

Mar 7, 1991

Appl. No.:

7/665774

Inventors:

Mohamed A. El-Sharkawi - Renton WA
Subrahmanyam S. Venkata - Woodinville WA
Mingliang Chen - Kirkland WA
George Andexler - Everett WA
Tony Huang - Seattle WA

Assignee:

Board of Regents of the University of Washington - Seattle WA

International Classification:

G05F 170

US Classification:

323211

Abstract:

A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor.