James J Zeng

US Patent:

20070081372, Apr 12, 2007

Filed:

Oct 6, 2006

Appl. No.:

11/544104

Inventors:

James Xiong Zeng - Westwood MA, US
David Liu - Newton MA, US

International Classification:

H02M 7/5387

US Classification:

363132000

Abstract:

Techniques for high performance inverter charger systems are described herein. In one embodiment, a power supply system includes, but is not limited to, an inverter to generate an AC (alternating current) output based on a DC (direct current) input, a current sensing circuit coupled to the inverter to sense an amount of current drawn from the inverter, and a microcontroller coupled to the inverter and the current sensing circuit to reduce the AC output of the inverter according to a predetermined algorithm stored within the microcontroller, in response to a detection that the amount of current drops below a predetermined threshold. Other methods and apparatuses are also described.

US Patent:

56361076, Jun 3, 1997

Filed:

Nov 15, 1995

Appl. No.:

8/558175

Inventors:

Qun Lu - Lexington MA
Fei Ma - Malden MA
James J. Zeng - Brookline MA

Assignee:

International Power Devices, Inc. - Boston MA

International Classification:

H02M 3335

US Classification:

363 20

Abstract:

A DC--DC converter including a transformer having a primary winding and a tapped secondary winding; an output filter made up of a filter inductor and a filter capacitor connected in series with one side of the output filter connected to the tap terminal of the secondary winding; a first unidirectional device and a second unidirectional device connected in series with each other and with opposite polarities, there being a common node between them, the first unidirectional device electrically coupled to the first terminal of the secondary winding, the second unidirectional device electrically coupled to the second terminal of the secondary winding, and the output filter electrically coupled to the common node; a first switch connected in series with the primary winding; and a clamping circuit connected between two of the terminals of the secondary winding, wherein the clamping circuit includes a clamping capacitor connected in series with a second switch.