1
Neal George Stewart, Wing Ling Cheng, Chau Hon Yu: Adaptive pulse width modulated resonant Class-D converter. Astec International, Coudert Brothers, November 16, 1999: US05986895 (175 worldwide citation)

Switching losses at high line in variable-input Class-D resonant DC-to-DC power converters regulated by changing the duty cycle of the switching transistors are avoided by making the turn-off time of the discharging switch dependent upon the current in the resonant transformer primary circuit, there ...


2
Neal George Stewart, Man Keung Tse: Integrated power supply frame including integrated circuit (IC) mounting and cooling. Astec International, February 9, 1999: US05870284 (20 worldwide citation)

The present invention encompasses a mounting structure on which both a power supply and a integrated circuit (IC) chip module are mounted. In one embodiment, the present invention encompasses a mounting structure for mounting a power supply and an integrated circuit (IC) chip module on a printed cir ...


3
David A Cross, Neal George Stewart: Line harmonic correcting flyback power converter. Astec International, Coudert Brothers, May 30, 2000: US06069800 (9 worldwide citation)

Effective harmonic correction without frequency, power or voltage limitations is achieved in a single-stage DC-to-DC converter by disconnecting the bulk capacitor of a typical single-stage converter during low voltage conditions, and by using various phase and cycle modulation techniques associated ...


4
Wing Ling Cheng, Neal George Stewart, John Michael Groves, Man Keung Tse, Rex William James Whittle, Alastair Alexander Keir: Power supply system for high density printed circuit boards. Coudert Brothers, May 4, 1999: US05901038 (3 worldwide citation)

The present invention is a mounting structure for a power supply. The mounting structure of the present invention allows power to be coupled from a power supply to a predetermined area on a motherboard adjacent one or more high power demand components, such as an IC microprocessor chip. The mounting ...


5
Neal George Stewart, Wing Ling Cheng: Energy saving high frequency series buck AC voltage regulator system. Edge Electrons, Idea Intellectual, Margaret A Burke, Sam T Yip, May 22, 2018: US09979312 (1 worldwide citation)

An energy saving alternate current (AC) series voltage regulator comprises an AC high frequency (HF) series voltage buck power regulator, a bypass contactor (K1), a bidirectional AC semiconductor device (S1) connected in parallel with the bypass contactor and a control circuitry. Under the condition ...


6
Neal George Stewart, Wing Ling Cheng: High frequency series AC voltage regulator. EDGE ELECTRONS, Idea Intellectual, Margaret A Burke, Sam T Yip, November 14, 2017: US09819279 (1 worldwide citation)

An AC voltage regulator that regulates the output AC voltage level regardless of the varying AC input voltage utilizing high frequency series inductors that only process a proportion of the total output power and uses unipolar semiconductor low loss switches in series with one or more rectifiers.


7
Neal George Stewart: Algorithm for passive power factor compensation method with differential capacitor change and reduced line transient noise. Edge Electrons, Idea Intellectual, Margaret A Burke, Sam T Yip, July 18, 2017: US09712048

A computer-implementable control algorithm that measures: 1) the reactive power; 2) the power factor; 3) the voltage; and 4) the line frequency. The algorithm calculates the differential compensation capacitance required that is either positive (capacitance to be added), or negative (capacitance to ...


8
Neal George Stewart, Wing Ling Cheng: High frequency series AC voltage regulator. Power Quality Engineering, Ella Cheong Hong Kong, Sam T Yip, September 29, 2015: US09148058

A bidirectional AC series voltage regulator that regulates an output AC voltage level regardless of the varying AC input voltage utilizing high frequency series inductors that only process a proportion of the total output power. The AC series voltage regulator detects the power inductor current dire ...


9
Jian Carlo Decena Zapata, Efren II Santos Cruzat, Neal George Stewart, Gordon Currie, Wing Ling Cheng: System and method for high efficiency power quality correction. EDGE ELECTRONS, Idea Intellectual, Margaret A Burke, Sam T Yip, July 17, 2018: US10027120

A high-efficiency system for conducting power factor (PF) and harmonics correction in an electrical network, comprising a controller; a digital PFC capacitor array comprising two or more passive PFC capacitors, providing fine steps increments in the PF correction; and linear PFC capacitor arrays, pr ...


10
Neal George Stewart, Wing Ling Cheng: Fast response active reactive power (KVAR) compensator. Edge Electronics, Idea Intellectual, Margaret A Burke, Sam T Yip, April 10, 2018: US09941698

Legacy automatic variable capacitor KVAR compensation systems typically use either electromechanical devices such as relays or contactors of various forms and types to switch the selected capacitors in and out of the electrical system under some form of electronic control. These systems are slow and ...