Patents by Inventor Wai Ma
Wai Ma has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20240106542Abstract: An encoding method, a decoding method, and an optical module are described relating to data transmission technologies. The method, carried out by an optical module includes obtaining an optical transmission mode used for signal transmission. The method further includes receiving a signal on which outer-code encoding has been performed. The optical module determines, based on the optical transmission mode, an inner-code encoding scheme to be used by the optical module to perform inner-code encoding on the signal on which outer-code encoding has been performed. The method further includes performing, by using the inner-code encoding scheme, inner-code encoding on the signal on which outer-code encoding has been performed. The optical module outputs a signal on which inner-code encoding has been performed. As a result, error correction performance of the Ethernet may be improved.Type: ApplicationFiled: December 8, 2023Publication date: March 28, 2024Inventors: Zengchao Yan, Wai Kong Raymond Leung, Huixiao Ma
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Patent number: 11914895Abstract: A method for updating stored information and an apparatus. A controller performs error correction code (ECC) decoding on stored data information based on the stored data information and stored ECC check information to generate an error-corrected codeword, where the error-corrected codeword includes error-corrected data information. The controller generates candidate to-be-written data information based on the error-corrected data information and a data update indication. The controller performs a mask operation on the candidate to-be-written data information based on the stored data information, and writes unmasked content in the candidate to-be-written data information into a memory.Type: GrantFiled: April 14, 2021Date of Patent: February 27, 2024Assignee: HUAWEI TECHNOLOGIES CO. LTD.Inventors: Wai Kong Raymond Leung, Dongyu Geng, Qinhui Huang, Huixiao Ma
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Publication number: 20230387195Abstract: A semiconductor die includes: a semiconductor substrate; power semiconductor devices formed in the semiconductor substrate; and a field termination structure interposed between adjacent ones of the power semiconductor devices and between the power semiconductor devices and an edge of the semiconductor substrate.Type: ApplicationFiled: May 24, 2022Publication date: November 30, 2023Inventors: Kwok-Wai Ma, Frank Dieter Pfirsch
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Patent number: 9819339Abstract: A circuit for reducing collector-emitter voltage (VCE) overshoot in an insulated gate bipolar transistor (IGBT) is provided. The circuit includes circuitry operable to generate a pulse which has a rising edge synchronized to the moment when collector or emitter current of the IGBT begins to fall during turn-off of the IGBT and a width which is a fraction of a duration of the VCE overshoot. The circuitry is further operable to combine the pulse with a control signal applied to a gate of the IGBT so as to momentarily raise the gate voltage of the IGBT during turn-off of the IGBT to above a threshold voltage of the IGBT for the duration of the pulse. A corresponding method of reducing VCE overshoot in an IGBT also is provided.Type: GrantFiled: May 13, 2015Date of Patent: November 14, 2017Assignee: Infineon Technologies Austria AGInventors: Kwok Wai Ma, Sui Pung Cheung
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Publication number: 20160336936Abstract: A circuit for reducing collector-emitter voltage (VCE) overshoot in an insulated gate bipolar transistor (IGBT) is provided. The circuit includes circuitry operable to generate a pulse which has a rising edge synchronized to the moment when collector or emitter current of the IGBT begins to fall during turn-off of the IGBT and a width which is a fraction of a duration of the VCE overshoot. The circuitry is further operable to combine the pulse with a control signal applied to a gate of the IGBT so as to momentarily raise the gate voltage of the IGBT during turn-off of the IGBT to above a threshold voltage of the IGBT for the duration of the pulse. A corresponding method of reducing VCE overshoot in an IGBT also is provided.Type: ApplicationFiled: May 13, 2015Publication date: November 17, 2016Inventors: Kwok Wai Ma, Sui Pung Cheung
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Patent number: 7257146Abstract: A method and system for stabilizing energy consumption in multiple loads, or in single multi-phase loads. The method and system also compensates for unbalance in multi-phase loads. A central controller monitors variable reactances in the loads and identifies situations of power and/or current fluctuation and/or unbalance. It determines appropriate corrective action by the other loads/phases to compensate for the power and/or current change or unbalance due to the problematic load, and it issues control signals instructing variable reactor controllers associated with the other loads to adjust accordingly. The method and system may by applied to electric arc furnace installations. The system and method may be employed to maintain a predetermined level of unbalance in the system.Type: GrantFiled: September 1, 2005Date of Patent: August 14, 2007Assignee: Hatch Ltd.Inventors: Mohammad Sedighy, Thomas Lai Wai Ma
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Patent number: 7212561Abstract: A method and system for stabilizing energy consumption in multiple loads, or in single multi-phase loads. The method and system also compensates for unbalance in multi-phase loads. A central controller monitors variable reactances in the loads and identifies situations of power and/or current fluctuation and/or unbalance. It determines appropriate corrective action by the other loads/phases to compensate for the power and/or current change or unbalance due to the problematic load, and it issues control signals instructing variable reactor controllers associated with the other loads to adjust accordingly. The method and system may by applied to electric arc furnace installations. In this context, the method and system provide an electrode position controller coupled to the feed rate controller so as to predictively anticipate the introduction of new source material and lower the electrodes so as to prevent arc extinguishment while the variable reactors maintain predetermined power set-points.Type: GrantFiled: August 31, 2005Date of Patent: May 1, 2007Assignee: Hatch Ltd.Inventors: Mohammad Sedighy, Thomas Lai Wai Ma
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Patent number: 7212562Abstract: A method and system for stabilizing energy consumption in multiple loads, or in single multi-phase loads. A central controller monitors variable reactances in the loads and identifies situations of power and/or current fluctuation and/or unbalance. The central controller determines appropriate corrective action by the other loads/phases to compensate for the power and/or current change or unbalance due to the problematic load, and it issues control signals instructing electrode position controllers associated with the other loads to adjust accordingly. The method and system may by applied to electric arc furnace installations. The electrode position controllers may be used in conjunction with variable reactance control systems to take corrective action to address power and/or current changes or unbalances. The variable reactors respond orders of magnitude faster than the electrode positioning system.Type: GrantFiled: September 1, 2005Date of Patent: May 1, 2007Assignee: Hatch Ltd.Inventor: Thomas Lai Wai Ma
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Publication number: 20060202001Abstract: A method and system for heating a circuit board component to an approximately uniform temperature sufficient to reflow the connections between the circuit board component and the circuit board. The method and system include a supplemental gas heater having a diffuser plate. The circuit board is placed against the diffuser plate and heated gas is channeled through openings in the diffuser plate into vias in the circuit board to heat a circuit board component connected on the opposite side of the circuit board. Heated gas can be channeled through selected vias towards predetermined areas and/or specified connections such as towards those areas or connections where there is a temperature differential greater than approximately 10 degrees Celsius compared to other areas or connections across the circuit board component. Hot gas can be channeled through selected vias by baffling or patterning the diffuser plate, accordingly.Type: ApplicationFiled: March 8, 2005Publication date: September 14, 2006Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Raymond Birchall, Brian Chapman, Wai Ma, James Petrone, Nandakumar Ranadive
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Publication number: 20060050760Abstract: A method and system for stabilizing energy consumption in multiple loads, or in single multi-phase loads. The method and system also compensates for unbalance in multi-phase loads. A central controller monitors variable reactances in the loads and identifies situations of power and/or current fluctuation and/or unbalance. It determines appropriate corrective action by the other loads/phases to compensate for the power and/or current change or unbalance due to the problematic load, and it issues control signals instructing variable reactor controllers associated with the other loads to adjust accordingly. The method and system may by applied to electric arc furnace installations. In this context, the method and system provide an electrode position controller coupled to the feed rate controller so as to predicatively anticipate the introduction of new feed material and lower the electrodes so as to prevent arc extinguishment while the variable reactors maintain predetermined power set-points.Type: ApplicationFiled: September 1, 2005Publication date: March 9, 2006Inventor: Thomas Lai Wai Ma
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Publication number: 20050239347Abstract: A method to replace an electrical interface on a printed circuit board having a plurality of contact pads on a top surface, the contact pads being connected to conducting material extending through said circuit board. For the contact pad being replaced, drilling a hole through said printed circuit board at that location, and removing any remaining conductor material attached to the contact pad on the top board surface. Providing a replacement conductor/contact pad structure having a generally T-configuration with a stem and a head that completely surrounds the stem, wherein said head has a diameter greater than the diameter of the drilled hole. Inserting the replacement conductor/contact pad into the hole with said stem extending beyond the second surface of the board with the bottom surface of the head being in contact with the first surface of said board. A replacement conductor/contact pad on repaired board is also described.Type: ApplicationFiled: June 27, 2005Publication date: October 27, 2005Applicant: International Business Machines CorporationInventors: Bruce Chamberlin, Mark Hoffmeyer, Wai Ma, Arch Nuttall, James Stack
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Publication number: 20050174738Abstract: A heat sink attachment structure includes an integrated circuit chip mounted on a substrate surface, and a thermal interface layer in contact with the integrated circuit chip. A heat sink is in contact with the thermal interface layer, and at least one spacer member is in contact between the substrate surface and the heat sink, wherein the at least one spacer member is provided with an adhesive material on top and bottom surfaces thereof.Type: ApplicationFiled: February 6, 2004Publication date: August 11, 2005Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Roger Lam, Wai Ma, Vincent Montalbano, Arch Nuttall, Nandu Ranadive
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Publication number: 20050061850Abstract: An apparatus for applying solder to an electronic circuit board substrate includes a solder wave device for generating a molten wave of solder and, above that, a movable substrate holder. The substrate holder includes a support for an electronic circuit board substrate inclined at an angle with respect to the direction and an opening on a bottom thereof for access of a protruding connector disposed near an end of the substrate to the molten solder wave. The angle of incline is sufficient to prevent a component disposed at a distance from the end of the substrate from contacting the molten solder wave when the substrate holder is moved over the solder wave device. A shield in the substrate holder prevents the component not to be soldered from contacting the molten solder wave.Type: ApplicationFiled: September 18, 2003Publication date: March 24, 2005Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Todd Buley, Brian Chapman, Roger Lam, Wai Ma, John Weir
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Patent number: 6603795Abstract: A power control system for an AC electric arc furnace. The control system includes variable reactors located intermediate a furnace power supply and arc electrodes that are height adjustable. The control system monitors operating characteristics of the furnace that are indicative of the active power consumption of the furnace and adjusts the variable reactors and the electrode height so as to minimize variations in the active power consumption. Loss of electrode arc can be predicted and countered by lowering the electrodes and decreasing the reactance of the variable reactors.Type: GrantFiled: February 8, 2001Date of Patent: August 5, 2003Assignees: Hatch Associates Ltd., Satcon Power Systems Canada Ltd.Inventors: Thomas Lai Wai Ma, Mohammad Sedighy, Brian Kenneth Perkins, Theodorus Anthonius Gerritsen, Janos Rajda
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Patent number: 6573691Abstract: Variable shunt and series connected reactors are used in a complimentary combination in an electric arc furnace to provide improved flicker control. A power control system for an time-varying AC load, such as an electric arc furnace, connected to an AC power supply line includes a first variable reactance intermediate the power supply line and the load, and a second variable reactance connected in parallel with the power supply line. A control system is provided for (i) monitoring load current and adjusting the first variable reactance in response to changes in the monitored load current; and (ii) monitoring reactive power draw by the load and adjusting the second variable reactance in response to changes in the monitored reactive power draw. The first variable reactance and second variable reactance are each primarily used to mitigate flicker at different times during the load operation.Type: GrantFiled: October 17, 2001Date of Patent: June 3, 2003Assignees: Hatch Associates Ltd., Satcon Power Systems Canada Ltd.Inventors: Thomas Lai Wai Ma, Brooke Armstrong Stratton
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Publication number: 20030076075Abstract: Variable shunt and series connected reactors are used in a complimentary combination in an electric arc furnace to provide improved flicker control. A power control system for an time-varying AC load, such as an electric arc furnace, connected to an AC power supply line includes a first variable reactance intermediate the power supply line and the load, and a second variable reactance connected in parallel with the power supply line. A control system is provided for (i) monitoring load current and adjusting the first variable reactance in response to changes in the monitored load current; and (ii) monitoring reactive power draw by the load and adjusting the second variable reactance in response to changes in the monitored reactive power draw. The first variable reactance and second variable reactance are each primarily used to mitigate flicker at different times during the load operation.Type: ApplicationFiled: October 17, 2001Publication date: April 24, 2003Inventors: Thomas Lai Wai Ma, Brooke Armstrong Stratton
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Patent number: 6519274Abstract: A power control system for an AC electric arc furnace. The control system includes variable reactors located intermediate a furnace power supply and arc electrodes that are height adjustable. The control system monitors operating characteristics of the furnace that are indicative of the active power consumption of the furnace and adjusts the variable reactors and the electrode height so as to minimize variations in the active power consumption. Loss of electrode arc can be predicted and countered by lowering the electrodes and decreasing the reactance of the variable reactors.Type: GrantFiled: February 8, 2001Date of Patent: February 11, 2003Assignees: Hatch Associates Ltd., Satcon Power Systems Canada Ltd.Inventors: Thomas Lai Wai Ma, Mohammad Sedighy, Brian Kenneth Perkins, Theodorus Anthonius Gerritsen, Janos Rajda
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Publication number: 20020136260Abstract: A power control system for an AC electric arc furnace. The control system includes variable reactors located intermediate a furnace power supply and arc electrodes that are height adjustable. The control system monitors operating characteristics of the furnace that are indicative of the active power consumption of the furnace and adjusts the variable reactors and the electrode height so as to minimize variations in the active power consumption.Type: ApplicationFiled: February 8, 2001Publication date: September 26, 2002Inventors: Thomas Lai Wai Ma, Mohammad Sedighy, Brian Kenneth Perkins, Theodorus Anthonius Gerritsen, Janos Rajda
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Patent number: 6437252Abstract: Described is a method for minimizing switching noise in the high- and mid-frequency range on printed circuit cards or boards by means of a plurality of surface mounted decoupling capacitors. A novel configuration and implementation of capacitor pads including the connecting vias is also presented. As a result the parasitic inductance of the pads and vias can be significantly reduced. Thus the effectiveness of the decoupling capacitors in the mid and high frequency range can be increased, the voltage drop can be reduced and the system performance can be increased. Several design rules for the new pad via configuration lead to the significant reduction of the parasitic inductance. The proposal is especially important for high integrated system designs on boards and cards combined with increased cycle times.Type: GrantFiled: December 19, 2000Date of Patent: August 20, 2002Assignee: International Business Machines CorporationInventors: Simone Rehm, Roland Frech, Erich Klink, Helmut Virag, Thomas-Michael Winkel, Wiren Becker, Bruce Chamberlin, Wai Ma
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Patent number: D706483Type: GrantFiled: April 18, 2013Date of Patent: June 3, 2014Assignee: Johnson Wai Aquarium Supply Co., Ltd.Inventor: William Chi Wai Ma