Patents by Inventor Ali Djabbari
Ali Djabbari 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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Patent number: 7977921Abstract: Voltage conversion and charging circuitry and method for converting an alternating current (AC) voltage to a direct current (DC) voltage for charging an energy storage element (e.g., battery or supercapacitor). An output capacitance, which is initially charged quickly for use in the slower charging of a battery, also maintains the charge on an input capacitance which provides power for the charging control circuitry during such charging process. In accordance with a preferred embodiment, the DC charging current is substantially constant during a first time interval following which the DC charging power is substantially constant during a second time interval.Type: GrantFiled: August 15, 2008Date of Patent: July 12, 2011Assignee: National Semiconductor CorporationInventors: Ahmad Bahai, Ali Djabbari, Qingguo Liu, Jianhui Zhang
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Patent number: 7969133Abstract: A method for providing maximum power point tracking for an energy generating device using a local buck-boost converter coupled to the device is provided. The method includes operating in a tracking mode, which includes initializing a conversion ratio for the buck-boost converter based on a previous optimum conversion ratio. A device power associated with the initialized conversion ratio is calculated. The conversion ratio is repeatedly modified and a device power associated with each of the modified conversion ratios is calculated. A current optimum conversion ratio for the buck-boost converter is identified based on the calculated device powers. The current optimum conversion ratio corresponds to one of a buck mode, a boost mode and a buck-boost mode for the buck-boost converter.Type: GrantFiled: May 14, 2008Date of Patent: June 28, 2011Assignee: National Semiconductor CorporationInventors: Jianhui Zhang, Ali Djabbari, Gianpaolo Lisi
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Patent number: 7962249Abstract: A central array controller for an energy generating array is provided. The array includes a plurality of energy generating devices, and each energy generating device is coupled to a corresponding local converter. The central array controller includes a diagnostic module that is capable of receiving, from each local converter in the array, device data for the energy generating device corresponding to the local converter. In one embodiment, the diagnostic module is also capable of receiving, from each local converter in the array, local converter data for the local converter.Type: GrantFiled: May 14, 2008Date of Patent: June 14, 2011Assignee: National Semiconductor CorporationInventors: Jianhui Zhang, Ali Djabbari, Gianpaolo Lisi
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Publication number: 20110115436Abstract: A system includes multiple power modules, each having multiple power cells coupled in series. Each power module has a charge that is based on charges of the power cells in that power module. The system also includes multiple active cell balancing circuits, each configured to substantially balance the charges of the power cells in an associated one of the power modules. The system further includes an active module balancing system configured to substantially balance the charges of the power modules by charging a first subset of the power modules and/or discharging a second subset of the power modules. The active module balancing system could include multiple module balancing circuits, each associated with one of the power modules and configured to charge or discharge its associated power module. A direct current (DC) bus can be configured to transport DC power between the module balancing circuits.Type: ApplicationFiled: September 15, 2010Publication date: May 19, 2011Applicant: National Semiconductor CorporationInventors: Jianhui Zhang, Ali Djabbari, Qingguo Liu, Ahtnad Bahai
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Publication number: 20110084646Abstract: A system includes multiple photovoltaic panels having a combined output profile that defines energy or power generated by the photovoltaic panels over time. Each photovoltaic panel is configured to generate a peak amount of energy or power at a different time. The system also includes a storage device having a charging profile and configured to be charged by the photovoltaic panels. The charging profile defines a maximum amount of energy or power sinkable by the storage device at a given time. The output profile and the charging profile are substantially matched such that a maximum level of the output profile is approximately equal to the maximum amount of energy or power sinkable by the storage device. The maximum level of the output profile could be substantially constant over time between first and second peak amounts of energy or power generated by different photovoltaic panels.Type: ApplicationFiled: October 14, 2010Publication date: April 14, 2011Applicant: National Semiconductor CorporationInventors: Gianpaolo Lisi, Ali Djabbari
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Patent number: 7863993Abstract: An oscillator, including amplifier circuitry and resonant circuitry, for providing an oscillation signal with a controllable frequency while maintaining a substantially constant steady state magnitude. Controllable reactive circuitry, included as part of the amplifier circuitry, has a reactance which can be controlled such that the resistive components of the amplifier circuitry and resonant circuitry impedances remain substantially equal. When in the form of serially coupled, controllable capacitances, the controllable reactive circuitry is controlled such that a ratio of changes in the controllable capacitances is approximately equal to a negative ratio of the capacitance values.Type: GrantFiled: September 8, 2008Date of Patent: January 4, 2011Assignee: National Semiconductor CorporationInventors: Mounir Bohsali, Ali Kiaei, Gerard Socci, Masood Yousefi, Ali Djabbari, Ahmad Bahai
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Publication number: 20100327659Abstract: A solar panel array for use in a solar cell power system is provided. The solar panel array includes a string of solar panels and multiple voltage converters. Each voltage converter is coupled to a corresponding solar panel in the string of solar panels. The solar panel array also includes multiple maximum power point tracking (MPPT) controllers. Each MPPT controller is coupled to a corresponding solar panel in the string of solar panels. Each MPPT controller is configured to sense an instantaneous power unbalance between the corresponding solar panel and an inverter.Type: ApplicationFiled: April 16, 2010Publication date: December 30, 2010Applicant: National Semiconductor CorporationInventors: Gianpaolo Lisi, Ali Djabbari, Gerand Socci, Andrew Ronald Chemistruck, Rajaram Subramoniam, Jianhui Zhang, Kosha Mahmodieh
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Publication number: 20100288327Abstract: A string over-voltage protection system and method for arrays of photovoltaic panels. The system and method includes a device for use in a photovoltaic array power system. The device includes a voltage converter. The voltage converter is adapted to be coupled to a photovoltaic panel in a string of photovoltaic panels. The device also includes a string over-voltage protection circuit. The string over-voltage protection circuit is coupled to the voltage converter. The string over-voltage protection circuit senses a string voltage and determines if a string over-voltage condition exists. Additionally, the string over-voltage protection circuit is configured to disable the voltage converter in the event of a string over-voltage condition.Type: ApplicationFiled: May 13, 2009Publication date: November 18, 2010Applicant: National Semiconductor CorporationInventors: Gianpaolo Lisi, Ali Djabbari, Jianhui Zhang
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Publication number: 20100215995Abstract: A battery includes multiple conductive battery plates and a complex electrolytic material located between the conductive battery plates. The battery also includes a conductive sensor wire located within the complex electrolytic material. The conductive sensor wire may be configured to generate a magnetic field within the complex electrolytic material based on an electrical signal flowing through the conductive sensor wire. The battery may further include a temperature sensor wire within the complex electrolytic material.Type: ApplicationFiled: February 10, 2010Publication date: August 26, 2010Applicant: National Semiconductor CorporationInventors: Peter J. Hopper, Kyuwoon Hwang, Ali Djabbari, William French, Qingguo Liu
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Patent number: 7737743Abstract: Phase-locked loop (PLL) circuitry in which a sampling phase detector samples the output signal in accordance with the reference signal and a frequency detector detects the output signal frequency in accordance with the reference signal.Type: GrantFiled: March 7, 2008Date of Patent: June 15, 2010Assignee: National Semiconductor CorporationInventors: Xiang Gao, Eric A. M. Klumperink, Bram Nauta, Mounir Bohsali, Ali Kiaei, Gerard Socci, Ali Djabbari
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Publication number: 20100039840Abstract: Voltage conversion and charging circuitry and method for converting an alternating current (AC) voltage to a direct current (DC) voltage for charging an energy storage element (e.g., battery or supercapacitor). An output capacitance, which is initially charged quickly for use in the slower charging of a battery, also maintains the charge on an input capacitance which provides power for the charging control circuitry during such charging process. In accordance with a preferred embodiment, the DC charging current is substantially constant during a first time interval following which the DC charging power is substantially constant during a second time interval.Type: ApplicationFiled: August 15, 2008Publication date: February 18, 2010Applicant: National Semiconductor CorporationInventors: Ahmad Bahai, Ali Djabbari, Qingguo Liu, Jianhui Zhang
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Publication number: 20090284078Abstract: A system for integrating local maximum power point tracking (MPPT) into an energy generating system having centralized MPPT is provided. The system includes a system control loop and a plurality of local control loops. The system control loop comprises a system operating frequency, and each local control loop comprises a corresponding local operating frequency. Each of the local operating frequencies is spaced apart from the system operating frequency by at least a predefined distance. For a particular embodiment, a settling time corresponding to the local operating frequency of each local control loop is at least five times faster than a time constant corresponding to the system operating frequency.Type: ApplicationFiled: June 23, 2009Publication date: November 19, 2009Applicant: National Semiconductor CorporationInventors: Jianhui Zhang, Ali Djabbari, Gianpaolo lisi
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Publication number: 20090283128Abstract: A method for activating a local converter for one of a plurality of energy generating devices in an energy generating array is provided. The local converter includes a power stage and a local controller. The method includes comparing a device voltage for the energy generating device to a voltage activation level. The local converter is automatically activated when the device voltage exceeds the voltage activation level.Type: ApplicationFiled: May 14, 2008Publication date: November 19, 2009Applicant: NATIONAL SEMICONDUCTOR CORPORATIONInventors: Jianhui Zhang, Ali Djabbari, Gianpaolo Lisi
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Publication number: 20090284998Abstract: A method for providing a maximum power point tracking (MPPT) process for an energy generating device is provided. The method includes coupling a local converter to the energy generating device. A determination is made regarding whether the local converter is operating at or below a maximum acceptable temperature. A determination is made regarding whether at least one current associated with the local converter is acceptable. When the local converter is determined to be operating at or below the maximum acceptable temperature and when the at least one current associated with the local converter is determined to be acceptable, the MPPT process is enabled within the local converter.Type: ApplicationFiled: June 23, 2009Publication date: November 19, 2009Applicant: National Semiconductor CorporationInventors: Jianhui Zhang, Ali Djabbari, Gianpaolo Lisi
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Publication number: 20090284232Abstract: A method for selecting between centralized and distributed maximum power point tracking in energy generating system is provided. The energy generating system includes a plurality of energy generating devices, each of which is coupled to a corresponding local converter. Each local converter includes a local controller for the corresponding energy generating device. The method includes determining whether the energy generating devices are operating under quasi-ideal conditions. The energy generating system is placed in a centralized maximum power point tracking (CMPPT) mode when the energy generating devices are operating under quasi-ideal conditions and is placed in a distributed maximum power point tracking (DMPPT) mode when the energy generating devices are not operating under quasi-ideal conditions.Type: ApplicationFiled: May 14, 2008Publication date: November 19, 2009Applicant: NATIONAL SEMICONDUCTOR CORPORATIONInventors: Jianhui Zhang, Ali Djabbari, Gianpaolo Lisi
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Publication number: 20090284240Abstract: A method for providing maximum power point tracking for an energy generating device using a local buck-boost converter coupled to the device is provided. The method includes operating in a tracking mode, which includes initializing a conversion ratio for the buck-boost converter based on a previous optimum conversion ratio. A device power associated with the initialized conversion ratio is calculated. The conversion ratio is repeatedly modified and a device power associated with each of the modified conversion ratios is calculated. A current optimum conversion ratio for the buck-boost converter is identified based on the calculated device powers. The current optimum conversion ratio corresponds to one of a buck mode, a boost mode and a buck-boost mode for the buck-boost converter.Type: ApplicationFiled: May 14, 2008Publication date: November 19, 2009Applicant: NATIONAL SEMICONDUCTOR CORPORATIONInventors: Jianhui Zhang, Ali Djabbari, Gianpaolo Lisi
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Publication number: 20090045848Abstract: A phase-frequency detection system and method for enhancing performance of the frequency detector in a phase-frequency detection system. Filtering of the frequency detector inputs makes operation of the frequency detector more robust in the presence of intersymbol interference within the incoming data signal and other non-ideal characteristics such as noise and crosstalk.Type: ApplicationFiled: August 15, 2007Publication date: February 19, 2009Applicant: National Semiconductor CorporationInventors: Ali Kiaei, Gerard G. Socci, Ali Djabbari, Ahmad Bahai
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Patent number: 5581303Abstract: A programmable CPU running at a video display rate, or a sub-multiple thereof, is used to generate the timings by loading control registers on the fly. In a preferred embodiment, a very reduced instruction set is used to generate VSYNC, HSYNC, and CSYNC signals. The CPU executes instructions out of an Instruction SRAM. The CPU's main goal is to load a pair of backing registers before a down counter reaches the value of zero.Type: GrantFiled: January 18, 1995Date of Patent: December 3, 1996Assignee: Radius Inc.Inventors: Ali Djabbari, Douglas J. Gilbert