Patents by Inventor Julu Sun
Julu Sun 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: 20230283185Abstract: A power supply device, a circuit control method and a power supply system, belonging to the field of power supply conversion technologies. The power supply device can ensure that a second-stage conversion circuit has a sufficiently high valley voltage by means of a valley-fill circuit without using an electrolytic capacitor or other large-volume capacitors, thereby ensuring that the output voltage of the power supply device is overall stable. On the other hand, the power supply device can, by controlling the voltage of an energy storage unit, utilize the ability of the energy storage unit to store electric energy as far as possible whilst ensuring that the voltage does not exceed a specific voltage, so as to lower the requirements on the voltage resistance of the energy storage unit, thereby realizing the miniaturized design of the power supply device and improving the portability of the power supply device.Type: ApplicationFiled: May 11, 2023Publication date: September 7, 2023Inventors: Chen TIAN, Jialiang ZHANG, Jingpeng ZHU, Weiwei LU, Juanjuan SUN, Julu SUN
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Publication number: 20230268843Abstract: A power supply, a power supplying method, and a computer-readable storage medium are provided. The power supply includes a rectifier circuit and a valley-fill circuit. The rectifier circuit is used for voltage transformation of an input AC voltage to obtain a first pulsating DC voltage. The valley-fill circuit includes at least one energy storage capacitor and is used for storing energy through the at least one energy storage capacitor when the first pulsating DC voltage output by the rectifier circuit is in a first preset range and providing energy through the at least one energy storage capacitor when the first pulsating DC voltage output by the rectifier circuit is lower than a preset threshold, thereby to increase the valley voltage of the first pulsating DC voltage.Type: ApplicationFiled: May 2, 2023Publication date: August 24, 2023Inventors: Chen TIAN, Jialiang ZHANG, Jingpeng ZHU, Weiwei LU, Juanjuan SUN, Julu SUN
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Publication number: 20230261498Abstract: Provided are a power supply apparatus, and a charging method and system. The apparatus includes: a rectifier module (210) configured to rectify an alternating current (alternating current) voltage to obtain a first pulsating direct current (direct current) voltage; a conversion module (300) configured to convert the first pulsating direct current voltage to obtain a stable direct current voltage; and a valley-fill circuit (220) having an input terminal connected to an output terminal of the rectifier module (210) and an output terminal connected to an input terminal of the conversion module (300). The valley-fill circuit (220) is configured to release electric energy to the conversion module (300) when a voltage value of the first pulsating direct current voltage is smaller than a first voltage threshold, to increase a valley voltage of the first pulsating direct current voltage inputted to the conversion module (300).Type: ApplicationFiled: April 20, 2023Publication date: August 17, 2023Inventors: Chen Tian, Jialiang Zhang, Jingpeng Zhu, Weiwei Lu, Juanjuan Sun, Julu Sun
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Patent number: 8587965Abstract: A current-input-type parallel resonant DC/DC converter and a method thereof are provided. The converter includes an inverter-circuit for inverting/converting an input DC current into a positive-and-negative alternating square-wave-current, a resonant-network for converting the square-wave-current into a sine-voltage, a transformer for realizing the isolation of the power transmission, a full-wave rectifier-circuit for rectifying the sine-voltage, and an output-filter-circuit for producing a DC output-voltage.Type: GrantFiled: August 12, 2011Date of Patent: November 19, 2013Assignees: FSP-Powerland Technology Inc., FSP Technology Inc.Inventors: Ming Xu, Julu Sun
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Publication number: 20120039092Abstract: A current-input-type parallel resonant DC/DC converter and a method thereof are provided. The converter includes an inverter-circuit for inverting/converting an input DC current into a positive-and-negative alternating square-wave-current, a resonant-network for converting the square-wave-current into a sine-voltage, a transformer for realizing the isolation of the power transmission, a full-wave rectifier-circuit for rectifying the sine-voltage, and an output-filter-circuit for producing a DC output-voltage.Type: ApplicationFiled: August 12, 2011Publication date: February 16, 2012Applicants: FSP TECHNOLOGY INC., FSP-POWERLAND TECHNOLOGY INC.Inventors: Ming Xu, Julu Sun
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Publication number: 20120039103Abstract: A single-stage AC/DC converter is provided, and which includes a power-frequency follow-current circuit, an isolated transmission circuit (ITC), a high-frequency chopper modulation circuit (HFCMC), a power-frequency and high-frequency AC rectifying-circuit and a filter-circuit. The input of the ITC is connected to the output of an external power-frequency power source, the current-modulating side of the ITC is connected to the input of the HFCMC, the output of the ITC is connected to the input of the power-frequency and high-frequency AC rectifying-circuit, the output of the HFCMC is connected to the input of the external power-frequency power source through the power-frequency follow-current connected in series with the HFCMC , and the output of the power-frequency and high-frequency AC rectifying circuit is connected to a load through the filter circuit connected in series with the power-frequency and high-frequency AC rectifying-circuit.Type: ApplicationFiled: August 11, 2011Publication date: February 16, 2012Applicants: FSP TECHNOLOGY INC., FSP-POWERLAND TECHNOLOGY INC.Inventors: Ming Xu, Julu Sun, Chao Sun
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Patent number: 7872886Abstract: Improved regulation and transient response are provided by a power supply architecture providing both unregulated and regulated voltage converters in parallel but deriving input power from separate power supplies connected in series wherein regulated and unregulated branches each provide a substantially fixed and constant proportion of the output current. The series connection of input power sources may provide a further feedback mechanism in addition to feedback for regulation which enhances overall performance. As a perfecting feature of the invention, inductor-less resonant converters which are switched in an interleaved fashion may be used in the unregulated branch while substantially cancelling the characteristic large output voltage ripple thereof.Type: GrantFiled: February 20, 2008Date of Patent: January 18, 2011Assignee: Virginia Tech Intellectual Properties, Inc.Inventors: Ming Xu, Julu Sun, Ya Liu, Fred C. Lee
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Patent number: 7746041Abstract: A voltage converter having four switches Q1, Q2, Q3, Q4, connected in series and operated in pairs in a complementary fashion. An input voltage is provided across the four switches. A middle capacitor is connected in parallel with two middle switches Q2, Q3. Voltage output is provided across switches Q3 and Q4 (i.e. at a midpoint of the four switches). Series-connected output capacitors can be connected in parallel with the set of four switches. The middle capacitor alone or in combination with parallel connected capacitors, when connected to the input voltage or output terminals functions as a capacitive voltage divider for voltage conversion and/or regulation with extremely high efficiency and which can provide either step-down or step-up function. Also, an output inductor can be provided as a perfecting feature to further increase efficiency. Alternatively, two of the four switches can be replaced with rectifying diodes.Type: GrantFiled: March 27, 2007Date of Patent: June 29, 2010Assignee: Virginia Tech Intellectual Properties, Inc.Inventors: Ming Xu, Julu Sun, Fred C. Lee
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Publication number: 20090206804Abstract: Improved regulation and transient response are provided by a power supply architecture providing both unregulated and regulated voltage converters in parallel but deriving input power from separate power supplies connected in series wherein regulated and unregulated branches each provide a substantially fixed and constant proportion of the output current. The series connection of input power sources may provide a further feedback mechanism in addition to feedback for regulation which enhances overall performance. As a perfecting feature of the invention, inductor-less resonant converters which are switched in an interleaved fashion may be used in the unregulated branch while substantially cancelling the characteristic large output voltage ripple thereof.Type: ApplicationFiled: February 20, 2008Publication date: August 20, 2009Inventors: Ming Xu, Julu Sun, Ya Liu, Fred C. Lee
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Publication number: 20070296383Abstract: A voltage converter having four switches Q1, Q2, Q3, Q4, connected in series and operated in pairs in a complementary fashion. An input voltage is provided across the four switches. A middle capacitor is connected in parallel with two middle switches Q2, Q3. Voltage output is provided across switches Q3 and Q4 (i.e. at a midpoint of the four switches). Series-connected output capacitors can be connected in parallel with the set of four switches. The middle capacitor alone or in combination with parallel connected capacitors, when connected to the input voltage or output terminals functions as a capacitive voltage divider for voltage conversion and/or regulation with extremely high efficiency and which can provide either step-down or step-up function. Also, an output inductor can be provided as a perfecting feature to further increase efficiency. Alternatively, two of the four switches can be replaced with rectifying diodes.Type: ApplicationFiled: March 27, 2007Publication date: December 27, 2007Inventors: Ming Xu, Julu Sun, Fred C. Lee
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Patent number: 7265525Abstract: A voltage converter uses a component such as a JFET or four-terminal power MOSFET having no body diode and exhibiting no body diode conduction characteristic as a synchronous rectifier to reduce switching losses and body diode conduction losses and to support high frequency switching so that use of smaller components and higher current densities can be achieved. These effects are enhanced by a self-driven circuit utilizing positive feedback to enhance switching speed and reduce switching losses which increase with switching frequency.Type: GrantFiled: March 31, 2005Date of Patent: September 4, 2007Assignee: Virginia Tech Intellectual Properties, Inc.Inventors: Ming Xu, Julu Sun, Jinghai Zhou, Fred C. Lee
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Patent number: 7254047Abstract: Power converters having reduced body diode conduction loss, reduced reverse recovery loss and lower switching noise, among other benefits, have a resonant capacitor Cr connected across an unfiltered output. The resonant capacitor Cr resonates with the leakage inductance Lk of the transformer. The resonant capacitor and leakage inductance are selected such that ½ a LC resonance period is equal to an ON time of each secondary switch S1 S2. The resonance provides zero current switching for secondary switches S1 S2, eliminates zero body diode conduction during dead times, and eliminates reverse recovery losses in the secondary switches. The present invention is applicable to many different circuit topologies such as full bridge, active clamp forward, push-pull forward, and center-tap secondary. The present converters provide high energy conversion efficiency and high frequency operation.Type: GrantFiled: March 31, 2005Date of Patent: August 7, 2007Assignee: Virginia Tech Intellectual Properties, Inc.Inventors: Yuancheng Ren, Julu Sun, Ming Xu, Fred C. Lee
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Publication number: 20060226819Abstract: A voltage converter uses a component such as a JFET or four-terminal power MOSFET having no body diode and exhibiting no body diode conduction characteristic as a synchronous rectifier to reduce switching losses and body diode conduction losses and to support high frequency switching so that use of smaller components and higher current densities can be achieved. These effects are enhanced by a self-driven circuit utilizing positive feedback to enhance switching speed and reduce switching losses which increase with switching frequency.Type: ApplicationFiled: March 31, 2005Publication date: October 12, 2006Inventors: Ming Xu, Julu Sun, Jinghai Zhou, Fred Lee
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Publication number: 20060109696Abstract: Power converters having reduced body diode conduction loss, reduced reverse recovery loss and lower switching noise, among other benefits, have a resonant capacitor Cr connected across an unfiltered output. The resonant capacitor Cr resonates with the leakage inductance Lk of the transformer. The resonant capacitor and leakage inductance are selected such that ½ a LC resonance period is equal to an ON time of each secondary switch S1 S2. The resonance provides zero current switching for secondary switches S1 S2, eliminates zero body diode conduction during dead times, and eliminates reverse recovery losses in the secondary switches. The present invention is applicable to many different circuit topologies such as full bridge, active clamp forward, push-pull forward, and center-tap secondary. The present converters provide high energy conversion efficiency and high frequency operation.Type: ApplicationFiled: March 31, 2005Publication date: May 25, 2006Inventors: Yuancheng Ren, Julu Sun, Ming Xu, Fred Lee