Patents by Inventor Pitleong Wong
Pitleong Wong 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: 11757367Abstract: A flyback switching circuit and control method thereof is disclosed, by setting a reference value greater than zero configured for controlling a turn-off time of a first transistor of the flyback switching circuit, a drain-source voltage of a main power transistor of the flyback switching circuit is consistent with the reference value greater than zero before the main power transistor is turned on, so that a turn-on power consumption of the main power transistor is reduced and a system efficiency is improved.Type: GrantFiled: September 16, 2021Date of Patent: September 12, 2023Assignee: JOULWATT TECHNOLOGY CO., LTDInventors: Pitleong Wong, Yang Yang
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Publication number: 20230282156Abstract: Disclosed is an LED driver circuit, a multi-wire communication device and a method for an LED display system. The device comprises a controller providing at least one of a configuration data packet, a brightness data packet, and a display data packet; the LED driver circuits, wherein the LED driver circuits are cascaded to provide a first data channel using first data ports and second data ports, the LED driver circuits are connected in parallel to provide a second data channel using third data ports. The device relays an enable signal or an address data packet stage by stage using the first data channel, transmit at least one of the configuration data packet, the brightness data packet and the display data packet in parallel using the second data channel. The number of the cascaded LED driver circuits can be infinite, the number of data wires is reduced, data rate is increased.Type: ApplicationFiled: December 14, 2022Publication date: September 7, 2023Applicant: Joulwatt Technology Co., Ltd.Inventor: Pitleong WONG
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Publication number: 20230147234Abstract: A dynamic automotive turn signal circuit includes at least one drive control module configured to receive a power supply signal from a body control module (BCM) to start operation, where the drive control module outputs first control signals at different delays through a delay unit; and a light emitting diode (LED) light set connected to the drive control module and lit based on the first control signals. A dynamic automotive turn signal system is further provided. The dynamic automotive turn signal circuit and the dynamic automotive turn signal system uses an external resistor to preset a high-precision delay circuit to realize the function of dynamic flowing turn signals. The external resistor can be used to configure a turn-on delay and a turn-off delay of the internal driver chip, such that the channel turn-on time and turn-off time can be flexibly adjusted.Type: ApplicationFiled: November 7, 2022Publication date: May 11, 2023Applicant: Joulwatt Technology Co., Ltd.Inventors: Pitleong WONG, Jianyu XIE
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Publication number: 20220352738Abstract: A charging control method of power supply equipment and power supply equipment are provided. The power supply equipment includes a power stage circuit and a battery. An input power supply charges the battery through the power stage circuit. The power stage circuit includes a linear regulator and a switched capacitor converter. The linear regulator is connected with the switched capacitor converter. The linear regulator and/or the switched capacitor converter are/is selected for charging management according to charging power of the battery and/or a voltage of the battery. The charging control method can achieve relatively high charging efficiency when the battery is charged with a large current, and can achieve accurate control of the voltage of the battery when the battery is charged with a small current.Type: ApplicationFiled: April 29, 2022Publication date: November 3, 2022Applicant: Joulwatt Technology Co., Ltd.Inventor: Pitleong Wong
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Patent number: 11463079Abstract: The present disclosure provides a power transistor driving method. When a power transistor is turned off, a drain-source voltage of the power transistor is detected, and when the power transistor is an N-type component, and a change rate of the drain-source voltage of the power transistor along with time is lower than a first slope threshold, the power transistor is pulled down in a first current; when the change rate of the drain-source voltage of the power transistor along with the time is higher than the first slope threshold, a driving pole of the power transistor is pulled down in a second current; and when the change rate of the drain-source voltage of the power transistor along with the time is lower than the first slope threshold again, a pull-down switch is turned on or the driving pole of the power transistor is pulled down in a third current.Type: GrantFiled: November 9, 2020Date of Patent: October 4, 2022Assignee: Joulwatt Technology (Hangzhou) Co., LTD.Inventors: Pitleong Wong, Liyu Lin, Xunwei Zhou
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Publication number: 20220216701Abstract: An X-capacitor discharge method applied to a switched-mode power supply, wherein the switched-mode power supply comprises an X-capacitor, a rectifier circuit and a switching circuit; the X-capacitor discharge method comprises: arranging a first diode, wherein an anode of the first diode is connected to a first end of the X-capacitor, and a cathode of the first diode is configured as a first node; when it is detected that a voltage of the first node is higher than a first voltage threshold, pulling down the first node through a first sampling current, and performing a timing; and if a time for which the voltage of the first node continues to be higher than the first voltage threshold reaches a first threshold time, pulling down the first node through a first pull-down current. An X-capacitor discharge circuit applied to the switched-mode power supply is provided.Type: ApplicationFiled: August 11, 2021Publication date: July 7, 2022Applicant: Joulwatt Technology Co., Ltd.Inventors: Pitleong Wong, Mengyi HUANG
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Publication number: 20220006393Abstract: A flyback switching circuit and control method thereof is disclosed, by setting a reference value greater than zero configured for controlling a turn-off time of a first transistor of the flyback switching circuit, a drain-source voltage of a main power transistor of the flyback switching circuit is consistent with the reference value greater than zero before the main power transistor is turned on, so that a turn-on power consumption of the main power transistor is reduced and a system efficiency is improved.Type: ApplicationFiled: September 16, 2021Publication date: January 6, 2022Applicant: Joulwatt Technology Co., Ltd.Inventors: Pitleong WONG, Yang YANG
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Patent number: 11218136Abstract: The present disclosure provides a power transistor driving method, a driving circuit and a switching circuit. When the power transistor is an N-type component, a driving pole of the power transistor is pulled down in a first current, and when a time period recorded by the timer reaches a first time period, a pull-down switch is turned on or the driving pole of the power transistor is pulled down in a second current; the driving pole of the power transistor is pulled down by the pull-down switch; when a timer is started from a moment at which the power transistor is turned off, the first time period is higher than a time period from a moment at which a switching tube is turned off to a moment at which the change rate of the drain-source voltage of the power transistor along with the time is higher than the first slope.Type: GrantFiled: November 12, 2020Date of Patent: January 4, 2022Assignee: JOULWATT TECHNOLOGY (HANGZHOU) CO. LTD.Inventors: Pitleong Wong, Liyu Lin, Xunwei Zhou
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Patent number: 11165355Abstract: A clamping switch abnormality detection method, a clamping switch abnormality detection circuit and a switch circuit are provided, wherein an active clamping flyback circuit includes a clamping switch, a main switch and a transformer. When a clamping switch control signal is active, a switching node voltage or a voltage on an auxiliary winding or an magnetizing inductor current is detected, and when the switching node voltage or the voltage on the auxiliary winding or the magnetizing inductor current oscillates, or the switching node voltage is less than a first voltage threshold or the voltage on the auxiliary winding is less than a second voltage threshold, the clamping switch is abnormal or a clamping switch driving circuit is abnormal. The switching node is a common node of the transformer and the main switch, and the transformer includes a primary winding, a secondary winding and the auxiliary winding.Type: GrantFiled: February 7, 2020Date of Patent: November 2, 2021Assignee: JOULWATT TECHNOLOGY (HANGZHOU) CO., LTD.Inventors: Pitleong Wong, Xianghua Jiang, Xunwei Zhou
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Patent number: 11152866Abstract: An active clamping flyback circuit and a control method are disclosed, comprising a flyback circuit, a clamping circuit and a clamping control circuit. The active clamping flyback circuit comprises a transformer, a main transistor, and a freewheeling diode or a synchronous rectifier, an output feedback circuit is coupling to an auxiliary winding of the transformer and outputs a feedback voltage through a divided voltage The clamping circuit comprises a first capacitor and a first transistor coupling in series, In a discontinuous conduction mode, the clamping control circuit starts timing from a turn-off time of the first transistor, and ends timing until the feedback voltage is reduced to zero voltage, to obtain a first time, The clamping control circuit adjusts a turn-off moment of next switching cycle of the first transistor so that the first time of the next switching cycle is close to a first threshold.Type: GrantFiled: December 13, 2019Date of Patent: October 19, 2021Assignee: JOULWATT TECHNOLOGY (HANGZHOU) CO., LTDInventors: Pitleong Wong, Xianghua Jiang, Xunwei Zhou
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Publication number: 20210152094Abstract: A clamping switch abnormality detection method, a clamping switch abnormality detection circuit and a switch circuit are provided, wherein an active clamping flyback circuit includes a clamping switch, a main switch and a transformer. When a clamping switch control signal is active, a switching node voltage or a voltage on an auxiliary winding or an magnetizing inductor current is detected, and when the switching node voltage or the voltage on the auxiliary winding or the magnetizing inductor current oscillates, or the switching node voltage is less than a first voltage threshold or the voltage on the auxiliary winding is less than a second voltage threshold, the clamping switch is abnormal or a clamping switch driving circuit is abnormal. The switching node is a common node of the transformer and the main switch, and the transformer includes a primary winding, a secondary winding and the auxiliary winding.Type: ApplicationFiled: February 7, 2020Publication date: May 20, 2021Applicant: Joulwatt Technology (Hangzhou)Co.,LTD.Inventors: Pitleong Wong, Xianghua JIANG, Xunwei ZHOU
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Publication number: 20210152169Abstract: The present disclosure provides a power transistor driving method. When a power transistor is turned off, a drain-source voltage of the power transistor is detected, and when the power transistor is an N-type component, and a change rate of the drain-source voltage of the power transistor along with time is lower than a first slope threshold, the power transistor is pulled down in a first current; when the change rate of the drain-source voltage of the power transistor along with the time is higher than the first slope threshold, a driving pole of the power transistor is pulled down in a second current; and when the change rate of the drain-source voltage of the power transistor along with the time is lower than the first slope threshold again, a pull-down switch is turned on or the driving pole of the power transistor is pulled down in a third current.Type: ApplicationFiled: November 9, 2020Publication date: May 20, 2021Inventors: Pitleong WONG, Liyu LIN, Xunwei ZHOU
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Publication number: 20210152159Abstract: The present disclosure provides a power transistor driving method, a driving circuit and a switching circuit. When the power transistor is an N-type component, a driving pole of the power transistor is pulled down in a first current, and when a time period recorded by the timer reaches a first time period, a pull-down switch is turned on or the driving pole of the power transistor is pulled down in a second current; the driving pole of the power transistor is pulled down by the pull-down switch; when a timer is started from a moment at which the power transistor is turned off, the first time period is higher than a time period from a moment at which a switching tube is turned off to a moment at which the change rate of the drain-source voltage of the power transistor along with the time is higher than the first slope.Type: ApplicationFiled: November 12, 2020Publication date: May 20, 2021Inventors: Pitleong WONG, Liyu LIN, Xunwei ZHOU
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Publication number: 20210058002Abstract: An active clamping flyback circuit is disclosed, comprising a flyback circuit, a clamping circuit and a clamping control circuit, wherein the flyback circuit comprises a transformer, a main transistor, and a freewheeling diode or a synchronous rectifier, an output feedback circuit is coupling to an auxiliary winding of the transformer and outputs a feedback voltage through a divided voltage; the clamping circuit comprises a first capacitor and a first transistor coupling in series, one end of the first capacitor is coupling to a high voltage end, one end of the first transistor is coupling to a common end of the main transistor and a primary winding of the transformer; the clamping control circuit adjusts a turn-off time of next switching cycle of the first transistor so that the first time of the next switching cycle is close to a first threshold.Type: ApplicationFiled: December 13, 2019Publication date: February 25, 2021Applicant: Joulwatt Technology (Hangzhou) Co., Ltd.Inventors: Pitleong WONG, XIANGHUA JIANG, XUNWEI ZHOU
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Patent number: 10886913Abstract: Disclosed a drive method, a drive circuit for a power switch and a power supply system. During the turning-on period of the power switch, which can be roughly divided into three processes, a current limiting module is used to limit the current flowing through the power switch for preventing current overshoot, a logic control module is used for controlling the current limiting module not to operate before the turning-on period and the control terminal of the power switch is turned off; during the turning-on period, a feedback circuit adjusts the gate voltage of the power switch for controlling the current flowing through the power switch to reach a predetermined limited value quickly and then maintain at the limited value until the power switch is fully turned on. The current limiting module can be employed in various embodiments.Type: GrantFiled: August 28, 2017Date of Patent: January 5, 2021Assignee: JOULWATT TECHNOLOGY (HANGZHOU) CO., LTDInventors: Pitleong Wong, Libin Huang, Yuancheng Ren, Xunwei Zhou
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Patent number: 10715125Abstract: A circuit and a method for detecting a current zero-crossing point, and a circuit and method for detecting a load voltage are disclosed. The circuit for detecting current zero-crossing point includes: a load power supply circuit, a voltage-dividing resistor, a transistor switch, a zero-crossing detection circuit; the load power supply circuit includes: a load, a diode, and a transformer; one end of a primary winding of the transformer is connected with the operating voltage input terminal, the other end of the primary winding of the transformer is connected with a first end of the transistor switch and a first end of the voltage-dividing resistor, a second end of the voltage-dividing resistor and a second end of the transistor switch are connected with the ground, the load voltage is controlled by the transistor switch.Type: GrantFiled: July 30, 2019Date of Patent: July 14, 2020Assignee: JOULWATT TECHNOLOGY (HANGZHOU) CO., LTDInventors: Pitleong Wong, Yang Lu, Yue Ji, Yuancheng Ren, Xunwei Zhou
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Patent number: 10644517Abstract: Disclosed a battery balance circuit, a control method for battery balance and a battery system. The battery balance circuit is implemented on basis of a circuit structure having a plurality of cascaded balance modules, in which a judgement of abnormal states of batteries or balance modules is realized together with synchronizations of the detection of battery states and battery balance. When the judgement of abnormal states of batteries (including the abnormal states of battery voltages, battery temperatures and battery currents) is made, the balance modules stop balancing by transferring signals, meanwhile, when the balance modules restore from the abnormal state, they restore balance. The disclosure increases the judgement of abnormal states, and implements detection and alarm at abnormal states.Type: GrantFiled: September 28, 2017Date of Patent: May 5, 2020Assignee: JOULWATT TECHNOLOGY (Zhangjiagang) CO., LTD.Inventors: Libin Huang, Pitleong Wong, Yuancheng Ren, Xunwei Zhou
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Patent number: 10644604Abstract: A flyback switching power supply, comprising a main power switch, a transformer and a rectifier is described. The transformer comprises a primary winding and a secondary winding, the main power switch is connected with the primary winding, the rectifier is connected with the secondary winding. When the output voltage of the flyback switching power supply is lower than a first threshold value, the rectifier is controlled to be turned on for a transient period; by detecting the negative current flowing through the main power switch, performing integral operation on the voltage across the auxiliary winding, and sampling the peak voltage of the drain-to-source voltage of the main power switch for several times, whether the rectifier is turned on can be determined if the output voltage at the secondary side is lower than the threshold voltage, and the main power switch is controlled to be turned on accordingly.Type: GrantFiled: May 8, 2019Date of Patent: May 5, 2020Assignee: JOULWATT TECHNOLOGY (HANGZHOU) CO., LTD.Inventors: Pitleong Wong, Xunwei Zhou
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Patent number: 10505442Abstract: The present invention provides a synchronous rectification control circuit, a method and a flyback switching circuit. A drive circuit outputs a drive signal to control the turn-on and turn-off of a synchronous rectification transistor; a threshold comparison circuit controls the drive circuit to output a pull-up drive signal to turn on the synchronous rectification transistor when a drain-source voltage is lower than a preset low threshold voltage and controls the drive circuit to output a pull-down drive signal to turn off the synchronous rectification transistor when the drain-source voltage is higher than or equal to a preset high threshold voltage; a voltage regulation control circuit controls the drive circuit to output a drive signal for pulling up a voltage of the drive signal to a preset pull-up voltage high value when the drain-source voltage is lower than a preset voltage regulation reference value.Type: GrantFiled: September 28, 2017Date of Patent: December 10, 2019Assignee: JOULWATT TECHNOLOGY (HANGZHOU) CO., LTD.Inventors: Pitleong Wong, Yuancheng Ren, Xunwei Zhou, Junming Zhang, Yiqing Jin
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Patent number: 10506684Abstract: A protection circuit and an illumination driving circuit are described herein. The protection circuit comprises a detection circuit, detecting a current flowing through a first switch to obtain a current detection signal and determining whether there is leakage at an input terminal according to the current detection signal; a control circuit, controlling the first switch to switch on intermittently, detecting the current flowing through the first switch by the detection circuit during a switch-on period of the first switch, and keeping the load at a disconnection state if the detection circuit determines there is leakage; and the first switch, connected to the input terminal, and a control terminal of the first switch being connected to the control circuit, and the first switch being controlled by the control circuit to be switched on intermittently. The present invention has the protection function and enhances safety during load removing and installation processes.Type: GrantFiled: April 21, 2017Date of Patent: December 10, 2019Assignee: JOULWATT TECHNOLOGY (HANGZHOU) CO., LTD.Inventors: Junming Zhang, Guoqiang Liu, Pitleong Wong, Yuancheng Ren, Xunwei Zhou