Patents by Inventor Srikanth Lakshmikanthan
Srikanth Lakshmikanthan 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: 20240128805Abstract: Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for wireless charging using time-division multiplexing. In some implementations, a wireless charger is configured to concurrently charge multiple devices by providing power wirelessly to individual devices in different time periods. The wireless charger can perform time-division multiplexing by selectively directing the output of a single driver circuit to different power transfer coil segments at different times. The wireless charging sessions of multiple devices can be maintained by repeating a pattern of activating different power transfer coil segments one by one in successive time periods.Type: ApplicationFiled: December 20, 2023Publication date: April 18, 2024Inventors: Veera Venkata Siva Nagesh Polu, Liang Jia, Srikanth Lakshmikanthan
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Patent number: 11949251Abstract: The present disclosure provides for a wearable device having a wireless power receiving system that may inductively receive or transmit power. The wireless power receiving system includes a receiver coil having a profile that follows a contour of a bottom cover of the wearable device. A transmitter coil from a wireless charging device has a complementary profile that mates with the profile defined by the receiver coil. In one example, the wireless power receiving system includes a shielding, and a receiver coil attached to the shielding. The receiver coil further includes an inner wall and an outer wall connected by a top surface of a coil body. The inner wall defines a center opening in the receiver coil, wherein the receiver coil is conical in shape.Type: GrantFiled: October 8, 2020Date of Patent: April 2, 2024Assignee: Google LLCInventors: Qi Tian, Liang Jia, Tressa Christie Scott, Srikanth Lakshmikanthan
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Patent number: 11923696Abstract: This document describes a passive adapter for wireless charging of an electronic device and associated methods and systems. The described passive adapter includes two coils connected by a capacitor and separated by a core material that prevents mutual coupling between the coils. These two coils may have differing sizes, such that one coil can size-match to a transmitter coil of an existing wireless charger and the second coil can size-match to a smaller (or larger) receiver coil in a wireless-power receiver to charge a battery of the wireless-power receiver. In aspects, these two coils may be separated by a distance that enables the passive adapter to act as a passive repeater by bridging a space between the transmitter coil and the receiver coil.Type: GrantFiled: February 12, 2020Date of Patent: March 5, 2024Assignee: Google LLCInventors: Liang Jia, Srenik Suresh Mehta, Srikanth Lakshmikanthan
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Patent number: 11916478Abstract: In general, techniques are described that are directed to a device that includes a power storage device, an electrical load, and a first regulated power converter including components configured to generate, during a first time period and using electrical energy received from a power source external to the device, a first power signal to charge the power storage device. A second regulated power converter includes components configured to determine a charging current at which to charge the power storage device, determine a total amount of current flowing to the power storage device that includes current sourced by the second power converter less current sinked by the electrical load, and generate, during a second time period that is non-overlapping with the first time period, using electrical energy from the power source and based on determined the total amount of current, a second power signal to charge the power storage device.Type: GrantFiled: August 31, 2020Date of Patent: February 27, 2024Assignee: Google LLCInventors: Chao Fei, Douglas Osterhout, Srikanth Lakshmikanthan, Liang Jia, Li Wang
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Patent number: 11881730Abstract: Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for wireless charging using time-division multiplexing. In some implementations, a wireless charger is configured to concurrently charge multiple devices by providing power wirelessly to individual devices in different time periods. The wireless charger can perform time-division multiplexing by selectively directing the output of a single driver circuit to different power transfer coil segments at different times. The wireless charging sessions of multiple devices can be maintained by repeating a pattern of activating different power transfer coil segments one by one in successive time periods.Type: GrantFiled: September 6, 2019Date of Patent: January 23, 2024Assignee: Google LLCInventors: Veera Venkata Siva Nagesh Polu, Liang Jia, Srikanth Lakshmikanthan
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Publication number: 20230221813Abstract: An example active stylus includes a core comprising: a main cylinder having a first end, a second end; a first supplemental cylinder disposed at the first end of the main cylinder and having a diameter that is larger than a diameter of the main cylinder; a second supplemental cylinder disposed between the first supplemental cylinder and the second end of the main cylinder and having a diameter that is larger than the diameter of the main cylinder; and a wireless charging receive coil configured to transduce flux of a magnetic field generated by a wireless charging transmit coil into electrical current, wherein the wireless charging receive coil is positioned around a longitudinal axis of the main cylinder of the core and between the first supplemental cylinder and the second supplemental cylinder.Type: ApplicationFiled: August 31, 2020Publication date: July 13, 2023Inventors: Liang Jia, Srikanth Lakshmikanthan, Liyu Yang
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Publication number: 20230179010Abstract: In general, techniques are described that are directed to a device having a first power storage device and a second power storage device connected in series. A first power converter may generate, using electrical energy sourced from the first power storage device and the second power storage device, a first power signal to power a first set of components. A second power converter may generate, using electrical energy sourced from the first power storage device and not the second power storage device, a second power signal to power a second set of components.Type: ApplicationFiled: May 4, 2020Publication date: June 8, 2023Inventors: Chao Fei, Douglas Osterhout, Srikanth Lakshmikanthan
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Publication number: 20230105296Abstract: Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for wireless charging using time-division multiplexing. In some implementations, a wireless charger is configured to concurrently charge multiple devices by providing power wirelessly to individual devices in different time periods. The wireless charger can perform time-division multiplexing by selectively directing the output of a single driver circuit to different power transfer coil segments at different times. The wireless charging sessions of multiple devices can be maintained by repeating a pattern of activating different power transfer coil segments one by one in successive time periods.Type: ApplicationFiled: September 6, 2019Publication date: April 6, 2023Inventors: Veera Venkata Siva Nagesh Polu, Liang Jia, Srikanth Lakshmikanthan
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Publication number: 20220302734Abstract: In general, techniques are described that are directed to a device that includes a power storage device, an electrical load, and a first regulated power converter including components configured to generate, during a first time period and using electrical energy received from a power source external to the device, a first power signal to charge the power storage device. A second regulated power converter includes components configured to determine a charging current at which to charge the power storage device, determine a total amount of current flowing to the power storage device that includes current sourced by the second power converter less current sinked by the electrical load, and generate, during a second time period that is non-overlapping with the first time period, using electrical energy from the power source and based on determined the total amount of current, a second power signal to charge the power storage device.Type: ApplicationFiled: August 31, 2020Publication date: September 22, 2022Inventors: Chao Fei, Douglas Osterhout, Srikanth Lakshmikanthan, Liang Jia, Li Wang
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Patent number: 11417461Abstract: This document describes techniques and apparatuses directed at reducing inductive-charging power loss. In aspects, a mobile device includes a multi-layer flexible printed circuit board (FPCB) coil that forms a receiver coil having a Litz-wire structure. The FPCB coil includes a multi-trace bundle, having traces systematically routed throughout the different layers of the FPCB coil to reduce eddy current losses.Type: GrantFiled: February 16, 2021Date of Patent: August 16, 2022Assignee: Google LLCInventors: Liyu Yang, Liang Jia, Srikanth Lakshmikanthan, Li Wang, Qi Tian, YungChih Chen, Veera Venkata Siva Nagesh Polu, Stefano Saggini, Mario Ursino, Ruben Specogna
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Patent number: 11342796Abstract: Methods, systems, and techniques for safely controlling wireless charging in the presence of a foreign object are presented. A method includes determining a power difference between a power transmitted by a wireless charger and a power received by an electronic device, determining a level of misalignment of the electronic device with respect to the wireless charger; estimating an amount of power difference due to the level of misalignment of the electronic device with respect to the wireless charger, adjusting a power difference threshold for the wireless charger based on the estimated amount of power difference, and controlling operation of the wireless charger based on the power difference and the adjusted power difference threshold.Type: GrantFiled: September 7, 2018Date of Patent: May 24, 2022Assignee: Google LLCInventors: Qi Tian, Veera Venkata Siva Nagesh Polu, Liang Jia, Liyu Yang, Jae-won Hwang, Rahul Apte, Srikanth Lakshmikanthan, Srenik Suresh Mehta, Robert Thomas Shone
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Publication number: 20220139615Abstract: This document describes techniques and apparatuses directed at reducing inductive-charging power loss. In aspects, a mobile device includes a multi-layer flexible printed circuit board (FPCB) coil that forms a receiver coil having a Litz-wire structure. The FPCB coil includes a multi-trace bundle, having traces systematically routed throughout the different layers of the FPCB coil to reduce eddy current losses.Type: ApplicationFiled: February 16, 2021Publication date: May 5, 2022Applicant: Google LLCInventors: Liyu Yang, Liang Jia, Srikanth Lakshmikanthan, Li Wang, Qi Tian, YungChih Chen, Veera Venkata Siva Nagesh Polu, Stefano Saggini, Mario Ursino, Ruben Specogna
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Publication number: 20220115918Abstract: The present disclosure provides for a wearable device having a wireless power receiving system that may inductively receive or transmit power. The wireless power receiving system includes a receiver coil having a profile that follows a contour of a bottom cover of the wearable device. A transmitter coil from a wireless charging device has a complementary profile that mates with the profile defined by the receiver coil. In one example, the wireless power receiving system includes a shielding, and a receiver coil attached to the shielding. The receiver coil further includes an inner wall and an outer wall connected by a top surface of a coil body. The inner wall defines a center opening in the receiver coil, wherein the receiver coil is conical in shape.Type: ApplicationFiled: October 8, 2020Publication date: April 14, 2022Inventors: Qi Tian, Liang Jia, Tressa Christie Scott, Srikanth Lakshmikanthan
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Publication number: 20220029530Abstract: An example power adapter includes a rectifier configured to convert an input alternating current (AC) power signal on an AC bus into an input direct current (DC) power signal on an input DC bus; a split differential mode (DM) choke connected to the input DC bus, wherein the split DM choke comprises a first DM choke on a high side of the input DC bus and a second DM choke on a low side of the input DC bus; and a switched mode power converter configured to output, using the input DC power signal, an output DC power signal on an output DC bus.Type: ApplicationFiled: March 26, 2020Publication date: January 27, 2022Inventors: Yiming Li, Shuo Wang, Honggang Sheng, Douglas Osterhout, Srikanth Lakshmikanthan
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Publication number: 20210366647Abstract: Shielded electrical transformers and power converters using those transformers are disclosed. In some implementations, a shielded electrical transformer includes a magnetic core, a primary winding, a first secondary winding, and a second secondary winding. The transformer includes a first shielding winding that has a same voltage potential direction as the primary winding and is connected in series with the primary winding to carry current that passes through the primary winding. The transformer also includes a second shielding winding that has a voltage potential direction opposite the primary winding and is connected from primary ground to a floating terminal. The first secondary winding, the second secondary winding, the first shielding winding, and the second shielding winding can each have an approximately equal number of turns.Type: ApplicationFiled: August 5, 2019Publication date: November 25, 2021Inventors: Chao Fei, Honggang Sheng, Douglas Osterhout, Liang Jia, Srikanth Lakshmikanthan
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Patent number: 11171522Abstract: Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for improving wireless charging. In some implementations, an electronic device determines a power demand of the electronic device. The electronic device includes a wireless power receiver including a wireless power receiving coil configured to receive power through inductive coupling with a wireless charge. The electronic device determines an operating voltage or operating frequency for the wireless charger based on the power demand of the electronic device. The electronic device sends, to the wireless charger, data indicating the operating voltage or operating frequency for the wireless charger.Type: GrantFiled: April 24, 2019Date of Patent: November 9, 2021Assignee: Google LLCInventors: Liang Jia, Qi Tian, Liyu Yang, Veera Venkata Siva Nagesh Polu, Srikanth Lakshmikanthan, Rahul Apte, Jae-won Hwang, Srenik Suresh Mehta
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Patent number: 10945213Abstract: Methods, systems, and devices, including machine-readable media, for dynamic battery power management are disclosed. In some implementations, an electronic device that is powered by a battery senses a voltage provided by the battery and an electric current provided by the battery. The electronic device determines a present state of the battery. The electronic device determines a current limit for the electronic device based on the sensed voltage and electric current and the determined present state of the battery. The electronic device manages power use of the electronic device to maintain electric current draw from the battery at or below the electric current limit.Type: GrantFiled: March 13, 2019Date of Patent: March 9, 2021Assignee: Google LLCInventors: Enrique Romero Pintado, Liang Jia, Srikanth Lakshmikanthan, Eklavya Singh
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Publication number: 20200358314Abstract: A computing device can include a housing, a display secured by the housing, a charging coil included in a back side of the housing, the back side of the housing being on an opposite side from the display, and at least one magnet adjacent to the charging coil.Type: ApplicationFiled: May 7, 2019Publication date: November 12, 2020Inventors: Vijayasekaran Boovaragavan, Veera Venkata Siva Nagesh Polu, Srikanth Lakshmikanthan, Douglas Osterhout, Liang Jia, Chao Fei, Zhenxue Xu
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Publication number: 20200343777Abstract: Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for improving wireless charging. In some implementations, an electronic device determines a power demand of the electronic device. The electronic device includes a wireless power receiver including a wireless power receiving coil configured to receive power through inductive coupling with a wireless charge. The electronic device determines an operating voltage or operating frequency for the wireless charger based on the power demand of the electronic device. The electronic device sends, to the wireless charger, data indicating the operating voltage or operating frequency for the wireless charger.Type: ApplicationFiled: April 24, 2019Publication date: October 29, 2020Inventors: Liang Jia, Qi Tian, Liyu Yang, Veera Venkata Siva Nagesh Polu, Srikanth Lakshmikanthan, Rahul Apte, Jae-won Hwang, Srenik Suresh Mehta
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Publication number: 20200220368Abstract: An adapter can include a voltage doubler rectifier, a first stage converter, and a second stage converter. The voltage doubler rectifier can have a switch and can be configured to rectify a received voltage in response to the switch being in a first position, and to rectify and effectively double the received voltage in response to the switch being in a second position. The first stage converter can be coupled to the voltage doubler rectifier and can be a first type of converter. The first type of converter can be either an isolated converter or a non-isolated converter. The second stage converter can be coupled to the first stage converter and can be a second type of converter. The second type of converter can be either the isolated converter or the non-isolated converter. The second type of converter can be different from the first type of converter.Type: ApplicationFiled: January 8, 2019Publication date: July 9, 2020Inventors: Chao Fei, Honggang Sheng, Douglas Osterhout, Srikanth Lakshmikanthan