# US 10,308,123 B2 · Vehicle-side beacon mode for wireless electric vehicle charging > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,308,123 B2 - Document ID: US10308123B2 - Status: Granted - Kind: B2 - Application number: 15/491,697 - Filed: 2017-04-19 - Published: 2018-10-25 - Granted: 2019-06-04 - Earliest claimed: 2017-04-19 - Assignees: WiTricity Corporation - Applicants: WiTricity Corporation - Inventors: Jonathan Beaver; Chang-Yu Huang; Michael Le Gallais Kissin; Nicholas Athol Keeling; Mickel Bipin Budhia - Web page: https://patentgrep.com/patent/US10308123B2 ## CPC - B60L 53/62: in response to charging parameters, e.g. current, voltage or electrical charge - B60L 5/005: {without mechanical contact between the collector and the power supply line} - B60L 5/42: for collecting current from individual contact pieces connected to the power supply line - B60L 53/122: Circuits or methods for driving the primary coil, e.g. supplying electric power to the coil - B60L 53/124: Detection or removal of foreign bodies - B60L 53/126: Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver - B60L 53/22: Constructional details or arrangements of charging converters specially adapted for charging electric vehicles - B60L 53/305: {Communication interfaces} - B60L 53/32: {by charging in short intervals along the itinerary, e.g. during short stops} - B60L 53/36: by positioning the vehicle - B60L 53/39: with position-responsive activation of primary coils - B60L 53/66: Data transfer between charging stations and vehicles - H02J 7/42: with electronic devices having internal batteries, e.g. mobile phones - H02J 50/12: of the resonant type - H02J 50/80: involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices - H02J 2105/37: exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] - H02M 3/1584: {with a plurality of power processing stages connected in parallel} - H02M 7/797: using semiconductor devices only - Y02T 10/70: Energy storage systems for electromobility, e.g. batteries - Y02T 10/7072: Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors - Y02T 90/12: Electric charging stations - Y02T 90/14: Plug-in electric vehicles - Y02T 90/16: Information or communication technologies improving the operation of electric vehicles - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract The present disclosure describes aspects of a vehicle-based beacon mode for wireless electric vehicle charging. In some aspects, a circuit for receiving wirelessly transferred power includes a coil connected to boost circuitry configured to convert received power to a form suitable for storage. The circuit also includes beacon circuitry connected to a voltage source that, in combination with portions of the boost circuitry, enables current to be driven into the coil to generate a beacon signal. Based on this beacon signal, a base charging unit can detect the presence of the circuit and initiate the wireless transmission of power to the circuit without additional out-of-band communication. Further, the beacon circuitry may be compatible with, or protected from, current of the received power such that the circuit can seamlessly transition from generating the beacon signal to converting the received power without active reconfiguration, synchronization, or state control. ## Claims ### Claim 1 A circuit for receiving wirelessly transmitted power, the circuit comprising: a coil to receive the wirelessly transmitted power; a first inductor having a first terminal connected to a first terminal of the coil; a second inductor having a first terminal connected to a second terminal of the coil; power conversion circuitry connected between an energy storage device and at least one respective second terminal of the first inductor or the second inductor; and beacon circuitry connected to a voltage source, a lower potential, and the respective second terminals of the first inductor and second inductor, the beacon circuitry including: a first switch connected between the voltage source and the second terminal of the first inductor; and a second switch connected between the lower potential and the second terminal of the second inductor. ### Claim 2 (depends on 1) The circuit as recited in claim 1, wherein the beacon circuitry further comprises: a third switch connected between the voltage source and the second terminal of the second inductor; and a fourth switch connected between the lower potential and the second terminal of the first inductor. ### Claim 3 (depends on 2) The circuit as recited in claim 2, wherein the first, second, third, and fourth switches of the beacon circuitry are implemented as an asymmetric H-bridge to drive, from the voltage source, current into the first inductor and second inductor of the circuit to generate a beacon signal. ### Claim 4 (depends on 1) The circuit as recited in claim 1, wherein the second switch is implemented using a larger or higher-rated switch device than the first switch. ### Claim 5 (depends on 1) The circuit as recited in claim 1, wherein the first inductor and the second inductor of the circuit are implemented as DC inductors. ### Claim 6 (depends on 1) The circuit as recited in claim 1, wherein the power conversion circuitry comprises boost circuitry that includes the second switch and a diode connected between the energy storage device and the second terminal of the second inductor. ### Claim 7 (depends on 1) The circuit as recited in claim 1, further comprising a capacitor connected between the first terminal of the coil and the second terminal of the coil. ### Claim 8 (depends on 1) The circuit as recited in claim 1, wherein the beacon circuitry further comprises a diode connected between the first switch and the voltage source. ### Claim 9 (depends on 1) The circuit as recited in claim 1, wherein the voltage source to which the beacon circuitry is connected is the energy storage device to which the power conversion circuitry is connected. ### Claim 10 (depends on 1) The circuit as recited in claim 1, wherein the energy storage device is a rechargeable battery of an electric vehicle and the voltage source to which the beacon circuitry is connected is separate from the rechargeable battery of the electric vehicle. ### Claim 11 (depends on 10) The circuit as recited in claim 10, wherein the voltage source is configured to provide voltage at a higher level than a voltage of the rechargeable battery. ### Claim 12 (depends on 1) The circuit as recited in claim 1, further comprising: a first diode connected from the first terminal of the coil to the lower potential; or a second diode connected from the second terminal of the coil to the lower potential. ### Claim 13 A method for generating a beacon signal to initiate transmission of power by a wireless power transmitter, the method comprising: generating, via beacon circuitry of a wireless power receiver, alternating current by which to provide the beacon signal, the beacon circuitry including a first switch connected between a voltage source and a first terminal of a first inductor of the wireless power receiver and a second switch connected between a potential that is lower than the voltage source and a first terminal of a second inductor of the wireless power receiver; applying, through the first inductor and the second inductor of the wireless power receiver, the alternating current to a coil of the wireless power receiver to transmit the beacon signal such that the beacon signal is detectable by the wireless power transmitter, the alternating current applied via a second terminal of the first inductor connected to a first terminal of the coil and via a second terminal of the second inductor connected to a second terminal of the coil; monitoring the coil of the wireless power receiver for other alternating current indicating reception of power from the wireless power transmitter; initiating, responsive to detecting the other alternating current and via conversion circuitry of the wireless power receiver, conversion of the other alternating current to direct current using at least a portion of the beacon circuitry of the wireless power receiver, the conversion circuitry being operably coupled between an energy storage device and one of the first inductor or the second inductor; and charging, with the direct current, the energy storage device operably coupled with the conversion circuitry of the wireless power receiver. ### Claim 14 (depends on 13) The method as recited in claim 13, wherein applying the alternating current to the coil comprises alternately connecting, via the first switch of the beacon circuitry and a third switch of the beacon circuitry that is connected between the voltage source and the second inductor, each of the respective inductors to the voltage source. ### Claim 15 (depends on 13) The method as recited in claim 13, further comprising ceasing, responsive to detecting the other current, the application of the alternating current to the coil of the wireless power receiver. ### Claim 16 (depends on 13) The method as recited in claim 13, wherein a frequency at which the alternating current is applied to the coil of the wireless power receiver is within a range of approximately 75 kHz to 125 kHz. ### Claim 17 (depends on 13) The method as recited in claim 13, further comprising: altering, over a range of frequencies, a frequency at which the alternating current is applied to the coil of the wireless power receiver; monitoring, over the range of frequencies, an amount of the alternating current in the coil or an amount of the alternating current drawn by the coil; and determining, within the range of frequencies, an approximate resonant frequency of the coil based on the monitored amount of current. ### Claim 18 (depends on 13) The method as recited in claim 13, further comprising: altering, over a range of frequencies, a frequency at which the alternating current is applied to the coil of the wireless power receiver; receiving, from the wireless power transmitter, an indication of an amplitude of the beacon signal relative the range of frequencies; and determining, based on the indication, an approximate resonant frequency of the coil of the wireless power receiver. ### Claim 19 An apparatus for receiving wirelessly transmitted power, the apparatus comprising: a coil configured to receive wirelessly transmitted power; a first portion of boost circuitry comprising a first inductor having a first terminal connected to a first terminal of the coil and a second terminal connected to an energy storage device, and a first switch connected between the second terminal of the first inductor and a lower potential; a second portion of boost circuitry comprising a second inductor having a first terminal connected to a second terminal of the coil and a second terminal connected to the energy storage device, and a second switch connected between the second terminal of the second inductor and the lower potential; and beacon circuitry comprising a third switch connected between a voltage source and one of the respective second terminals of the first inductor or the second inductor. ### Claim 20 (depends on 19) The apparatus as recited in claim 19, wherein the third switch is connected between the voltage source and the second terminal of the first inductor and the beacon circuitry further comprises a fourth switch connected between the voltage source and the second terminal of the second inductor. ### Claim 21 (depends on 20) The apparatus as recited in claim 20, wherein the first switch or the second switch is implemented using larger switch device than the third switch or the fourth switch. ### Claim 22 (depends on 20) The apparatus as recited in claim 20, wherein: the third switch or the fourth switch of the beacon circuitry is connected to the voltage source via a first diode; or the second terminal of the first inductor or the second terminal of the second inductor is connected to the energy storage device via a second diode. ### Claim 23 (depends on 19) The apparatus as recited in claim 19, further comprising current injection circuitry that includes: a first diode connected from the first terminal of the first inductor to the lower potential; or a second diode connected from the first terminal of the second inductor to the lower potential. ### Claim 24 (depends on 19) The apparatus as recited in claim 19, wherein the coil of the apparatus is tuned to resonate within a range of approximately 75 kHz to 125 kHz. ### Claim 25 (depends on 19) The apparatus as recited in claim 19, wherein the apparatus is embodied as part of a wireless electric vehicle charging system or a dynamic electric vehicle charging system. ### Claim 26 A wireless power receiver comprising: means for generating alternating current by which to provide a beacon signal, the means for generating including a first switch connected between a voltage source and a first terminal of a first inductor of the wireless power receiver and a second switch connected between a potential that is lower than the voltage source and a first terminal of a second inductor of the wireless power receiver; means for applying, through the first inductor and the second inductor, the alternating current to terminals of a coil of the wireless power receiver to transmit the beacon signal such that the beacon signal is detectable by a wireless power transmitter, the means for applying including a second terminal of the first inductor that is connected to a first terminal of the coil and a second terminal of the second inductor that is connected to a second terminal of the coil; means for monitoring the coil of the wireless power receiver for other alternating current indicating reception of the power from the wireless power transmitter; means for converting, in response to detecting the other alternating current, the other alternating current of the received power to direct current, the means for converting coupled between an energy storage device and one of the first inductor or the second inductor; and means for charging, with the direct current, the energy storage device operably coupled with the means for converting of the wireless power receiver. ### Claim 27 (depends on 26) The wireless power receiver as recited in claim 26, wherein the means for applying the alternating current comprise an asymmetric H-bridge connected to the respective inductors, the asymmetric H-bridge including the first switch and the second switch of the means for applying. ### Claim 28 (depends on 27) The wireless power receiver as recited in claim 27, wherein the means for converting the other alternating current to the direct current comprise at least a portion of the asymmetric H-bridge. ### Claim 29 (depends on 26) The wireless power receiver as recited in claim 26, further comprising means for determining a resonant frequency of the coil of the wireless power receiver. ### Claim 30 (depends on 14) The method as recited in claim 14, wherein: the beacon circuitry further comprises a fourth switch connected between the first inductor and the potential that is lower than the voltage source; and the first switch, the second switch, the third switch, and the fourth switch of the beacon circuitry are implemented as an asymmetric H-bridge to drive, from the voltage source, current into the first inductor and second inductor of the circuit to generate the beacon signal.