POWER RECIVER HAVING MAGNETIC SIGNATURE AND METHOD FOR OPERATING SAME

• US 20160301245A1
• Filed: 11/07/2014
• Published: 10/13/2016
• Est. Priority Date: 11/11/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: PowerbyProxi Limited (Apple Inc.)
• Inventors: KUMAR, Arunim, GRAY, Nigel
• Granted Patent: US 10,270,280 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00045 Authentication, i.e. circuits for checking compatibility between one component, e.g. a battery or a battery charger, and another component, e.g. a power source
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

There is provided a contactless power system, power receiver and method of operating such, in which the power receiver of the system is configured to receive power transmitted by a power transmitter of the system via contactless electromagnetic coupling of respective receiving and transmitting coils. The power receiver further has circuitry for reflecting a unique magnetic signal to the transmitting coil of the power transmitter upon receipt of a power pulse by the receiver coil of the power receiver.

Claims

1. A contactless power system comprising a power transmitter having a transmitting coil and a power receiver having a receiving coil, the power receiver being configured to receive a power pulse transmitted by the power transmitter via contactless electromagnetic coupling of the respective coils, wherein the power receiver comprises preload circuitry for reflecting a unique magnetic signal to the transmitting coil upon receipt of the power pulse.

2. A system as claimed claim 1, wherein the preload circuitry of the power receiver comprises a switchable load which sinks an amount of energy produced in the power receiver by the received power pulse for a predetermined amount of time, wherein the amount of energy providing the unique magnetic signal.

3. A system as claimed claim 2, wherein the switchable load comprises one or more resistive elements having resistance values selected to sinks a selected amount of the energy produced in the power receiver by the received power pulse thereby producing a selected magnetic signal.

4. A system as claimed claim 2, wherein the preload circuitry of the power receiver comprises a first capacitive element configured to charge upon receipt of the power pulse over a first time period and to cause switching of the switchable load at the end of the first time period.

5. A system as claimed claim 4, wherein the switchable load is configured to be switched off at the end of the first time period thereby stopping the sinking of energy by the switchable load.

6. A system as claimed claim 5, wherein the capacitance values of the first capacitive element is selected so that the first time period causes the switchable load to sink a selected amount of the energy produced in the power receiver by the received power pulse thereby producing a selected magnetic signal.

7. A system as claimed claim 4, wherein the preload circuitry of the power receiver comprises a second capacitive element configured to charge upon receipt of the power pulse and to discharge upon cessation of the power pulse, the elapsed time between charging and discharging providing a second time period, the second capacitive element being connected to the first capacitive element to cause discharging of the first capacitive element at the end of the second time period.