System and method for providing and controlling inductive power charging

• US 9,548,625 B2
• Filed: 06/17/2015
• Issued: 01/17/2017
• Est. Priority Date: 01/08/2012
• Status: Active Grant

• Current Assignee: Powermat Technologies, Ltd.
• Original Assignee: Powermat Technologies, Ltd.
• Inventors: Mach, Elieser, Moshkovich, Oz, Podkamien, Ian, Koren, Yuval
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): PEREZ BORROTO, ALFONSO
• Application Number:
  US14/741,523
• Publication Number:
  US 20150288217A1
• Time in Patent Office: 580 Days
• Field of Search: 307/104
• US Class Current: 1/1
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• 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 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

Wireless power transfer between power transmitters and power receivers may be established by a digital ping phase during which the wireless power transmitter applies a power signal and waits for a valid response message from the power receiver. The response message may include an identification code and a checksum byte used by the power transmitter to validate the identification code. When a valid response is received, the power transmitter transitions to a power transfer phase.

Claims

1. A method for managing a wireless power transfer from a wireless power transmitter to a wireless power receiver by said power transmitter, said method comprising:

establishing said wireless power transfer; and

terminating said wireless power transfer,

wherein said establishing said wireless power transfer comprises executing a digital ping, comprising;

applying, by said power transmitter, a power signal triggering a momentary activation of a primary inductor;

waiting, by said power transmitter, for a valid response message;

if said valid response message is received within a guard-time then transitioning to a power transfer phase; and

if no said valid response message is received within the guard-time then transitioning to a standby phase, and

further wherein said terminating said wireless power transfer comprises executing a termination sequence, comprising;

monitoring, by said power transmitter, for an end-of-charge (EOC) signal; and

if no said EOC signal is received then continuing said wireless power transfer; and

if said EOC signal is received then ending said wireless power transfer.

2. The method of claim 1 further comprising removing the power signal if no valid response message is received within the guard-time.

3. The method of claim 1, said valid response message comprising an identification signal having at least a preamble byte, a header byte, a characteristic identification code, and a checksum byte.

4. The method of claim 3, wherein said characteristic identification code comprises a body including at least a start bit, a string of eight bits representing a byte, and a stop bit.

5. The method of claim 3 further comprising said wireless transmitter validating said response message by comparing the received checksum byte with a calculated value.

6. The method of claim 3, wherein said checksum byte comprises a cyclic redundancy check (CRC).

7. The method of claim 1, wherein said response message comprises a body including at least a start bit, a string of eight bits representing a byte, and a stop bit.

8. A wireless power transmitter operable to transfer power wirelessly to a wireless power receiver, said wireless power transmitter operable to establish wireless power transfer by executing a digital ping comprising:

applying a power signal triggering a momentary activation of a primary inductor;

waiting for a valid response message; and

if said valid response message is received within a guard-time then transitioning to a power transfer phase until an end-of-charge (EOC) signal is received; and

if no said valid response message is received within the guard-time then transitioning to a standby phase.

9. The wireless power transmitter of claim 8 further operable to remove the power signal if no valid packet is received within the guard-time.

10. The wireless power transmitter of claim 8 said response message comprising an identification signal having at least a preamble byte, a header byte, a characteristic identification code, and a checksum byte.

11. The wireless power transmitter of claim 10 wherein said characteristic identification code comprises a body including at least a start bit, a string of eight bits representing a byte, and a stop bit.

12. The wireless power transmitter of claim 10 further operable to validate said response message by comparing the received checksum byte with a calculated value.

13. The wireless power transmitter of claim 10 wherein said checksum byte comprises a cyclic redundancy check (CRC).

14. The wireless power transmitter of claim 8, wherein said response message comprises a body including at least a start bit, a string of eight bits representing a byte, and a stop bit.

15. The wireless power transmitter of claim 8 operable in at least one phase selected from a ping phase, an identification phase, a standby phase and said power transfer phase.