System and method for providing and controlling inductive power charging
View Patent ↗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.
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.