Wireless charging system with start-up negotiation
A wireless power transmission system has a wireless power receiving device that is located on a charging surface of a wireless power transmitting device. The wireless power transmitting device uses measurement circuitry such as coil impedance measurement circuitry or impulse-response circuitry that makes coil inductance measurements to monitor the charging surface for the presence of the wireless power receiving device. In response to detecting that the wireless power receiving device is present on the charging surface, the wireless power transmitting device and the wireless power receiving device establish a wireless communications link. The wireless power transmitting device transmits information on wireless power transmission capabilities of the wireless power transmitting device to the wirelessly power receiving device. The receiving device selects desired settings and transmits these to the transmitting device.
1. A wireless power transmitting device having a charging surface configured to receive a wireless power receiving device, wherein the wireless power receiving device has a wireless power receiving coil configured to receive wireless power signals from the wireless power transmitting device, the wireless power transmitting device comprising:
a wireless power transmitting coil;
inverter circuitry coupled to the wireless power transmitting coil, wherein the inverter circuitry is configured to supply a drive signal to the wireless power transmitting coil to produce the wireless power signals;
measurement circuitry coupled to the wireless power transmitting coil to detect when the wireless power receiving device is present; and
control circuitry configured to:
detect that the wireless power receiving device is present on the charging surface using the measurement circuitry;
in response to detecting that the wireless power receiving device is present on the charging surface, establish a wireless communications link with the wireless power receiving device; and
wirelessly receive a wireless power transmission sleep timer setting over the wireless communications link.
2. The wireless power transmitting device defined in claim 1 wherein the control circuitry is further configured to:
wirelessly transmit information on wireless power transmission capabilities of the wireless power transmitting device over the wireless communications link, wherein the wirelessly received wireless power transmission sleep timer setting is selected by the wireless power receiving device based on the transmitted information on the wireless power transmission capabilities.
3. The wireless power transmitting device defined in claim 2 wherein the transmitted information on the wireless power transmission capabilities includes at least one wireless power transmission frequency for use in providing the drive signal to the wireless power transmitting coil with inverter and wherein the control circuitry is further configured to:
wirelessly receive a wireless power transmission frequency setting over the wireless communications link, wherein the wirelessly received wireless power transmission frequency setting is selected by the wireless power receiving device based on the transmitted information on the wireless power transmission capabilities.
4. The wireless power transmitting device defined in claim 2 wherein the transmitted information on the wireless power transmission capabilities includes information on at least one wireless power transmission modulation scheme and wherein the control circuitry is further configured to:
wirelessly receive a wireless power transmission modulation scheme setting over the wireless communications link, wherein the wirelessly received wireless power transmission modulation scheme setting is selected by the wireless power receiving device based on the transmitted information on the wireless power transmission capabilities.
5. The wireless power transmitting device defined in claim 4 wherein the wireless power transmission modulation scheme setting comprises a wireless power transmission modulation scheme setting selected from the group consisting of: a pulse-width modulation scheme setting, an amplitude modulation scheme setting, and a phase shift modulation scheme setting.
6. The wireless power transmitting device defined in claim 2 wherein the transmitted information on the wireless power transmission capabilities includes: information on a wireless power transmission pulse-width modulation scheme, a wireless power transmission amplitude modulation scheme setting, and a wireless power transmission phase shift modulation scheme setting.
7. The wireless power transmitting device defined in claim 1 wherein the control circuitry is further configured to wirelessly receive wireless power transmission duty cycle settings over the wireless communications link.
8. The wireless power transmitting device defined in claim 1 wherein the measurement circuitry comprises impulse response measurement circuitry and wherein the control circuitry is configured to detect that the wireless power receiving device is present on the charging surface by using the measurement circuitry to measure a coil inductance associated with the wireless power transmitting coil.
9. A wireless power transmitting device having a charging surface configured to receive a wireless power receiving device, wherein the wireless power receiving device has a wireless power receiving coil configured to receive wireless power signals from the wireless power transmitting device, the wireless power transmitting device comprising:
a wireless power transmitting coil;
inverter circuitry coupled to the wireless power transmitting coil, wherein the inverter circuitry is configured to supply a drive signal to the wireless power transmitting coil to produce the wireless power signals;
measurement circuitry coupled to the wireless power transmitting coil to detect when the wireless power receiving device is present; and
control circuitry configured to:
detect that the wireless power receiving device is present on the charging surface using the measurement circuitry;
in response to detecting that the wireless power receiving device is present on the charging surface, establish a wireless communications link with the wireless power receiving device; and
wirelessly receive a wireless power transmission modulation scheme setting over the wireless communications link.
10. The wireless power transmitting device defined in claim 9 wherein the wireless power transmission modulation scheme comprises a wireless power transmission modulation scheme selected from the group consisting of:
a pulse-width modulation scheme setting, an amplitude modulation scheme setting, and a phase shift modulation scheme setting.
11. The wireless power transmitting device defined in claim 10 wherein the measurement circuitry comprises impulse response measurement circuitry and wherein the control circuitry is configured to detect that the wireless power receiving device is present on the charging surface by using the measurement circuitry to measure a coil inductance associated with the wireless power transmitting coil.
12. The wireless power transmitting device defined in claim 11 wherein the control circuitry is further configured to:
wirelessly transmit information on wireless power transmission capabilities of the wireless power transmitting device over the wireless communications link, wherein the wirelessly received wireless power transmission modulation scheme setting is selected by the wireless power receiving device based on the transmitted information on the wireless power transmission capabilities.
13. The wireless power transmitting device defined in claim 12 wherein the control circuitry is further configured to wirelessly receive a wireless power transmission duty cycle setting from the wireless power receiving device over the wireless communications link.
14. The wireless power transmitting device defined in claim 12 wherein the control circuitry is further configured to wirelessly receive a wireless power transmission sleep timer setting from the wireless power receiving device over the wireless communications link.
15. A wireless power transmitting device having a charging surface configured to receive a wireless power receiving device, wherein the wireless power receiving device has a wireless power receiving coil configured to receive wireless power signals from the wireless power transmitting device, the wireless power transmitting device comprising:
a wireless power transmitting coil;
inverter circuitry coupled to the wireless power transmitting coil, wherein the inverter circuitry is configured to supply a drive signal to the wireless power transmitting coil to produce the wireless power signals;
measurement circuitry coupled to the wireless power transmitting coil to detect when the wireless power receiving device is present;
control circuitry configured to:
detect that the wireless power receiving device is present on the charging surface using the measurement circuitry;
in response to detecting that the wireless power receiving device is present on the charging surface, establish a wireless communications link with the wireless power receiving device; and
wirelessly receive minimum and maximum duty cycle wireless power transmission settings over the wireless communications link.
16. The wireless power transmitting device defined in claim 15 wherein the control circuitry is further configured to:
wirelessly transmit information on wireless power transmission capabilities of the wireless power transmitting device over the wireless communications link, wherein the minimum and maximum duty cycle wireless power transmission settings comprise wireless power transmitting settings selected by the wireless power receiving device based on the transmitted information on the wireless power transmission capabilities.
17. The wireless power transmitting device defined in claim 16 wherein the transmitted information on the wireless power transmission capabilities includes a wireless power transmission frequency setting for the inverter to provide the drive signal to the wireless power transmitting coil and wherein the control circuitry is further configured to:
wirelessly receive the wireless power transmission frequency setting over the wireless communications link.
18. The wireless power transmitting device defined in claim 16 wherein the transmitted information on the wireless power transmission capabilities includes a wireless power transmission modulation scheme setting for use in providing the drive signal to the wireless power transmitting coil with the inverter and wherein the control circuitry is further configured to:
wirelessly receive the wireless power transmission modulation scheme setting over the wireless communications link.
19. The wireless power transmitting device defined in claim 16 wherein the transmitted information on the wireless power transmission capabilities includes a wireless power transmission sleep timer setting for the control circuitry and wherein the control circuitry is further configured to:
wirelessly receive the wireless power transmission sleep timer setting over the wireless communications link.
20. The wireless power transmitting device defined in claim 15 wherein the measurement circuitry comprises impulse response measurement circuitry and wherein the control circuitry is configured to detect that the wireless power receiving device is present on the charging surface by using the measurement circuitry to measure a coil inductance associated with the wireless power transmitting coil.