POWER RECEIVER, NON-CONTACT POWER TRANSMISSION SYSTEM, AND METHOD OF CONTROLLING RECEIVED-POWER VOLTAGE

• US 20150340881A1
• Filed: 12/24/2013
• Published: 11/26/2015
• Est. Priority Date: 01/16/2013
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: NAKANO, Hiroaki, HASHIGUCHI, Takaaki, KOZAKAI, Osamu, FUJIMAKI, Kenichi, BUNSEN, Keigo
• Granted Patent: US 10,199,868 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 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage

Abstract

A device configured to receive power (20B), the device comprising a coil (21L) having a resistance, and at least one circuit (30) configured to calculate a target voltage value based on an amount of power received by the device and the resistance of the coil, and control received power voltage based on the calculated target voltage value.

Claims

1. A device configured to receive power, the device comprising:

a coil having a resistance; and

at least one circuit configured to;

calculate a target voltage value based on an amount of power received by

the device and the resistance of the coil, and

control received power voltage based on the calculated target voltage value.

2. The device of claim 1, wherein the at least one circuit is configured to control the received power voltage at least in part by:

determining whether the calculated target voltage value exceeds a threshold; and

terminating control of the received power voltage, when it is determined that the calculated target voltage value exceeds the threshold.

3. The device of claim 1, wherein the at least one circuit is configured to control the received power voltage at least in part by:

requesting a change in an amount of power transmitted to the device, when it is determined that the received power voltage is not equal to the target voltage value.

4. The device of claim 3, wherein requesting the change in the amount of power comprises:

requesting an increase in the amount of power transmitted to the device, when it is determined that the received power voltage is less than the target voltage value.

5. The device of claim 4, wherein requesting the change in the amount of power comprises:

requesting a decrease in the amount of power transmitted to the device, when it is determined that the received power voltage is greater than the target voltage value.

6. The device of claim 3, wherein requesting the change in the amount of power transmitted to the device comprises:

transmitting, to a second device, a request to change the amount of power transmitted by the second device to the device.

7. The device of claim 6, wherein transmitting the request to change the amount of power comprises transmitting information to the second device by using amplitude modulation.

8. The device of claim 1, wherein the at least one circuit is further configured to:

measure temperature of the coil; and

control the received power voltage further based on the measured temperature.

9. The device of claim 8, wherein the at least one circuit is configured to control the received power voltage at least in part by:

determining whether the measured temperature is less than a threshold temperature; and

increasing the target voltage value, when it is determined that the measured temperature is less than the threshold temperature.

10. The device of claim 1, wherein the at least one circuit is configured to calculate the target voltage value so as to achieve a specified power transmission efficiency between the coil and a second coil magnetically coupled to the coil.

11. The device of claim 1, wherein the at least one circuit is configured to calculate the target voltage value by:

calculating a load resistance value based, at least in part, on the resistance of the coil; and

calculating the target voltage value using the calculated load resistance value and the amount of power received by the device.

12. The device of claim 11, wherein calculating the load resistance value comprises calculating the load resistance value according to:

R_L=R√

{square root over (1+(kQ)²)}

where R_L is the load resistance value, R is the resistance of the coil, k is a coupling coefficient between the coil and the second coil, and Q is a geometric mean of Q values for the coil and the second coil.

13. The device of claim 1, further comprising:

rectifying circuitry configured to generate a rectified signal by rectifying an alternating-current signal obtained at least in part by using the coil.

14. The device of claim 13, further comprising:

a low dropout regulator configured to generate voltage based on the rectified signal.

15. The device of claim 14, further comprising:

a charge control circuit,

wherein the low dropout regulator is configured to supply the generated voltage to the charge control circuit.

16. The device of claim 13, further comprising a DC-DC converter configured to perform voltage conversion based on the rectified signal.

17. The device of claim 16, further comprising:

a charge control circuit,

wherein the DC-DC converter is configured to supply voltage to the charge control circuit.

18. The device of claim 1, further comprising:

a resonance capacitor connected in series with the coil.

19. A method for use in connection with receiving power using a device comprising a coil, the coil having a resistance, the method comprising:

using at least one circuit to;

calculate a target voltage value based on an amount of power received by the device and the resistance of the coil, and

control received power voltage based on the calculated target voltage value.

20. A system comprising:

a first device configured to transmit power; and

a second device configured to receive power from the first device, the second device comprising;

a coil having a resistance; and

at least one circuit configured to;

calculate a target voltage value based on an amount of power received by the second device and the resistance of the coil, and

control received power voltage based on the calculated target voltage value.