Power receiver, non-contact power transmission system, and method of controlling received-power voltage

• US 10,199,868 B2
• Filed: 12/24/2013
• Issued: 02/05/2019
• 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, Bunsen, Keigo, Hashiguchi, Takaaki, Kozakai, Osamu, Fujimaki, Kenichi
• Primary Examiner(s): Borroto, Alfonso Perez
• Application Number:
  US14/759,987
• Publication Number:
  US 20150340881A1
• Time in Patent Office: 1,869 Days
• Field of Search: 307104
• 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 first device configured to receive power, the first device comprising:

a first coil having a resistance;

rectifying circuitry configured to generate a rectified signal based on rectification of an alternating-current signal received by the first coil;

a voltage detection section configured to detect a received power voltage of the rectified signal; and

at least one circuit configured to;

calculate a target voltage value of a first voltage to be supplied from the rectifying circuitry, wherein the target voltage value is calculated based on an amount of the power received by the first device and the resistance of the first coil; and

control the detected received power voltage to be equal to the calculated target voltage value.

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

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

terminate the control of the detected received power voltage, in response to the determination that the calculated target voltage value exceeds the threshold.

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

request a change in an amount of power transmitted to the first device, based on a determination that the detected received power voltage is different from the calculated target voltage value.

4. The first device of claim 3, wherein the at least one circuit is further configured to:

request an increase in the amount of the power transmitted to the first device, based on a determination that the detected received power voltage is less than the calculated target voltage value.

5. The first device of claim 3, wherein the at least one circuit is further configured to:

request a decrease in the amount of the power transmitted to the first device, based on a determination that the detected received power voltage is greater than the calculated target voltage value.

6. The first device of claim 3, wherein the at least one circuit is further configured to:

transmit, to a second device, the request to change the amount of the power transmitted to the first device.

7. The first device of claim 6, wherein the at least one circuit is further configured to:

transmit, to the second device, the request to change the amount of the power by amplitude modulation.

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

measure a temperature of the first coil; and

control the received power voltage based on the measured temperature.

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

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

increase the target voltage value, based on the determination that the measured temperature is less than the threshold temperature.

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

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

calculate a load resistance value based on the resistance of the first coil; and

calculate the target voltage value based on the calculated load resistance value and the amount of the power received by the first device.

12. The first device of claim 11, wherein the at least one circuit is further configured to:

calculate the load resistance value based on;

R_L=R√

(1+(kQ)²)

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

13. The first device of claim 1, further comprising:

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

14. The first device of claim 13, further comprising:

a charge control circuit,

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

15. The first device of claim 1, further comprising a DC-DC converter configured to convert a second voltage based on the rectified signal.

16. The first device of claim 15, further comprising:

a charge control circuit, wherein the DC-DC converter is further configured to supply the second voltage to the charge control circuit.

17. The first device of claim 1, further comprising:

a resonance capacitor connected in series with the first coil.

18. A method, comprising:

in a device including a coil and configured to receive power;

generating, by rectifying circuitry, a rectified signal based on rectification of an alternating-current signal received by the coil;

detecting, by a voltage detection section, a received power voltage of the rectified signal;

calculating, using a circuit, a target voltage value of a voltage to be supplied from the rectifying circuitry, wherein the target voltage value is calculated based on an amount of the power received by the device and a resistance of the coil, and

controlling, using the circuit, the detected received power voltage to be equal to the calculated target voltage value.

19. A system, comprising:

a first device configured to transmit power; and

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

a coil having a resistance;

rectifying circuitry configured to generate a rectified signal based on rectification of an alternating-current signal received by the coil;

a voltage detection section configured to detect a received power voltage of the rectified signal; and

at least one circuit configured to;

calculate a target voltage value of a voltage to be supplied from the rectifying circuitry, wherein the target voltage value is calculated based on an amount of the power received by the second device and the resistance of the coil, and

control the detected received power voltage to be equal to the calculated target voltage value.