System and method for providing inductive power at multiple power levels

Patent metadata

Field	Value
Publication number	US-10770927-B2
Application number	US-201314412843-A
Country	US
Kind code	B2
Filing date	Jul 4, 2013
Priority date	Jul 5, 2012
Publication date	Sep 8, 2020
Grant date	Sep 8, 2020

Abstract

A system and method for inductively providing electrical power at a plurality of power levels to electrical devices. The system may include an inductive power outlet unit conductively coupled to a power supply and an inductive power receiver unit associated with the electrical device. The inductive power outlet unit includes a driver device operable to generate power at a plurality of power levels and electrical power is transferred to the electrical device at a power level selected from the plurality of power levels, in accordance with electrical power requirements of the electrical device. The power receiver may be operable in a plurality of modes having a secondary inductor configured to operate selectively with a plurality of inductance values.

First claim

The invention claimed is:

1. An inductive power outlet for inductively powering a receiver having a secondary coil, the inductive power outlet comprising:
at least one primary inductor inductively coupled to the secondary coil having together a resonant frequency; and
a driver configured to generate power by applying an AC voltage across the at least one primary inductor by converting a DC voltage supplied by a power supply, wherein the AC voltage has a frequency substantially different than the resonant frequency,
wherein the driver comprises a plurality of electronic switches configured to be selectively activated to generate the power at a plurality of power levels, and
wherein the inductive power outlet utilizes a feedback signal received from the receiver to selectively activate the switches to generate the power at the plurality of power levels.

2. The inductive power outlet of claim 1 , wherein the plurality of electronic switches are configured to operate as a full-bridge rectifier and as a half-bridge rectifier to apply the AC voltage across the inductor for generating different power levels.

3. The inductive power outlet of claim 1 , wherein the driver is also configured to regulate energy transmitted by the primary inductor by adjusting a duty cycle of the AC voltage for generating different power levels.

4. The inductive power outlet of claim 1 , wherein the driver activates a combination of electronic switches in a first power mode and a different combination of electronic switches in a second power mode.

5. The inductive power outlet of claim 1 , wherein the frequency of the AC voltage is either lower or higher than the resonant frequency, and wherein a variation of the frequency of the AC voltage within a range of frequencies results in a variation of the AC voltage within a range of AC voltages accordingly.

6. The inductive power outlet of claim 1 , wherein the feedback signal is configured to adjust the frequency of the AC voltage.

7. The inductive power outlet of claim 1 , wherein the inductive power outlet regulates the energy transmitted by the primary inductor according to power requirements of the receiver.

8. An inductive power receiver, used for charging a device, inductively powered by an outlet having a primary inductor, the receiver comprising:
at least one secondary coil inductively coupled to the primary inductor, having together a resonant frequency, is configured to receive power by an AC voltage generated at the primary inductor;
a rectifier for rectifying the AC voltage to a DC voltage used for charging the device;
a power monitor continually monitoring a DC power transferred for charging the device; and
a feedback signal generator coupled to the power monitor used for generating feedback signals corresponding to the power transferred to the device.

9. The receiver of claim 8 , wherein the receiver is configured to operate with the AC voltage having a frequency either higher or lower than the resonant frequency.

10. The receiver of claim 9 , wherein the frequency of the AC voltage can vary within a range of frequencies, and wherein the DC power varies according to the frequency of the AC voltage.

11. The receiver of claim 8 , wherein the feedback signal includes data pertaining to power requirements of the device.

12. The receiver of claim 8 , wherein the device is selected from the group consisting of a mobile communications device; a navigation system; a computing device; a laptop computer; a net-book; a tablet computer; an electronic reading device; a media player;
and any combination of two or more thereof.

13. An inductive power transfer system comprising at least one inductive power outlet for inductively powering a receiver having a secondary coil, the inductive power outlet comprising:
at least one primary inductor inductively coupled to the secondary coil having together a resonant frequency; and
a driver configured to generate power by applying an AC voltage across the at least one primary inductor by converting a DC voltage supplied by a power supply, wherein the AC voltage has a frequency substantially different than the resonant frequency,
wherein the driver comprises a plurality of electronic switches configured to be selectively activated to generate the power at a plurality of power levels, and
wherein the inductive power outlet utilizes a feedback signal received from the receiver to selectively activate the switches to generate the power at the plurality of power levels,
the inductive power outlet being inductively coupled to at least one receiver of claim 8 .

14. The system of claim 13 , wherein the plurality of electronic switches are configured to operate as a full-bridge rectifier and as a half-bridge rectifier to apply the AC voltage across the inductor for generating different power levels.

15. The system of claim 14 , wherein the driver is also configured to regulate energy transmitted by the primary inductor by adjusting a duty cycle of the AC voltage, consequently generating the power at different power levels.

16. The system of claim 13 , wherein the driver activates a combination of electronic switches in a first power mode and a different combination of electronic switches in a second power mode.

17. The system of claim 13 , wherein the frequency of the AC voltage is either lower or higher than the resonant frequency, and wherein a variation of the frequency of the AC voltage within a range of frequencies results in a variation of the AC voltage within a range of AC voltages accordingly.

18. The system of claim 13 , wherein the feedback signal includes data pertaining to power requirements of the device.

19. The receiver of claim 8 , wherein the feedback signal includes data pertaining to power requirements of the device, and wherein the inductive power outlet regulates the AC voltage according to power requirements of the receiver.

20. The system of claim 13 , wherein the device is selected from the group consisting of a mobile communications device; a navigation system; a computing device; a laptop computer; a net-book; a tablet computer; an electronic reading device; a media player; and any combination of two or more thereof.

Assignees

• Powermat Tech Ltd

Inventors

• Rofe Arik
• Mach Elieser
• Greenwald Oola
• Raveh Guy
• Ashery Moti
• Gluzman Ilya
• Kdoshim Moti

Classifications

• H02J50/80 Primary

  involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices · CPC title

• H02J50/90

  involving detection or optimisation of position, e.g. alignment · CPC title

• H02J50/12 Primary

  of the resonant type · CPC title

• Y02B70/10

  Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes · CPC title

• H01F38/14

  Inductive couplings {(for wireless supply or distribution of electric power using inductive coupling H02J50/10)} · CPC title