System and method for enabling ongoing inductive power transmission

• US 9,006,937 B2
• Filed: 05/21/2014
• Issued: 04/14/2015
• Est. Priority Date: 07/02/2008
• Status: Active Grant

• Current Assignee: Powermat Technologies, Ltd.
• Original Assignee: Powermat Technologies, Ltd.
• Inventors: Azancot, Yossi, Rofe, Arik, Greenwald, Oola, Ben-Shalom, Amir, Ashery, Moti, Leibovitz, Alfred
• Primary Examiner(s): CAVALLARI, DANIEL J
• Application Number:
  US14/283,981
• Publication Number:
  US 20140252872A1
• Time in Patent Office: 328 Days
• Field of Search: 307/104
• US Class Current: 307/104
• CPC Class Codes: H01F 2038/143 for signals
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• 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 7/00045 Authentication, i.e. circuits for checking compatibility between one component, e.g. a battery or a battery charger, and another component, e.g. a power source
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02M 3/3376 with automatic control of output voltage or current
• CPC Class Codes: H02M 7/4815 Resonant converters H02M7/4811 and H02M7/4826 take precedence
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: Y02B 70/10 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

Abstract

An inductive power transfer system and method for transferring power to an electrical device wirelessly. The system includes an inductive power outlet and an inductive power receiver. During operation, instruction signals are sent from the inductive power outlet to the inductive power receiver. When no instruction signals are transferred, the system is configured to deactivate such that power is drawn by the system only during operation.

Claims

1. An inductive power receiver operable to receive power from at least one inductive power outlet and to provide power to an electric load, the inductive power receiver comprising:

at least one secondary inductive coil for forming an inductive couple with at least one primary inductive coil associated with the at least one inductive power outlet;

a signal transmitter operable to provide feedback signals for the inductive power outlet; and

a regulator operable to compare power received by the inductive power receiver with reference values and to select instruction signals accordingly;

wherein the inductive power receiver is operable to send a perpetuation signal for the inductive power outlet when the power received lies within a permissible range of values, the perpetuation signal for instructing the inductive power outlet to continue driving the primary inductive coil at the same power level.

2. The inductive power receiver of claim 1 wherein the inductive power receiver is further operable to send at least one instruction signal for the inductive power outlet during a specified time duration.

3. The inductive power receiver of claim 1 wherein the inductive power receiver is further operable to send a power increase signal for the inductive power outlet when the power received lies below a threshold value.

4. The inductive power receiver of claim 1 wherein the inductive power receiver is further operable to send a power decrease signal for the inductive power outlet when the power received lies above a threshold value.

5. The inductive power receiver of claim 1 wherein the signal transmitter comprises a signal generator, a switching unit and an ancillary load.

6. The inductive power receiver of claim 5 wherein the instruction signals are selected from a set of pulses generated by connecting the ancillary load to the secondary inductive coil at one of a plurality of specified characteristic frequencies.

7. The inductive power receiver of claim 6 wherein the perpetuation signal has a characteristic frequency of 500 hertz.

8. An inductive power outlet operable to transfer power to an electric load via at least one inductive power receiver, the inductive power outlet comprising:

at least one primary inductive coil for forming an inductive couple with at least one secondary inductive coil associated with the at least one inductive power receiver;

a signal receiver for receiving feedback signals from the inductive power receiver; and

a driver operable to provide an oscillating driving voltage to the primary inductive coil according to instruction signals received concurrently with inductive power transfer between the primary and secondary inductive coils;

wherein the driver is operable to continue driving the primary inductive coil at the same power level when a perpetuation signal is received.

9. The inductive power outlet of claim 8 wherein the driver is further operable to terminate operation if no instruction signal is received from the inductive power receiver within a specified time duration.

10. The inductive power outlet of claim 8 wherein the driver is further operable to increase the power level when a power increase signal is received from the inductive power receiver.

11. The inductive power outlet of claim 8 wherein the driver is further operable to decrease the power level when a power decrease signal is received from the inductive power receiver.

12. The inductive power outlet of claim 8 wherein the signal receiver comprises a detector operable to detect when an ancillary load is connected to the secondary inductor;

and a processor.

13. The inductive power outlet of claim 12 wherein the instruction signals are selected from a set of detectable pulses in primary coil voltage or primary coil current, each pulse having one of a plurality of specified characteristic frequencies.

14. The inductive power outlet of claim 13 wherein the perpetuation signal has a characteristic frequency of 500 hertz.

15. A method for transferring power inductively comprising:

driving, for a first limited time duration, at least one primary inductive coil of an inductive power outlet at a first power level, the power outlet having at least one driver and at least one signal receiver;

inducing a secondary voltage in a secondary inductive coil of a power receiver having an instruction signal generator;

sending, when power received lies within a specified range of values, a perpetuation signal from the power receiver; and

continuing driving the at least one primary inductive coil at the first power level for a second limited time duration in response to receiving the perpetuation signal.

16. The method of claim 15 further comprising terminating driving the at least one primary inductive coil if no instruction signal is received during the first limited time duration.

17. The method of claim 15 further comprising sending a power increase signal to the inductive power outlet when the power received lies below a threshold value.

18. The method of claim 15 further comprising sending a power decrease signal to the inductive power outlet when the power received lies above a threshold value.

19. The method of claim 15 wherein the perpetuation signal is transferred concurrently with uninterrupted inductive power transfer between the power outlet and the power receiver.

20. The method of claim 15 further comprising sending a termination signal to the inductive power outlet when no power is required.