TRANSMISSION-GUARD SYSTEM AND METHOD FOR AN INDUCTIVE POWER SUPPLY

• US 20140125146A1
• Filed: 01/10/2014
• Published: 05/08/2014
• Est. Priority Date: 03/17/2008
• Status: Active Grant

• Current Assignee: Powermat Technologies, Ltd.
• Original Assignee: Powermat Technologies, Ltd.
• Inventors: AZANCOT, Yossi, BEN-SHALOM, Amir, GREENWALD, Oola, ROFE, Arik, LEI-BOVITZ, Alfred, RHODES, Dov, MEYUHAS, Noam
• Granted Patent: US 9,048,696 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H01F 2038/143 for signals
• CPC Class Codes: H01F 27/266 Fastening or mounting the core on casing or support on coil H01F27/30
• CPC Class Codes: H01F 27/36 Electric or magnetic shields or screens movable for varying inductance H01F21/10
• CPC Class Codes: H01F 27/366 made of ferromagnetic material
• 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 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• 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 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence

Abstract

A transmission-guard is disclosed for preventing an inductive power outlet from transmitting power in the absence of an inductive power receiver. A transmission lock is associated with an inductive power outlet and a transmission key is associated with an inductive power receiver. The transmission lock is configured to prevent a primary inductor from connecting to the power supply unless triggered by a release signal via the transmission key

Claims

1. An inductive power transfer system comprising at least one inductive power outlet operable to transfer power to an inductive power receiver, said inductive power outlet comprising:

a platform for supporting said inductive power receiver;

at least one primary inductive coil embedded in said platform, said primary inductive coil;

a driver wired to said primary inductive coil and operable to provide a driving voltage across said primary inductive coil;

wherein;

said primary inductive coil is configured to form an inductive couple having a characteristic resonant frequency with at least one secondary inductive coil wired to an electric load, said secondary inductive coil associated with said inductive power receiver; and

said driving voltage oscillates at a transmission frequency significantly different from said characteristic resonant frequency of said inductive couple.

2. The system of claim 1 wherein said driver comprises a switching unit for intermittently connecting said primary inductive coil to said power supply.

3. The system of claim 1 wherein said transmission frequency lies within a range in which induced voltage varies approximately linearly with frequency.

4. The system of claim 1 said inductive power outlet comprising a signal detector adapted to detect a first signal and a second signal, and said driver is configured to:

increase said transmission frequency when said first signal is detected by the detector, and

decrease said transmission frequency when said second signal is detected by the detector.

5. The system of claim 1 said driver being configured to adjust said transmission frequency in response to feedback signals.

6. The system of claim 5 wherein said feedback signals carry data pertaining to the operational parameters of said electric load.

7. The system of claim 6 wherein said operational parameters are selected from the group consisting of:

required operating voltage for said electric load;

required operating current for said electric load;

required operating temperature for said electric load;

required operating power for said electric load;

measured operating voltage for said electric load;

measured operating current for said electric load;

measured operating temperature for said electric load;

measured operating power for said electric load;

power delivered to said primary inductive coil;

power received by said secondary inductive coil, and

a user identification code.

8. The system of claim 4 wherein said detector is selected from the list comprising optical detectors, radio receivers, audio detectors and voltage peak detectors.

9. The system of claim 1 wherein said driver further comprises a voltage monitor for monitoring the amplitude of a primary voltage across said primary coil.

10. The system of claim 9 wherein said voltage monitor is configured to detect significant increases in primary voltage.

11. The system of claim 1 comprising a power converter selected from the group comprising:

a transformer, a DC-to-DC converter, an AC-to-DC converter, an AC-to-AC converter, a flyback transformer, a flyback converter, a full-bridge converter, a half-bridge converter and a forward converter.

12. The system of claim 1 incorporated into at least one application selected from a group consisting of:

inductive chargers, inductive power adaptors, power tools, kitchen appliances, bathroom appliances, computers, media players, office equipment, implanted devices, pace makers, trackers and RFID tags.