Transmission-guard system and method for an inductive power supply
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.
1. An 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;
an alignment mechanism configured to facilitate alignment between said primary inductive outlet and said inductive power receiver such that an inductive couple is formed between said primary inductive coil and a secondary inductive coil of said inductive power receiver, said inductive couple having a characteristic resonant frequency; and
a driving circuit wired to said primary inductive coil, said driving circuit comprising a switching unit configured and operable to provide an oscillating driving voltage across said primary inductive coil such that a secondary voltage is induced in the secondary inductive coil;
wherein said driving circuit is configured and operable to produce said oscillating driving voltage at a transmission frequency substantially different from said characteristic resonant frequency of said inductive couple.
2. The inductive power outlet 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.
3. The inductive power outlet of claim 1 said driver being configured to adjust said transmission frequency in response to feedback signals.
4. The inductive power outlet of claim 3 wherein said feedback signals carry data pertaining to the operational parameters of said electric load.
5. The inductive power outlet of claim 4 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.
6. The inductive power outlet of claim 2 wherein said detector is selected from the list comprising optical detectors, radio receivers, audio detectors and voltage peak detectors.
7. The inductive power outlet of claim 1 wherein said driver further comprises a voltage monitor for monitoring the amplitude of a primary voltage across said primary coil.
8. The inductive power outlet of claim 7 wherein said voltage monitor is configured to detect significant increases in primary voltage.
9. The inductive power outlet 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.
10. The inductive power outlet 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.
11. The inductive power outlet of claim 1 wherein said alignment mechanism comprises a first magnetic element configured to engage a second magnetic element associated with the power receiver.
12. The inductive power outlet of claim 1 wherein said alignment mechanism comprises an audible indication.
13. The inductive power outlet of claim 1 wherein said alignment mechanism comprises a visual indication.
14. The inductive power outlet of claim 1 wherein said alignment mechanism comprises a tactile indication.
15. A method for transferring power from an inductive power outlet to an inductive power receiver, said method comprising:
providing at least one primary inductive coil embedded in a platform;
forming an inductive couple between said primary inductive coil and a secondary inductive coil of said inductive power receiver, said inductive couple having a characteristic resonant frequency; and
providing an oscillating driving voltage across said primary inductive coil such that a secondary voltage is induced in the secondary inductive coil, wherein said oscillating driving voltage has a transmission frequency substantially different from said characteristic resonant frequency of said inductive couple.
16. The method of claim 15 further comprising increasing said transmission frequency by an incremental value when a signal of a first type is detected from said inductive power receiver.
17. The method of claim 15 further comprising decreasing said transmission frequency by an incremental value when a signal of a second type is detected from said inductive power receiver.