CONTROLLING INDUCTIVE POWER TRANSFER SYSTEM
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Accused Products
Abstract
An inductive power transfer system comprises a primary unit operable to generate an electromagnetic field and at least one secondary device, separable from the primary unit, and adapted to couple with the field when the secondary device is in proximity to the primary unit so that power can be received inductively by the secondary device from the primary unit without direct electrical conductive contacts therebetween. The system detects if there is a substantial difference between, on the one hand, a power drawn from the primary unit and, on the other hand, a power required by the secondary device or, if there is more than one secondary device, a combined power required by the secondary devices. Following such detection, the system restricts or stops the inductive power supply from the primary unit. Such a system can detect the presence of unwanted parasitic loads in the vicinity of the primary unit reliably.
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Citations
52 Claims
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1-20. -20. (canceled)
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21. A method of controlling inductive power transfer in an inductive power transfer system, the system including a primary unit operable to generate an electromagnetic field and a secondary device, separate from the primary unit, and adapted to couple with the field when the secondary device is in proximity to the primary unit so that power is received inductively by the secondary device from the primary unit without direct electrical conductive contacts therebetween, the method comprising:
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measuring a characteristic of a secondary power in the secondary device, the secondary power based on power received inductively from the primary unit; generating power requirement information representative of the measured characteristic of power and a parasitic load of the secondary device; and transmitting the power requirement information to the primary unit. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
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36. An inductive power transfer system comprising:
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a primary unit operable to generate an electromagnetic field; a secondary device, separate from the primary unit, and adapted to couple with the field when the secondary device is in proximity to the primary unit so that power is received inductively by the secondary device from the primary unit without direct electrical conductive contacts therebetween; a measuring unit for measuring a characteristic of secondary power in the secondary device; and communication circuitry for receiving, in the primary unit, power requirement of the secondary device representative of the measured characteristic of secondary power and a parasitic load of the secondary device. - View Dependent Claims (37, 38, 39, 40, 41, 42)
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43. A secondary device for receiving power inductively from a primary unit, the secondary unit comprising:
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a secondary coil adapted to couple inductively with a primary coil of the primary unit when in proximity to the primary unit such that power is received inductively by the secondary unit without direct electrical conductive contacts therebetween; a measuring unit for measuring a characteristic of secondary power in the secondary device; and communication circuitry for transmitting, to the primary unit, power information, the power information being representative of the measured characteristic of secondary power and a parasitic load of the secondary device. - View Dependent Claims (44, 45, 46, 47)
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48. An inductive power supply comprising:
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a primary unit operable to generate an electromagnetic field to supply power wirelessly to a secondary device, separate from the primary unit, and adapted to couple with the field when the secondary device is in proximity to the primary unit so that power is transmitted inductively from the primary unit to the secondary device without direct electrical conductive contacts therebetween; power measuring circuitry configured to measure a power in the primary unit; communication circuitry for receiving, in the primary unit, power information from the secondary device, wherein the power information is representative of a measured characteristic of secondary power in the secondary device and a parasitic load of the secondary device; and a control unit for determining if there is a substantial difference between, on the one hand, the measured power in the primary unit and, on the other hand, the power information, wherein the control unit is operable, following such determination of a substantial difference, to restrict or stop the inductive power supply from the primary unit. - View Dependent Claims (49, 50, 51, 52)
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Specification