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.

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.

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.

Abstract: There is disclosed an inductive power transfer system comprising a primary unit and a secondary device separable from the primary unit, the primary unit comprising a power transfer surface and more than two field generators each operable to generate an electromagnetic field, the field generators being located at different positions relative to the power transfer surface, the secondary device comprising a power receiver having a secondary coil, the system further comprising: determining means for determining at least one of the position and the orientation of the power receiver relative to the power transfer surface; and controlling means for controlling the field generators such that at least one first field generator and at least one second field generator, selected in dependence upon such determination, are active in a substantially opposite sense to one another so as to direct magnetic flux through the secondary coil thereby supplying power to the secondary device, and further such that a third one of the

Abstract: The present invention provides methods and apparatus for reducing power consumption. One method includes detecting the presence of an object, identifying whether the object is a valid device and restricting power if it is not a valid device. Another method includes temporarily applying a low amount of power to the primary unit to detect a load, supplying more power to determine if it is a valid secondary device, and restricting power if it is not. An apparatus for reducing power consumption includes two power inputs, where the lower power input powers a sense circuit. A switch selectively decouples the higher power input from the primary subcircuit during detection mode and couples the higher power input to the primary subcircuit during power supply mode.

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.

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.

Abstract: The present invention provides methods and apparatus for reducing power consumption. One method includes detecting the presence of an object, identifying whether the object is a valid device and restricting power if it is not a valid device. Another method includes temporarily applying a low amount of power to the primary unit to detect a load, supplying more power to determine if it is a valid secondary device, and restricting power if it is not. An apparatus for reducing power consumption includes two power inputs, where the lower power input powers a sense circuit. A switch selectively decouples the higher power input from the primary subcircuit during detection mode and couples the higher power input to the primary subcircuit during power supply mode.

Abstract: The present invention provides methods and apparatus for reducing power consumption. One method includes detecting the presence of an object, identifying whether the object is a valid device and restricting power if its not a valid device. Another method includes temporarily applying a low amount of power to the primary unit to detect a load, supplying more power to determine if its a valid secondary device, and restricting power if its not. An apparatus for reducing power consumption includes two power inputs, where the lower power input powers a sense circuit. A switch selectively decouples the higher power input from the primary subcircuit during detection mode and couples the higher power input to the primary subcircuit during power supply mode.

Abstract: There is disclosed an inductive power transfer system comprising a primary unit and a secondary device separable from the primary unit, the primary unit comprising a power transfer surface and more than two field generators each operable to generate an electromagnetic field, the field generators being located at different positions relative to the power transfer surface, the secondary device comprising a power receiver having a secondary coil, the system further comprising: determining means for determining at least one of the position and the orientation of the power receiver relative to the power transfer surface; and controlling means for controlling the field generators such that at least one first field generator and at least one second field generator, selected in dependence upon such determination, are active in a substantially opposite sense to one another so as to direct magnetic flux through the secondary coil thereby supplying power to the secondary device, and further such that a third one of the

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.

Abstract: There is disclosed an inductive power transfer system including a primary unit and a secondary device separable from the primary unit, the primary unit may include a power transfer surface and more than two field generators each operable to generate an electromagnetic field. The field generators may be located at different positions relative to the power transfer surface. The secondary device may include a power receiver having a secondary coil.

Abstract: The present invention provides methods and apparatus for reducing power consumption. One method includes detecting the presence of an object, identifying whether the object is a valid device and restricting power if its not a valid device. Another method includes temporarily applying a low amount of power to the primary unit to detect a load, supplying more power to determine if its a valid secondary device, and restricting power if its not. An apparatus for reducing power consumption includes two power inputs, where the lower power input powers a sense circuit. A switch selectively decouples the higher power input from the primary subcircuit during detection mode and couples the higher power input to the primary subcircuit during power supply mode.

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.

Abstract: A sensor arrangement for monitoring a oil reservoir comprises a sensor array (1) comprising a plurality of sensor units (5) located over an area to be monitored; an interrogator unit (30) comprising a transmitter (402) for transmitting optical signals and receiver for obtaining data on the reservoir from the sensor units, a demodulator (418) for demodulating the received signals, and a recorder (420) for recording the demodulated signals. The arrangement includes an uplink optical cable (408) for transmitting the signals to the sensor array and a downlink optical cable (410) for transmitting signals from the array to the receiver. At least one of the optical cables has an optical amplifier (412, 414). The arrangement enables the interrogator to be remote from the array, for example 150 km or more, obviating the need for significant power to be supplied at the array.

Abstract: The present invention provides methods and apparatus for reducing power consumption. One method includes detecting the presence of an object, identifying whether the object is a valid device and restricting power if its not a valid device. Another method includes temporarily applying a low amount of power to the primary unit to detect a load, supplying more power to determine if its a valid secondary device, and restricting power if its not. An apparatus for reducing power consumption includes two power inputs, where the lower power input powers a sense circuit. A switch selectively decouples the higher power input from the primary subcircuit during detection mode and couples the higher power input to the primary subcircuit during power supply mode.

Abstract: The specification discloses a wireless power charging system in which undesired frequencies in the primary coil are cancelled. Exemplary undesired frequencies are the harmonics of the primary coil drive signal. The system includes a sense transformer/coil, an injection transformer/coil, and a compensation signal generator. The sense transformer/coil senses the signal in the primary coil. The compensation signal generator receives the sensed signal and generates an injection signal whose constituent parts are equal in amplitude to, but pi phase different from, each undesired frequency. The combined signal is injected into the primary through the injection transformer/coil so that the injection signal cancels the undesired frequencies in the primary coil.

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.

Abstract: There is disclosed an inductive power transfer system comprising a primary unit and a secondary device separable from the primary unit, the primary unit comprising a power transfer surface and more than two field generators each operable to generate an electromagnetic field, the field generators being located at different positions relative to the power transfer surface, the secondary device comprising a power receiver having a secondary coil, the system further comprising: determining means for determining at least one of the position and the orientation of the power receiver relative to the power transfer surface; and controlling means for controlling the field generators such that at least one first field generator and at least one second field generator, selected in dependence upon such determination, are active in a substantially opposite sense to one another so as to direct magnetic flux through the secondary coil thereby supplying power to the secondary device, and further such that a third one of the

Abstract: The specification discloses a wireless power charging system in which undesired frequencies in the primary coil are cancelled. Exemplary undesired frequencies are the harmonics of the primary coil drive signal. The system includes a sense transformer/coil, an injection transformer/coil, and a compensation signal generator. The sense transformer/coil senses the signal in the primary coil. The compensation signal generator receives the sensed signal and generates an injection signal whose constituent parts are equal in amplitude to, but pi phase different from, each undesired frequency. The combined signal is injected into the primary through the injection transformer/coil so that the injection signal cancels the undesired frequencies in the primary coil.