Abstract: An IPT system magnetic flux pad includes two substantially planar coils (17) in close proximity to each other above a magnetically permeable core (14). The coils (17) each define a pole area (11, 12) and the distance between one or more adjacent turns of the coils (17) located in a region between the pole areas (11, 12) being different from the distance between one or more adjacent turns of the coils (17) located outside the region between the pole areas (11, 12).

Abstract: An IPT system magnetic flux pad includes two substantially planar coils (17) in close proximity to each other above a magnetically permeable core (14). The coils (17) each define a pole area (11, 12) and the distance between one or more adjacent turns of the coils (17) located in a region between the pole areas (11, 12) being different from the distance between one or more adjacent turns of the coils (17) located outside the region between the pole areas (11, 12).

Abstract: A circuit for energizing a magnetic flux coupling apparatus has a pick-up coil for receiving power inductively, a storage capacitor for storing energy from the received power, and an inverter for supplying electrical energy from the storage capacitor to the magnetic flux coupling apparatus. The circuit allows power transfer to a load to be supplied by the flux coupling apparatus to exceed the power received from the pick-up.

Abstract: A roadway powered electric vehicle system includes a power supply (101) which makes power available inductively to one or more modules (111) provided in or under a roadway. Modules (111) make a magnetic field selectively available to one or more vehicles travelling over the roadway corresponding to the location of the vehicle. The presence or strength of the magnetic field provided on the roadway may be dependent upon the vehicle type or category.

Abstract: A magnetic structure for wireless power transfer has a plurality of pieces of magnetically permeable material arranged along a first dimension. Each piece is separated from a neighbouring piece by a gap defining a separation distance which is selected to prevent partial saturation of a region of the structure.

Abstract: The present invention provides a multi-coil inductive power transfer primary comprising a plurality of coil. A power transfer regime is selected based on a determined load on each of the plurality of coils.

Abstract: An Inductive Power Transfer System pickup provides a controlled AC power supply by controlled variation of the phase angle between the pickup coil induced voltage (jwMI) and the tuning capacitor C voltage. The phase angle can be varied by maintaining the tuning capacitor C voltage substantially constant for a selected time period. Switches S1 and S2 may be used to clamp the tuning capacitor C voltage at substantially zero volts during the selected time period. Switch S1 can be operated to prevent a rise in positive voltage across the tuning capacitor, and switch S2 can be used to prevent the voltage across the tuning capacitor from going negative.

Abstract: A method of charging a battery includes coupling an electricity network or subnetwork to the battery using inductive power transfer, transferring electrical energy to the battery from the electricity network or subnetwork and varying the inductive power transfer using a controller of the electricity network or subnetwork according to at least one predetermined criteria of the electricity network or subnetwork.

Abstract: An inductive charging apparatus includes a primary conductor with at least one node for creating a magnetic field and at least one intermediate resonant circuit including a first coil for receiving inductive power from the node, a second coil operable in use to be driven by current from the first coil to generate a magnetic field for power transfer, and a tuning capacitor coupled to the first and second coils for resonance therewith.

Abstract: A method of charging a battery includes coupling an electricity network or subnetwork to the battery using inductive power transfer, transferring electrical energy to the battery from the electricity network or subnetwork and varying the inductive power transfer using a controller of the electricity network or subnetwork according to at least one predetermined criteria of the electricity network or subnetwork.

Abstract: Disclosed herein is an inductive power transfer (IPT) compensation circuit and method for reflecting a controlled reactance to a primary conductor at a selected operating frequency, compensating for reactive loads reflected to the primary conductor by one or more other pick-ups inductively coupled with the primary conductor in use. The compensation circuit comprises a first switch means coupled to a resonant circuit and operable to reflect a capacitive reactance to the primary conductor; a second switch means coupled to the resonant circuit and operable to reflect an inductive reactance to the primary conductor; and control means adapted to control operation of the first and second switch means to compensate for inductive and capacitive reactances, respectively, in the primary conductor.

Abstract: Inductive power transfer flux coupling apparatus includes a first coil arranged in a first layer and configured to generate or receive a magnetic coupling flux in a flux coupling region, and a second coil. At least part of the second coil being arranged in a second layer and is configured to generate a magnetic flux that reflects flux from the first coil.

Abstract: A roadway powered electric vehicle system includes a power supply (101) which makes power available inductively to one or more modules (111) provided in or under a roadway. Modules (111) make a magnetic field selectively available to one or more vehicles travelling over the roadway corresponding to the location of the vehicle. The presence or strength of the magnetic field provided on the roadway may be dependent upon the vehicle type or category.

Abstract: The present invention relates to a current multiplier primarily in the field of power conversion. The invention relates to a controlled current multiplier with a resonant winding to assist with, for example, power conversion. In particular, but not solely, the invention may broadly consist in a current multiplier comprising: a primary winding associated with a power source; a secondary winding associated with a load; a resonant winding associated with a capacitance; and a control means for controlling an output of the secondary winding to the load, the control means associated with the primary or resonant winding. This allows, for instance, control of the high current output to be placed on a low current winding.

Abstract: The present invention provides a magnetic flux pad for generating or receiving magnetic flux, comprising at least three coils positioned such that the windings thereof are in substantially the same plane, and a power supply or pickup controller operable to selectively energise or receive power from two or more of the coils such that a magnetic field is produced or received by at least one of a plurality of pairs of the at least three coils. In preferred embodiments, the three or more coils are substantially mutually decoupled, overlapping, and/or equidistantly spaced from one another.

Abstract: An inductive power transfer (IPT) pick-up circuit has a full-wave rectifier (D1-D4) coupled to a resonant circuit (L1 C1) and adapted to rectify an AC current received from the resonant circuit. A pair of inductors (L2 L3) are provided, being arranged to couple the rectifier to an output (VLoad) of the pick-up circuit and alternately store and release energy to the output.

Abstract: The present application relates to the detection of moving vehicles and other objects, in particular though not exclusively for the application of switching stationary charging pads for moving electric vehicle charging. There is provided an electric vehicle detecting apparatus for switching a charging pad for charging a vehicle transmitting a locating signal, the apparatus comprising two sensors separated in the direction of travel of the vehicle, and a detector arranged to detect the vehicle by comparing the locating signals received by each of the two sensors.

Abstract: An inductive power transfer system (IPT) pick-up comprises: a pick-up coil capable of generating a voltage by magnetic induction from a primary conductive pathway, and a tuning capacitor associated with the pick-up coil to provide a first pick-up resonant circuit; a first output associated with a first control means to substantially control the voltage or current provided by the first output; a further resonant circuit connected in series or parallel with the first pick-up resonant circuit; and a second output associated with a second control means to control the voltage or current provided by the second output and a method of providing an additional independently controllable output from an IPT pick-up having a resonant pick-up circuit is also disclosed.

Abstract: An (PT system magnetic flux pad includes two substantially planar coils (17) in close proximity to each other above a magnetically permeable core (14). The coils (17) each define a pole area (11, 12) and the distance between one or more adjacent turns of the coils (17) located in a region between the pole areas (11, 12) being different from the distance between one or more adjacent turns of the coils (17) located outside the region between the pole areas (11, 12).

Abstract: An Inductive Power Transfer (IPT) pick-up apparatus includes a magnetically permeable core, a first coil, being wound about the core so as to be inductive coupled therewith such that a current induced in the first coil is most sensitive to a first directional component of magnetic flux and a second coil, being wound about the core so as to be inductively coupled therewith such that a current induced in the second coil is most sensitive to a second directional component of magnetic flux. The first directional component is substantially orthogonal to the second directional component.