A contactless power supply (100) is provided for providing power along a driving surface (106). The contactless power supply includes first and second conductive elements (102,104) each adapted to generate a magnetic flux when driven with a time-varying cu...

Circuitry for use in a primary unit of an inductive power transfer system to generate an electromagnetic field so as to transfer power wirelessly by electromagnetic system to one or more secondary units of the system, the or each secondary unit having a lo...

A circuit for powering a remote device comprises an inverter operating at the operating frequency, a tank circuit including a capacitor and an inductor for transferring power to the remote device and a phase comparator. The phase comparator compares the ph...

A method of operating an inductive power supply for a remote device comprises applying power to a tank circuit within the inductive power supplyestablishing an inductive coupling between the inductive power supply and the remote device; and monitoring at l...

A contactless power supply for inductively providing power to a remote device comprising: an inverter, the inverter having a duty cycle and an operating frequency; a resonant circuit coupled to the inverter, the resonant circuit having a primary for transf...

An inductive power transfer system (1) comprises a primary unit (10) operable to generate an electromagnetic field and at least one secondary device (30), separable from the primary unit, and adapted to couple with the field when the secondary device is in...

An inductive power transfer system (1) comprises a primary unit (10) operable to generate an electromagnetic field and at least one secondary device (30), separable from the primary unit, and adapted to couple with the field when the secondary device is in...

Wireless power receiving apparatus (150) is retrofitted to a portable electrical device (100) to enable the device to receive power wirelessly. The apparatus (150) comprises a power-receiving element (200) adapted to be attached to the device (100), e.g. b...

Wireless power receiving apparatus (150) is retrofitted to a portable electrical device (100) to enable the portable electrical device (100) to receive power wirelessly. The wireless power receiving apparatus (150) comprises a power-receiving element (200)...