Circuitry for inductive power transfer
First Claim
1. 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 induction to one or more secondary units of the system, the or each secondary unit having a load and being separable from the primary unit, the circuitry comprising:
- a resonance network;
a primary circuit;
a driving circuit operable to supply said resonance network and said primary circuit with a drive signal so as to cause said primary circuit to generate said electromagnetic field, said resonance network and said primary circuit collectively having a frequency response, said frequency response having a first resonant peak at a first frequency defined primarily by said resonance network and a second resonant peak at a second frequency defined primarily by said primary circuit, wherein said drive signal is supplied at a frequency between said first frequency and said second frequency;
wherein said first frequency, said second frequency, and said drive signal frequency are different frequencies.
1 Assignment
0 Petitions
Accused Products
Abstract
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 induction to one or more secondary units of the system, the or each secondary unit being separable from the primary unit, the circuitry comprising: a plurality of drivable portions, each portion comprising a primary coil or a dummy coil; driving means operable to supply both or at least two of said portions with drive signals so as to cause those driven portions that have a said primary coil to generate said electromagnetic field; and control means operable, in dependence upon a feedback signal indicative of a characteristic of the primary or dummy coil of one or more of the driven portions, to control the circuitry so as to tend to regulate said feedback signal, wherein the circuitry is configured so that; those portions that are driven are connected together in parallel and have a tuned resonant response; and said control tends to regulate such a characteristic of each of said driven coils.
-
Citations
22 Claims
-
1. 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 induction to one or more secondary units of the system, the or each secondary unit having a load and being separable from the primary unit, the circuitry comprising:
-
a resonance network; a primary circuit; a driving circuit operable to supply said resonance network and said primary circuit with a drive signal so as to cause said primary circuit to generate said electromagnetic field, said resonance network and said primary circuit collectively having a frequency response, said frequency response having a first resonant peak at a first frequency defined primarily by said resonance network and a second resonant peak at a second frequency defined primarily by said primary circuit, wherein said drive signal is supplied at a frequency between said first frequency and said second frequency; wherein said first frequency, said second frequency, and said drive signal frequency are different frequencies. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. A method for designing a primary unit configured for generating an electromagnetic field for wirelessly transferring power to one or more secondary units, the or each secondary unit being separable from the primary unit, the method comprising:
-
selecting a target frequency of the primary unit; selecting an inductance value of a resonance network inductor and a capacitance value of a resonance network capacitor so that the frequency response of said resonant network in isolation includes a resonant frequency; selecting an inductance value of a primary circuit inductor and a capacitance value of a primary circuit capacitor so that the frequency response of said primary circuit in isolation includes a resonant frequency; selecting an inductance ratio so that the combined frequency response of said resonant network and said primary circuit includes a first resonant peak at a first frequency defined primarily by said resonance network and a second resonant peak at a second frequency defined primarily by said primary circuit, wherein said target frequency falls between said first frequency and said second frequency; wherein said combined frequency response includes a valley portion between said first frequency and said second frequency, said valley portion defined primarily by a combination of said resonance network and said primary circuit. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
-
Specification