WIRELESS INDUCTIVE POWER TRANSFER
First Claim
1. A power transmitter for wirelessly providing power to a power receiver via an inductive power signal;
- the power transmitter comprising;
a resonance circuit for generating the inductive power signal, the resonance circuit comprising a capacitive impedance and an inductive impedance;
a driver for generating a drive signal for the resonance circuit, the drive signal having an operating frequency and being arranged to generate the timing signal to have transitions synchronized to the drive signal; and
a frequency modification circuit for controlling a resonance frequency of the resonance circuit by slowing a state change for at least one of the capacitive impedance and the inductive impedance for a fractional time interval of each of at least a plurality of cycles of the drive signal, the frequency modification circuit being arranged to align at least one of a start time and an end time for the fractional time interval to at least some transitions of the timing signal.
1 Assignment
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Accused Products
Abstract
A wireless power transfer system includes a power receiver and a power transmitter providing power using an inductive power signal. The power transmitter comprises a resonance circuit (201) comprising a capacitive impedance (503) and an inductive impedance (501). A driver (203) generates a drive signal for the resonance circuit. A frequency modification circuit (505) controls the resonance frequency of the resonance circuit (201) by slowing a state change for at least one of the capacitive impedance (503) and the inductive impedance (501) for a fractional time interval of at least some cycles of the drive signal. The frequency modification circuit (505) is arranged to align at least one of a start time and an end time for the fractional time interval to transitions of a timing signal. In the power transmitter, the driver (203) generates the timing signal to have transitions synchronized to the drive signal. The slowing may be by impeding current flow between the capacitive and inductive impedance (503, 501).
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Citations
15 Claims
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1. A power transmitter for wirelessly providing power to a power receiver via an inductive power signal;
- the power transmitter comprising;
a resonance circuit for generating the inductive power signal, the resonance circuit comprising a capacitive impedance and an inductive impedance; a driver for generating a drive signal for the resonance circuit, the drive signal having an operating frequency and being arranged to generate the timing signal to have transitions synchronized to the drive signal; and a frequency modification circuit for controlling a resonance frequency of the resonance circuit by slowing a state change for at least one of the capacitive impedance and the inductive impedance for a fractional time interval of each of at least a plurality of cycles of the drive signal, the frequency modification circuit being arranged to align at least one of a start time and an end time for the fractional time interval to at least some transitions of the timing signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
- the power transmitter comprising;
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14. A method of operation for a power transmitter for wirelessly providing power to a power receiver using an inductive power signal, the power transmitter comprising a resonance circuit for generating the inductive power signal, the resonance circuit comprising a capacitive impedance and an inductive impedance;
- the method comprising;
a driver generating a drive signal for the resonance circuit, the drive signal having an operating frequency, and generating the timing signal to have transitions synchronized to the drive signal; a frequency modification circuit controlling a resonance frequency for the resonance circuit by slowing a state change for at least one of the capacitive impedance and the inductive impedance for a fractional time interval of each of at least a plurality cycles of the drive signal, the controlling of the resonance frequency including aligning at least one of a start time and an end time for the fractional time interval to at least some transitions of the timing signal.
- the method comprising;
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15. A wireless power transfer system comprising a power receiver and a power transmitter arranged to wirelessly provide power to the power receiver using an inductive power signal;
- the power transmitter comprising;
a resonance circuit for generating the inductive power signal, the resonance circuit comprising a capacitive impedance and an inductive impedance; a driver for generating a drive signal for the resonance circuit, the drive signal having an operating frequency and being arranged to generate the timing signal to have transitions synchronized to the drive signal; and a frequency modification circuit for controlling a resonance frequency of the resonance circuit by slowing a state change for at least one of the capacitive impedance and the inductive impedance for a fractional time interval of each of at least a plurality of cycles of the drive signal, the frequency modification circuit being arranged to align at least one of a start time and an end time for the fractional time interval to at least some transitions of the timing signal.
- the power transmitter comprising;
Specification