Tuning of primary and secondary resonant frequency for improved efficiency of inductive power transfer
First Claim
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1. A coupled coil system for wireless power transfer between a transmitter and receiver, comprising:
- a receive coil in the receiver;
a transmit coil in the transmitter;
a first filter electrically connected to the receive coil and operable to be dynamically tuned to resonate with a leakage inductance of the transmit coil at a first frequency, the first filter comprising one of;
a variable capacitor; and
a plurality of individual capacitors that each may be selectively activated or deactivated to provide a selectable capacitance; and
a processor coupled to the receive coil and configured to select and modify the capacitance of the first filter in response to a power transfer efficiency value that is one of measured, approximated, predicted, or received by the processor.
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Abstract
Wireless power transfer systems having improved tolerance for coil misalignment are disclosed. These systems efficiently transfer power to accessories having a variety of power modes. For example, a power transmitter may vary the amount of power transmitted to a power receiver in response to changes in the power requirements of that power receiver. The power transmitter and the power receiver may be mutually tuned to filter or substantially reduce respective leakage inductances at both a primary and secondary operating frequency.
138 Citations
7 Claims
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1. A coupled coil system for wireless power transfer between a transmitter and receiver, comprising:
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a receive coil in the receiver; a transmit coil in the transmitter; a first filter electrically connected to the receive coil and operable to be dynamically tuned to resonate with a leakage inductance of the transmit coil at a first frequency, the first filter comprising one of; a variable capacitor; and a plurality of individual capacitors that each may be selectively activated or deactivated to provide a selectable capacitance; and a processor coupled to the receive coil and configured to select and modify the capacitance of the first filter in response to a power transfer efficiency value that is one of measured, approximated, predicted, or received by the processor. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification